1. Monday, 19 September Chapter 11 The Endocrine System
Classes of hormones
The adrenal gland
Fates of hormones
Renin-Angiotensin-Aldosterone System
Control of hormone secretion
Hormone interactions (permissive effects)

2. 1QQ # 6
Stress leads to the secretion of epinephrine which alters the metabolism of many cell types. Describe the effects of EPI on two different cell types and explain how these effects are beneficial to the person.
Starting with the arrival of carbohydrates in the stomach list the sequence of events, cell types, and hormone(s) that comprise a feedforward mechanism. What is the purpose of this feedforward mechanism?
Beginning with the ingestion of a large amount of sugar, list the sequence of events in a reactive hypoglycemic person that ultimately leads to a headache, fast heart rate, and cold, clammy skin.

3. Endocrine Organs (Table 11-1)
Hormone
Paracrine agent
Autocrine agent
Neurotransmitter
Neuromodulator
Pituitary Gland
Thyroid Gland
Pancreas
Gonads
Gastrointestinal Tract
Heart
Kidney
Hypothalamus
Liver
Etc.
Hormone: chemical messengers
carried by blood to target cells upon which they act.
Only those cells having receptors
Can respond to a given hormone
Analogy: SSNs and receptors

4. 3 Chemical Classes of Hormones
1: Amine hormones (from amino acid tyrosine)
Thyroid hormones
Adrenal medullary hormones (catecholamines)
2: Peptide hormones (peptides & proteins)
3: Steroid Hormones (derivatives of cholesterol)
Why does the chemical class matter?

5. NT Fig. 11.01 Amine Hormones Adrenal medulla
Thyroid Hormones Not soluble in plasma, bound & free
Amine Hormones
Adrenal medulla NT
Catecholamines soluble in plasma
11.01.jpg

6. Steroid hormones
Fig
not soluble in plasma, not storable in vesicles
Bound & Free
11.03.jpg
Target cells have intracellular receptors. Changes is gene expression. Timecourse?

7. Fig. 11.02 Guess peptide! Peptide Hormones
Examples of Peptide Hormones: Insulin, glucagon prolactin, erythropoietin, parathyroid hormone, gastrin, leptin, growth hormone, oxytocin, vasopressin, FSH, LH, GHRH, and many more!
Peptide Hormones
Soluble in plasma
e.g. Beta cell
Guess peptide!
11.02.jpg
Cell surface receptors on target cells

8. Know Table 11-2 p 323 Hormone class Major form in plasma
Location of receptors
Signal transduction mechanisms
Rate of excretion / metabolism

9. Questions so far?

10. Hormones of the Adrenal Cortex
Fig
Hormones of the Adrenal Cortex
11.05.jpg
Adrenal Gland
Part of Sympathetic Nervous System

11. Hormones of the Adrenal Cortex
Androgens
DHEA
“Andro”
Glucocorticoids
11.04b.jpg
Mineralicorticoid
What regulates the secretion of cortisol and aldosterone?

12. Gonadal Steroids (not adrenal cortex)
Fig
Gonadal Steroids (not adrenal cortex)
Estrogens
11.06.jpg
King DS, Sharp RL, Vukovich MD, Brown GA, Reifenrath TA, Uhl NL, Parsons KA . Effect of oral androstenedione on serum testosterone and adaptations to resistance training in young men: a randomized controlled trial. JAMA 1999; 281(21):2020-8

13. What happens to hormones once released?
Be able to give
Examples.
Ex: Renin
Fast if free
Slow if bound
T4 to T3 and Testosterone to Estradiol

14. Renin-angiotensin-aldosterone
Renin is an enzyme released from kidney cells into bloodstream, its “substrate” is a plasma protein called Angiotensinogen.
Renin
Angiotensinogen from liver, an ever-present plasma protein
Angiotensin I
Angiotensin converting enzyme (ACE)
Angiotensin II
Thirst
Zona Glomerulosa of Adrenal Cortex
Arterial smooth muscle … vasoconstriction…increase blood pressure
Aldosterone
Promotes Na+ retention in Kidney

15. Blood Pressure
(-)
Renin from Juxtaglomerular cells in Kidney
Multi-step process involving Angiotensin I and II
Angiotensin II
Aldosterone
K+ in plasma
_______
Na+ reabsorption in kidney
thirst
Plasma volume
Drink
Blood pressure
vasoconstriction

16. What happens to hormones once released?
Be able to give
Examples.
Ex: Renin
Fast if free
Slow if bound
T4 to T3 and Testosterone to Estradiol

17. Factors that affect hormone secretion
Integrator!
11.09.jpg
Recall example: beta cells of Islets of Langerhans
Secretion is usually pulsative, may be diurnal.

18. 16.08.jpg

19. Fig
Permissive effect
Thyroid hormone stimulates production of beta-adrenergic receptors
11.08.jpg