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Flashcards in test one Deck (115):
1

protein hormone binds GPCR coupled to adenylate cyclase pathway?

actives g protein which results in activation or inhibition of adenylate cyclase which affects intracellular camp which activates PKA which phosphorylates substrates

2

where do hormones go from prohormone to hormone

Golgi apparatus packages them and then they are cleaved in vessicles

3

thyroid hormone receptor activation pathway

thyroid hormone diffuses through membrane and t3 binds TR in nucleus and dimerizes with RXR t4 enters it is deiodinated to t3 dimer binds HRE resulting in gene transcription/ has nongenomic effect as well

4

Pancreatic hormones?

Insulin glucagon somatostatin

5

adrenal medula hormones?

norepi epi

6

epi and norepi synthesis pathway and storage location

tyrosin to L-dopa to dopamine to norepi to epi synthesized and stored in chromaffin granules

7

TSH effect on thyoid

1) increases activity of Na/I transporter on basolateral side 2) iodide leaves the cell into the follicular lumen via pendrin channel 3)TSH stimulates iodination of thyroglobulin 4) TSH stimulates conjugation of iodinated tyrosiines linked to thyroglobulin 5)Tsh stimulates endocytosis 6)TSH stimulates proteolosis 7)TSH stimulates secretion of t3 t4 8)stimulates growth factor effect causing hyperplasia of thyroid gland

8

protein hormone binds GPCR coupled to phospholipase A2 pathway?

Activates G protein which results in activation of PLA2 which cleaves membrane phospholipids to produces lysophospholipid and arachidonic acid. Arachadonic acid is converted into eicosanoids

9

thyroid hormones?

T3 T4 calcitonin

10

hormones produced by posterior pituitary?

oxytocin ADH

11

hormones produced by hypothalamus?

TRH CRH GnRH GHRH somatostatin dopamine

12

Protein hormone receptors

gpcr, guanylate cyclase, receptor tyrosine kinase

13

epi release pathwy

preganglionic sympathetics release acetylcholine that causes postganglionic chromaffin cells to depolarize which causes voltage gated ca channels to open exocytosing epi accompanied by atp release

14

adrenal cortex hormones?

cortisol aldosterone adrenal androgens

15

where are preprohormones synthesized?

RER

16

IMPORTANT Thyrotropin releasing hormone (TRH) pathway

TRH bind Activates GPCR which results in activation of PLA2 which cleaves membrane phospholipids to produces lysophospholipid and arachidonic acid. Arachadonic acid is converted into eicosanoids

17

ovaries hormones?

estradiol progesterone

18

dopamine synthesis pathway

L-tyrosine -> L-DOPA->Dopamine

19

beta adrenergic receptor pathways

epi binds beta 1 and 2 along with dopamine DA1 resulting in stimulatory effect activating adenyl cyclase increasing cAMP

20

endocrine paracrine and autocrine signaling definitions

Endocrine Hormone crosses a large distance to a target tissue Paracrine Hormone crosses an extracellular space to regulate nearby cells Autocrine Hormone binds receptors on or in the cell secreting it

21

What is the precursor for amine hormones?

all synthesized from tyrosine

22

kidney hormones?

renin 1,25-dihydroxycholecalciferol

23

what regulates steroid hormones

regulated by trophic hormones from the pituitary

24

Steroid hormone activation pathway

diffuses through the membrane activates cytoplasmic receptors or nuclear receptors which activate HRE which initiates gene transcription

25

thyroid hormone sythesis

classified as lipophilic from tyrosine follicular cells secrete iodine and thyroglobulin, iodination of tyrosine molecules on thyroglobulin then conjugation creates t3 and t4 then its endocytosed into folicular cells, proteolysis occurs from thyroglobulin in endolysosome, t3 t4 must be carried by carrier protein

26

what transporter allows for the uptake of dopamine into chromaffin granules for conversion to epi?

VMAT 1 which can also uptake epi back into chromaffin granule

27

where are prohormones synthesized?

SER post translational modification

28

steroid hormone sythesis

from cholesterol LDL in blood or de novo from Acetyl-CoA Cholesterol is converted to the universal precursor, Pregnenolone 20 % from aceteyl coa 80% from LDL

29

protein hormone binds GPCR coupled to phospholipase C pathway?

gpcr coupled to phospholipase c (PLC) which cleaves PIP2 into IP3 and DAG IP3 releases ER plasma ca stores which activate ca dependent kinases including PKC DAG also activates PKC

30

hormones produced by anterior pituitary?

TSH LH FSH ACTH MSH GH prolactin

31

where are the receptors for protein hormones versus steroid hormones and amine hormones?

