Brainscape's Knowledge GenomeTM

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


See full index

MCAT Biology > Nervous System > Flashcards

Nervous System Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards AP® Biology flashcards Biology 101 flashcards
1
Q

What do oligodendrocytes produce; and where

A

myelin in this CNS

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

purpose of myelin and what is it

A

a fatty membrane that prevents signal loss or crossing of signals; also increases the speed of conduction along the axon

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

dendrites purpose

A

receive incoming messages from other cells

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

What do Schwann cells do

A

produce myelin in the PNS

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

What are the nodes of ranvier; purpose

A

small breaks in the myelin sheath allow for rapid signal conduction.

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

The nerve terminal or synaptic bouton (knob) purpose

A

maximizes transmission of the signal to the next neuron and releases neurotransmitters

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

together the synaptic cleft, nerve terminal, and postsynaptic membrane are known as the _

A

synapse

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

What are the 3 types of nerves; signal direction

A

sensory (afferent) sensory receptors to the CNS
motor (efferent) CNS to muscles and glands
mixed (interneurons) in brain and spinal cord; linked to reflexive behavior

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

neurons must be supported and myelinated by other cells called

A

glial cells or neuroglia

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

Types of glial cells and their functions

A

astrocytes= nourish neurons and form the blood-brain barrier.
Ependymal cells= line the ventricles of the brain and produce cerebral spinal fluid, serves as a shock absorber
Microglia= are phagocytic cells that ingest and break down waste products and pathogens in the CNS
oligodendrocytes and schwann cells= create myelin

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

purpose of the blood brain barrier

A

controls transmission of solutes from the bloodstream into nervous tissue

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

which two types of glial cells, if nonfunctioning, will make an individual most susceptible to a CNS infection

A

microglia and astrocytes

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

Neurons use all of nothing messages called

A

action potentials

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

321 Nokia mnemonic

A

3 Na out, 2 K in, 1 ATP used. Na/K ATPase

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

What is the resting membrane potential for neurons

A

-70 mV

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

What makes the resting membrane potential of neurons dynamic

A

slow leak sodium and potassium channels

17
Q

Neurons can receive both excitatory and inhibitory input. Excitatory input causes _ and inhibitory input causes _

A

depolarization

hyper-polarization

18
Q

When is an action potential triggered?

A

when the axon hillock receives enough excitatory input to reach the threshold.

19
Q

Explain the two types of summation in signaling

A

temporal summation= multiple signals are integrated during a relatively short period of time
Spatial summation= the additive effects are based on the number and location of the incoming signals (can be both excitatory and inhib)

20
Q

When a neuron is brought to threshold what happens; mechanism

A

V-gated sodium channels open

21
Q

When do V-gated Na channels become inactivated in a neuron

A

when Vm approaches +35 mV

22
Q

Describe the 3 states of V-gated Na channels during action potential

A

open @ threshold to +35 mV
closed @ resting to threshold
inactive @ +35mV to resting potential

23
Q

the efflux of K+ in neurons causes _

A

hyperpolarization

24
Q

When do V-gated K+ channels open

A

positive potential inside the cell caused by Na+ influx

25
Q

What are the two types of refractory periods

A 
absolute= no amount of stimulation can cause another action potential to occur.
relative= must be a greater than normal stimulation to cause an action potential
26
Q

increased length of the axon results in _

A

higher resistance and slow conduction

27
Q

When the signal “hops” from node to node it is called

A

saltatory conduction

28
Q

When action potential reaches the nerve terminal _ opens; and triggers _ of _ causing exocytosis of _

A

v-gated Ca channels open
fusion of membrane-bound vesicles
the neurotransmitter

29
Q

Neurotransmission must be regulated; what are the 3 mechanisms that do this and examples

A
  • acetylcholine (ACh) is broken down by acetylcholinesterase (AChE) (ENZYMATIC DEGRADATION)
  • neurotransmitters like serotonin, dopamine, and norepinephrine can be brought back into the presynaptic neuron by reuptake carriers (REUPTAKE)
  • gaseous signaling neurotransmitters like nitric oxide can diffuse out of the synaptic cleft (DIFFUSION)
30
Q

What neural structure initiates the action potential

A

the axon hillock

31
Q

What is white and grey matter; and location in the brain and spinal cord

A

white matter consists of axons in myelin sheaths
grey matter consists of unmyelinated cells bodies and dendrites.
in the brain white matter lies deeper than grey matter
in the spine grey matter lies deeper than white matter

32
Q

What does the somatic nervous system consist of

A

sensory and motor neurons in skin, joint, and muscles

33
Q

What does the autonomic nervous system do

A

regulates heartbeat, respiration, digestion, and grandular secretion

34
Q

Key signaling difference between SNS and ANS

A

the ANS requires both a preganglionic and postganglionic neuron; requires 2 instead of 1

35
Q

The ANS is divided into the _ and _ ; purposes, Neurotransmitter

A 
parasympathetic= conserve energy, sleeping and resting stages, reduces heart rate and constricts bronchi, ACh
sympathetic= activated via stress, fight or flight, increases HR, relaxes bronchi, dilates eyes, epinephrine
36
Q

Describe polysynaptic and monosynaptic reflex arcs and examples

A

monosynaptic arcs= single synapse between sensory neuron; knee-jerk reaction
polysynaptic arcs= 1 interneuron between the sensory and motor neurons; withdraw reflex, stepping on a nail.

37
Q

What is the difference between nerves and tracts

A

nerves may carry more than one type of information; tracts can carry only one type of information

38
Q

What is the likely consequence if a surgeon slips a dorsal root ganglion

A

loss of sensation at that level

MCAT Biology (6 decks)

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