EndocrinePhysiologyPointsToPonder
1. What is a hormone?
A chemical signal
2. What makes a chemical a hormone?
Hormone are secreted by a cell or group of cell
3. The difference between a “hormone” and “neurohormone” is........................
Neurohormones are secreted by nervous tissue
4. Which organ/tissue secretes neurohomrones? (name two)
The posterior pituitary gland and the adrenal medulla
5. Name some neurohormones.
Acetylcholine and epinephrine
6. Remember: Secretions of endocrine cells/gland go first to the extracellular
space and then to the blood. Secretions of exocrine glands travel through a
duct (pancreatic ducts, salivary gland ducts). You can see exocrine
secretions go to the outside (to lumens of tubes: GIT and respiratory
system, genitourinary system).
7. Hormones travel in the blood. This means that all cells are exposed/get in
touch with different hormones. However, not all cells respond to all
hormones/or to every hormone they are exposed to. What determines
whether a cell will respond to particular hormone? Clue: the presence of a
receptor for that hormone on or in the cell.
, 8. Cell “A” has 10 receptors for ADH and cell “B” has 100 receptors for ADH. Which cell is
more responsive to ADH?
9. What is paracrine signaling or paracrine molecule? How is it different from endocrine or
autocrine?
Paracrine signaling secrete things to the adjacent cells. Endocrine hormones usually
secrete to epithelial cells. Autocrine hormones act on the same cells.
10. The pituitary gland is often dubbed the “master gland”. Why? Give examples.
11. Classify hormones by chemical nature and give examples for each.
Steroids: derived from cholesterol, se hormones, adrenal cortex hormones
Peptide or proteins: made up of only few amino acid residues: insulin and glucagon
Amines: derived from modification of amino acids
12. Explain the cellular mechanisms of action of Lipid-soluble hormones (e.g., steroid
hormones) and Water-soluble hormones (e.g., peptide/protein hormones). Be able to
draw a very general pathway for each.
Steroid hormones are lipid-soluble hormones and they can penetrate the cell membrane
and interact with intracellular receptors (cytoplasmic or nuclear). Peptide hormones are
lipophilic (water soluble) . They are usually unable to enter the target cell and therefore
bind to receptors located in the cell membrane.
13. True or False: Steroid hormones may/can have receptors in the cytoplasm, in the
nucleus and on the cell membrane.
14. What is genomic and nongenomic effects of steroid hormones (just be able to visualize
the difference/pathway).
Cholesterol is the parent compound for all steroid hormones. It can be further
synthesized by enzymes to form the end product. (Non-genomic)
Steroid hormones act primarily on intracellular receptors. When acting on a receptor it
can activate or repress one or more genes. (Genomic)
, 15. These organs secrete steroid hormones: adrenal cortex, testes, ovaries,
corpus luteum, placenta, kidneys. What are the hormones that these organs
secrete?
Adrenal cortex secrete cortisol, aldosterone, and androgens
Testes secrete testosterone
Ovaries secrete estrogen and progesterone
Corpus Luteum secretes estrogen and progesterone
Placenta secretes estrogen and progesterone
Kidney secretes 1,25 Dihdroxycholecalciferol
16. Define catecholeamines.
Catecholamines include epinephrine, norepinephrine, and dopamine. They are
neurohormones that bind to cell membrane receptors the way peptide hormones do.
17. Give examples of amine hormones
Tyrosine, Catecholamines, and thyroid hormones
18. What is synergism? Permissiveness? Antagonism? Look at slide # 11
Synergism is the effect of interacting hormone s more than additive (more than
expected)
A permissive hormone allows another hormone to exert its full effect
19. Why is the pituitary gland believed to be made of two glands?
The pituitary gland is actually two glands with different embryological origins that fused
during development. It sits in a protected pocket of bone, connected to the brain by a
thin stalk.