For protein and amine Hormones the receptors are in the membrane (cell surface) while steroid hormone receptors are inside the cell

32

what determines which genes are activated by HRE's

specificity of receptors and expression of receptors which is not regulated by the hormone itself

33

Corpus luteum hormones?

estradiol progesterone

34

Parathyroid hormones?

PTH

35

ANP activation pathway

ANP binds guanylyl cyclase increasing intracellular cGMP

36

Leptin receptor binding and pathway

Leptin binds RTK-> causing phosphylation cascade activating enzymes specifically activates Jak Stat pathway

37

what is a marker for adrenal medula activity

chromaffin A

38

Placenta hormones?

HCG HPL Estriol progesterone

39

alpha adrenergic receptor pathways

norepi bind alpha 2 receptor with dopamine DA2= inhibitory effect on adenylly cyclase reducing cAMP levels norepi binds alpha 1= Coupled to Phospholipase C Activates G protein which activats (PLC) that cleaves (PIP2) into (IP3) and DAG IP3 releases endoplasmic reticulum Ca2+ stores, thereby activating Ca2+ dependent kinases, including protein kinase C (PKC).

40

Thyrotropin releasing hormone (TRH) pathway

Coupled to Phospholipase A2

–Activates G protein which results in activation of PKA2 which cleaves membrane phospholipids to produces lysophospholipid and arachidonic acid.

–Arachadonic acid is converted into eicosanoids

41

where is the pituitary gland located?

in the sella turcica of the sphenoid bone

42

what connects the hypothalimus to the pituitary?

a hallow stalk called the infundibulum which is very easily damaged during head trauma

43

A common complication of a pituitary tumors includes?

compression o fthe optic chiasm resulting in peripheral blindness (tunnel vision)

usually associted with the anterior pituitary and excess GH secretion

44

Embreological origin of posterior pituitary lobe?

neuroectoderm, part of diencephalon

45

embreological origin of the anterior pituitary lobe

oral ectoderm, outpouching of the oropharynx

46

Parts of nuerohypophysis/ posterior lobe of pituitary

Retains histological features of brain tissue

Contains axons of neurons whose cell bodies are in the hypothalamus

Pars nervosa – largest part; contains neurosecretory axons

-Infundibulum – contintuous w/ median eminence; connects pituitary & hypothalamus

-Median eminence - contains hypothalamohypophyseal tracts

47

Adenohypophysis/ Anterior Lobe of the Pituitary

-Dark- staining epithelial tissue

-Portions:

-Pars distalis – largest part

-Pars intermedia – thin wall separating anterior and posterior lobes

-Pars tuberalis – forms a collar around the infundibulum

48

What embreological remnant is somteimes seen inside pars intermedia

can contain a remnant of the embryonic hypophyseal pouch (Rathke's puch) and/or colloid-filled cysts

49

Growth hormone

(somatotropin, GH)

Stimulates liver & other organs to secrete insulin-like growth factor I (IGF-I), which in turn

stimulates division of progenitor cells located in growth plates & skeletal muscles, resulting in body growth

Growth hormone-releasing hormone promotes secretion of GH by the pituitary; Somatostatin inhibits secretion of GH

50

Prolactin (PRL)

Promotes mammary gland development; initiates milk formation; stimulates secretion of casein, lactalbumin, lipids, and carbohydrates into the milk

Dopamine inhibits release of prolactin

51

Adrenocorticotropic

hormone (ACTH)

Stimulates secretion of glucocorticoids & gonadocorticoids by the zona fasciculate & zona reticularis of the adrenal cortex

Corticotrophin-releasing hormone stimulates synthesis of ACTH

52

Follicle-stimulating

hormone (FSH)

Stimulates follicular development in the ovary & spermatogenesis in the testis

Gonadotropin-releasing hormone stimulates secretion of FSH

53

Luteinizing

hormone (LH)

Regulates final maturation of ovarian follicle, ovulation, & corpus luteum formation; stimulates steroid secretion by follicle and corpus luteum; in males, essential for androgen secretion by the Leydig (interstitial) cells of the testis

Gonadotropin-releasing hormone stimulates secretion of LH

54

Thyrotropic

hormone (TSH)

Stimulates growth of thyroid epithelial cells; stimulates production & release of thyroglobulin and thyroid hormones

Thyrotropin-releasing hormone stimulates release of TSH; Somatostatin inhibits secretion of TSH

55

what do acidophils secrete?

GH & PRL

56

what do basophils secrete?

ACTH, FSH, LH, & TSH

Corticotropes:

secrete ACTH

Thyrotropes:

secrete TSH

Gonadotropes:

secrete LH & FSH

57

in the hypothalumus where do the cell bodies of neurosecretory nuerons reside?

