Unit 8 |
[Microeconomics] |
Unit 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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*
2.unknown
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
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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?
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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
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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
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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
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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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