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BMS 752 (Medical Physiology) > Physiological regulation > Flashcards

Flashcards in Physiological regulation Deck (124):
1

what are two methods for cells, tissues, and organs regulation

extrinsic and intrinsic

2

how does physiologic regulation take place

through communication between structures using chemical signals

3

what are the two extrinsic regulatory systems of the body

nervous and endocrine system

4

what are the two mechanisms of intercellular communication

direct and indirect

5

direct intercellular communication

when ions and molecules pass directly from the cytoplasm of one cell to another

6

indirect intercellular communication

ligands released from one cell bind to a receptor on another

7

four functional classifications of chemical messangers

  1. paracrine
  2. autocrine
  3. neurotransmitters
  4. hormones

 

8

paracrine

a ligand secreted into the ECF which travels by diffusion and binds to a neighboring cell

9

autocrine

a ligand secreted by a cell into the ECF that binds on its own receptors

10

neurotransmitters

ligands secreted from neurons, into a synapse, and bind to a post synaptic receptor

11

hormones

ligands secreted into blood by endocrine cells, transported by the blood to a target cell receptor

12

what are the five structural classifications of chemical messangers

  1. amino acids
  2. amines
  3. steroids
  4. proteins
  5. eicosanoids

 

13

what is the primary function of amino acid messangers

neurotransmitters in the CNS

14

what are four common specific amino acid messangers

  1. glutamate
  2. aspartate
  3. glycine
  4. GABA

 

15

what are four groups of amine ligands

  1. catecholamines
  2. thyroid hormones
  3. serotonin
  4. histamine

 

16

what amino acid are catecholamines derived from

tyrosine

17

what are three catecholamines

  1. epinephrine
  2. norepinephrine
  3. dopamine

18

epinephrine

a catecholamine secreted by the adrenal medulla

19

norepinephrine

a catecholamine that acts as a CNS and PNS neurotransmitter and as a hormone secreted from the adrenal medulla

20

dopamine

a catecholamine CNS neurotransmitter

21

what is the difference between a neurotransmitter and hormone

where they are found

22

what amino acid are T1 an T2 derived from

tyrosine

23

what tyoe of ligand are thyroid hormones

amines

24

serotonin

an amine neurotransmitter derived from tryptophan

25

histamine

a paracrine amine ligand derived from histadine

26

where are steroid ligands derived from

cholesterol

27

what are 5 types of steroid ligand

  1. glucocorticoids
  2. mineralocorticoids
  3. androgens
  4. estrogens
  5. progestines

 

28

what is the main glucocorticoid

cortisol

29

what is the primary mineralocorticoid

aldosterone

30

what is the primary androgen

testosterone

31

what is the primary estrogen

estradiol

32

what is the primary progestin

progesterone

33

what type of ligand has the largest number of chemical messangers

protein

34

eicosanoids

paracrine ligands derived from arachidonic acid produced by virtually all cels of the body

35

Vmax

the maximum rate at which a ligand will bind to its receptor

36

what influences Vmax

the number of ligands up to Vmax, then only increasing the proteins will change anything

37

KM

the concentration of a ligand that will elict a reaction rate 1/2 of Vmax

38

what is KM a measure of

affinity of a ligand for its receptor

39

what ligands are transported in blood

hormones

40

what three ligands are transported by diffusion

autocrines, paracrines, neurotransmitters

41

how are hormones transported in blood

some can dissolvle in blood, some need a protein carrier

42

T/F receptors show specificity for a messanger

true

43

T/F most receptor/ligand binding is permanent

false, it is temporary and reversible

44

How many different receptors can a ligand bind to

usually more than one, but different receptors have a different affinity for a single messanger

45

T/F most target cells have receptors for only one ligand

false, most have receptors for many different ligands

46

at a subsaturation point for different ligands, which will bind more readily to the receptor

the ligand with the highest affinity

47

how can you have two different ligands with the same Vmax but differet KM

KM is based on affinity between the receptor ligand, Vmax is a measure of saturation point.

