1. Endocrine Control
Chapter 32

2. An Orchestra of Hormones
Hormones influence the growth, development, and reproductive cycles of nearly all animals
They influence behavior, physical appearance, and well-being

3. Hormones
Secreted by endocrine glands, endocrine cells, and certain neurons
Animal hormones travel through the bloodstream to nonadjacent target cells

4. Other Signaling Molecules
Neurotransmitters
Local signaling molecules
Pheromones

5. Endocrine System Main Sources Pituitary gland Adrenal glands
Thyroid gland
Parathyroid glands
Pineal gland
Thymus gland

6. HYPOTHALAMUS PINEAL GLAND PITUITARY GLAND THYROID GLAND
PARATHYROID GLANDS
THYMUS GLAND
ADRENAL GLANDS
PANCREATIC ISLETS
OVARIES
Fig. 32.2b, p. 523
TESTES

7. Responses to Hormones Vary
Different hormones activate different responses in the same target cell
Not all types of cells respond to a particular hormone

8. Two Main Hormone Types Steroid hormones Peptide hormones
Derived from cholesterol
Estrogens, progestins, androgens (such as testosterone), cortisol, aldosterone
Peptide hormones
Peptides, proteins, or glycoproteins
Glucagon, ADH, oxytocin, TRH, insulin, somatotropin, prolactin, FSH, LH, TSH

9. Steroid Hormone Action
Most diffuse across the plasma membrane and bind to a receptor
Hormone-receptor complex acts in nucleus to inhibit or enhance transcription (protein synthesis)

10. hormone-receptor complex
Steroid Hormones
hormone
Most diffuse across the plasma membrane and bind to a receptor
Hormone-receptor complex acts in nucleus to inhibit or enhance transcription
receptor
hormone-receptor complex
gene product

11. Protein Hormone Hormone binds to a receptor at cell surface
glucagon
Hormone binds to a receptor at cell surface
Binding triggers a change in activity of enzymes inside the cell
glucagon receptor
cyclic AMP
+ Pi
ATP
cAMP activates
protein kinase A
Protein kinase A converts phosphorylase
kinase to active form and inhibits an
enzyme required for glucagon synthesis.

12. The Hypothalamus Region in the brain Contains hormone-secreting cells
Interacts with pituitary
pituitary gland

13. HYPOTHALAMUS PITUITARY GLAND
bone at base of cranial cavity
anterior lobe
posterior lobe
Fig. 32.2a, p. 522

14. Pituitary Gland Two lobes
Posterior lobe (neurohypophysis) stores and secretes hormones that were synthesized in the hypothalamus
Anterior lobe (adenohypophysis) produces and secretes its own hormones

15. Posterior Lobe Antidiuretic hormone (ADH ) Oxytocin (OCT)
cell body in hypothalmus
Antidiuretic hormone (ADH )
Oxytocin (OCT)
axons
to the general circulation

16. cell body in hypothalmus
POSTERIOR LOBE OF PITUITARY
oxytocin
ADH
axons
kidney tubules
mammary
glands
smooth muscle in wall of the uterus
to the general circulation
Fig. 32.5, p. 527

17. Anterior Pituitary
ACTH
TSH
FSH LH
PRL
STH

18. Cell bodies secrete releasing and inhibiting hormones
growth-promoting effects on most cells
ANTERIOR LOBE OF PITUITARY
STH
(GH)
ACTH
PRL
Capillary bed at base of hypothalmus
TSH
FSH LH
both act on:
adrenal cortex
thyroid
gonads
mammary glands
Capillary bed in anterior pituitary
Fig. 32.6, p. 527

19. Feedback Mechanisms Negative feedback Positive feedback
An increase in concentration of a hormone triggers activities that inhibit further secretion
Positive feedback
An increase in concentration of a hormone triggers activities that stimulate further secretion

20. Control of Cortisol Secretion (1)
Hypothalamus senses decline in glucose and secretes a releasing hormone (CRH)
CRH stimulates anterior pituitary to secrete ACTH
ACTH acts on the adrenal cortex to stimulate cortisol secretion

21. Control of Cortisol Secretion (2)
Inhibits blood glucose uptake by muscle and other tissues
Causes breakdown of proteins to amino acids and conversion to glucose
Causes degradation of adipose tissue to fatty acids for use as energy source

22. Control of Cortisol Secretion (3)
Decrease in glucose uptake and release of glucose from protein breakdown causes blood glucose level to rise
Hypothalamus and anterior pituitary detect the increase and decrease secretion of CRH and ACTH
Adrenal cortex decreases cortisol secretion

23. Thyroid Gland Disorders
Goiter
Hyperthyroidism
Hypothyroidism

24. Feedback Control of Ovaries
Pituitary produces hormones (LH, FSH) that stimulate egg maturation and ovulation in the ovary
They also stimulate ovary to produce progesterone and estrogen
After ovulation, rising levels of these hormones inhibit further secretion of LH and FSH

25. Control of Glucose Metabolism
insulin
Glucose uptake
Glucose to glycogen
Glucose falls
Glucose is absorbed
Cells use glucose
Glucose rises
Glycogen to glucose
glucagon

26. Diabetes Mellitis
Disease in which excess glucose accumulates in blood, then urine
Effects include
Excessive urination
Constant thirst
Weight loss
Ketone formation and acid-base imbalances

27. Two Types of Diabetes Type 1 Type 2 Auto-immune disease
Usually appears in childhood
Treated with insulin injections
Type 2
Target cells don’t respond
Usually appears in adults
Treated with diet, drugs