Physiological regulation Flashcards Preview

BMS 752 (Medical Physiology) > Physiological regulation > Flashcards

Flashcards in Physiological regulation Deck (124)
Loading flashcards...
1
Q

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

A

extrinsic and intrinsic

2
Q

how does physiologic regulation take place

A

through communication between structures using chemical signals

3
Q

what are the two extrinsic regulatory systems of the body

A

nervous and endocrine system

4
Q

what are the two mechanisms of intercellular communication

A

direct and indirect

5
Q

direct intercellular communication

A

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

6
Q

indirect intercellular communication

A

ligands released from one cell bind to a receptor on another

7
Q

four functional classifications of chemical messangers

A
  1. paracrine
  2. autocrine
  3. neurotransmitters
  4. hormones
8
Q

paracrine

A

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

9
Q

autocrine

A

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

10
Q

neurotransmitters

A

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

11
Q

hormones

A

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

12
Q

what are the five structural classifications of chemical messangers

A
  1. amino acids
  2. amines
  3. steroids
  4. proteins
  5. eicosanoids
13
Q

what is the primary function of amino acid messangers

A

neurotransmitters in the CNS

14
Q

what are four common specific amino acid messangers

A
  1. glutamate
  2. aspartate
  3. glycine
  4. GABA
15
Q

what are four groups of amine ligands

A
  1. catecholamines
  2. thyroid hormones
  3. serotonin
  4. histamine
16
Q

what amino acid are catecholamines derived from

A

tyrosine

17
Q

what are three catecholamines

A
  1. epinephrine
  2. norepinephrine
  3. dopamine
18
Q

epinephrine

A

a catecholamine secreted by the adrenal medulla

19
Q

norepinephrine

A

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

20
Q

dopamine

A

a catecholamine CNS neurotransmitter

21
Q

what is the difference between a neurotransmitter and hormone

A

where they are found

22
Q

what amino acid are T1 an T2 derived from

A

tyrosine

23
Q

what tyoe of ligand are thyroid hormones

A

amines

24
Q

serotonin

A

an amine neurotransmitter derived from tryptophan

25
Q

histamine

A

a paracrine amine ligand derived from histadine

26
Q

where are steroid ligands derived from

A

cholesterol

27
Q

what are 5 types of steroid ligand

A
  1. glucocorticoids
  2. mineralocorticoids
  3. androgens
  4. estrogens
  5. progestines
28
Q

what is the main glucocorticoid

A

cortisol

29
Q

what is the primary mineralocorticoid

A

aldosterone

30
Q

what is the primary androgen

A

testosterone

31
Q

what is the primary estrogen

A

estradiol

32
Q

what is the primary progestin

A

progesterone

33
Q

what type of ligand has the largest number of chemical messangers

A

protein

34
Q

eicosanoids

A

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

35
Q

Vmax

A

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

36
Q

what influences Vmax

A

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

37
Q

KM

A

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

38
Q

what is KM a measure of

A

affinity of a ligand for its receptor

39
Q

what ligands are transported in blood

A

hormones

40
Q

what three ligands are transported by diffusion

A

autocrines, paracrines, neurotransmitters

41
Q

how are hormones transported in blood

A

some can dissolvle in blood, some need a protein carrier

42
Q

T/F receptors show specificity for a messanger

A

true

43
Q

T/F most receptor/ligand binding is permanent

A

false, it is temporary and reversible

44
Q

How many different receptors can a ligand bind to

A

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

45
Q

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

A

false, most have receptors for many different ligands

46
Q

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

A

the ligand with the highest affinity

47
Q

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

A

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

48
Q

what is the relationship between KM and affinity

A

the ligand with the highest affinity has a lower KM

49
Q

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

A

the Vmax will also double

50
Q

what three factors determine the magnitude of cell response

A
  1. messanger concentration
  2. number of receptors on target cell
  3. affinity between receptor and ligand
51
Q

receptor agonist

A

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

52
Q

receptor antagonist

A

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

53
Q
A

dopamine

54
Q
A

epinephrine

55
Q
A

norepinephrine

56
Q

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

A
  1. steroid hormones
  2. T3 and T4
57
Q

where do lipid soluble (lipoholic) ligands have their receptors

A

inside the cell

58
Q

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

A
  1. proteins
  2. amino acids
  3. amines (except thyroid hormone)
59
Q

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

A

on the cell memrbane

60
Q

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

A
  • 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
Q

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

A
  1. ion channels
  2. enzymes
62
Q

what is a fast response receptor? give two examples

A

when the plasma membrane receptor and effector are the same protein

nicotinic receptor and tyrosine kinase receptor

63
Q

nicotinic receptor

A

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

64
Q

what does a nicotinic receptor do on skeletal muscle

A

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

65
Q

what is a calcium channel?

