Unit 8

[Microeconomics]

image1.jpgUnit 8 Assignment: Research Paper Final

Name: -

Course Number: -

Section Number: -

Unit Number: - 8 Research

Date: -

Research paper

This paper must:

· Be between 2 and 3 pages (600 to 900 words) in length – double spaced.

· Use correct grammar, punctuation, and spelling and follow the APA format.

· Have an introduction, a development, and a conclusion. In the development you should present your arguments or assessment of the issue you selected while staying objective. In the conclusion, however, you can take a position and state your opinion.

· This being an Economics course, your arguments should pertain to the economy.

· Your arguments should be supported as much as possible by articles or studies that have been made on the subject. If you mention statistics or any data or numbers, your source should be clearly stated; otherwise your argument will not be valid. Most sources should be less than 3 years old.

· Include a list of references (URLs, articles, books, etc.) in a separate Bibliography / Webliography.

The Grading Rubric that will be used to evaluate your paper can be found in the Syllabus in the Course Home

---------------------

References:

Microeconomics: Unit 8 Assignment: Final Research Paper

Content (125 points)

Points Possible

Points Earned

· Paper is 2 to 3 pages in length and effectively Addresses the requirements of the Final paper

· Included a working title.

15

· Clearly presented in an introduction.

20

· Well defined thesis statement that incorporates three main points.

30

· Three major points that are tied to the thesis statement and are succinctly discussed in the body of the paper.

30

· Two details for each of the three major points supported with reliable sources in the body of the paper.

15

· Conclusion provides a summary of the main points.

15

Analysis (70 points)

Work demonstrates synthesis of concepts, research, and experience

30

Work demonstrates the student’s ability to tie relevant information to real-life applications.

20

Analysis exceeds basic comprehension to demonstrate higher-order thinking.

20

Writing (40 points)

· Correct use of APA 6th edition format, all sources used to support the paper are referenced

· In-text citations and reference list at the end of your paper are both included.

20

Sentences are clear, concise, and direct; tone is appropriate, spelling, grammar, and punctuation are correct.

20

Total

235

Chapter 17

Lecture Notes

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Endocrine System

  • Endocrine system
  • Regulates and controls many metabolic processes
  • Helps maintain body homeostasis
  • e.g., maintaining blood glucose levels during erratic food intake
  • Serves as one of the two major control systems of the body
  • with the nervous system

*

Introduction to the Endocrine System

Learning Objectives:

1) Compare and contrast the actions of the endocrine system and the nervous system to control body function.

Describe the general functions controlled by the endocrine system.

*

Introduction to the Endocrine System

  • The endocrine system
  • Composed of endocrine glands located throughout the body
  • synthesize and secrete hormones
  • released into the blood and transported through the body
  • Target cells
  • cells with a specific receptor for a hormone
  • bind hormone
  • initiates or inhibits selective cell activities

*

Introduction to the Endocrine System: Comparison of the Two Control Senses

  • Features in common with nervous system
  • Release chemical substances, ligands
  • Bind to cellular receptor on particular target cells
  • Initiates cellular change in target cells

*

Introduction to the Endocrine System: Comparison of the Two Control Senses

  • Features different from nervous system
  • Hormones transported within blood to target cells
  • Causes metabolic changes in target cells
  • Target any cells with receptors
  • Exhibit longer reaction times
  • More widespread effects throughout the body
  • Longer-lasting effects (minutes to days and weeks)

*

Table 17.1

Figure 17.1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Endocrine

gland

Target cells

Blood

(b) Endocrine system

Hormone

Neuron

Nerve

signal

Neurotransmitter

Target cells

(a) Nervous system

*

Introduction to the Endocrine System: Comparison of the Two Control Senses

The nervous system responds rapidly (in milliseconds to seconds).

The endocrine system responds more slowly (seconds to hours).

Compare and contrast the response time of the nervous and endocrine systems.

*

Introduction to the Endocrine System: General Functions of the Endocrine System

  • Functions of the endocrine system
  • Maintaining homeostasis of blood composition and volume
  • regulate amount of substances dissolved in blood
  • e.g., glucose, cations, anions
  • regulate blood volume, cellular concentration, and platelet number
  • Controlling reproductive activities
  • affect development and function
  • affect expression of sexual behaviors

*

Introduction to the Endocrine System: General Functions of the Endocrine System

  • Functions of the endocrine system (continued)
  • Regulating development, growth, and metabolism
  • regulatory roles in embryonic cell division and differentiation
  • involved in catabolism and anabolism of proteins, carbohydrates, and lipids
  • Controlling digestive processes
  • influence secretory processes
  • influence movement through digestive tract

*

Endocrine Glands

Learning Objectives:

1) Distinguish between the two types of organization of endocrine cells.

Identify the major endocrine glands and their location within the body.

Explain the three reflex mechanisms for regulating secretion of hormones.

*

Endocrine Glands: Location of the
Major Endocrine Glands

  • Composition
  • Secretory endocrine cells
  • Derived from epithelium with connective tissue framework
  • Have extensive blood supply
  • facilitates rapid uptake of hormones
  • Two organizations:
  • single organ with endocrine function
  • cells in small clusters in organs with another function

*

Endocrine Glands: Location of the
Major Endocrine Glands

Endocrine Organs

  • Single organ that is entirely endocrine in function
  • Include:
  • pituitary gland
  • pineal gland
  • thyroid gland
  • parathyroid glands
  • adrenal glands

*

Pineal Gland

Pituitary Gland

Thyroid Gland

Parathyroid Glands

Adrenal Glands

Endocrine Glands

Endocrine Glands: Location of the
Major Endocrine Glands

Endocrine Cells Within Other Organs

  • Housed in tissue clusters in specific organs
  • Secrete one or more hormones
  • organ with additional primary function
  • Include:
  • hypothalamus, skin, thymus
  • heart, liver, stomach
  • pancreas, small intestine
  • kidneys, gonads

See Table 17.2: Endocrine Glands and Organs Containing Endocrine Cells

*

Organs Containing Endocrine Cells

Hypothalamus

Skin

Thymus

Heart

Kidneys

Liver

Stomach

Small Intestines

Pancreas

Testis

Ovaries

Figure 17.3

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Organs containing endocrine cells

Major endocrine glands

Parathyroid glands

Pituitary gland

Pineal gland

Posterior surface of

thyroid gland

Thyroid gland

Adrenal

cortex

Adrenal

medulla

Adrenal gland

Adrenal glands

Hypothalamus

Skin

Thymus

Heart

Liver

Stomach

Pancreas

Small intestine

Kidney

Gonads

Testes (male)

Ovaries (female)

*

Table 17.2

Endocrine Glands: Location of the
Major Endocrine Glands

Pituitary gland, pineal gland, thyroid gland, parathyroid glands, and adrenal glands

What are the major endocrine organs in the human body?

*

Endocrine Glands: Location of the
Major Endocrine Glands

Hypothalamus, skin, thymus, heart, liver, stomach, pancreas, small intestine, kidneys, and gonads

What are the organs that have another primary function and contain endocrine cells?

*

Endocrine Glands: Stimulation of
Hormone Synthesis and Release

  • Endocrine reflexes
  • Regulated secretion of hormone controlled through reflex
  • Preprogrammed response to certain stimuli
  • Initiated by one of three types of stimulation:
  • hormonal, humoral, or nervous

*

  • Endocrine reflexes (continued)
  • Hormonal stimulation
  • e.g., thyroid stimulating hormone released from anterior pituitary
  • stimulates thyroid gland to secrete thyroid hormone

Figure 17.4a

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2

Hormonal stimulation:

Release of a hormone in response

to another hormone

Anterior pituitary releases thyroid-stimulating

hormone (TSH).

