Ch. 3 (Nervous System)

studied byStudied by 0 people
0.0(0)
get a hint
hint

What structures make up the nervous system?

1 / 184

encourage image

There's no tags or description

Looks like no one added any tags here yet for you.

Studying Progress

0%
New cards
185
Still learning
0
Almost done
0
Mastered
0
185 Terms
1
New cards

What structures make up the nervous system?

the brain, spinal cord, nerves, neural support cells, and certain sensory organs (eye, ear)

New cards
2
New cards

What is the functional unit of the nervous system?

neuron

New cards
3
New cards

What are the major structures of the neuron?

several dendrites, a single branched axon, and cell body (soma)

New cards
4
New cards

What describes the regenerative capabilities of neurons?

they cannot divide

New cards
5
New cards

What substances are neurons highly dependent upon for chemical energy?

glucose

New cards
6
New cards

neurons use what process to move glucose from the blood into the cell?

facilitated transport

(Note: not uniquely dependent on insulin for this transport)

New cards
7
New cards

What describes how neurons store nutrients?

contain low stores of glycogen and oxygen

(Note: depend on blood mostly for these nutrients)

New cards
8
New cards

What is the structure where the soma connects to the axon called?

axon hillock

(Note: action potentials are generated here)

New cards
9
New cards

What structure receives information and transfers it to the cell body in the neuron?

dendrites

New cards
10
New cards

What structure transfers impulses away from the cell body in the neuron?

axon

New cards
11
New cards

What distinguishes gray and white matter?

  • white: myelinated axons

  • gray: neuronal cell bodies (no myelin)

New cards
12
New cards

What category of nervous tissue cells are capable of cell division?

glial cells

New cards
13
New cards

Which glial cells produce myelin in the central nervous system (CNS)?

oligodendrocytes

New cards
14
New cards

Which glial cells produce myelin in the peripheral nervous system (PNS)

Schwann cells

New cards
15
New cards

What are the fatty sheaths that act as insulators in the nervous system?

myelin sheaths

New cards
16
New cards

Myelin sheaths are separated by what divisions?

nodes of Ranvier

New cards
17
New cards

The nodes of Ranvier allow the action potential to do what?

travel continuously down the axon jumping from node to node

(Note: this process is called saltatory conduction, which speeds up the impulse)

New cards
18
New cards

What is the only type of animal that has myelinated axons?

vertibrates

New cards
19
New cards

What are the phagocytes of the CNS?

microglia

New cards
20
New cards

What cells use cilia to circulate cerebrospinal fluid

ependymal cells

New cards
21
New cards

What are groups of cell bodies in the PNS that serve as support cells?

satellite cells

New cards
22
New cards

What is a kind of satellite cell that provides physical support to neurons of the CNS and maintains the mineral and nutrient balance?

astrocytes

New cards
23
New cards

What are the three types of neurons important to the DAT?

  1. sensory (afferent) neurons

  2. association (interneuron) neurons

  3. motor (efferent) neurons

New cards
24
New cards

What kind of neuron receives the initial stimulus from the brain (ex: neurons in the skin)?

sensory (afferent) neuron

New cards
25
New cards

What kind of neuron is located in the spinal cord and brain, and receives impulses from sensory neurons and sends impulses to motor neurons?

association (interneuron) neuron

New cards
26
New cards

Which neurons are integrators as they evaluate impulses for the appropriate response?

association (interneuron) neuron

New cards
27
New cards

What percentage of neurons are interneurons?

99%

New cards
28
New cards

In which neural pathway are interneurons often found?

reflex arcs

(Note: note required for reflex arc though)

New cards
29
New cards

What neurons travel from the brain/spinal cord and stimulate effectors?

motor (efferent) neurons

(Note: May stimulate muscles, sweat glands, or cells in the stomach to secrete gastrin

New cards
30
New cards

What are target cells that elicit some response?

effectors

New cards
31
New cards

What is an electrical signal that is transmitted along a nerve fiber, allowing us to send signals to perform actions like raising an arm to catch a ball or recoiling a hand when touching a hot stove.

nerve impulse

New cards
32
New cards

What is the mechanism behind a nerve impulse?

polarized neurons

(Note: high concentration of Na+ is presented outside the cell and a high concentration of K+ inside)

New cards
33
New cards

What channel maintains the resting potential of a neuron?

Na+/K+ ATPase pump

(Note: 3Na+ are pumped out for every 2K+ brought in, resulting in the net removal of one positive charge from the intracellular space)

New cards
34
New cards

What are the steps of nerve impulse transmission?

  1. resting potential

  2. action potential

  3. repolarization

  4. hyperpolarization

  5. refractory period

New cards
35
New cards

What is the typical resting potential of a neuron?

-70 mV

New cards
36
New cards

What is the first step of an action potential?

a stimulus causes gated ion channels to open and Na+ ions enter the axon, depolarizing the neuron.

New cards
37
New cards

What measure needs to be reached in order for an action potential to occur?

the threshold level, which is around -50 mV

(Note: if the threshold level is not reached, no action potential occurs!)

New cards
38
New cards

What is the direct result of the threshold level being reached in terms of ion channels?

opening of voltage gated Na+ channels down the entire length of the neuron

(Note: All or nothing event!)

New cards
39
New cards

What happens during the repolarization phase in terms of ion channels?

in response to the Na+ flow in, more gated ion channels let K+ out of the cell, restoring polarization

New cards
40
New cards

Which ions are in and which ions are out after repolarization?

Na+ are now IN and the K+ are OUT!

New cards
41
New cards

What describes hyperpolarization in terms of ions?

too much K+ is released (~ -80 mV)

New cards
42
New cards

What term describes the period where the neuron will not respond to a new stimulus until Na+/K+ pumps return the ions to their resting potential locations?

refractory period

New cards
43
New cards

What term describes when Na+ channels are inactivated and there is no chance of responding to a new stimulus?

absolute refractory period

(Note: sets an upper limit to action potential frequency)

New cards
44
New cards

What period is it called when an abnormally large stimulus can create an action potential after the absolute refractory period?

relative refractory period

New cards
45
New cards

What is the function of the refractory period?

prevents an action potential from moving backwards

New cards
46
New cards

What metric is related to the frequency of action potential firing, or how many nervous cells contribute to result in the action potential?

strength of a neural signal

New cards
47
New cards

What is the name of the ion channel that will close in the presence of ATP, causing K+ to be unable to escape?

K-ATP sensitive channel

(Note: when exposed to ATP, this event causes depolarization, activating voltage dependent calcium channels (VDCC) to open, which results in the exocytosis of insulin)

New cards
48
New cards

What is the event called when a signal travels from a pre-synaptic neuron to a post-synaptic neuron?

signal transmission

New cards
49
New cards

What are the two types of signal transmission in the nervous system?

electrical and chemical

New cards
50
New cards

Which type of signal transmission is a bidirectional action potential

electrical

New cards
51
New cards

Which type of signal transmission is a unidirectional action potential that is most typical in animal cells?

chemical

New cards
52
New cards

Over what kind of membrane does an electrical transmission occur?

gap junction

New cards
53
New cards

In what tissues is electrical signal transmission common?

cardiac and visceral smooth muscle

New cards
54
New cards

What are the steps of transmission across a synapse?

  1. Ca 2+ gates open

  2. synaptic vessels release neurotransmitter

  3. neurotransmitter binds with post-synaptic receptors

  4. post-synaptic membrane is either excited or inhibited

  5. Neurotransmitter is degraded/ recycled/diffused away

New cards
55
New cards

When the Ca 2+ gates open during synaptic transmission, what event allows Ca2+ to enter the cell via VDCC's (are also found in beta cells!)?

depolarization

New cards
56
New cards

Influx of calcium ions during synaptic transmission causes what event?

release of neurotransmitters into the synaptic cleft

New cards
57
New cards

By what mechanism do neurotransmitters diffuse across the synapse during synaptic transmission?

brownian motion

New cards
58
New cards

In synaptic transmission, what is the result called when Na+ gates open and the membrane is depolarized, allowing an action potential to be generated if threshold potential is succeeded?

excitatory post synaptic potential (EPSP)

New cards
59
New cards

In synaptic transmission, what is the result called when K+ gates open and the membrane is hyperpolarized, making it more difficult to generate an action potential?

inhibitory post synaptic potential (IPSP)

New cards
60
New cards

What are the mechanisms in which neurotransmitters can be cleared from the synapse?

  • broken down by enzymes in the cleft

  • reuptaken

  • diffused

New cards
61
New cards

What are the factors that alter the rate at which impulses travel?

  • diameter

  • myelination

New cards
62
New cards

Which type of diameter will allow an action potential to travel faster?

larger diameter

(Note: less resistance to flow of ions)

New cards
63
New cards

Which type of myelination will allow action potential to travel faster?

more myelination

(Note: Na+ ions can't leak out, thereby driving saltatory conduction to occur faster)

New cards
64
New cards

What neurotransmitter is secreted at neuromuscular junctions and cause muscle contraction or relaxation?

Acetylcholine (Ach)

New cards
65
New cards

In the parasympathetic nervous system, Ach is released from which nerves?

pre and post ganglionic nerves

New cards
66
New cards

What enzyme breaks down Ach?

acetylcholinesterase

(Note: terminates the signal)

New cards
67
New cards

In what tissues is Ach found?

  • nerve tissue

  • muscle tissue

(Note: both central and peripheral tissues)

New cards
68
New cards

In which nerve fibers is Ach found?

sensory and motor fibers

New cards
69
New cards

What neurotransmitter is located at the neuromuscular junction in invertebrates?