A

a fast ion channel found on the cell membrane

66
Q

what are 4 thinsg that happens when calcium channels open

A
  1. the PM depolarizes
  2. muscles contract
  3. secreton
  4. calcium binds to calmodulin
67
Q

what happens when calcium binds to calmodulin

A

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

68
Q

tyrosine kinase receptor

A

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

69
Q

what are G protein linked receptors

A

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

70
Q

T/F G protein effectors are always enzymes

A

false, they can be ion channels too

71
Q

slow response receptors

A

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

72
Q

two examples of slow response receptors

A
  1. muscarinic receptor
  2. adrenergic receptor
73
Q

five step process for G linked receptor interactions

A
  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
Q

what are the 3 parts of a G protein

A
  1. alpha
  2. beta
  3. y
75
Q

six steps for how adenylate cyclase produces a cellular response

A
  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
Q

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

A

cAMP

IP3 and DAG

77
Q

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

A
  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
Q

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

A

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

79
Q

what is the action of DAG in the cell

A

activation of protein kinase C and phosphorlyation of protein

80
Q

what is signal amplification in reference to cyclic AMP

A

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

81
Q

what are the primary endocrine organs (9)

A
  1. hypothalamus
  2. pituitary
  3. pineal
  4. thyroid
  5. parathyroid
  6. thymus
  7. adrenal
  8. pancreas
  9. gonads
82
Q

primary endocrine organ

A

an organ whose only job is to secrete or store ligands

83
Q

secondary endocrine organs (6)

A
  1. heart
  2. liver
  3. stomach
  4. small intestine
  5. kidney
  6. skin
84
Q

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

A

true

85
Q

where do most hypothalamic hormones bind

A

to receptors on the pituitary

86
Q

adenohypophysis

A

the anterior lobe of the pituitary

87
Q

neurohypophysis

A

posterior lobe of the pituitary

88
Q

what two hormones are secreted from the posterior pituitary

A
  1. oxytocin
  2. ADH
89
Q

describe the process for the posterior pituitary to secrete hormones

A
  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
Q

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

A
  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
Q

what two things regulate the secrete of anterior pituitary hormones

A
  1. negative feed back from the trophic hormones
  2. negative feed back from organ stimulated by pituitary hormones
92
Q

how does caffiene influence energy production

A

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

93
Q

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

A

changing the production of the stimulating ligand

changing the rate of clearance

94
Q

what are the hormones released by the hypothalamus

A
  1. PRH
  2. PIH
  3. TRH
  4. CRH
  5. GRHR
  6. GHIH
  7. GnRH
95
Q

PRH/PIH

A

prolaction releasing/inhibiting hormone

96
Q

TRH

A

thyroid releasing hormone

97
Q

CRH

A

corticosteroid releasing hormone

98
Q

GHRH/GHIH

A

growth hormone releasing/inhibiting hormone

99
Q

GnRh

A

gonadotropin releasing hormone

100
Q

what are the hormones released by the anterior pituitary

A
  1. prolactin
  2. TSH
  3. ACTH
  4. GH
  5. LH
  6. FSH
101
Q

TSH

A

thyroid stimulating hormone

102
Q

ACTH

A

adrendocorticotropic hormone

103
Q

LH

A

lutenizing hormone

104
Q

FSH

A

follicle stimulating hormone

105
Q

what are three ways blood hormone levels are controlled

A
  1. secretion rate
  2. carrier protein binding
  3. clearance rate
106
Q

how is secretion rate regulated

A

negative feedback through end product inhibition

107
Q

how do carrier proteins regulate blood hormone levels

A

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

108
Q

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

A

enzymes

lipophobic (extracellular) are broken down more quickly

109
Q

four types of hormone interaction

A
  1. antagonistic
  2. addittive
  3. synergistic
  4. permissive
110
Q

antagonistic hormone interaction (example)

A

two hormones that have opposite effects (insulin and glucagon)

111
Q

additive hormone effects (example)

A

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
Q

synergistic hormone effects (example)

A

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

(GH and insulin)

113
Q

permissive hormone effects 9example)

A

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

114
Q

what are the four main hypothalamic-pituitary axes

A
  1. tthyroid
  2. adrenal
  3. liver
  4. gonads
115
Q

name and describe the axis that produces thyroid hormone

A

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
Q

name and describe the axis that produces cortisol

A

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
Q

name and describe the axis that produces GH

A

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
Q

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

A

somatostatin

119
Q

describe the gonadal axis

A
  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
Q

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

what hormones will GnRH produce?

A

FSH and LH

androgens and estrogens

121
Q

what type of receptor is a muscarinic receptor?

what does it do?

A

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
Q

what type of receptor is a nicotinic receptor

what does it do?

A

a fast ion channel

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

123
Q

what type of receptor is tyrosine kinase?

what does it do?

A

a fast response enzyme

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

124
Q

describe an example of signal amplification

A
  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