Anterior pituitary

TSH stimulates

thyroid gland to

release thyroid

hormone (TH).

Capillary

TH

Thyroid

gland

TSH

(a)

1

*

  • Endocrine reflexes (continued)
  • Humoral stimulation
  • respond to changing level of nutrients or ions
  • act on target cells to offset further loss or eliminate excess

Figure 17.4b

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

1

2

Humoral stimulation:

Release of a hormone in response to changes

in level of nutrient or ion in the blood

Blood glucose levels increase.

Increased

blood

glucose

Increased

blood glucose

stimulates

pancreas to

release insulin.

Pancreas

Insulin

(b)

*

  • Endocrine reflexes (continued)
  • Nervous stimulation
  • e.g., release of epinephrine and norepinephrine by adrenal medulla in response to sympathetic nervous stimulation

Figure 17.4c

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

1

2

Nervous system stimulation:

Release of a hormone in response to

stimulation by the nervous system

Sympathetic nervous system increases

in activity.

Spinal cord

Nerve

signal

Adrenal gland

Epinephrine and

norepinephrine

Sympathetic

preganglionic

axons stimulate

adrenal medulla

to release

epinephrine and

norepinephrine.

Preganglionic axon

(c)

*

Endocrine Glands: Stimulation of
Hormone Synthesis and Release

Hormonal, humoral (blood level), or nervous stimulation

Endocrine reflexes are stimulated by one of which three types of stimulation?

*

Hormones

Learning Objectives:

1) Name the three structural categories of circulating hormones, and give examples within each category.

Distinguish the hormones that are lipid-soluble from those that are water-soluble.

Describe the general function of local hormones.

*

Hormones: Categories of
Circulating Hormones

Steroid Hormones

  • Lipid-soluble molecules synthesized from cholesterol
  • Includes steroids produced in gonads
  • Includes steroid synthesized by adrenal cortex
  • Calcitriol sometimes classified in this group

*

Hormones: Categories of
Circulating Hormones

Protein Hormones

  • Most hormones are in this category
  • Composed of small chain of amino acids
  • Water-soluble
  • Includes polypeptides, between 14 to 199 amino acids
  • e.g., insulin, glucagon, parathyroid hormone
  • Includes oligopeptides, between 3 to 10 amino acids
  • e.g., oxytocin, antidiuretic hormone
  • Includes glycoproteins
  • composed of proteins with attached carbohydrate
  • e.g., follicle-stimulating hormone, thyroid-stimulating hormone

*

Hormones: Categories of
Circulating Hormones

Biogenic Amines

  • Modified amino acids
  • Includes:
  • catecholamines released from adrenal medulla
  • thyroid hormone released from thyroid gland
  • Water-soluble except for thyroid hormone
  • contains two tyrosine amino acids containing a nonpolar ring

*

Figure 17.5

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

O

C

O

Biogenic amine

Protein hormone

Steroid hormone

• Lipid-soluble

• Formed from cholesterol

• Produced by gonads and adrenal cortex

HO

H3C

Example: Cortisol

(a)

(b)

H3C

CH2OH

OH

Example: Norepinephrine

CH2

H2N

CH2

HO

OH

HO

COOH

Example: Parathyroid hormone

H2N

(c)

• Water-soluble (except thyroid hormone)

• Derived from amino acid that is

modified (e.g., tyrosine)

• Water-soluble

• Consists of amino acid chains

• Three subgroups

Polypeptides

Oligopeptides

Glycoproteins

*

Hormones: Categories of
Circulating Hormones

Steroid hormones: lipid-soluble

Protein hormones: water-soluble

Biogenic amines: water-soluble (except thyroid hormone)

Which of the three categories of hormones are water-soluble, and which are lipid-soluble?

*

Hormones: Local Hormones

  • Local hormones
  • Large group of signaling molecules
  • Do not circulate within the blood
  • Released from cells that produce them
  • Bind with same cell or neighboring cells
  • sometimes not classified as hormones

*

Hormones: Local Hormones

  • Eicosanoids (e.g. leukotrienes, prostaglandins, thromboxanes)
  • A primary type of local hormone
  • Formed from fatty acids containing chain of 20 carbon atoms
  • Derived from phospholipids within cell’s plasma membrane
  • Functions:
  • Play role in inflammation as part of body’s defenses
  • Initiate smooth muscle contraction
  • Stimulate pain receptors
  • Other local signaling functions

*

Hormone Transport

Learning Objectives:

1) Compare the transport of water-soluble hormones with that of lipid-soluble hormones.

*

Hormone Transport: Transport in the Blood

  • Transport of water-soluble hormones
  • Readily dissolve
  • Are easily transported in aqueous environment
  • E.g., parathyroid hormone
  • Transport of lipid-soluble hormones
  • Do not readily dissolve
  • Require carrier molecules
  • water-soluble proteins synthesized by the liver
  • “ferry” the hormone molecules within the blood

*

Hormone Transport: Transport in the Blood

  • Transport of lipid-soluble hormones (continued)
  • Binding between hormone and carrier only temporary
  • may detach and reattach
  • bound hormone, attached to carrier
  • Unbound (free) hormone, not attached
  • only unbound hormone able to exit blood and bind target organs
  • small percentage of hormone in blood
  • Other transporter functions
  • protects hormone and prevents destruction
  • why some water-soluble hormones are transported by carrier protein molecules

*

Target Cells: Interactions with Hormones

Learning Objectives:

1) Describe how lipid-soluble hormones reach their target cell receptors and the type of cellular change they initiate.

Describe how water-soluble hormones induce cellular change in their target cells.

*

Target Cells: Interactions with Hormones

  • Hormone targets
  • Hormones contacting all tissues of the body
  • Only interact with target cells
  • Hormones generally with several types of receptor cells
  • Interactions between hormones and receptors
  • differences between lipid-soluble and water-soluble hormones

*

Target Cells—Interactions with Hormones: Lipid-soluble Hormones

  • Lipid-soluble hormone interactions
  • Relatively small, nonpolar molecules
  • Able to diffuse across the plasma membrane
  • Bind to intracellular receptors in cytosol or nucleus
  • form hormone-receptor complex
  • Results in synthesis of new protein

*

Figure 17.7

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

The unbound lipid-soluble

hormone diffuses readily through

the plasma membrane and binds

with an intracellular receptor,

either within the cytosol or

the nucleus to form a

hormone-receptor complex.

The hormone-receptor complex

then binds with a specific

DNA sequence called a

hormone-response element.

This binding stimulates mRNA

synthesis.

mRNA exits the nucleus and

is translated by a ribosome in

the cytosol. A new protein

is synthesized.

1

2

3

4

1

2

3

4

Unbound hormone

Bound

hormone

Carrier

protein

Hormone

Hormone-receptor

complex

Hormone-

receptor

complex

Hormone-

response

element

mRNA

synthesis

mRNA

Interstitial fluid

Cytosol

Plasma

membrane

Protein

Blood

Ribosome

mRNA

Amino

acids

Hormone

receptor

Nuclear

membrane

DNA

*

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*

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Target Cells—Interactions with Hormones: Lipid-soluble Hormones

Hormones bind to receptors in the nucleus or the cytosol, forming a hormone-receptor complex.

Where are lipid-soluble hormone receptors located?

