Nervous and Endocrine System - Hormones

Question 1

What are hormones?

Answer 1

-Chemicals produced by one cell that affect cell/tissue/organs elsewhere in the body.
-Regulators speed up or slow down other processes. (Homeostasis)
-Target hormones: specific tissues (FSH)
-Non target hormones: affect many tissues (epinephrine)

Question 2

What are endocrine and exocrine hormones?

Answer 2

-Endocrine hormones: released into the blood stream.
-Exocrine hormones: released into ducts other than the circulatory system.

Question 3

Describe a steroid

Answer 3

-1 of the 2 types of hormones.
-Fat soluble hormone.
-Diffuses into the cytoplasm (crosses the cell membrane on its own).
-Combines with receptors and diffuses into nucleus to directly turn on a gene which then begins to manufacture a particular protein.

Question 4

Describe a protein

Answer 4

-1 of the 2 types of hormones.
-Water soluble hormone (can’t cross cell membrane).
-Binds to receptors on cell membrane which stimulates a chain reaction.
-Eventually enzymes in the cytoplasm to begin producing the needed product.

Question 5

Describe negative feedback

Answer 5

-The nervous system and endocrine system work together in maintaining homeostasis.
-Nervous system typically acts quickly while the endocrine system responds more slowly and is longer lasting.
-Many hormones are regulated by negative feedback.
-Counteracts the initial change, maintaining homeostasis or stability.

Question 6

What does the hypothalamus do?

Answer 6

-Regulates the release of many hormones.
-Hypothalamic releasing/inhibiting factors, produced by neurosecretory cells.
-Secreted into a portal system and stimulate or inhibit the release of hormones from the anterior pituitary (front).
-Neurosecretory cells produce ADH and oxytocin.
-Neuronal axons transport the hormones to the posterior pituitary for storage.
-ADH and oxytocin are released from axon endings into the bloodstream.

Question 7

What are tropic hormones?

Answer 7

-Hormones whose targets are other endocrine glands.
-Hypothalamus controls their secretion.

Question 8

What is the pituitary?

Answer 8

-Two lobes both connected to the hypothalamus.

Question 9

What hormones does the posterior pituitary secret?

Answer 9

-Anti-diuretic hormone.
-Oxytocin.

Question 10

What hormones does the Anterior pituitary secret?

Answer 10

-TSH (Thyroid stimulating hormone).
-ACTH (Adrenocorticotropic hormone).
-Gonadotropic hormones: FSH (follicle stimulating hormone) and LH (luteinizing hormone).
-Prolactin.
-hGH (human growth hormone).

Question 11

What is the function of the Anti-diuretic hormone?

Answer 11

-Stimulates water reabsorbtion.

Question 12

What is the function of oxytocin?

Answer 12

-Promotes uterine contractions during labour and stimulates milk production.

Question 13

What is the function of TSH (thyroid stimulating hormone)?

Answer 13

-Stimulates thyroid to release thyroxine.

Question 14

What is the function of ACTH (adrenocorticotropic hormone)?

Answer 14

-Stimulates adrenal cortex to produce cortisol, aldosterone, and sex hormones.

Question 15

What are Gonadotropic hormones?

Answer 15

-FSH (follicle stimulating hormone).
-LH (luteinizing hormone).
-Targets the gonads (ovaries in females and testes in males), for overall reproduction health, and regulating reproduction processes.

Question 16

What is the function of FSH (follicle stimulating hormone)?

Answer 16

-Sperm and egg production.

Question 17

What is the function of LH (luteinizing hormone)?

Answer 17

-Sex hormone production (testosterone/estrogen+progesterone).

Question 18

What is the function of prolactin?

Answer 18

-Targets mammary glands after child birth only.
-Sustains milk production.

Question 19

What is the function of hGH (human growth hormone)?

Answer 19

-Targets soft tissue and bones.
-Increase protein synthesis, cell division and growth, and the breakdown and release of stored body fat.
-Dwarfism, giantism and acromegaly all result from to much or little hGH.

Question 20

What is thyroxine?

Answer 20

-Produced by the thyroid gland.
-Stimulated by the release of TSH from anterior pituitary.
-Thyroxine stimulates most cells to increase the metabolism of fats, proteins, and carbohydrates for energy.
-Iodine is very important to thyroxine production and is actively transported into the thyroid 25x higher than other places.

Question 21

What is hypothyroidism?

Answer 21

-Low quantities of thyroxine produced.
-In children: lack of growth and mental delays.
-In adults: fatigue, hair loss, weight gain - slow metabolism.

Question 22

What is hyperthyroidism?

Answer 22

-Overproduction of thyroxine.
-Anxiety, insomnia, weight loss - excess metabolism are all symptoms.

