Lecture 8: Introduction to Endocrine System

Question 1

What is autocrine signaling?

Answer 1

Cell secretes a hormone or chemical messenger that binds to self receptors

Question 2

What is paracrine signaling?

Answer 2

Cell produces a hormone or chemical messenger to induce changes in nearby cells

Question 3

What is endocrine signaling?

Answer 3

Feedback loops of hormones released by internal glands of an organism directly into the circulatory system, regulating distant target organs

Question 4

What is neuroendocrine signaling?

Answer 4

Release of a hormone from a nerve cell that has an effect on another cell

Question 5

What hormones are released from the hypothalamus?

Answer 5

TRH
CRH
GnRH
GHRH
Somatostatin
Dopamine

Question 6

What hormones are released from the anterior pituitary?

Answer 6

FSH
LH
ACTH
TSH
MSH
Prolactin
Growth Hormone

Question 7

What hormones are released from the posterior pituitary?

Answer 7

Oxytocin

ADH (Vasopressin)

Question 8

What hormones are released from the thyroid?

Answer 8

T3, T4

Calcitonin

Question 9

What hormones are released from the parathyroid?

Answer 9

PTH

Question 10

What hormones are released from the pancrease?

Answer 10

Insulin

Glucagon

Question 11

What hormones are released from the adrenal medulla?

Answer 11

Norepinephrine

Epinephrine

Question 12

What hormones are released from the kidney?

Answer 12

Renin

Calcitriol

Question 13

What hormones are released from the adrenal cortex?

Answer 13

Cortisol
Aldosterone
Adrenal Androgens

Question 14

What hormones are released from the testes?

Answer 14

Testosterone

Question 15

What hormones are released from the ovaries?

Answer 15

Estradiol

Progesterone

Question 16

What hormones are released from the corpus luteum?

Answer 16

Estradiol

Progesterone

Question 17

What hormones are released from the placenta?

Answer 17

HCG
Estriol
Progesterone
hPL

Question 18

What are the three type of hormones?

Answer 18

Protein/peptide
Steroid
Amines

Question 19

What are characteristics of peptide hormones?

Answer 19

Synthesized from preprohormone
Stored in secretory vesicles
Water soluble
Membrane receptors

Question 20

What are characteristics of steroid hormones?

Answer 20

Synthesized from cholesterol
Lipid soluble
Cytosol or nuclear receptors

Question 21

What synthesizes and secretes steroid hormones?

Answer 21

Adrenal Cortex
Gonads
Corpus Luteum
Placenta

Question 22

What are amines derived from?

Answer 22

Tyrosine

Question 23

What are catecholamines?

Answer 23

Synthesized in cytosol

Cell-membrane associated receptors

Question 24

What are thyroid hormones?

Answer 24

Synthesized and stored in thyroid gland

Nuclear receptors

Question 25

If a hormone has a high protein binding rate, does it have a slow slow or fast metabolic clearing rate?

Answer 25

Slow (Long-acting)

Question 26

What is an example of hormone secretion via neural mechanism?

Answer 26

Sympathetic preganglionic innervation of adrenal medulla to release catecholamines

Question 27

What is positive feedback?

Answer 27

Hormones continue to secrete other hormones, amplifying its effect greatly Not common

Question 28

Where is positive feedback found?

Answer 28

Ovulation | Labor Contractions

Question 29

What is negative feedback?

Answer 29

Hormone secretion will inhibit or balance other hormones to have controlled effects

Question 30

What is an example of major endocrine axes?

Answer 30

Hypothalamus --> Anterior Pituitary --->Target Tissue

Question 31

What is the first tier of the endocrine axes?

Answer 31

Hypothalamus

Question 32

What is the function of the suprachiasmatic nucleus (SCN)?

Answer 32

Impose a circadian rhythm

Question 33

What is the function of the pineal gland?

Answer 33

Release melatonin which influences SCN on day/night cycle

Question 34

What is up-regulation?

Answer 34

Increase number of receptors or sensitivity of target tissue when hormone levels are low

Question 35

What are ways to cause up-regulation?

Answer 35

Increase synthesis of new receptors Decrease the rate of degradation of existing receptors Activate current receptors

Question 36

What is down-regulation?

Answer 36

Reduce number of receptors or sensitivity or target tissue when hormone levels are high

Question 37

What are ways to cause down-regulation?

Answer 37

Decrease receptor synthesis Increase the rate of degradation of existing receptors Deactivate current receptors

Question 38

What different pathways do GPCR receptors activate?

Answer 38

1) Adenylyl cyclase and cAMP | 2) Phospholipase C and IP3/DAG/Ca2+

Question 39

How do steroid hormones work?

Answer 39

After steroid hormones bind to cytosol/nuclear receptors, the complex binds to DNA to activate certain genes to produce new protein (hormone).

Question 40

What happens when cGMP kinases are activated?

Answer 40

Relaxation of vascular smooth muscles (NO)