*

Target Cells—Interactions with Hormones: Water-soluble Hormones

  • Water-soluble hormone interactions
  • Polar molecules unable to cross plasma membrane
  • Initiate series of biochemical events, signal transduction pathway
  • initiated by the hormone, the first messenger
  • Results in formation of second molecule
  • termed second messenger (e.g., cAMP)
  • modifies some cellular activity

*

Figure 17.8

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

1

2

3

4

Hormone (first messenger) binds to receptor and

induces shape change to activate the receptor.

Activated G protein (with GTP) is released from the

receptor and moves along the inside of the plasma

membrane, which results in formation or availability

of second messenger (see figure 17.9).

GDP is "bumped off"

and GTP binds to

G protein; G protein

is then activated.

Water-soluble hormone

Interstitial

fluid

Receptor

protein

GDP: Guanine diphosphate

GTP: Guanine triphosphate

Cytosol

GDP

Inactive

G protein

Activated

G protein

GTP

G protein

GDP

Receptor

Hormone

G protein

binds to

activated

receptor.

GTP

*

Figure 17.9a

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

1

2

3

3

Activated G protein binds to and causes activation

of the plasma membrane enzyme adenylate

cyclase.

cAMP serves as the “second messenger” by

activating protein kinase A (a phosphorylating

enzyme that adds phosphate to other molecules;

these molecules may be activated or inhibited as a

result).

Adenylate cylase converts ATP molecules to cAMP

molecules.

1

2

Interstitial fluid

Adenylate cyclase

GTP

Activated

G protein

ATP

Activated

protein kinase

A enzymes

Cytosol

cAMP

(a) Activated G protein “turns on” adenylate cyclase.

*

Figure 17.9b

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

1

2

3b

3c

Activated G protein binds to and causes activation

of the plasma membrane enzyme phospholipase C.

Phospholipase C splits PIP2 into two second

messengers: DAG (diaclyglycerol) and IP3 (inositol

triphosphate).

DAG activates protein kinase C (a phosphorylating

enzyme).

1

2

IP3 increases Ca2+ in cytosol (by stimulating Ca2+

release from the endoplasmic reticulum [ER] and

entry across the plasma membrane from the

interstitial fluid).

Ca2+ acts as a third messenger to activate protein

kinase enzymes (Ca2+ does this directly or by first

binding to calmodulin). Ca2+ may also alter activity

of ion channel within the plasma membrane.

Activated protein

kinase enzymes

3a

Activated

protein

kinase C

Ion channel

Interstitial fluid

Phospholipase C

PIP2

Cytosol

GTP

Activated

G protein

Endoplasmic

reticulum

(b) Activated G protein “turns on” phopholipase C.

3c

3b

IP3

3a

DAG

DAG

3c

Ca2+

Calmodulin

Ca2+

*

Target Cells—Interactions with Hormones: Water-soluble Hormones

Action of Water-Soluble Hormones

  • Multiple results possible from hormone activation
  • e.g., activation or inhibition of enzymatic pathways
  • stimulation of growth through cellular reproduction
  • stimulation of cellular secretions
  • changes in membrane permeability
  • muscle contraction or relaxation
  • result dependent on hormone, messenger types, and enzymes phosphorylated

*

Target Cells: Degree of Cellular Response

Learning Objectives:

1) Compare and contrast the three types of hormone interactions.

*

Target Cells—Degree of Cellular Response: Receptor Interactions

  • Interaction types
  • Target cell binding different hormones
  • Synergistic interactions
  • activity of one hormone reinforcing activity of another hormone
  • e.g., female reproductive structures
  • more influenced by both estrogen and progesterone than either alone

*

Target Cells—Degree of Cellular Response: Receptor Interactions

  • Interaction types (continued)
  • Permissive interactions
  • activity of one hormone requiring second hormone
  • e.g., oxytocin required for milk ejection
  • requires prolactin release to produce breast milk

*

Target Cells—Degree of Cellular Response: Receptor Interactions

  • Interaction types (continued)
  • Antagonistic interactions
  • activity of one hormone opposing effects of another hormone
  • e.g., glucagon and insulin
  • glucagon increasing blood glucose levels
  • insulin decreasing blood glucose levels

See Figure 17.11: Endocrine System: Major Control System of the Body

*

Figure 17.10b

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Hormone interactions

(b)

Adipose cell

Liver cell

Muscle cell

Representative

target cell

Different target cells can

house various types of

receptors, allowing them

to bind multiple hormones
simultaneously.

When multiple hormones
bind to a target cell

simultaneously, their

interactions can produce
different effects.

Antagonistic

Permissive

One hormone

causes opposite

effect of another.

First hormone

allows action of

second hormone.

Target cell receptors

Synergistic

Hormones work

together to produce

greater effect.

*

Target Cells—Degree of Cellular Response: Receptor Interactions

The activity of one hormone reinforces the activity of another hormone.

What effects are seen when hormones act synergistically?

*

Pineal Gland

Name the hormone produced by the pineal gland.

Describe the general functions of melatonin.

Endocrine Glands: Location of the
Major Endocrine Glands

Pineal gland

  • Small structure forming posterior region of epithalamus
  • Composed primarily of pinealocytes secreting melatonin
  • makes us drowsy
  • cyclic production with increased levels at night
  • affects synthesis of hypothalamic hormone
  • responsible for synthesis of two hormones from anterior pituitary
  • involved in regulation of reproductive system

*

Pineal Gland

The Hypothalamus and the Pituitary Gland

Learning Objectives:

Identify the two hormones released from the posterior pituitary and describe how the hypothalamus controls their release.

Explain how the hypothalamus controls the release of hormones from the anterior pituitary.

List the hormones released from the hypothalamus that control the anterior pituitary.

Identify and briefly describe the functions of the hormones produced by the anterior pituitary.

*

The Hypothalamus and the Pituitary Gland

  • The hypothalamus
  • Influences or controls many endocrine glands
  • Has direct control over hormone release from pituitary gland
  • Has indirect control over hormone release from:
  • thyroid and adrenal glands
  • liver, testes, and ovaries

*

Hypothalamus – Pituitary

Hypothalamus

Infundibulum

Pituitary gland

Sella turcica

The Hypothalamus and the Pituitary Gland: Hypothalamus and Posterior Pituitary

  • Hormones stored in posterior pituitary
  • Synthesized in hypothalamus by neurosecretory cells
  • packed within secretory vesicles
  • transported by fast axonal transport
  • released from synaptic knobs of neurons
  • Oxytocin
  • produced by paraventricular nucleus
  • Antidiuretic hormone (ADH)
  • produced by supraoptic nucleus

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Posterior Pituitary

  • Hormones stored in posterior pituitary (continued)
  • Nerve signal sent from hypothalamus
  • Travels along hypothalamo-hypophyseal tract
  • Hormones released into bloodstream from posterior pituitary

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Posterior Pituitary

Oxytocin and antidiuretic hormone

What two hormones are stored in the posterior pituitary?

