Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CSF block 4 > nerve/mm/cell communication > Flashcards

nerve/mm/cell communication Flashcards

1
Q

what is endocrine signaling? example?

A

source of the signal is distant from the target, signal travels in blood, insulin

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

what is paracrine signaling?

A

cells release signals that affect neighboring cells

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

examples of paracrine signaling (2)

A

1- vascular endothelial cells secrete vasodilators and vasoconstrictors that act on the neighboring smooth muscle
2- tumor derived growth factors bind nearby epithelial cells to trigger blood vessel formation

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

what is juxtracrine signaling? example?

A

cells in very close proximity or direct contact, glial cells guiding axons during nervous system development

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

what is autocrine signaling?

A

cell responds to a signal that it has generated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is an example of autocrine signaling?

A

stimulation of the EGFR receptor leads to increased levels of VEF, VEGF leaves the cell and binds to different receptors on the same cell

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

what is intracrine signaling? what type of receptor is required?

A

cell responds to a signal that it generated without the signal leaving the cell, intracellular receptor is required

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

what is an example of intracrine signaling?

A

estrogen-like molecules enter cell and encounter enzymes in the cell that change the molecules into signals that active receptors inside the cell

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

what are the 4 basic steps of signal transduction

A

signal released
signal binds receptor
transduction
response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are ligand gated ion channels?

A

ligand binds to receptor causing a conformational change that opens or closes the ion channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

describe the GABA receptor

A

GABA is an inhibitory neurotransmitter, when GABA binds to GABA receptors, it opens Cl- channel, Cl- enters the cell and hyperpolarizes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

describe IP3

A

IP3 binds IP3 channel on SER in smooth muscle, this allows Ca to leave SER and enter cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe RyR

A

RyR is on SER, when activated it causes release of Ca from RER to increase cytosolic Ca

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

describe K(ATP)

A

K(ATP) channel is inhibited when ATP binds, this leads to depolarization that allows for Ca release, that causes insulin release from b-cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the neurotransmitter in skeletal muscle?

A

acetylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what receptors do ACh bind on skeletal muscle?

A

nicotinic ACh receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

describe what happens when ACh binds nicotinic receptors on skeletal muscle

A

ACh binds nicotinic receptors, this opens the Na channels in the receptor and Na flows into cell causing depolarization, wave of depolarization travels on membrane to T-tubule where it contacts DHP receptor, DHP receptor is activated and it activates RyR-1 receptor (which is physically linked) and RyR-1 opens to release Ca from SER, Ca binds to troponin-C allowing for the myosin-binding sites on actin to be exposed

18
Q

3 general ways that signal termination occurs with ligand-gated ion channels

A

inactivation of receptors, inactivation of ion channels and membrane transporters (like SERCA)

19
Q

describe the basic structure of a G-protein receptor

A

7 membrane spanning domains, g protein with 3 subunits (a,b,y)

20
Q

describe general action of g-protein linked receptor

A

signal binds to G-protein receptor on membrane, G-protein receptor activated G-protein by GDP –> GTP, activated G-protein dissociates from receptor, a-GTP and By subunits dissociate, a-GTP and By subunits associate with effectors, a-catalyzed hydrolysis of GTP–>gdp inactivates a and promotes reassembly of aBy trimer

21
Q

what is the neurotransmitter and receptor for GaS?

A

epinephrine and B-adrenergic receptor

22
Q

explain the steps of GaS

A

epinephrine binds to B-adrenergic receptor
receptor is activated and it exchanges GDP–GTP to activate G-protein
G-protein interactions with adenylyl cyclase (effector)
activated adenylyl cyclase forms cAMP from ATP
increased cAMP levels activate protein kinase A

23
Q

what is the “effector” in GaS?

A

adenylyl cyclase

24
Q

what is the 2nd messenger in GaS?

A

cAMP

25
Q

what is the action of protein kinase A?

A

phosphorylates serene and threonine residues on proteins to active the proteins

26
Q

how is GaS terminated?

A

receptor inactivation by endocytosis, Gprotein inactivation, phosphodiesterase degradation of cAMP, phosphatase dephospho rylation of proteins

27
Q

describe the effects of cholera toxin

A

causes constitutive activation of adenylyl cyclase to increase cAMP levels

28
Q

describe the effects of pertussis toxin

A

inactivates the inhibitor of adenylyl cyclase to increase cAMP levels

29
Q

what is the neurotransmitter and receptor for Gaq?

A

norepinephrine and a-adrenergic receptor

30
Q

discuss the activity of Gaq

A

norepinephrine binds to a-adrenergic receptor
conversion of GDP to GTP activates G protein
activated G protein interacts with phospholipase C to activate it
activated phospholipase C will yield IP3 and diacyl glycerol

31
Q

what is the consequence of increased IP3?

A

IP3 binds to IP3 receptors on the SER to increase cytosolic calcium

32
Q

what is the consequence of increased diacyl glycerol?

A

diacyl glycerol activates protein kinase C

33
Q

describe Ca and calmodulin

A

Calcium binds calmodulin to activate it

activated calmodulin can then activate a protein kinase

34
Q

how is the Gaq signal terminated?

A

receptor inactivation, G protein inacgivation, degradation of IP3 or DAG, SERCA pumps or phosphatase mediated dephospho rylation of proteins

35
Q

what ligands use nuclear receptors?

A

retinoic acid, bit D, steroids, thyroid hormone

36
Q

how do intracellular receptors effect cells?

A

mainly by the alteration of transcript because ligands can directly bind DNA, this is slower than Gproteins

37
Q

what is the action of tamoxifen?

A

SERM that occupies the estrogen binding site but does not stimulate proliferation

38
Q

what are the 2 forms of guanylyl cyclase?

A

membrane bound “particulate” form

soluble form in cytosol

39
Q

what is the function of guanylyl cyclase?

A

makes cGMP from GTP

40
Q

what does cGMP regulate?

A

regulates smooth muscle tone and neurotransmission

41
Q

what class of enzymes will inactivate cGMP?

A

phosphodiesterase

42
Q

describe the MOA of viagra

A

viagra is a PDE-5 inhibitor, by inhibiting PDE-5, there are increased cGMP levels in cell, increased cGMP levels activate MLCP which causes relaxation in smooth muscle, relaxation results in vasodilation and erection

CSF block 4 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions