Brainscape's Knowledge GenomeTM

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


See full index

Vet Physiology > synaptic and neuromuscular transmission > Flashcards

synaptic and neuromuscular transmission Flashcards

1
Q

neuron structural types

A

structural classification based on # of processes that extend from the cell body

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

what are multipolar neurons?

A

3 or more processes extending from cell body
** MAJOR TYPE IN CNS and EFFERENT PNS

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

what are bipolar neurons?

A
  • only 2 processes
  • retina, olfactory system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are unipolar neurons?

A
  • single, short processes from cell body, then branches into 2 or more
  • peripheral processes associated with sensory perception
  • primary afferent PNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are electrical synapses?

A
  • current flows between cells via GAP JUNCTIONS
  • in cardiac and some smooth muscle
  • very fast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are chemical synapse?

A
  • gap between presynaptic and postsynaptic cells- synaptic cleft
    1. AP in presynaptic cell causes voltage-gated Ca2+ channels to open
  1. Ca2+ influx causes release of neurotransmitter from presynaptic terminal
  2. neurotransmitter binds ligand-gated Na+ channel on postsynaptic cell, leading to depolarization (can be excitatory or inhibitory)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

describe synaptic arrangements

A

neurons are arranged in circuits where input cells synapse on output cells
- output cell may or may not fire an action potential depending on amount of excitation provided by the input cells

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

one-to-one synapses

A
  • neuromuscular junction
  • single AP in motoneuron cases single AP in muscle fiber
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

one-to-many synapses

A
  • found in some motoneurons of spinal cord
  • spinal AP in motorneurons causes many APs in postsynaptic cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

many-to-one synapses

A
  • many presynaptic cells converge on a postsynaptic cell
  • common
  • need convergence of multiple input neurons to cause an AP -> sum inputs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

net= depolarization=

A

excite

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

net= hyperpolarization=

A

inhibit

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

common to use many-to-one arrangement

A

inputs are excitatory or inhibitory

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

excitatory postsynaptic potential (EPSPs)

A
  • pre-synaptic neuron depolarizes post-synaptic neuron, brings neuron’s membrane potential to threshold opens Na and K channels
  • Ach, NE, Epi, dopamine, glutamate, serotonin are excitatory neurotransmitters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

inhibitory postsynaptic potentials (IPSPs)

A
  • pre-synaptic neuron hyper polarizes post-synaptic neuron and membrane potential moves away from threshold, opens Cl channels
  • GABA, glycine are inhibitory neurotransmitters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

temporal summation

A
  • two inputs arrive at postsynaptic cell in rapid succession
  • effects are additive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

spatial summation

A
  • two or more inputs arrive at postsynaptic cell simultaneously
  • both inputs could be excitatory -> depolarization
  • one could be excitatory, one inhibitory -> cancels/nothing
18
Q

synaptic fatigue

A

repeated stimulation yields a smaller than expected response

19
Q

ionotropic receptors

A
  • ligand-gated ion channels that usually open in response to binding of neurotransmitter
  • usually located along dendrites or cell bodies and receive incoming information from other neurons
20
Q

effects on post-synaptic neuron by neurotransmitters

A
  • may be excited due to Na influx causing depolarization
  • may be inhibited due to either K efflux or chloride influx causing hyperpolarization
  • Ca influx?: may or may not cause depolarization, Ca usually associated with 2nd messenger system
21
Q

What does Glutamate (AA) do?

A
  • primary excitatory neurotransmitters in the CNS
22
Q

what are the types of glutamate receptors?

A
  • AMPA
  • NMDA
23
Q

what does AMPA do?

A
  • allows both Na and K to cross membrane, but gradient drives Na is stronger -> net effect depolarization
24
Q

what does NMDA do?

A

depends on glutamate binding AND voltage, when around RMP, Mg ions blocks binding site/movement of other ions- when glutamate binds AND depolarization, Mg block removed

25
Q

Acetylcholine

A
  • only neurotransmitter used at neuromuscular junction
  • also used by autonomic nervous system (PSNS and SNS)
26
Q

Glycine and GABA (both AA)

A
  • both neurotransmitters are used in the CNS and both are chloride channels
27
Q

what does the binding of Glycine and GABA cause?

A

inhibition since increase in Cl permeability is inhibitory

28
Q

GABAa receptor associated with…

A

chloride

29
Q

what are metabotropic receptors?

A
  • located along dendrites or cell bodies, receive incoming information, slower than ionotropic receptors
  • can use G-protein-coupled receptors (GPCR)
30
Q

steps in GPCR?

A
  1. G-protein activated when neurotransmitter binds receptor
  2. G-protein alpha subunit binds GTP
  3. beta y subunit may activate an ion channel (K+ channel) -> direct G-protein gating
  4. alpha subunit may activate enzymes that promote second messenger synthesis
  • enzymes: phospholipase C, adenylyl cyclase, DAG
  • second messengers: IP3, CAMP
31
Q

what neurotransmitters activate G-protein-coupled receptors?

A
  • norepinephrine (NE)
  • glutamate (metabotropic receptor)
  • GABA (GABAb receptor)
32
Q

what does norepinephrine (NE) do?

A

uses alpha- or beta- adrenergic receptors

33
Q

beta-adrenergic GPCRs couple to a stimulatory G-protein subunit ->

A

initiates cAMP second messenger system

34
Q

alpha-2 adrenergic receptors couple to an inhibitory G-protein and…

A

suppress the cAMP system

35
Q

Alpha-1 adrenergic receptors couple to G-protein, Gq ->

A

activates the phospholipase C second messenger system

36
Q

Glutamate (metabotropic receptor)

A
  • acts on post-synaptic sites in CNS
  • modulates cell excitability and synaptic transmission via second messenger pathways
37
Q

3 groups of Glutamate receptors

A
  • group 1: increase neuron excitability; activate phospholipase C pathway
  • group 2 and 3: suppress neuron excitability, inhibit adenylyl cyclase pathway
38
Q

GABA (GABAb receptor)

A
  • found in CNS and autonomic division of peripheral nervous system
  • GABA acting via G-proteins linked to K channels -> hyper polarize cell at end of AP
39
Q

neurotransmitters based on chemical properties

A
  • acetylcholine
  • biogenic amines: norepinephrine, epinephrine, dopamine, serotonin (5-HT), histamine
  • amino acids: glutamate, glycine, gamma-aminobutyric acid (GABA)
  • neuropeptides
40
Q

neuropeptides

A

synthesized and packaged in nerve cell body instead of axon terminal

41
Q

neuromodulators

A
  1. may act on pre-synaptic cell to alter amount of neurotransmitter released
  2. may be co-secreted with neurotransmitter to alter response of post-synaptic cell
42
Q

neurohormones

A

released from neurons into blood

Vet Physiology (5 decks)

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