-Paraventricular nucleus

-Supraoptic nucleus

58

pareventricular nucle secrete what stored where?

secrete oxytocin stored in the posterior pituitary

59

supraoptic nucle secrete what stored where

secrete adh stored in the posterior pituitary

60

Oxytocin action and secreted by what 

Pars nervosa:

-Oxytocin – promotes contraction of smooth muscle, particularly uterus during labor & myoepithelial cells of the mammary gland during suckling (secreted by paraventricular nucleus)

61

ADH action stored where

-ADH – (vasopressin) acts on kidneys, regulates water homeostasis and osmolarity of body fluids (secreted by supraoptic nucleus) stored in pars nervosa

62

Is the posterior pituitary lobe an endocrine gland?

The posterior lobe of the pituitary is not an endocrine gland because it doesn’t synthesize any hormones!

63

where does the anterior pituitary and infundibulum get its blood suply from?

superior hypophyseal a. - gives rise to the primary capiliary plexus

64

posterior pituitary blood supply

inferior hypophyseal a. – gives rise to the secondary capillary plexus

The abundant blood supply connecting the pituitary & hypothalamus allows the hypothalamus to regulate cells of the anterior pituitary

65

How do hypolthalmic hormones reach the posterior pituitary?

Hypothalamic hormones reach the posterior pituitary via neurons;

hypothalamic hormones are stored here.

66

how do hypothalmic hormones reach the anterior pituitary

hypothalamohypophyseal portal system; hypothalamic hormones

regulate synthesis & secretion of anterior pituitary hormones.

67

embreological orgin of the adrenal cortex?

-external portion; distinct histological & functional layers; steroid secretion;

     originates from mesoderm; 90% of glandular tissue

68

embreological orgin of adrenal medulla?

-internal portion; secretion of catecholamines (epinephrine & norepinephrine)

     originates from neural crest; 10% of glandular tissue

69

layers of the adrenal cotex from superficial to deep

Zona glomerulosa thin

zona fasciculata thickest layer

zona reticularis

70

what does the zona glomerulosa secrete

Secretion of mineralocorticoids

esp. aldosterone, which regulates salt balance

71

what does the zona fasiculata secrete?

Secretion of glucorticoids: cortisol & corticosterone; regulation of glucose & fatty acid metabolism

72

what does the Zona reticularis

Secretion of androgens esp. dehyroepiandosterone (DHEA); secretes very small amounts of glucorticoids

73

what is the embryological origin of pancreatic islets and acinar cells?

endoderm

74

what is the embreological origin of the thyroid

Thyroid gland originates as endoderm from the inferior pharynx. It migrates inferiorly to form the butterfly-shaped thyroid gland

75

delta cells of the pancreas secrete what?

somatostatin

76

f cells or pp cells of pancreas secrete what?

pancreatic polypeptide

77

parafollicular (c) cells sectete what in thyroid and have what histo characteristics

calcitonin floating not attached to lumen do not contat colloid

78

what is the emreologic origin of parathyroid glands

Parathyroid glands are derived from the 3rd & 4th pharyngeal pouches (endoderm)

79

what cells secrete parathyoid hormone?

priciple ceels in parathyroid glands

80

PTH funciton 

PTH indirectly stimulates osteoclast activity within bone marrow, in an effort to release more ionic calcium (Ca2+) into the blood to elevate serum calcium (Ca2+) levels.

81

calcitonin funciton

t acts to reduce blood calcium (Ca2+), opposing the effects of parathyroid hormone (PTH).[4]

82

embreological origin of pineal gland and location

part of the diencephalon which is part of the neural tube found posterior to the 3rd ventrical of the brain

83

pineal gland function

during dark conditions secretes melatonin a tryptophan which is important for regulating circadian rythmes

84

what are corpora arenacea and where are they found?

-Concretions of calcium & magnesium salts

-Increase in number and size with age

-No understood function or effect on pineal function

found in the pineal gland dark basophilic dots

USE THESE TO IDENTIFY PINEAL GLAND

85

86

somatostatin function secreted by

Inhibits secretion of: insulin, glucagon, gastrin, thyroid stimulating hormone, vasoactive intestinal peptide, growth hormone

d cells and hypothalamus

87

pancreatic polypeptide function

stimulates gastric chief cells/ inhibites bile secretion and intestinal motility and pancreatic enzymes and bicarb secretion

88

D1 cells (not delta cells) produce what that does what?

VIP which VIP stimulates contractility in the heart, causes vasodilation, increases glycogenolysis, lowers arterial blood pressure and relaxes the smooth muscle of trachea, stomach and gall bladder

89

EC cells of pancreas secrete what 

secretin, motulin and substance p, secretin induces bicar secretion and pancreatic enzymnes, motulin gastric motility, substance p is a neurotransmitter

90

epsilon cells in the pancreas secrete what

ghrelin, stimulates apetite is released with fasting and weight loss

91

what receptor does insulin bind?

RTK receptor quickly degraded in the plasma by insulinase

92

insulin release pathway in detail

1.HIGH glucose in blood = glucose moved down its [gradient] into beta cell via GLUT 2 channels via facilitated diffusion

2.Hexokinase (only works at high glucose concentrations)  converts glucose into G-6-P to keep the concentration gradient for glucose high = Glucose will be pulled into beta cell as long as plasma glucose is high

3.Beta cells have Na/K pumps and ATP-gated K channels that are open at rest giving beta cells a RMP around   -70mV

4.As glucose is brought into beta cell it is converted into ATP = [ATP] in the beta cell rises = closes ATP gated K+ channels = loss of K efflux causes beta cell to depolarize = opens v-gated Ca++ channels. Calcium interacts with snare proteins and secretory granules of insulin and C-peptide are released into bloodstream

5.3-5 minutes after blood glucose levels fall ATP levels fall in the beta cell, ATP gated K+ channels open again, the cell repolarizes, and no more insulin is secreted

93

glut 1 location and action

RBC's and blod vessels lining the brain, skeletal muscle and fat

basal glucose uptake

94

glut 2

expressed by pacreatic betal cells and hepatocytes low affinity allows for uptake only when plasma glucose is high

95

glut 3 location and function

primarily in neurons together glut 1 and glut 3 allow glucose to cross the blood brain barrier

96

glut 4 location and function

insulin responsive primarily in striated muscle, fat, remain in vesicals until insulin present moves into membrane

97

glucagon primary effects and receptor pathway

gpcr activates adenyly cyclase activating PKA, glycogenolysis, gluconeogenesis, fatty acid beta oxydation

98

What are the effects of insulin on K+ levels in cells?

insulin fascilitaes the entry of K in cells

99

glp-1 (incretin) does what?

activation leads to increased insulin secretion and inhibition of glucagon secretion... decreased gastric emtying and decreased hunger this response is blunted in t2DM

100

epinephrin and norepi effect on insulin release

inhibit incretin (glp-1) pathway release of insulin... they help to maintain blood glucose levels

101

what does DPP-IV do?

it degrades glp-1... drugs that inhibit DPP-IV are used for T2DM treatment

102

what are the three cuases for obesity induced or t2dm?

–Decreased GLUT-4 uptake of glucose in response to insulin release

–Decreased ability of insulin to repress hepatic glucose production

–Inability of insulin to repress hormone-sensitive lipase (HSL) or increase lipoprotein lipase (LPL) in adipose tissue

103

a decrease in plasma protein concentration would have what affect on total Ca and plasma Ca concentration

total ca would decrease with protein but plasma ca would stay the same

104

How does acidemia effect free plasma Ca concentrations?

acidemia leads to increase in ionized ca concentration due to less affinity for albumin not an increase in total ca concentration

105

how does alkylosis effect free Ca concentrations?

would result in less free ca due to increased binding to albumin no change in total ca levels

106

hypocalcemia symptoms

numbness in fingertips and extremities,

hyperflexia, overresponive reflexes, muscle twitching, when ca is low sodium channels become HYPEREXCITABLE

107

Hypercalcemia symptoms

•Constipation

•Polyuria

•Polydipsia

•Hyporeflexia

•Lethargy

•Coma…death

decreased action potentials, increased secretion in kidneys

108

PTH release mechanism

ca binds gpcr coupled to phospholipase C leads to ip3 binding intracellular ca channel which inhibits PTH release from chief cells/ if low ca nothing to inhibit pth release

109

chronic hyper or hypo calcemia changes to PTH gene transcription

chronic hpercalcemia leads to increase breakdown and decrecreasede sythesis of PTH/ chronic hypocalcemia leads to secondary hyperparathyroidism increased PTH 

110

where is the parathyroid receptor found and action?

osteoblasts causes a brief increase in bone formation but an increase in cytokine release that leads to more osteoclast activity resulting in net  bone resorption and increased free ca

also acts on kidney to activate vit D and increase calcium resoprtion by activating ca channels and increaseing number of ca na pumps also blocks phasphate absortion in order to promote free ca/ active form of vit D causes more ca to be absorbed in the gut tube

111

calcitonin receptor location and function

receptor on osteoclasts it inhibits osteclast activity and is releaesed from thyroid

112

1-25 dihydroxycholecalciferol (vit d) actions (calcitriol)

increased absorption by the gut tube and increaced bone resorption by acting on osteoblasts to release rankl wich activates osteoclasts

DOES THE OPPOSTITE OF PTH FOR PHOSPHATE nit promotes absorption in kidney

113

alkaline phosphate is a marker for what?

bione formation/ you will see an increase with pth becasue of osteblast activation

114

osteomalacia pathaology?

due to severe vit d deficiancy in adults

115