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Anterior Pituitary

  • Hormone release from anterior pituitary
  • Specific hormones within hypothalamus released
  • Travel through from primary plexus to secondary plexus
  • Hormones released from anterior pituitary
  • reach target cells through the bloodstream

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Anterior Pituitary

Hormones of the Hypothalamus

  • Termed regulatory hormones
  • secreted into blood to regulate anterior pituitary hormones
  • Releasing hormones
  • stimulate secretion of specific anterior pituitary hormones
  • Inhibiting hormones
  • deter secretion of specific anterior pituitary hormones

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Anterior Pituitary

Hormones of the Hypothalamus (continued)

  • Thyrotropin-releasing hormone
  • increases secretion of thyroid-stimulating hormone
  • Prolactin-releasing hormone
  • increases secretion of prolactin
  • Gonadotropin-releasing hormone
  • increases secretion of follicle-stimulating hormone and luteinizing hormone

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Anterior Pituitary

Hormones of the Hypothalamus (continued)

  • Corticotropin-releasing hormone
  • increases secretion of adrenocorticotropic hormone
  • Growth hormone-releasing hormone
  • increases secretion of growth hormone

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Anterior Pituitary

Hormones of the Anterior Pituitary

  • Seven hormones
  • Most tropic hormones
  • stimulated cells to secrete hormones
  • exception prolactin
  • Thyroid-stimulating hormone (TSH)
  • regulates release of thyroid hormone from thyroid gland

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Anterior Pituitary

Hormones of the Anterior Pituitary (continued)

  • Prolactin
  • regulates mammary growth and breast milk production
  • may help androgen production in males
  • Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
  • collectively called gonadotropins
  • regulate hormone synthesis by the gonads
  • regulate production and maturation of gametes

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Anterior Pituitary

Hormones of the Anterior Pituitary (continued)

  • Adrenocorticotropic hormone (ACTH)
  • stimulates adrenal cortex to produce and secrete glucocorticoids
  • Growth hormone
  • stimulates cell growth and cell division
  • affects most body cells
  • particularly affects skeletal and muscular system
  • stimulates liver to release insulin-like growth factor 1 and 2
  • have overlapping function with growth hormone

*

The Hypothalamus and the Pituitary Gland: Hypothalamus and Anterior Pituitary

Hormones of the Anterior Pituitary (continued)

  • Melanocyte-stimulating hormone (MSH)
  • stimulates rate of melanin synthesis by melanocytes in skin
  • stimulates distribution of melanocytes in skin
  • usually ceases prior to adulthood, except in disease

See Table. 17.3: Comparison of Posterior and Anterior Pituitary

See Table 17.4: Hypothalamic Hormones that Stimulate the Anterior Pituitary

*

Figure 17.14

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Releasing hormones: TRH, PRH, GnRH, CRH, GHRH

Inhibiting hormones: PIH, GIH

Regulatory hormones of hypothalamus

Tropic hormones of anterior pituitary

Thyroid-stimulating hormone

(TSH) stimulates thyroid gland

to release thyroid hormone.

Anterior pituitary

Posterior pituitary

Infundibulum

Muscle

Prolactin (PRL) acts on mammary

glands to stimulate milk production.

Follicle-stimulating hormone (FSH)

and luteinizing hormone (LH) act on

gonads (testes and ovaries) to stimulate

development of gametes (sperm and oocyte).

Testis

Ovary

Thyroid

Mammary gland

TSH

Growth hormone (GH) acts on all

body tissues, especially cartilage,

bone, muscle, and adipose

connective tissue to stimulate growth.

Adipose

connective tissue

Bone

Adrenal cortex

Adrenocorticotropic hormone (ACTH)

acts on the adrenal cortex to cause

release of corticosteroids

(e.g., cortisol).

Adrenal gland

FSH and LH

GH

ACTH

Hypothalamus

PRL

*

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The Hypothalamus and the Pituitary Gland: Hypothalamus and Anterior Pituitary

Thyrotropin-releasing factor

What hormone increases secretion of thyroid-stimulating hormone?

*

Representative Hormones
Regulated by the Hypothalamus

Learning Objectives:

1) Describe the homeostatic system involving growth hormone.

Discuss how thyroid hormones are produced, stored, and secreted.

Explain the control of thyroid hormone by the hypothalamus and pituitary.

Name the hormone produced by the parathyroid glands and describe its function.

Name the three zones of the adrenal cortex and the hormones produced in each zone.

Describe how the hypothalamus controls the release of glucocorticoid (cortisol) and the effects of cortisol.

Briefly describe hormonal responses to stress.

*

Representative Hormones Regulated by the Hypothalamus: Growth Hormone

  • Growth hormone characteristics
  • Functions include:
  • stimulation of linear growth at epiphyseal plate
  • hypertrophy of muscle
  • many other physiologic changes
  • Release controlled by growth hormone-releasing hormone (GHRH)
  • release influenced by:
  • age, time of day, and nutrient levels
  • stress and exercise

*

Figure 17.16a-b

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

GH release changes with age.

At any given age, there are daily

fluctuations in the release of GH.

Notice that in a normal sleep-wake

cycle, peak GH levels correspond to

the early stages of the normal sleep

cycle, allowing the most growth to

occur while we are sleeping. Nocturnal

(nightly) peaks account for the

majority of the GH released daily.

Growth hormone levels fluctuate with

age. Children and adolescents

experience the highest amounts of

GH; young adolescents have almost

double that of young adults (700 μg

per day in young adolescents versus

400 μg per day in young adults).

GH release fluctuates based on the time of day (circadian rhythm).

GH (μg\mL)

5

0

0

8

2000

1500

1000

500

10

20

30

40

80

70

60

50

Age in years

(a)

GH (μg\mL)

25

20

15

10

24

Time of day

16

(b)

Sleep

*

Figure 17.16c-d

GH release changes in response to nutrient blood levels

Growth hormone release is regulated by the level of

nutrient molecules in the blood. Growth hormone levels

increase in reponse to an increase in amino acid levels and

to a decrease in glucose levels or fatty acids levels.

Increase in

amino acids

Decrease in

glucose or fatty acids

(c)

GH release is altered by stress.

Emotional, physical, and chemical stress, including surgery, trauma,

exercise, or electroshock therapy increase GH release (although severe

emotional stress can cause a decrease in GH release in children).

(d)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

*

Representative Hormones Regulated by the Hypothalamus: Growth Hormone

  • Growth hormone targets
  • Hepatocytes
  • release insulin-like growth factor (IGF)
  • overlapping function with GH
  • responsible for greater response
  • stimulated to increase glycogenolysis and gluconeogenesis
  • increases blood glucose levels
  • rise referred to as diabetogenic

*

Representative Hormones Regulated by the Hypothalamus: Growth Hormone

  • Growth hormone targets (continued)
  • All cells with receptors for GH or IGF
  • Bone and muscle particularly affected
  • activates second messengers
  • increases protein synthesis
  • increases mitosis, cell differentiation
  • in muscle, increased uptake of amino acids

*

Representative Hormones Regulated by the Hypothalamus: Growth Hormone

  • Growth hormone targets (continued)
  • Adipose tissue
  • stimulated to increase lipolysis and decreased lipogenesis
  • thus increases levels of glycerol and fatty acids in blood
  • with glucose, provide molecules necessary for generating ATP

See Table B.3: Regulating Growth with Growth Hormone

*

Representative Hormones Regulated by the Hypothalamus: Growth Hormone

  • Growth hormone target feedback
  • With increased levels of GH or IGF
  • hypothalamus stimulated to release growth hormone-inhibiting hormone
  • inhibits release of GH from anterior pituitary
  • GH release also directly inhibited by itself

*

Figure 17.15

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

3

3

4

7

8

5

6

6

Growth hormone

Stimulation

Inhibition

STIMULUS

Variables that influence the release

of GHRH from the hypothalamus:

• Age

• Nutrient levels in the blood

• Stress and exercise

• Time of day

Hypothalamus

CONTROL CENTER

RECEPTOR

Increased levels of both GH

and IGF inhibit the release

of GHRH from the

hypothalamus; Increased

levels of GH also inhibits

the release of GH from the

anterior pituitary.

