Central Nervous System Flashcards
(128 cards)
1
Q
Gyri
A
folds on surface of cerebrum
2
Q
Sulci
A
grooves between folds of the cerebrum
3
Q
Fissures
A
deep grooves between the folds of cerebrum
4
Q
diencephalon
A
area between cerebrum and brainstem
5
Q
cerebellum
A
portion of the brain in posterior inferior region that processes coordination and movement
6
Q
proprioception
A
position of joints
7
Q
Wernicke’s Area
A
specialized area in the brain that helps with understanding speech
8
Q
Broca’s Area
A
specialized area in the brain that has to do with producing meaningful speech
9
Q
Nerves
A
whitish fiber or bundle of fibers that transmits impulses of sensation to brain or spinal cord, or to the muscles and organs
10
Q
What does the cell body do?
A
carries genetic information, maintains neuron’s structure, and provides energy for activities
11
Q
Dendrites
A
Fibrous roots that branch out from cell body, receiving and processing signals from axons of other neurons
12
Q
Central Nervous System
A
CNS is the processing center of the body; consists of brain and spinal cord
13
Q
Neurotransmitters
A
chemical substance that is released at end of nerve fiber by arrival of nerve impulse; when diffused across synapse or junction, causes transfer of impulse to another nerve fiber, muscle fiber, or other structure
14
Q
axons
A
long, threadlike part of nerve cell along which impulses are conducted from cell body to other cells
15
Q
axon terminal
A
found at terminal ends of axons; typically where synapses with other neurons take place; neurotransmitters stored there to communicate with other neurons via these synapses
16
Q
sensory nerves
A
also called afferent nerves; nerve fibers responsible for bringing sensory information from outside world to brain; senses such as vision, hearing, smell, taste, touch, pain, temperature, proprioception
17
Q
motor nerves
A
also called efferent nerves; transmits impulses from CNS out to peripheral organs to cause an effect or action
18
Q
somatic nervous system
A
voluntary; part of the peripheral nervous system associated with voluntary control via skeletal muscles
19
Q
autonomic nervous system
A
involuntary; part of the peripheral nervous system that regulates involuntary physiologic processes, including heart rate, blood pressure, respiration, digestion, sexual arousal; contains three anatomically distinct divisions: sympathetic, parasympathetic, enteric
20
Q
skeletal muscle
A
muscle connected to the skeleton to form part of mechanical system which moves limbs and other parts of body
21
Q
smooth muscle
A
muscle tissue in which contractile fibrils aren’t highly ordered, occurring in the gut and other organs; not under voluntary control
22
Q
synapse
A
junction between two nerve cells; minute gap across which impulses pass by diffusion of a neurotransmitter
23
Q
myofibrils
A
very fine contractile fibers; groups of myofibrils extend in parallel columns along striated muscle fibers; made of thick and thin myofilaments, which give the muscles striped appearance
24
Q
sarcomere
A
fundamental unit of contraction; region between two z-lines; consists of central A-band (thick filaments) and two halves of I-band (thin filaments)
25
actin
thin filaments of protein that form with myosin, making up contractile filaments of muscle cells; involved in motion
26
myosin
thick filaments of fibrous protein that form with actin, making up contractile filaments of muscle cells; involved in motion
27
main parts of the brain
outer cerebrum, inner diencephalon
28
diencephalon
thalamus, hypothalamus, epithalamus, subthalamus
29
cerebrum
largest portion of nervous system; two hemispheres with white matter bridge called "corpus callosum"
30
describe the surface of the cerebrum
folds called gyri and sulci (grooves), and deeper grooves called fissures
31
name the 4 lobes
frontal, parietal, temporal, occipital
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frontal lobe involved in:
motor movements, concentration, planning, problem solving, smell, emotions
33
parietal lobes involved in:
process sensory information (but not hearing, smell, and vision)
34
temporal lobes involved in:
hearing, smell, memory, abstract thought, making judgments
35
occipital lobe involved in:
processing visual information
36
name the two fissures and what they divide
longitudinal fissure divides parietal lobes, lateral fissure divides temporal & parietal lobes
37
central sulcus is located:
midway on lateral aspect of cerebrum, separating frontal from parietal lobes.
