1. Hormones and endocrine system
Chapter 45
Hormones and endocrine system

2. Hormones
You only need a little bit of the hormone to cause a response (remember how the signal gets amplified! Look back at chapter 11)
Protein-based hormones
Receptor on the plasma membrane (don’t go inside!)
Water-soluble
Lipid-based hormones
Receptor is inside the cell (go inside the cell!)

3. Signaling Review

4. Receptors
Same receptor, same hormone, different cell - different pathways (first two)
Same type of cell, same hormone, different receptor - different response

5. The Master Gland (Pituitary)
Under the hypothalamus
Posterior Pituitary
Directly connected to hypothalamus by neurosecretory cells
Only STORES hormones that are produced by the hypothalamus
Anterior Pituitary
Indirectly connected to hypothalamus (still under its control) by capillary portal system
Makes its own hormones and releases them
POST PITUITARY DOES NOT MAKE HORMONES

6. Posterior Pituitary Antidiuretic Hormone (ADH) Oxytocin
Targets kidney tubules
Retention of water
Oxytocin
“Swift birth”
Targets mammary glands, uterine muscles
Let down of milk

7. Anterior Pituitary Adrenocorticotrophic Hormone
Assists in synthesizing corticosteroids, which are responsible for stress response
Thyroid Stimulating Hormone
Regulates body temperature, thirst and hunger
Follicle Stimulating Hormone
Stimulates the maturation of egg and sperm
Luteinizing Hormone
Stimulates secretion of sex steroids from the gonads
Prolactin
Stimulates milk production in breasts
Melanocyte Stimulating Hormone
Regulates the function of skin pigment cells (melanocytes)
Growth Hormone
Growth in bones, tissues, and other body systems

8. Tropic vs nontropic Tropic Nontropic Both Target endocrine glands
Ex. TSH stimulates the thyroid to produce thyroxine
Nontropic
Direct effect on target cells, tissues
Ex. Melanocyte Stimulating Hormone (MSH)- affects skin cells, Prolactin- Affects cells in the mammary glands to make milk, Thyroxine
Both
Ex. Growth hormone – tells bone and tissue cells to grow (nontropic), causes liver to make insulin- like growth factors which tell other cells to grow (tropic)

9. Issues Acromegaly Too much Human Growth Hormone
You can see it in the hands, jaw, and brow ridge
Can by caused by a pituitary tumor, which causes the production of too much growth hormone