 

48

what is the relationship between KM and affinity

the ligand with the highest affinity has a lower KM

49

what happens to Vmax if the number of receptor proteins is doubled

the Vmax will also double

50

what three factors determine the magnitude of cell response

  1. messanger concentration
  2. number of receptors on target cell
  3. affinity between receptor and ligand

 

51

receptor agonist

an exogenous compound that binds to a receptor and causes a normal biologic response

52

receptor antagonist

an exogenous compound that binds to a receptor and produces no response

53

Q image thumb

dopamine

54

Q image thumb

epinephrine

55

Q image thumb

norepinephrine

56

what two types of ligands can pass the cell membrane without a carrier

  1. steroid hormones
  2. T3 and T4

 

57

where do lipid soluble (lipoholic) ligands have their receptors

inside the cell

58

what are three types of ligands that can't cross the cell membrane

  1. proteins
  2. amino acids
  3. amines (except thyroid hormone)

 

59

where are the receptors for non-lipid soluble (lipophobic) ligands found

on the cell memrbane

60

how do ligands with intracellular receptors create a response in the cell

  • hormones bind to receptor
  • hormone/receptor complex binds to DNA at a promotor
  • allow for gene expression and protein synthesis
  • new protein produces a response

 

61

what are two plasma membrane receptors that a ligand will bind with

  1. ion channels
  2. enzymes

 

62

what is a fast response receptor? give two examples

when the plasma membrane receptor and effector are the same protein

nicotinic receptor and tyrosine kinase receptor

63

nicotinic receptor

a fast ion channel receptor found on the PM of in muscle and nervous tissue

64

what does a nicotinic receptor do on skeletal muscle

opens ion channels, allowing Na and K into the cell, which depolarizes the cell membrane

65

what is a calcium channel? 

a fast ion channel found on the cell membrane

66

what are 4 thinsg that happens when calcium channels open

  1. the PM depolarizes
  2. muscles contract
  3. secreton
  4. calcium binds to calmodulin

 

67

what happens when calcium binds to calmodulin

protein kinase is formed, which phosphorylates protein to cause a response in the cell

68

tyrosine kinase receptor

a fast PM enzyme that phosphorylates tyrosine with ATP to make PTP and cause a cellular response

69

what are G protein linked receptors

a receptor that needs to use an intermediary G protein to couple with intracellular effectors and produce a response

70

T/F G protein effectors are always enzymes

false, they can be ion channels too

71

slow response receptors

receptors that are not bound to their effector and need an intermediary G protein to for a response

72

two examples of slow response receptors

  1. muscarinic receptor
  2. adrenergic receptor

 

73

five step process for G linked receptor interactions

  1. a receptor is inactive with a GDP bound to it
  2. ligand binding releases GDP
  3. GTP is phosphylated to GTP
  4. GTP alpha and beta parts disassociated
  5. one of the parts binds with the effector

74

what are the 3 parts of a G protein

  1. alpha
  2. beta
  3. y

 

75

six steps for how adenylate cyclase produces a cellular response

  1. catecholamines bind to adrenergic receptor
  2. receptor releases GDP
  3. GTP binds to adenylate cyclase
  4. GTP + ATP + adenylate cyclase produces cAMP
  5. cAMP activates protein kinase
  6. protein is phosphorylated

76

what is the second messanger in the adenylate cyclase reaction? phospholipase C?

cAMP

IP3 and DAG

77

what is the process by which phospholipase C produces IP3 and DAG

  1. epinephrine binds to adrenergic receptors
  2. receptor release GDP
  3. GDP --> GTP
  4. GTP binds with phospholipase C
  5. IP3 and DAG are produced

 

78

what is the action of IP3 produced by phospholipase C in the cell? what process is started

IP3 binds to ion channels on the smooth ER which release Ca, which binds to calmodulin, allowing for the production of protein kinase

79

what is the action of DAG in the cell

activation of protein kinase C and phosphorlyation of protein

80

what is signal amplification in reference to cyclic AMP

the concept that a single ligand can produce several reactions inside the cell 

81

what are the primary endocrine organs (9)

 

  1. hypothalamus
  2. pituitary
  3. pineal
  4. thyroid
  5. parathyroid
  6. thymus
  7. adrenal
  8. pancreas
  9. gonads

82

primary endocrine organ

an organ whose only job is to secrete or store ligands

83

secondary endocrine organs (6)

  1. heart
  2. liver
  3. stomach
  4. small intestine
  5. kidney
  6. skin

 

84

T/F together the hypothalamus and pituitary regulate almost every body system

true

85

where do most hypothalamic hormones bind

to receptors on the pituitary

86

adenohypophysis

the anterior lobe of the pituitary

87

neurohypophysis

posterior lobe of the pituitary

88

what two hormones are secreted from the posterior pituitary

  1. oxytocin
  2. ADH

 

89

describe the process for the posterior pituitary to secrete hormones

  1. ADH and oxytocin are made in the hypothalamus 
  2. hormones are packed and sent to the neural endings in the pituitary
  3. when stimulated the hypothalamic neurons release hormones into the blood 

 

90

describe the interaction between the hypothalamus and anterior pituitary to secrete hormones

  1. neurosecretory cells in the hypothalamus produce releasing hormones
  2. releasing hormones are secreted in to the hypothalamic-pituitary portal system
  3. the portal system carries releasing hormones to the anterior pituitary and stimulates the secretion of trophic hormones

