Transcript BIO 342 HUMAN PHYSIOLOGY

Monday, 15 September
Chapter 11 The Endocrine System
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Classes of hormones
The adrenal gland
Fates of hormones
Renin-Angiotensin-Aldosterone System
Control of hormone secretion
Hormone interactions (permissive effects)
Hypothalamus & Pituitary
The story of Aunt Dot
Endocrine disorders (lab)
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
Renin-angiotensin-aldosterone
Renin is released from kidney cells into
bloodstream, its “target” in a plasma protein.
Angiotensinogen
from liver, a plasma
protein
Renin
Angiotensin I
Angiotensin converting enzyme
(ACE)
Angiotensin II
Zona Glomerulosa of Adrenal Cortex
Aldosterone
Thirst
Arterial smooth muscle …
vasoconstriction…increase blood
pressure
Promotes Na+ retention in Kidney
Renin from
(-)
Juxtaglomerular
cells in Kidney
Multi-step process involving
Angiotensin I and II
Angiotensin II
thirst
Aldosterone
Na+ reabsorption in kidney
Drink
Plasma volume
vasoconstriction
Blood pressure
K+ in plasma
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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
Factors that affect hormone secretion
Integrator!
Recall example:
beta cells of Islets of Langerhans
Secretion is usually pulsative, may be diurnal.
Fig. 11.08
Permissive
effect
Thyroid hormone stimulates production of beta-adrenergic receptors
Questions so far?
Fig. 11.12a
Fig. 11.12b
Neurohypophysis
Adenohypophysis
Vasopressin (= Antidiuretic hormone)
Oxytocin
Typical Blood Flow
Artery – arteriole- capillary –venule- vein –heart
Portal System
Artery – arteriole- capillary –portal vessel –
capillary –venule- vein –heart
1. Hypothalamo-hypophyseal portal system
2. Hepatic portal system
3. Vasculature of nephrons
Tropic hormones control the function
Trophic hormones promote survival and growth of targets
P P
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P
Hypothalamo-hypophyseal portal system
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Releasing Hormone
Release-inhibiting Hormone
P
S