NET EFFECT

Increased protein synthesis,

mitosis, and cell

differentiation–especially in

cartilage, bone, and

muscle; release of stored

nutrients into the blood.

Amino acids

Bone

Muscle

EFFECTORS: Effectors respond to

GH and/or IGF in the following ways:

Increased growth

Increased amino acid uptake which results in protein synthesis

Stimulated mitosis

Cell differentiation

Increased lipolysis

Decreased lipogenesis

Increased glycogenolysis

and gluconeogenesis

Decreased glycogenesis

Adipose connective

tissue

Liver tissue

In response to GHRH, the anterior pituitary

releases growth hormone (GH).

GH stimulates hepatocytes to release

insulin-like growth factor (IGF) into the

blood.

Both GH and IGF stimulate target

cells (effectors).

The hypothalamus releases

growth hormone–releasing

hormone (GHRH) into the

hypothalamo-hypophyseal

portal system.

The hypothalamus

responds to various

stimuli.

GH

IGF

GH

GH

IGF

Hepatocytes

Liver

GH

Glycerol

Fatty acids

Glucose

All cells

GHRH

GH

5

4

IGF

2

2

1

1

*

Representative Hormones Regulated by the Hypothalamus: Growth Hormone

All cells, especially bone and muscle: increased amino acid uptake and protein synthesis; stimulated mitosis and cell differentiation.

Liver: increased glycogenolysis and gluconeogenesis.

Adipose tissue: increased lipolysis and decreased lipogenesis.

What are the primary target organs/tissues of GH and IGF? Describe the effect on each.

*

Representative Hormones Regulated by the Hypothalamus: Growth Hormone

Clinical View: Disorders of Growth Hormone Secretion

  • Pituitary dwarfism
  • inadequate growth hormone production
  • due to hypothalamic or pituitary problem
  • short stature and low blood sugar
  • Pituitary gigantism
  • too much growth hormone
  • excessive growth and increased blood sugar
  • enormous internal organs
  • die at early age if untreated

*

Representative Hormones Regulated by the Hypothalamus: Growth Hormone

Clinical View: Disorders of Growth Hormone Secretion (continued)

  • Acromegaly
  • excessive growth hormone production in adult
  • enlargement of bones of face, hands, and feet
  • increased release of glucose
  • internal organs increased in size
  • results from loss of feedback control of growth hormone

*

Thyroid Gland

Figure 17.17a

Thyroid cartilage

Superior thyroid artery

Superior thyroid vein

Left lobe of thyroid gland

Isthmus of thyroid gland

Right lobe of thyroid gland

Cricoid cartilage

Inferior thyroid artery

Inferior thyroid veins

(a)

Trachea

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

a © The McGraw-Hill Companies, Inc./Photo and Dissection by Christine Eckel

*

Figure 17.17b

LM 400x

Capillary

Connective

tissue

capsule

(b)

Follicular cell

Parafollicular cell

Thyroid follicle

Follicle lumen (contains colloid)

b: © The McGraw-Hill Companies, Inc./Al Telser, photographer

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

  • Thyroid hormone synthesis
  • iodide ion moved by active transport into follicular cells
  • two I- joined to form molecular iodine
  • thyroglobulin, a glycoprotein, synthesized in follicular cells
  • bind together to form immature thyroid hormone
  • stored in colloid in this form

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Anatomy of the Thyroid Gland (continued)

  • Thyroid hormone release
  • some colloid internalized by exocytosis into follicular cell
  • travels to lysosome
  • enzyme releases mature thyroid from precursor
  • released into blood stream

*

Figure 17.18

I2

1

1

2a

2a

I– uptake. Iodide ion (I–) is moved by active

transport into follicular cells.

3

3

Transport to colloid. Both I2 and thyroglobulin are

transported into colloid.

4

4

MIT and DIT formation. One I2 binds to tyrosine

within thyroglobulin to form MIT; two I2 bind to

tyrosine to form DIT.

5

5

Pre-T3, pre-T4 formation. Within thyroglobulin

molecules, one DIT and one MIT join to form

pre-T3; or, two DIT join to form pre-T4.

6

6

Endocytosis into follicular cell. The modified

protein strand containing pre-T3 and pre-T4 is

endocytosed into follicular cell and taken to a

lysosome.

7

7

T3, T4 release. T3 and T4 are excised from

molecule and released into the blood.

I2 formation. Two I– join to form molecular iodine (I2).

2b

2b

Thyroglobulin synthesis. Thyroglobulin protein,

containing tyrosine amino acids, is synthesized in

follicular cells.

I–

T4

T3

Blood

I–

I–

I–

I–

Thyroid

follicle

Blood

Follicular cell

Colloid

Follicular cell

I–

I–

I2

Colloid

Tyr

Tyr

Tyr

Tyr

DIT

DIT

MIT

DIT

I2

I2

I2

I2

I2

I2

Tyr

Tyr

DIT

DIT

MIT

DIT

Tyr

Tyr

Pre-T4

Pre-T3

MIT: monoiodotyrosine

DIT: diiodotyrosine

T3: triiodothyronine

Tyrosine

Thyroglobulin

Lysosome

T4: tetraidothyronine

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Action of Thyroid Hormone

  • Thyrotropin-releasing hormone (TRH) released by hypothalamus
  • enters in response to decreased in blood levels of thyroid hormone
  • also stimulated by:
  • cold weather, pregnancy, high altitude, and hypoglycemia
  • TRH binding to cells of anterior pituitary
  • stimulates anterior pituitary to release thyroid-stimulating hormone (TSH)

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Action of Thyroid Hormone (continued)

  • TSH binding to receptors of follicular cells
  • stimulates release of thyroid hormone
  • has two forms released into circulation
  • triiodothyronine (T3)
  • tetraiodothyronine (T4)
  • T3 and T4 transported within blood by carrier molecules
  • randomly become unbound and exit blood

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Action of Thyroid Hormone (continued)

  • Thyroid hormone moved into target cells
  • binds intracellular receptors
  • T3 versus T4
  • much greater amount of T4 produced
  • T3 the most active form of thyroid hormone
  • most cells able to convert T4 to T3

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Action of Thyroid Hormone (continued)

  • Adjusts basal metabolic rate of many cells
  • Stimulates synthesis of sodium-potassium pumps in nervous tissue
  • Action generates heat
  • rise in temperature referred to as calorigenic effect
  • Stimulates increased amino acid and glucose uptake
  • Increases cellular respiration enzymes within mitochondria

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Action of Thyroid Hormone (continued)

  • Stimulates other target cells to meet additional ATP requirements
  • hepatocytes stimulated to increase glycogenolysis and gluconeogenesis
  • decreased glycogenesis
  • glucose released into bloodstream
  • adipose tissue cells stimulated to increase lipolysis
  • decreased lipogenesis
  • glycerol and fatty acids released into blood as alternative fuel molecules
  • saves glucose for the brain

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Action of Thyroid Hormone (continued)

  • Increased respiration rate
  • to meet additional oxygen demand
  • Increased heart rate and force of contraction
  • increases blood flow to tissues
  • increased receptors for epinephrine and norepinephrine on heart

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Action of Thyroid Hormone (continued)

  • Increased thyroid hormone
  • inhibits release of TRH from hypothalamus
  • inhibits release of TSH from anterior pituitary
  • causes release of growth inhibiting hormone
  • further inhibits release of TSH from anterior pituitary

See Table B.4: Regulating Metabolism with Thyroid Hormone

*

Figure 17.19

5

6

7

4

1

4

2

5

6

3

3

8

1

Thyroidhormone: T3//T4

STIMULUS

Hypothalamus is stimulated by one or more of the

following:

• Decreased thyroid hormone

Hypothalamus

CONTROL CENTER

RECEPTOR

TH levels increase,

inhibiting release of

TRH and TSH.

