Biology - Chapter 11.7: Endocrine System

Question 1

Three Types of Hormones

Answer 1

1) Peptide hormones
2) Steroid hormones
3) Amino-acid derived hormone

Question 2

Peptide Hormone Synthesis

Answer 2

• rough ER

- made of amino acids connected by peptide bonds

Question 3

Peptide Hormone Action

Answer 3

• Indirect stimulation
• Bind to cell surface receptors
• via secondary messengers or ligand-gated ion channels

Question 4

GPCRs

Answer 4

• G-protein coupled receptors
• cell surface receptors that initiate a secondary messenger response
• dissociates into subunits after activation (alpha beta gamma)

Question 5

RTKs

Answer 5

• Receptor tyrosine kinases
• cell surface receptors that dimerizes and initiates a second messenger response after binding to peptide hormone
• intracellular domains of RTKs cross-phosphorylate and initiate second messenger signaling within the cell

Question 6

Second messenger system allows for…

Answer 6

… quick and immediate physiological changes

Question 7

Steroid Hormone Synthesis

Answer 7

• smooth ER

- made up of fused 4-ring structure

Question 8

Steroid Hormone Examples

Answer 8

• All hormones produced by adrenal cortex (glucocorticoids, mineralocorticoids, androgenic steroids)
• All hormones produced by reproductive organs

Question 9

Steroid Hormone Action

Answer 9

• carried through blood-stream via protein carrier
• freely crosses cell membrane
• binds to receptors in cytoplasm or nucleus to form molecule-receptor complex
• these complexes bind to DNA and influence gene transcription (direct stimulation)

Question 10

Amino-acid derived hormones

Answer 10

can have properties that are similar to both peptide hormones and steroid hormones

Question 11

Amino-acid derived hormones synthesis

Answer 11

• rough ER and cytosol

- mainly derived from tyrosine

Question 12

Amino-acid derived hormones examples

Answer 12

• All hormones produced in adrenal medulla (epinephrine, norepinephrine)
• T3 and T4

Question 13

Posterior pituitary hormones

Answer 13

1) ADH: decreases urination by increasing water retention

2) Oxytocin: uterine contractions, lactation

Question 14

Anterior pituitary hormones

Answer 14

1) GnRH (gonadotropin-releasing): causes release of LH and FSH
2) TRH (thyrotropin-releasing): causes release of TSH
3) CRH (corticotropin-releasing): causes release of ACTH
4) GRH: causes release of GH (growth hormone)

Question 15

Hypothalamic-inhibiting hormones

Answer 15

-Released by hypothalamus to inhibit release of other hormones by anterior pituitary

Question 16

Tropic hormones

Answer 16

-Target other endocrine glands for further hormone release

Question 17

FSH

Answer 17

• tropic hormone released by anterior pituitary

- follice growth and sperm maturation

Question 18

LH

Answer 18

• tropic hormone released by anterior pituitary

- ovulation, corpus luteum formation and testosterone production

Question 19

ACTH

Answer 19

• tropic hormone released by anterior pituitary

- release of glucocorticoids from the adrenal gland to fight stress

Question 20

TSH

Answer 20

• tropic hormone released by anterior pituitary

- stimulates T3 and T4 production by the thyroid gland to increase metabolism

Question 21

Direct hormones

Answer 21

-targets organs directly for effects

Question 22

Prolactin

Answer 22

• direct hormone released by anterior pituitary

- stimulates mammary gland development and increases milk production

Question 23

Growth Hormone

Answer 23

• direct hormone released by anterior pituitary

- BIG BONES BOI

Question 24

Pineal gland

Answer 24

• releases melatonin

- regulates circadian rhythm

Question 25

3 Main Thyroid Hormones

Answer 25

1) Triiodothyronine (T3) 2) Thyroxine (T4) 3) Calcitonin

Question 26

T3

Answer 26

- Triiodothyronine - released in response to TSH - increases metabolism in body - has a negative feedback effect on TSH secretion

Question 27

T4

Answer 27

- Thyroxine - increases metabolism in body - less potent than T3 but is more stable in blood

Question 28

Calcitonin

Answer 28

- thyroid hormone - decreases blood calcium - stimulates osteoblasts - inhibits osteoclasts

Question 29

Hypothyroidism

Answer 29

- under-secretion of T3 and T4 - reduced levels of metabolism - over-secretion of TRH, enlarging thyroid gland

Question 30

Hyperthyroidism

Answer 30

- over-secretion of T3 and T4 - increased levels of metabolism in the body - hyperactive thyroid gland

Question 31

PTH

Answer 31

-parathyroid hormone -increases blood calcium -stimulates osteoclasts -

Question 32

Pancreas Exocrine Tissue

Answer 32

-Secretes digestive enzymes through pancreattic duct into small intestine

Question 33

Islets of Langerhans

Answer 33

- Endocrine pancreas glands - secretes: 1) glucagon 2) insulin 3) somatostatin

Question 34

Alpha cells

Answer 34

-secrete glucagon in response to low blood glucose which stimulate liver and fat tissue to release glucose storages

Question 35

Beta cells

Answer 35

- secrete insulin in response to high blood glucose levels | - insulin lowers glucose levels by stimulating the liver, muscles, and fat tissue to store glucose

Question 36

Insulin

Answer 36

lowers glucose levels by stimulating the liver, muscles, and fat tissue to store glucose

Question 37

Delta cells

Answer 37

-secretes somatostatin, which inhibits growth hormone

Question 38

Somatostatin

Answer 38

- inhibits growth hormone | - inhibits secretion of glucagon and insulin

Question 39

Adrenal cortex

Answer 39

- stimulated by secretion of ACTH from anterior pituitary - releases steroid hormones - produces glucocorticoids (cortisol), mineralocorticoids (aldosterone) - small amounts of sex hormones

Question 40

Glucocorticoids

Answer 40

- cortisol - raise blood glucagon levels for immediate fuel during periods of long-term stress - lowers immune response

Question 41

Mineraloccorticoids

Answer 41

- aldosterone | - increase blood volume and blood pressure by raising reabsorption of Na+

Question 42

Ovaries

Answer 42

-Progesterone and Estrogen

Question 43

Testes

Answer 43

-testosterone

Question 44

LH

Answer 44

Females: ovulation Males: testosterone production

Question 45

FSH

Answer 45

Females: follicle growth in ovaries (increased progesterone and estrogen) Males: stimulates sperm maturation