Hormones and Receptors

Question 1

Paracrine

Answer 1

Act on neighboring cells

Question 2

Autocrine

Answer 2

Chemical acts on the same cell that secretes it

Question 3

Tyrosine Derivatives

Answer 3

Epi, NE, Dopa, Thyroxine

Question 4

Steroids

Answer 4

Testosterone, cortisol, estrogens, aldosterone, vitamin D, progesterone

Question 5

Peptides

Answer 5

Oxytocin, vasopressin, Angiotensin, GRH, Thyrotropin Releasing Hormone

Question 6

Proteins

Answer 6

Insulin, glucagon, GH, ACTH, prolactin, TSH

Question 7

Peptide & protein synth

Answer 7

Synth as prehormone on ribosomes –> rER –> Golgi –> secreted by vesicular exocytosis

Question 8

Steroid Synth

Answer 8

Cholesterol precursor. Immediately released to blood stream bcuz membrane permeable need carrier proteins = long half lives)

Question 9

Hypothalamus

Answer 9

Interphase b/w brain & endocrine system.

Question 10

Hypothalamo-hypophyseal portal system

Answer 10

connects ant. pituitary and hypothalamus. Blood to median eminence (where hypothalamic hormones are released) through sup. hypophyseal art. –> cap bed –> 2nd cap bed in ant. lobe.

Question 11

TRH

Answer 11

Thyrotropin Releasing Hormone
Gq = Hydrolysis of membrane
phosphotidylinositol
Increase TSH
Up Prolactin

Question 12

TSH

Answer 12

Glycoprotein hormone
 Important for metabolism/basal metabolic
rate

Question 13

Prolactin

Answer 13

Polypeptide hormone that promotes mammogenesis, lactogenesis and galactopoesis
 Estrogen potentiates mammogenesis; progesterone inhibits lactogenesis and galactopoesis
Cytokine (JAK/STAT) Receptors

Question 14

GnRH

Answer 14

Gonadotropin Releasing Hormone
Gonadotrophs
 Gq
Up LH
Up FSH (both glycoprotein)

Question 15

CRH

Answer 15

Corticotropin Releasing Hormone
Gs
Up POMC
Up ACTH

Question 16

POMC

Answer 16

Prohormone: cleavage of POMC can yield ACTH, beta-endorphine, and alpha-MSH

Question 17

ACTH

Answer 17

Cleaved from POMC
 Cortisol fxn: gluconeogenesis, breakdown
fat and proteinmost is bound to transcortin (10-15 % bound to albumine) burst before waking and decreases thru day

Question 18

GHRH

Answer 18

Growth Hormone Releasing Hormone
Somatotrophs
Gs
Up GH

Question 19

GH

Answer 19

Stimulated by: sleep, ghrelin/arginine, hypoglycemia
 Inhibited by: obesity, FFAs, chronic glucocorticoids, hyperglycemia
 Direct: Stimulates gluconeogenesis (diabetogenic), increase lipolysis, and increase protein synthesis/muscle mass
 Indirect: GH (with insulin) releases IGF

Question 20

Somatostatin

Answer 20

Somatotrophs
Gi
Down GH
Down TSH

Question 21

PIH/Dopamine

Answer 21

Prolactin Inhibiting Factor defaullt state to inhibit PL
Lactotrophs
 D2 Dopamine receptor (Gi
Down Prolactin

Question 22

ADH

Answer 22

Secreted in response to increase in plasma osmolarity or decrease in BP
Receptors: V1 (Gq) & V2 (Gs)

Question 23

Oxytocin

Answer 23

During childbirth
o During sexual intercourse
o In response to suckling by infant during
breastfeeding