NET EFFECT

Increased metabolic rate,

which is supported by

increased release of stored

fuel molecules, and increased

delivery of O2.

Increased

heat

TH

TSH

The hypothalamus

releases

thyrotropin-releasing

hormone (TRH) into the

hypothalamo-hypophyseal

portalsystem.

The hypothalamus

responds to various

stimuli.

In response to TRH, the anterior pituitary

releases thyroid-stimulating hormone (TSH).

TSH stimulates the thyroid gland to release

thyroid hormone (TH) in to the blood.

TH then acts on target cells (effectors).

Thyroid

gland

TRH

TH

TH

TH (T3/T4) bound by

carrier protein (e.g.,

thyroglobulin)

EFFECTORS: Effectors respond to increased

levels of TH in the following ways:

Heart

Lungs

Adipose connective

tissue

All cells, especially

neurons

Liver tissue

Increased

metabolic rate

Increased

glucose uptake

Increased glycogenolysis

and gluconeogenesis

Decreased glycogenesis

Decreased lipogenesis

Increased lipolysis

These responses help meet increased O2

demand for aerobic cellular respiration

Increased heart rate

Increased force of contraction

Increased

breathing rate

Stimulation

Inhibition

• Other stimuli including cold weather, pregnacy, high

altitude, and hypoglycemia

Amino acids

Glucose

Glycerol

Fatty acids

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2

*

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3.unknown

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

All cells: increased metabolic rate and glucose uptake

Liver tissue: increased glycogenolysis and gluconeogenesis and decreased glycogenesis

Adipose tissue: increased lipolysis and decreased lipogenesis

Lungs: increased breathing rate

Heart: increased heart rate and force of contraction

What are the primary target organs/tissues of thyroid hormone? Describe the effect on each.

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Clinical View: Disorders of Thyroid Hormone Secretion

  • Hyperthyroidism
  • result from excessive production of TH
  • increased metabolic rate, weight loss, hyperactivity, and heat intolerance
  • caused by T4 ingestion, excessive stimulation by pituitary, or loss of feedback control in thyroid
  • treated by removing the thyroid (with daily hormone supplements)

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Clinical View: Disorders of Thyroid Hormone Secretion (continued)

  • Hypothyroidism
  • results from decreased production of thyroid hormone
  • low metabolic rate, lethargy
  • cold intolerance, weight gain, and photophobia
  • caused by decreased iodine intake, loss of pituitary stimulation of thyroid, postsurgical, or immune system destruction of thyroid
  • treated with thyroid hormone replacement

*

Representative Hormones Regulated by the Hypothalamus: Thyroid Gland and Hormone

Clinical View: Disorders of Thyroid Hormone Secretion (continued)

  • Goiter
  • enlargement of thyroid
  • typically due to insufficient dietary iodine
  • lack of dietary iodine preventing thyroid from producing thyroid hormone
  • once relatively common in United States
  • now iodine added to table salt

*

C cells of Thyroid Gland

  • C cells of thyroid secrete Calcitonin
  • Functions of Calcitonin:
  • Stimulates osteoblasts to use calcium to build bone (decreases blood calcium levels)
  • Stimulates kidneys to excrete calcium in urine (decreases blood calcium levels)
  • Works opposite PTH

Endocrine Glands: Location of the
Major Endocrine Glands

Endocrine Organs (continued)

  • Parathyroid glands
  • Four nodules on posterior thyroid gland
  • Two different cell types:
  • chief cells
  • source of parathyroid hormone
  • released in response to decreased blood calcium levels
  • return blood calcium to normal levels
  • oxphil cells
  • function unknown

*

Parathyroid Glands

Parathyroid Glands
High Magnification

Chief cells

Oxyphil cells

Adrenal Glands

Adrenal (Suprarenal) Glands

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Anatomy of the Adrenal Glands (continued)

  • Adrenal medulla
  • forms inner core of each adrenal gland
  • red-brown color due to extensive blood vessels
  • releases epinephrine and norepinephrine with sympathetic stimulation
  • Adrenal cortex
  • synthesizes more than 25 corticosteroids
  • yellow color due to lipids within cells
  • three regions producing different steroid hormones

*

Figure 17.20a

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Right adrenal gland

Right inferior suprarenal artery

Right suprarenal vein

Right renal artery

Right renal vein

Right kidney

Inferior vena cava

(a)

Abdominal aorta

Left kidney

Superior mesenteric artery

Left renal vein

Left renal artery

Left suprarenal vein

Left inferior suprarenal arteries

Left adrenal gland

Left middle suprarenal artery

Left superior

suprarenal arteries

Left inferior

phrenic artery

Right inferior

phrenic artery

Right superior

suprarenal arteries

Right middle

suprarenal artery

Celiac trunk

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Hormones of the Adrenal Cortex

  • Zona glomerulosa
  • thin, outer cortical layer
  • mineralocorticoids synthesized here
  • help regulate electrolyte concentration in body fluids
  • aldosterone, principal mineralocorticoid
  • stimulates sodium ion reabsorption (water follows) and potassium ion secretion at the kidneys

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Hormones of the Adrenal Cortex (continued)

  • Zona fasiculata
  • middle, largest layer
  • parallel cords of lipid-rich cells
  • glucocorticoids synthesized here
  • primary ones cortisol and corticosterone

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Hormones of the Adrenal Cortex (continued)

  • Zona reticularis
  • innermost region of cortex
  • secrete minor amounts of sex hormones, gonadocorticoids
  • primary ones, androgens, male sex hormones
  • converted to estrogen in females
  • androgen amount small compared to gonads
  • can result in elevated testosterone in adrenal tumors

*

Figure 17.20c-d

LM 35x

Capsule

Adrenal cortex

Adrenal medulla

(c)

Capsule

Adrenal cortex

Adrenal medulla

(d)

Adrenal medulla

Zona reticularis

Zona fasciculata

Zona glomerulosa

Capsule

d: © The McGraw-Hill Companies, Inc./Al Telser, photographer

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Action of Cortisol

  • Glucocorticoids
  • Cortisol and corticosterone most common
  • increase nutrient levels in blood
  • attempt to resist stress and repair injured tissue

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Action of Cortisol (continued)

  • Hypothalamic-pituitary-adrenal axis
  • corticotropin-releasing hormone (CRH) released from hypothalamus
  • triggered by decreased cortisol level
  • influenced by time of day and stress
  • binds receptors in anterior pituitary
  • stimulates adrenocorticotropic hormone (ACTH) release
  • ACTH binding to adrenal cortex cells
  • stimulates release of cortisol and corticosterone

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Action of Cortisol (continued)

  • Responses triggered by cortisol
  • hepatocytes with increased glycogenolysis and gluconeogenesis
  • adipose tissue with increased lipolysis and decreased lipogenesis
  • increased catabolism in most cells
  • amino acids released from liver cells
  • cells stimulated to have decreased glucose uptake

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Action of Cortisol (continued)

  • Corticosterone as treatment for chronic inflammation
  • at high doses, side effects of water and Na+ retention
  • inhibited release of inflammatory agents
  • suppression of the immune system
  • inhibited connective tissue repair

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Action of Cortisol (continued)

  • Increased cortisol
  • inhibits release of CRH from hypothalamus
  • inhibits release of ACTH from anterior pituitary

*

Page 685

Figure 17.21

2

3

1

3

5

4

High doses of cortisol:

Increase retention of Na+, H2O

4

5

6

6

7

8

1

2

Stimulation

Inhibition

Cortisol

STIMULUS

CONTROL CENTER

The hypothalamus

releases corticotropin-

releasing hormone

(CRH) into the

hypothalamo-hypophyseal

portal system.