Glutamate

(Note: most common CNS neurotransmitter in vertebrates. Is an amino acid)

New cards
70
New cards

What neurotransmitter is the inhibitory neurotransmitter among brain neurons

Gamma aminobutyric acid (GABA)

(Note: amino acid)

New cards
71
New cards

What neurotransmitter is the inhibitory neurotransmitter among synapses of the CNS outside the brain?

Glycine

(Note: amino acid)

New cards
72
New cards

What are the Amino acid-derived neurotransmitters (biogenic amines) that are secreted between neurons of the CNS?

epinephrine, norepinephrine, dopamine, and serotonin (5HT)

New cards
73
New cards

In which system do epinephrine/norepinephrine act?

sympathetic nervous system

New cards
74
New cards

From what nerves are epinephrine/norepinephrine released?

post ganglionic nerves

New cards
75
New cards

What neurotransmitters are short chains of amino acids and are a diverse group including substance P and endorphins?

neuropeptides

New cards
76
New cards

What neurotransmitters are not stored in vesicles and are actually synthesized and released into synapse directly?

gases

New cards
77
New cards

The autonomic and somatic nervous systems have which branches?

afferent (sensory) and efferent (motor) branches

New cards
78
New cards

Which division of the nervous system has sensory components which convey sensations from the eyes, nose, and other sensory organs to the brain + motor components transmitting impulses to the skeletal muscles?

somatic nervous system

New cards
79
New cards

Which division of the nervous system conveys sensory impulses form the blood vessels, heart, organs in the chest, abdomen, and pelvis via nerves to the brain. The motor component transmits signals to end organs.?

autonomic nervous system

New cards
80
New cards

Which nervous system consists of the interneurons, brain, and spinal cord?

central nervous system

New cards
81
New cards

The brain and spinal cord have three layers of protective covering called what?

meninges

(Note: right underneath the bone)

New cards
82
New cards

What are the layers of the meninges?

  1. dura mater

  2. arachnoid mater

  3. pia mater

(Note: from outer to innermost layer)

New cards
83
New cards

Which meninges layer is the outermost layer; thick, protects brain and spinal cord, has vein-like structures to carry blood from brain back to heart?

dura mater

New cards
84
New cards

Which meninges layer is middle layer with a spiderweb-like appearance?

arachnoid mater

New cards
85
New cards

Which meninges layer is a delicate innermost membrane covering the brain and spinal cord?

pia mater

New cards
86
New cards

Which space in the meninges is filled with cerebrospinal fluid (CSF)?

between arachnoid and pia mater

New cards
87
New cards

What substance is produced by tissue called choroid plexus in fluid-filled compartments in the CNS called ventricles

cerebrospinal fluid (CSF)

New cards
88
New cards

Where are the choroid plexi located?

ventricles

(Note: fluid-filled compartments in the CNS)

New cards
89
New cards

What does CSF act as?

a cushion and shock absorber

New cards
90
New cards

What substance circulates chemical substances throughout the brain and into the spinal cord?

CSF

New cards
91
New cards

What are the two types of brain matter?

  1. gray (outer cell bodies)

  2. white (inner axons)

New cards
92
New cards

What are the three main regions of the brain?

  1. forebrain

  2. midbrain

  3. hindbrain

New cards
93
New cards

What is the largest and most important brain region?

forebrain

(Note: contain cerebrum)

New cards
94
New cards

Which part of the forebrain processes sensory input, is important for perception, memory, voluntary movement, and learning?

cerebral cortex

New cards
95
New cards

Which part of the forebrain processes the sense of smell?

olfactory bulb

New cards
96
New cards

Which part of the forebrain relays sensory information between spinal cord and cerebral cortex?

thalamus

New cards
97
New cards

Which part of the forebrain is responsible for visceral function such as water balance, blood pressure regulation, temperature regulation, hunger, thirst, sex, circadian rhythms โ€” circadian rhythms coordinated suprachiasmatic nucleus?

hypothalamus

New cards
98
New cards

Which part of the forebrain houses the centers for planning/learning movement sequences?

basal ganglia

New cards
99
New cards

Which part of the forebrain is important for memory consolidation and spatial navigation?

hippocampus

New cards
100
New cards

Which region of the brain is the relay center for visual and auditory impulses, and motor control?

midbrain

New cards

Explore top notes

note Note
studied byStudied by 6 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 1651 people
Updated ... ago
4.8 Stars(13)
note Note
studied byStudied by 6 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 25 people
Updated ... ago
5.0 Stars(2)
note Note
studied byStudied by 10 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 3 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 4 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 61 people
Updated ... ago
5.0 Stars(1)

Explore top flashcards

flashcards Flashcard76 terms
studied byStudied by 9 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard153 terms
studied byStudied by 11 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard77 terms
studied byStudied by 15 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard166 terms
studied byStudied by 7 people
Updated ... ago
4.0 Stars(3)
flashcards Flashcard74 terms
studied byStudied by 10 people
Updated ... ago
5.0 Stars(2)
flashcards Flashcard35 terms
studied byStudied by 9 people
Updated ... ago
5.0 Stars