Question 23

What is goiter?

Answer 23

-Enlargement of the thyroid gland caused by insufficient iodine.
-Thyroxine can’t be made; continued secretion of TSH.

Question 24

What is calcitonin?

Answer 24

-Produced in the thyroid gland.
-Regulates high Ca2+ levels in the blood by targeting bones, intestine and kidneys to take up calcium.
-Necessary for skeletal development, blood clotting, nerve conduction, and muscle contraction.

Question 25

What is PTH (parathyroid hormone)?

Answer 25

-Released by the parathyroid glands in response to low blood Ca2+. -Stimulates bone breakdown and reabsorbtion of Ca2+ into the blood. -Kidneys are stimulated to reabsorb calcium from urine and activate vitamin D. -Atagonisgic (opposite) to calcitonin.

Question 26

What is the adrenal medulla?

Answer 26

-Inner layer of the adrenal gland. -Responsible for short-term stress response. -Neurons stimulate (sympathetic) the adrenal medulla to produce epinephrine (adrenaline) and norepinephrine (noradrenaline). -Similar to response of sympathetic nervous system (fight or flight). -Influences lasts 10x longer than nervous response. -Conversion of glycogen (storage) to glucose to increase blood glucose levels. (blood sugar) -Increases HR, breathing rate, cell metabolism, dilate blood vessels and pupils.

Question 27

What is the adrenal cortex?

Answer 27

-Outer layer of the adrenal gland. -Long term-stress response. -Stimulated by ACTH to produce glucocorticoids, mineralocorticoids and sex hormones.

Question 28

What are glucocorticoids (cortisol)?

Answer 28

-Produced by adrenal cortex. -Promotes breakdown of proteins to amino acids and fatty acid breakdown. -Main function is to raise blood glucose levels. -Negative feedback: response to hypothalamus and anterior pituitary to stop release of cortisol. -Natural anti-inflammatory.

Question 29

How can cortisol help with pain/injuries but be harmful to people with stressful jobs?

Answer 29

-Can help power through injury by reducing pain and swelling. (Pain telling you to slow down is less important than the imminent danger). -Can be harmful to people with stressful jobs -> body constantly pumps out cortisol because of stress -> results in constant high blood sugar levels -> can lead to diabetes, strokes or heart attacks.

Question 30

What is the function of mineralocorticoids (aldosterone)?

Answer 30

-Stimulates Na+ re-absorption and K+ secretion levels in the blood (kidneys). -Aldosterone release increases blood pressure. -Water gets reabsorbed because of osmosis.

Question 31

Describe the pancreas

Answer 31

-Both an exocrine and endocrine gland. -Produces insulin and glucagon.

Question 32

Describe insulin

Answer 32

-Produced by beta islet cells and released in response to high blood glucose levels (release is inhibited by negative feedback). -Stimulates body cells (liver, muscles, and organs) to become permeable to glucose. -Liver converts absorbed glucose to glycogen bringing blood glucose levels back to normal. -Once glycogen stores are filled, fat and proteins are used next.

Question 33

Describe glucagon

Answer 33

-Complementary to insulin (opposites). -Produced by alpha islet cells and released in response to low blood glucose. -Promotes liver to convert 1. Glycogen, 2. Fat, and 3. Protein (in that order) to glucose to bring blood glucose back to normal.

Question 34

What is diabetes mellatus?

Answer 34

-Results when the body does not produce enough insulin or does not respond properly to insulin. -Leads to hyperglycaemia: high blood glucose levels. -Results in fatigue (cells can’t take in glucose), thirst, excess urine/production, poor circulation. -To tell difference between type 1 and 2 you could taste test urine.

Question 35

What is type 1 hyperglycemia?

Answer 35

-Type 1 (Insulin-dependent): immune system produces antibodies against beta cells. -Treat w/ insulin.

Question 36

What is type 2 hyperglycemia?

Answer 36

-Type 2 (insulin-independent) (adult onset): insulin receptors stop responding to insulin. -Treat with high glucose diet and/or exercise. Genetics play a big factor.

Question 37

Describe testes

Answer 37

-Secrete testosterone (LH) (sex organs, skin, muscles, and bone) when stimulated by LH/FSH. -Stimulate spermatogenesis (FSH) and secondary sex characteristics (muscle mass, deeper voice, body hair, etc).

Question 38

Describe ovaries

Answer 38

-Secrete estrogen and progesterone when stimulated by LH/FSH. -Stimulate growth of endometrium and secondary sex characteristics (estrogen) (wider hips).

Question 39

What is diabetes inspidus?

Answer 39

-Lack of ADH. -Lots of dilute urine (no glucose in urine).