RECEPTOR

Hypothalamus

responds to various

stimuli.

In response to CRH, the anterior pituitary

releases adrenocorticotropic hormone

(ACTH).

ACTH stimulates the adrenal cortex to

release glucocorticoids (e.g., cortisol)

into the blood.

Cortisol stimulates target cells (effectors).

Cortisol levels

increase inhibiting

release of CRH

and ACTH.

NET EFFECT

Increase of all nutrients in

the blood.

Cortisol

EFFECTORS: Effectors respond

to cortisol in the following ways:

Liver

Stimulation of protein

catabolism (occurs in all

cells except hepatocytes)

Stimulation of lipolysis

Inhibition of lipogenesis

Stimulation of

gluconeogenesis (use

amino acids and fatty acids)

Adipose connective

tissue

All cells

ACTH

CRH

Hypothalamus

Variables that act on the hypothalamus:

• Negative feedback by cortisol

• Time of day

• Stress

Decrease inflammation

Suppress the immune system

Inhibit connective tissue repair

Cortisol bound by

carrier proteins

(e.g., CBG)

Amino acids

Glucose

Amino acids

Glycerol fatty acids

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4.unknown

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

CRH is released from the hypothalamus in response to decreased cortisol levels. Its release triggers the release of ACTH from the anterior pituitary. ACTH binds receptors within the adrenal cortex and stimulates the release of cortisol and corticosterone.

What is the relationship of CRH, ACTH, and cortisol?

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands and Cortisol

Clinical View: Disorders in Adrenal Cortex Hormone Secretion

  • Cushing syndrome
  • chronic exposure to excessive glucocorticoid hormones
  • seen in people taking corticosteroids for therapy
  • some cases when adrenal gland produces too much hormone
  • body obesity, hypertension, excess hair growth, kidney stones, and menstrual irregularities

*

Representative Hormones Regulated by the Hypothalamus: Adrenal Glands

Clinical View: Disorders in Adrenal Cortex Hormone Secretion (continued)

  • Addison disease
  • form of adrenal insufficiency
  • develops when adrenal glands fail
  • chronic shortage of glucocorticoids and sometimes mineralocorticoids
  • may develop from lack of ACTH or lack of response to ACTH
  • weight loss, fatigue and weakness, hypotension, and skin darkening
  • therapy of oral corticosteroids

*

Pancreatic Hormones

Learning Objectives:

1) Identify the primary types of pancreatic islet cells and the hormones they produce.

Describe the action of insulin in lowering blood glucose concentration.

Explain the action of glucagon in raising blood glucose concentration.

*

Pancreas

Pancreatic Hormones:
Anatomy of the Pancreas

  • Pancreas characteristics (continued)
  • Pancreatic islet cells
  • small clusters of endocrine cells scattered among acini
  • 1% of total pancreatic volume
  • composed of two primary cell types:
  • alpha cells secreting glucagon
  • beta cells secreting insulin

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

  • Blood glucose concentration
  • Pancreatic endocrine function
  • maintaining normal blood glucose
  • Normal range 70 to 110 mg of glucose/deciliter
  • Chronically high levels damaging to blood vessels and kidneys
  • Low levels resulting in lethargy, mental and physical impairment, and death (if too low)

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

Lowering High Blood Glucose Levels with Insulin

  • Insulin released from pancreas following food intake
  • Glucose levels detected by chemoreceptors
  • Target cells bound by insulin
  • activates second messengers in target cells

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

Lowering High Blood Glucose Levels with Insulin (continued)

  • In hepatocytes
  • glycogenesis stimulated
  • glycogenolysis and gluconeogenesis inhibited
  • glucose molecules removed from blood and stored as glycogen
  • In adipose tissue
  • lipogenesis stimulated and lipolysis inhibited
  • decreased fatty acid levels in blood
  • storage of fat increased

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

Lowering High Blood Glucose Levels with Insulin (continued)

  • Release of insulin
  • results in decrease in all nutrients in blood
  • increase in synthesis of storage forms of molecules
  • decrease of alternative nutrients
  • cells more likely to use available glucose
  • decreases with decreased glucose levels

*

Figure 17.24

4

5

2

3

4

1

2

3

Insulin

Pancreas

Stimulation

Inhibition

NETEFFECT

Decreased blood glucose

(fatty acids and amino

acids are also decreased

in the blood)

CONTROL CENTER

Beta cells within

pancreas release

insulin.

Beta cells within the

pancreas detect an

increase in blood

glucose levels.

RECEPTOR

Insulin stimulates target

cells (effectors).

Insulin

Negative feedback

Insulin release is inhibited

as blood glucose levels

decrease to normal.

Insulin

Liver tissue

Most cells

Increased uptake of

glucose by increasing

glucose transport

proteins in the plasma

membrane

Increased uptake

of amino acids, which

stimulates protein

anabolism

Increased lipogenesis

Decreased lipolysis

Increased glycogenesis

Decreased glycogenolysis

and gluconeogenesis

Adipose connective tissue

All cells

(especially muscle)

1

STIMULUS

Increase in blood glucose

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

EFFECTORS: Effectors respond

to insulin in the following ways:

Glucose

Glucose

Amino acids

Fatty acids

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

Raising Low Blood Glucose Levels with Glucagon

  • Levels detected by alpha cells in pancreas
  • Glucagon released in response to low blood glucose levels
  • can cause lethargy and death if it drops too low
  • binds plasma membrane receptors to activate second messengers
  • Facilitates nutrient breakdown and release

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

Raising Low Blood Glucose Levels with Glucagon (continued)

  • In hepatocytes
  • glycogenolysis and gluconeogenesis stimulated
  • glycogenesis inhibited
  • glucose released into blood
  • In adipose tissue
  • lipolysis stimulated
  • lipogenesis inhibited
  • fatty acids and glycerol released from storage into blood

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

Raising Low Blood Glucose Levels with Glucagon (continued)

  • Release of glucagon
  • increases glucose, glycerol, and fatty acids in blood
  • decreases storage forms of these nutrients
  • has no effect on protein components
  • inhibited by increased blood glucose levels

*

Figure 17.25

5

2

3

4

1

2

Glucagon

STIMULUS

Decrease in blood glucose

Pancreas

CONTROLCENTER

Alpha cells within

the pancreas

release glucagon.

RECEPTOR

Alpha cells within the

pancreas detect a

decrease in blood

glucose levels.

Gucagon stimulates target

cells (effectors).

Glucagon

Increased blood glucose

and fatty acid levels

(note—no change in
amino acids or proteins).

NET EFFECT

Negative feedback

Glucagon release is inhibited

as blood glucose levels

increase to normal.

Glucagon

Adipose connective tissue

Liver

Increased glycogenolysis

and gluconeogenesis

Decreased glycogenesis

Increased lipolysis

Decreased lipogenesis

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

3

Glucose

Glycerol fatty acids

4

EFFECTORS: Effectors respond

to glucagon in the following ways:

Stimulation

Inhibition

1

*

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*

5.unknown

Pancreatic Hormones:
Effects of Pancreatic Hormones

In hepatocytes glycogenolysis and gluconeogenesis are stimulated and glycogenesis is inhibited. In adipose tissue lipolysis is stimulated and lipogenesis is inhibited.