20. What is adenohypophysis? Secretions of adenohypophysis include.................. (Six
Hormones)
The anterior pituitary gland is called adenohypophysis, its hormones are
adenohypophyseal secretions. It secretes 6 hormones: Follicle-stimulating hormone,
1. What is a hormone?
A chemical signal
2. What makes a chemical a hormone?
Hormone are secreted by a cell or group of cell
3. The difference between a “hormone” and “neurohormone” is........................
Neurohormones are secreted by nervous tissue
4. Which organ/tissue secretes neurohomrones? (name two)
The posterior pituitary gland and the adrenal medulla
5. Name some neurohormones.
Acetylcholine and epinephrine
6. Remember: Secretions of endocrine cells/gland go first to the extracellular
space and then to the blood. Secretions of exocrine glands travel through a
duct (pancreatic ducts, salivary gland ducts). You can see exocrine
secretions go to the outside (to lumens of tubes: GIT and respiratory
system, genitourinary system).
7. Hormones travel in the blood. This means that all cells are exposed/get in
touch with different hormones. However, not all cells respond to all
hormones/or to every hormone they are exposed to. What determines
whether a cell will respond to particular hormone? Clue: the presence of a
receptor for that hormone on or in the cell.
, 8. Cell “A” has 10 receptors for ADH and cell “B” has 100 receptors for ADH. Which cell is
more responsive to ADH?
9. What is paracrine signaling or paracrine molecule? How is it different from endocrine or
autocrine?
Paracrine signaling secrete things to the adjacent cells. Endocrine hormones usually
secrete to epithelial cells. Autocrine hormones act on the same cells.
10. The pituitary gland is often dubbed the “master gland”. Why? Give examples.
11. Classify hormones by chemical nature and give examples for each.
Steroids: derived from cholesterol, se hormones, adrenal cortex hormones
Peptide or proteins: made up of only few amino acid residues: insulin and glucagon
Amines: derived from modification of amino acids
12. Explain the cellular mechanisms of action of Lipid-soluble hormones (e.g., steroid
hormones) and Water-soluble hormones (e.g., peptide/protein hormones). Be able to
draw a very general pathway for each.
Steroid hormones are lipid-soluble hormones and they can penetrate the cell membrane
and interact with intracellular receptors (cytoplasmic or nuclear). Peptide hormones are
lipophilic (water soluble) . They are usually unable to enter the target cell and therefore
bind to receptors located in the cell membrane.
13. True or False: Steroid hormones may/can have receptors in the cytoplasm, in the
nucleus and on the cell membrane.
14. What is genomic and nongenomic effects of steroid hormones (just be able to visualize
the difference/pathway).
Cholesterol is the parent compound for all steroid hormones. It can be further
synthesized by enzymes to form the end product. (Non-genomic)
Steroid hormones act primarily on intracellular receptors. When acting on a receptor it
can activate or repress one or more genes. (Genomic)
, 15. These organs secrete steroid hormones: adrenal cortex, testes, ovaries,
corpus luteum, placenta, kidneys. What are the hormones that these organs
secrete?
Adrenal cortex secrete cortisol, aldosterone, and androgens
Testes secrete testosterone
Ovaries secrete estrogen and progesterone
Corpus Luteum secretes estrogen and progesterone
Placenta secretes estrogen and progesterone
Kidney secretes 1,25 Dihdroxycholecalciferol
16. Define catecholeamines.
Catecholamines include epinephrine, norepinephrine, and dopamine. They are
neurohormones that bind to cell membrane receptors the way peptide hormones do.
17. Give examples of amine hormones
Tyrosine, Catecholamines, and thyroid hormones
18. What is synergism? Permissiveness? Antagonism? Look at slide # 11
Synergism is the effect of interacting hormone s more than additive (more than
expected)
A permissive hormone allows another hormone to exert its full effect
19. Why is the pituitary gland believed to be made of two glands?
The pituitary gland is actually two glands with different embryological origins that fused
during development. It sits in a protected pocket of bone, connected to the brain by a
thin stalk.
20. What is adenohypophysis? Secretions of adenohypophysis include.................. (Six
Hormones)
The anterior pituitary gland is called adenohypophysis, its hormones are
adenohypophyseal secretions. It secretes 6 hormones: Follicle-stimulating hormone,