 

91

what two things regulate the secrete of anterior pituitary hormones

  1. negative feed back from the trophic hormones 
  2. negative feed back from organ stimulated by pituitary hormones

 

92

how does caffiene influence energy production

it inhibits the action of phosphodiesterase, stopping it from breaking down cAMP into AMP to stop protein phosphorylation

93

what are two methods of regulating a hormonal response once it has started

changing the production of the stimulating ligand

changing the rate of clearance

94

what are the hormones released by the hypothalamus

  1. PRH
  2. PIH
  3. TRH
  4. CRH
  5. GRHR
  6. GHIH
  7. GnRH

 

95

PRH/PIH

prolaction releasing/inhibiting hormone

96

TRH

thyroid releasing hormone

97

CRH

corticosteroid releasing hormone

98

GHRH/GHIH

growth hormone releasing/inhibiting hormone

99

GnRh

gonadotropin releasing hormone

100

what are the hormones released by the anterior pituitary

  1. prolactin
  2. TSH
  3. ACTH
  4. GH
  5. LH
  6. FSH

 

101

TSH

thyroid stimulating hormone

102

ACTH

adrendocorticotropic hormone

103

LH

lutenizing hormone

104

FSH

follicle stimulating hormone

105

what are three ways blood hormone levels are controlled

  1. secretion rate
  2. carrier protein binding
  3. clearance rate

 

106

how is secretion rate regulated

negative feedback through end product inhibition

107

how do carrier proteins regulate blood hormone levels

lipoholic hormones can only have a concentration equal to the concentration of carrier proteins

108

what degrades hormones? are intracellular or extracellular hormones more quickly broken down

enzymes

lipophobic (extracellular) are broken down more quickly

109

four types of hormone interaction

  1. antagonistic
  2. addittive
  3. synergistic
  4. permissive

 

110

antagonistic hormone interaction (example)

two hormones that have opposite effects (insulin and glucagon)

 

111

additive hormone effects (example)

two hormones have the same effect through different mechanisms, so the effect is the sum of the individual effects (cortisol and GH on lipolysis)

112

synergistic hormone effects (example)

two hormones with the same action but the combination of their effect is greater than there individual sums

(GH and insulin)

113

permissive hormone effects 9example)

when one hormone needs another to do its function (estradiol produces receptors for progeterone)

114

what are the four main hypothalamic-pituitary axes

  1. tthyroid
  2. adrenal
  3. liver
  4. gonads

 

115

name and describe the axis that produces thyroid hormone

thyroid axis

  1. TRH is secreted by the hypothalamus into the blood
  2. TRH stimulates the anterior pituitary to produce TSH
  3. TSH released into the blood acts on the thyroid to produce TH

 

116

name and describe the axis that produces cortisol

adrenal axis

  1. CRH is produced in the hypothalamus and released into the blood
  2. CRH stimulates anterior pituitary produce of ACTH
  3. ACTH acts on the adrenal cortex to produce cortisol

 

117

name and describe the axis that produces GH

growth hormone axis

  1. GHRH is produced in the hypothalamus
  2. GHRH stimulates production of GH in the anterior pituitary
  3. GH acts on somatic cells to produce growth
  4. GH also acts on the liver to produce IGF

 

118

what hormone produced in the hypothalamus inhibits production of GH in the anterior pituitary

somatostatin

119

describe the gonadal axis

  1. GnRH is produced in the hypothalamus
  2. GnRH stimulates the production of LH and FSH in the anterior pituitary
  3. LH and FSH stimulate the production of androgens and estrogens from the gonads

 

120

what hormones are produced in the anterior pituitary in response to GnRH?

what hormones will GnRH produce?

FSH and LH

androgens and estrogens

121

what type of receptor is a muscarinic receptor?

what does it do?

slow response receptor bond it an ion channel

  • acetylcholine from a neuron binds to muscarinic receptors on smooth muscle or another neuron,
  • GDP is released and phosphorylated into GTP
  • GTP binds to an ion channel to allow flux

122

what type of receptor is a nicotinic receptor

what does it do?

a fast ion channel

when bound with acetylcholine nicotinic receptors open and allow flux of ions

123

what type of receptor is tyrosine kinase?

what does it do?

a fast response enzyme

when bound with a protein ligand it allows for the production of PTP, which affects intracellular change

124

describe an example of signal amplification

  1. catecholamine bind to adrenergic receptor
  2. receptor produces several G proteins
  3. each G protein activates one adenylate cylase
  4. each adenylate cyclase produces several cAMP
  5. each cAMP activates several protein kinases
  6. each protein kinase phosphorylates several proteins