What affect does glucagon have on hepatocytes and adipose tissue?

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

Clinical View: Abnormal Glucose Levels

  • Diabetes mellitus
  • inadequate uptake of glucose from blood
  • with chronically elevated glucose, blood vessels damaged
  • leading cause of retinal blindness, kidney failure, and nontraumatic amputations in the United States
  • associated with increased heart disease and stroke
  • Type 1 diabetes
  • absent or diminished release of insulin by pancreas
  • tends to occur in children and younger individuals
  • may have autoimmune component
  • requires daily injections of insulin

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

Clinical View: Abnormal Glucose Levels (continued)

  • Type 2 diabetes
  • from decreased insulin release or insulin effectiveness
  • obesity major cause in development
  • tends to occur in older individuals, but can occur in young adults
  • treatment with diet, exercise, and medications
  • Gestational diabetes
  • seen in some pregnant women
  • if untreated, causes risk to fetus and increases delivery complications
  • increases chance of later developing type 2 diabetes

*

Pancreatic Hormones:
Effects of Pancreatic Hormones

Clinical View: Abnormal Glucose Levels (continued)

  • Hypoglycemia
  • glucose levels below 60 mg/DL
  • numerous causes:
  • insulin overdose, prolonged exercise, alcohol use, liver or kidney dysfunction
  • deficiency of glucocorticoids or growth hormone, genetics
  • symptoms of hunger, dizziness, confusion, sweating, and sleepiness
  • glucagon given if individual unconscious and unable to eat

*

Kidneys et al.

  • Name the hormones and enzyme produced by the kidneys and describe their general functions.
  • Briefly describe the renin-angiotensin system.
  • Briefly describe the general functions of hormones produced by the thymus, heart, kidneys, gastrointestinal tract, gonads, adipose tissue. (See table 17-2 and lab notes)
  • Discuss the general affects of abnormal levels of hypothalamic, pituitary, thyroid, parathyroid, adrenal, and pancreatic hormones.

Kidneys

  • Not discussed in text in chapter 17, but will be discussed later
  • Produces erythropoietin (EPO)
  • Hormone that stimulates red blood cell production
  • Discussed further in chapter 18
  • Produces calcitriol, synthesized from vitamin D3
  • Hormone that promotes calcium and phosphate absorption along digestive tract
  • Produces renin, an enzyme that triggers activation of a hormone

Renin-Angiotensin System

  • Discussed further in upcoming chapters
  • Renin converts angiotensinogen to angiotensin I in the bloodstream
  • Angiotensin I is then converted to Angiotensin II, an active hormome
  • Angiotensin II does the following to increase blood volume and pressure:
  • Stimulates production of ADH and aldosterone
  • Increases thirst
  • Constricts blood vessels

Running head: RESEARCH PAPER OUTLINE 1

RESEARCH PAPER OUTLINE 8

Research paper outline

David Bumford

Kaplan University

Microeconomics

1-29-14

1). Working title

(i). Evaluating environmental regulation.

2). Thesis statement: the world is growing with the population increasing daily and the natural resources are few and continue to disintegrate thus we need to address this issue through environmental regulation. To keep our world going in the right direction, we have to search for alternative resource in energy. Current scientists have come up with ways to help in converting renewable resources which include wind turbines, biofuels water, and the sun into energy in powering the future. This paper seeks to address environmental regulation through; stating the purpose of recycling programs, assessing the impacts of these programs on consumers and firms, and evaluating the extent of these programs in achieving their purpose in environmental regulation.

3). Major points in the evaluation of environmental regulation.

(i). Purpose of recycling programs in environmental regulation.

a) Recycling diverts waste products from landfills through extension of their usefulness (Freeman, Kolstad, & NetLibrary, 2007).

b) Recycling programs which are robust improve community quality in life hence resulting to more desirable environment to live.

c) Recycling programs help to reduce greenhouse emissions in dangerous gases.

d) Conserves the natural resources through consumption of few raw materials.

(ii). Assessing the impacts of recycling programs on consumers and firms in the nation.

a) Recycling programs leads to healthy neighborhoods.

b) Recycling programs creates jobs through all the processes involved in turning the waste material into useful products.

c) They help to support sustainable industries as some companies depend of waste recycling to make business.

d) Recycling programs help to bring communities together through school participation or other programs in rebuilding environment.

e) Provides a sustainable growth in communities when waste reduction is made a priority.

f) Provides the consumers with cheap products from the recycling industries.

(iii). Evaluating the progress of the recycling programs in their effort of attaining their intention of regulating the environment.

A). Many private and government owned institution have teamed up to ensure proper adherence in rules regulating recycling programs to achieve clean environment.

4). Evidence of the major points.

i). The federal government provides regulations and rules which govern handling and disposal of waste products to ensure clean environment (Fiorino, 2006).).

a). The government provides regulation and rules governing transportation, generation, storage, treatment and the disposal of dangerous waste products through Resource Conservation and Recovery Act (RCRA).

b). The Toxic Substances Control Act (TSCA) give the regulation and manage disposal in PCB-containing waste products.

c). The Universal Waste Rule (UWR) streamline the collection requirements of hazardous waste products such as batteries, lamps, thermostats, pesticides and many more.

ii). Most of the research in waste product recycling programs show positive impacts of this program to the consumers, firms and government at large.

a). According to research by Recycling means Business of North Carolina, waste product recycling offer jobs to more people compared to bio-tech industries in that state.

b). A study by the Florida Recycling Economic Information in 2000 provides that recycling programs which are efficient, benefit community financially and improves aesthetic appeal of neighborhoods.

c). Markets for Aluminum states that many consumers buy more scrap aluminum where these plants are located and these smelted products are sold cheaper in the markets.

iii). Reports from private and government institutions in charge of environmental regulation speak positively in the progress of environmental recycling programs (Kuehr, Williams, & Workshop, 2003).

a). According to the HHS Environmental Justice Strategy, many programs of environmental regulation are making difference by giving grants to communities in the process of recruiting and training people living in vulnerable areas due to contaminants exposure.

b). Affordable Care Act provides new transformation in the community by offering grant recycling programs building the Economic Empowerment Zone Model.

References

Fiorino, D. J. (2006). The new environmental regulation. Cambridge, Mass: MIT Press.

Freeman, J., Kolstad, C. D., & NetLibrary, Inc. (2007). Moving to markets in environmental regulation: Lessons from twenty years of experience. Oxford: Oxford University Press.

Kuehr, R., Williams, E., & Workshop. (2003). Computers and the environment: Understanding and managing their impacts. Dordrecht [u.a.: Kluwer Acad. Publ.

Microeconomics: Unit 4 Assignment: Research Paper Outline

Content (23 points)

Points Possible

Points Earned

Included a working title

2

2

Well defined thesis statement that incorporates three main points. The thesis should be one sentence not a paragraph.

9

4

Three major points that are tied to the thesis statement

6

6

Two details (information or evidence with sources listed) for each of the three major points Your third point only has one detail.

6

5

Analysis (13 points)

Work demonstrates synthesis of concepts, research, and experience

5

5

Work demonstrates the student’s ability to tie relevant information to real-life applications.

4

4

Analysis exceeds basic comprehension to demonstrate higher-order thinking.

4

4

Writing (9 points)

Correct use of APA 6th edition format, all sources used to support the paper are referenced

4

4

Sentences are clear, concise, and direct; tone is appropriate, spelling, grammar, and punctuation are correct.

5

5

Total

45

39

David, Good work. Continue to work on your thesis. It should be one well crafted sentence.

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