Physiology Flashcards

1
Q

G-protein coupled receptors

A

7 transmembrane domain associated with G-protein. G-protein has alpha, beta, gamma subunits. Alpha subunit bound to ATP. Once GPCR binds ligand, ATP cleaved releasing G protein to activate second messengers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

G-protein coupled receptors associated with Gq

A
  1. “HAVe 1 M and M”
  2. H1
  3. Alpha 1
  4. V1
  5. M1
  6. M3
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

G-protein coupled receptors associated with Gs

A
  1. Beta 1
  2. Beta 2
  3. Beta 3
  4. D1
  5. H2
  6. V2
  7. Glucagon
  8. PTH
  9. TSH
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

G-protein coupled receptors associated with Gi

A
  1. MAD 2s.
  2. M2
  3. Alpha 2
  4. D2
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Cyclic GMP second messenger system

A
  1. Natriuretic peptides- BNP, ANP
  2. Nitric oxide
  3. G protein stimulates guanylate cyclase (GC)–>turns GTP into cGMP–> activates protein kinase G–> smooth muscle relaxation.
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Gi second messenger system

A

Ligand binds to R–> Gi activation–> decreases AC activity–> ATP not converted into cAMP–> cAMP does not activate PKA–> PKA does not inactivate MLCK allowing for myosin phosphorylation and smooth muscle contraction. PKA does not increase intracellular calcium in heart muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Gs second messenger system

A

Ligand binds to R–> Gs activation–> increases adenylyl cyclase–> turns ATP into cAMP–> cAMP activates Protein Kinase A (PKA). PKA increases intracellular calcium concentrations in the heart. PKA decreases intracellular calcium concentrations in smooth muscle (eg, bronchioles) and inhibits myosin light-chain kinase (thus inhibiting myosin phosphorylation and smooth muscle cell contraction contraction).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Gq second messenger system

A

Ligand binds to R–>Gq activation–>Phospholipase C–> breaks up lipid membrane PIP2 into DAG and IP3. DAG–> Protein Kinase C (PKC). IP3–> liberates intracellular Ca2+ from endoplasmic reticulum–> smooth muscle contraction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Alpha 1 receptor

A
  1. Sympathetic nervous system: Gq
  2. Increases vascular smooth muscle contraction (increased SVR)
  3. Increased pupillary sphincter muscle contraction (mydriasis)
  4. Increased intestinal and bladder sphincter muscle contraction (urinary retention).
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Alpha 2 receptor

A
  1. Sympathetic nervous system: Gi
  2. Decreased sympathetic (adrenergic outflow)
  3. Decreased insulin release
  4. Decreased lipolysis
  5. Increased platelet aggregation
  6. Decreased aqueous humor production
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Beta 1 receptor

A
  1. Sympathetic nervous system: Gs
  2. Increased heart rate
  3. Increased contractility
  4. Increased renin release
  5. Increased lipolysis
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Beta 2 receptor

A
  1. Sympathetic nervous system: Gs
  2. Vasodilation
  3. Bronchodilation
  4. Increased lipolysis
  5. Increased insulin release
  6. Decreased uterine tone (tocolysis)
  7. Ciliary muscle relaxation
  8. Increased aqueous humor production
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Beta 3 receptor

A
  1. Sympathetic nervous system: Gs
  2. Increased lipolysis
  3. Increased thermogenesis in skeletal muscle
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

M1 receptor (muscarininc AChR)

A
  1. Parasympathetic nervous system: Gq
  2. CNS
  3. Enteric nervous system
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

M2 receptor (muscarininc AChR)

A
  1. Parasympathetic nervous system: Gi
  2. Decreased heart rate
  3. Decreased atrial contractility
    * ***********
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

M3 receptor (muscarininc AChR)

A
  1. Parasympathetic nervous system: Gq
  2. Except sweat glands: sympathetic nervous system
  3. Increased exocrine gland secretions (eg, lacrimal, sweat, salivary, gastric acid)
  4. Increased gut peristalsis
  5. Increased bladder contraction
  6. Bronchoconstriction
  7. Increased pupillary sphincter muscle contraction (miosis)
  8. Ciliary muscle contraction (accommodation)
    * ***********
17
Q

D1 (dopamine) receptor

A
  1. Sympathetic nervous system: Gs
  2. Relaxes renal vascular smooth muscle
    * ***********
18
Q

D2 (dopamine) receptor

A
  1. CNS: Gi
  2. Modulates transmitter release, especially in the brain.
    * ***********
19
Q

H1 (histamine) receptor

A
  1. Gq
  2. Increased nasal and bronchial mucus production, increased vascular permeability, contraction of bronchioles, prurities, pain.
    * ***********
20
Q

H2 (histamine) receptor

A
  1. Gs
  2. Increased gastric acid secretion (parietal cells)
    * ***********
21
Q

V1 (vasopressin) receptor

A
  1. Gq
  2. Increased vascular smooth muscle contraction
    * ***********
22
Q

V2 (vasopressin) receptor

A
  1. Gs
  2. Increased H2O permeability and reabsorption in collecting tubules of kidney by increasing aquaporins at membrane.
  3. V2 is found in the 2 kidneys.
  4. Vasopressin = antidiuretic hormone (ADH)
    * ***********