Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

phys1020 > Nervous - Week 2 > Flashcards

Nervous - Week 2 Flashcards

1
Q

excitable cell

A

able to use the resting membrane potential to generate an action potential
e.g. muscle, neurons and some endocrine cells are excitable. all others are non-excitable

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

chemically-gated (ligand) and voltage gated channels

A

contribute to the movements of ions in and out of the cell along with Na+/K+ ATPase

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

what is depolarization

A

the process by which an ion moves in or out of the cell so that the inside of the cell becomes more positive relative to the RMP

voltage- gated Na+ channels open and Na+ rushes in causing inside of cell to be more positive RMP now

(from -70mV –> -30mV)

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

what is the resting potential of a cell

A

~ -70mV

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

resting potential

A
  • K+ channels are not fully closed at rest (making them leaky)
  • voltage-gated Na+ channels and chemically gated K+ channels are closed at rest
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is an excitable cell?

A

An excitable cell is able to use the resting membrane potential to generate an electrochemical impulse called an action potential.

Examples of excitable cells include neurons, muscle cells, and some endocrine cells.

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

What is the process by which excitable cells generate action potentials?

A

The action potential is generated through depolarization events within the cell.

Depolarization involves ions moving in and out of the cell, making the inside more positive.

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

What are the roles of protein channels and ion pumps in excitable cells?

A

They facilitate the movement of ions in and out of the cell at the plasma membrane.

This includes sodium, potassium, and calcium channels, as well as the sodium-potassium ATPase (Na+/K+-ATPase).

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

What triggers an action potential in an excitable cell?

A

An action potential is triggered when depolarization reaches a threshold of -55 mV.

Depolarizations below this threshold are called failed initiations.

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

What occurs during the depolarization phase of an action potential?

A

Voltage-gated Na+ channels open, allowing Na+ to enter the cell.

During this phase, voltage-gated K+ channels remain closed.

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

What happens during the repolarization phase of an action potential?

A

Voltage-gated K+ channels open, allowing K+ to exit the cell, while voltage-gated Na+ channels close.

This phase helps restore the resting membrane potential.

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

What is hyperpolarization in the context of an action potential?

A

Hyperpolarization is when the inside of the cell becomes more negative than the resting membrane potential.

This phase is also known as the relative refractory period.

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

What is the resting stage of an action potential?

A

The resting stage is when the resting membrane potential (RMP) has been restored, typically around -70 mV.

This is the state before the next action potential can occur.

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

Why are Na+ and K+ channels referred to as ‘voltage-gated’?

A

They are called ‘voltage-gated’ because a change in voltage triggers their opening.

Specifically, Na+ channels open when the voltage exceeds -55 mV.

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

What occurs when Na+ channels are inactive?

A

When Na+ channels are inactive, no Na+ can enter the cell, preventing the elicitation of another action potential.

This is during the repolarization phase.

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

What is the absolute refractory period?

A

The absolute refractory period is the time during which no action potential can be elicited, as the Na+ channels are closed.

This ensures that action potentials are fixed in height and amplitude.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the relative refractory period?

A

The relative refractory period occurs during hyperpolarization when an action potential can be generated but requires a larger intensity stimulus.

This is because the membrane is more negative than the resting potential.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is hyperpolarization

A

chemically gated K+ channels open to bring back into the cell

voltage-gated Na+ channels closed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

action potential

A

an electrochemical impulse generated through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is relative refractory period

A

another name for hyperpolarization

  • the cell overcorrecting itself, making the cell more negative than at resting potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

anatomy of a neuron

A

soma
dendrites
axon
axon terminals
myelin sheath
Schwann cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

soma

A

body of cell

24
Q

dendrites

A
  • projections of the soma and the site of communications with other neurons
25
axons
- projection of the cell body - directs the AP away from the soma
26
axon terminal
- end of axons - transmits info to the next cell through the release of neurotransmitters
27
myelin sheath
insulating layer formed around axon - made of proteins and fatty acids presence makes sure that the AP is transmitted fast along axon
28
Schwann cell
type of cell surrounding axon - produces myelin - ensured that neurons stay alive
29
node of ranvier
myelin-sheath gaps that are rich in ion channels - participate in fast propagation of AP
30
AP propogation
propagates unidirectionally due to the refactory periods
31
what is a refactory period
a period immediately following stimulation during which a nerve or muscle is unresponsive to further stimulation another A cannot be elicited while previous one is in absolute refactory period because the ion channels are inactive during that time
32
CNS
central nervous system - made of the brain and spinal chord
33
PNS
peripheral nervous system - made of the nerves that go from CNS to muscles and organs (heart, liver, stomach) divided into: - somatomotor - autonomic
34
somatomotor nervous system
going to skeletal muscle to power voluntary movement
35
autonomic nervous system
going to other organs that are automatically controlled by the brain and are not under voluntary control
36
glial cells
type of cell that provides physical and chemical support to neurons and maintain their environment make up 90% of the brain schwann cell is a type of glial celly
37
types of neurons
bipolar unipolar multipolar
38
bipolar neurons
2 processes extending from the cell body; one axon and one dendrite (with branches) - type of specialized neuron found in the retina of the eye
39
unipolar neurons
one process extending from the cell body (straight connection between the axon and dendrite) - locates in the peripheral nerves outside of the CNS - sensory in nature - transmit signals to and from the spinal chord - cell body lies in the middle of and off to one side of the axon
40
multipolar neurons
contain many branching dendrites and 1 axon are the most common in the CNS - connect CNS with the effector organs
41
gyri
bumps on the brain
42
sulci
dips/valleys in the brain
43
frontal lobe
forehead area primary motor cortex processes input from skeletal muscles - premotor cortex: works with prefrontal cortex to integrate movement with other sensory inputs to generate perception of stimuli
44
parietal lobe
top back of head contains primary somatosensory cortex - receives input from major senses
45
temporal lobe
bottom back side of head - contains primary auditory complex and auditory association areas - other sections of temporal lobe are involved in olfaction (smell) and short term storage
46
occipital lobe
back of the head responsible for vision
47
cerebellum
bottom back of head responsible for coordinated movements in the body - processes sensory info - coordinates execution of movement in the body
48
brainstem
controls basic function of the body like the heart rate and respiration made of midbrain, pons and medulla oblongata incorporates 9 cranial nerves
49
corpus callosum
dense bundle of nerve fibers - serves as a pathway and connection between 2 cerebral hemispheres - the connection allows the brain to integrate sensory and motor info from both sides of the body and coordinate whole body movement and function
50
thalamus
receives sensory input as it travels from the spinal cord and integrates sensory info before sending it to cortex
51
hypothalamus
controls variety of endocrine functions (body temp, thirst, food intake, etc) mainly through directing the release of hormones hypothalamus is under thalamus
52
midbrain
controls eye movement - exerts control over auditory and visual motor reflexes
53
pons
primary function to act as a relay station for transferring info between the cerebellum and cerebral cortex - also coordinates and controls breathing
54
medulla
portion of brainstem that has primary control over involuntary function such as breathing, BP and swallowing
55
pituitary gland
anterior pituitary derived from epithelial tissue of the hypothalamus posterior pituitary derived form neural tissue of hypothalamus
56
hormones
chemicals that cells use to communicate with each other "long distance" through the blood stream

phys1020 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions