Brainscape's Knowledge GenomeTM

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


See full index

Physiology FoM > Cell to cell communication > Flashcards

Cell to cell communication Flashcards

1
Q

Define autocrine

A

Communication within the same cell

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

Define paracrine

A

Communication with neighbouring cells

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

Define endocrine

A

Communication with distant cells

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

Describe the electrical mechanism of communication

A

Changes in resting potential, propagated along cell, neighbour depolarisations

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

Describe the chemical mechanism communication

A

Substances released act on target cells either via receptors or gap junctions

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

Describe action potential phases

A
  • Resting potential
  • Initial depolarisation
  • Main depolarisation
  • Peak
  • Repolarisation
  • Hyperpolarisation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe phase 0- resting potential

A

Negative due to fixed anions, Na+/K+ ATPase and selectively permeable membrane

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

Describe phase 1 - initial depolarisation

A
  • Cell bodies of neurons receive multiple signals- IPSPs and EPSPs
  • Begins to reach threshold, ligand-gated channels linked to receptor opened by ligand binding
  • Dendrites have synapses, charge enters, resting potential rises in small depolarisations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe phase 2- main depolarisation

A
  • Threshold potential, all or nothing principle (due to voltage-gated Na+ channels)
  • Threshold around -55mV- when Na+ channels open- increased Na+ permeability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe phase 3 -peak

A

Na+ entry continues until equilibrium potential of Na+ reached, however won’t reach 60mV- K+ efflux

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

Describe phases 4 and 5- re/hyperpolarisation

A
  • Driven by potassium efflux- membrane potential back to resting (Na+ channels close)
  • Efflux continues to -90mV- EP of K
  • No potassium gradient- channels close
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe refractory periods

A
  • During repolarisation Na+ channels closed irrespective of stimulus- absolute refractory
  • Hyperpolarisation- Na+ channels active- harder to reach threshold- relative refractory
  • Refractory periods keep transmission going forward
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What affects the speed of conduction?

A
  • Transmission of signal dependent on size and myelination

- Larger fibres are usually myelinated

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

Describe saltatory conduction

A
  • Large myelinated nerves

- Conduction jumps between node of Ranvier gaps

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

Describe the general function of synapses

A
  • Allow communication
  • Only at end so they ensure unidirectionality
  • Can have stimulatory or inhibitory neurotransmitters
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe how cellular communication occurs

A
  • Cells receive impulses via receptors
  • Neurotransmitters import their response
  • Target tissue contains receptors for neurotransmitters
17
Q

Describe the ionotropic receptor type

A
  • Ligand-gated ion channel, e.g. nicotinic cholinergic
18
Q

Describe the metabotropic receptor type

A

Linked to enzyme cascade (e.g. GPCR)

19
Q

Describe the intracellular receptor type

A

Control transcriptional and translational for mainly steroid hormones

20
Q

Describe affinity and efficacy

A
  • Ligands have both- identification of subtypes
  • Physiological antagonism
  • > 2 different ligands acting at different receptors and having opposing effects
21
Q

Describe the receptor action involving acetylcholine

A
  • Nicotinic receptor- ionotropic, depolarisation

- Muscarinic receptor- metabotropic, various (GPCR)

22
Q

Describe the receptor action involving GABA (gamma-aminobutyric acid)

A
  • Type A receptors, inotropic chloride channels, brain
23
Q

Describe the receptor action of glutamate

A
  • Various types, ionotropic Na/K channels
24
Q

Describe the receptor action involving noradrenaline

A
  • Alpha/beta adrenoreceptors, metabotropic, various
25
Q

What happens when chloride ions enter a cell?

A

Membrane potential becomes more negative, action potential is less likely

26
Q

What are excitatory and inhibitory inputs?

A
  • Dendrites receive info from multiple other neurons (come excitatory and some inhibitory)
  • Generation of AP in post-synaptic neuron depends on summation of responses
27
Q

What are EPSPs?

A
  • Excitatory post-synaptic potentials
  • Some neurotransmitters open ion channels- depolarisation (ACh + glutamate- Na+)
  • Increase potential toward threshold- anything that depolarises is excitatory
28
Q

What are IPSPs?

A
  • Some neurotransmitters open ion channels- hyperpolarisation- Cl channels activated by GABA
  • Decreased resting potential further from threshold
29
Q

What is summation?

A
  • Inputs added for overall change in potential
  • Threshold needs more EPSPs and less IPSPs
  • Temporal or spatial
30
Q

Describe temporal summation

A
  • Related to time, summation of multiple EPSPs from the same neuron
31
Q

Describe spatial summation

A
  • Related to space, summation of 2 or more EPSPs from different neurons simultaneously
32
Q

Describe electrical signalling

A
  • Nerves conduct electrically down axon (signalling still chemical)
  • Electrical coupling does exist between adjacent cells via gap junctions
  • Gap functions allow rapid ion movement by neighbouring cells
  • Allows spread of electrical communication and rapid movement of change in potential

Physiology FoM (6 decks)

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