38
thalamus
"relay station"; carries all sensory information to cerebral cortex except sense of smell (carried directly to frontal lobe of cerebral cortex by olfactory nerves); involved in emotions, since connected to the limbic system
39
examples of sensory information
auditory, visual, motor information
40
location of hypothalamus
inferior and anterior to the thalamus
41
hypothalamus
regulates hormones (endocrine system); regulates body temperature, thirst, hunger, sexual drive, involved in emotions, mood, sleep (reticular activating system)
42
pineal gland
small endocrine gland that secretes melatonin; located posterior to the diencephalon
43
brainstem
located between cerebral cortex and spinal cord; consists of midbrain, pons, medulla oblongata
44
medulla oblongata
most inferior portion of brainstem; controls heart rate, respiration, swallowing, vomiting, blood vessel diameter; contain spinal pathways called "tracts" that connect spinal cord to brain
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pons
middle section of brainstem; contains spinal cord tracts and nuclei which help control respiration & sleep
46
midbrain
most superior portion of brainstem; helps process motor and hearing information
47
reticular formation is located:
throughout brainstem; regulates sleep-wake cycles
48
limbic system
contains cerebrum, diencephalon; involved in reproduction, memory, emotions; contains cingulate gyrus, portions of thalamus, hypothalamus, mamillary and amygdaloid bodies, hippocampus, nucleus accumbens
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limbic system component locations
seems like most of them are located in the diencephalon
50
What is the autonomic nervous system?
maintains homeostasis in body even when unconscious; "visceral motor system" since ANS sends motor impulses to viscera
51
How is the ANS divided?
Sympathetic and parasympathetic
52
Sympathetic nervous system
Fight or flight; usually causes opposite effect from parasympathetic; increase heart rate, dilate air passages, dilate pupils, decrease digestive activity, increase amount of blood moving in cardiac and skeletal systems, decrease blood flow to skin, decrease urinary activity
53
Parasympathetic nervous system
"craniosacral division"; "rest and digest"; begins in cervical and lower lumbar spines and sends fibers to the same organs as sympathetic; pupil constriction; decrease heart rate, decrease breathing, increase digestion
54
nerves
can carry both sensory and motor information.
55
epineurium
outer layer of nerves; consists of dense connective tissue that surrounds and protects the nerve
56
fascicles
bundles of fibers inside a nerve
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perineurium
sheath that surrounds each fascicle
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endoneurium
thin layer of loose connective tissue that surrounds each
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plexi
combined spinal nerves; 4 major plexi in human body
60
4 major plexi in human body
cervical, brachial, lumbar, sacral
61
neurons vs neuroglia
neurons: cells that transmit messages and store information
neuroglia: nervous system cells that support cells (include astrocytes, oligodendrocytes, ependymal cells, microglia)
62
parts of a neuron
dendrites, cell body, axon hillock, axon, axon terminal
63
neurotransmitters
messages sent from presynaptic neuron to post-synaptic neuron; excitatory or inhibitory
64
There is a net ____ charge on the inside of the neuron.
negative
65
Why does the neuron have a net charge?
difference in membrane permeability to different electrolytes; slightly permeable to sodium and potassium
66
Cell membranes of neurons are slightly more permeable to _______
potassium
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Negatively charge ions like phosphates, sulfates, ATP, RNA and proteins can/cannot leave the cell
cannot
68
What is the ionic gradient?
When the inside of the cell becomes more negative due to more potassium moved out of the cell; some positive ions attracted back into the cell
69
What helps maintain both sodium and potassium gradients and how?
sodium-potassium pump uses ATP to move sodium out of the cell and potassium into the cell
70
What is resting membrane potential
-70 millivolts (mV)
71
What happens when a presynaptic neuron sends an excitatory neurotransmitter?
sodium gates on the post-synaptic neuron opens; cell is depolarized
72
What is the threshold level of a neuron?
-55mV; more sodium gates will open and depolarization will happen at a rapid rate
72
At resting potential, the cell is _____. When the sodium gates open, the cell is less ______?
polarized; less negative (more positive)
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Once neuron reaches threshold, what happens?
it will continue to depolarize until +30mV
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What is the rapid change in -55 mV to +30 mV?
action potential
75
Once the threshold is reached, the neuron stops going through depolarization. True/False?
false; once the threshold is reached, the neuron goes through cycle of depolarization to resting membrane potential
76
Where are action potentials generated?
axon hillock
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What happens during depolarization?
voltage gated sodium channels open; large influx of sodium ions into the cell causes more sodium channels to open
voltage gated potassium channels open; some potassium diffuses out of the cell
78
Depolarization is a _____ feedback system. Describe what happens when excitatory message reaches post-synaptic neuron.
positive; sodium gates open & sodium enters neuron cell. Cell is DEPOLARIZING as it is becoming less negative (less polar).
79
Why is there a net negative charge inside of the neuron's cell membrane?
phosphates, sulfates, ATP, RNA, & proteins are negatively charged ions inside of the neuron
80
Describe action potential, depolarization, & reaching threshold starting from resting membrane potential for a cell
depolarization is when resting membrane potential goes from -70mV to -55mV, and once it hits -55mV it will continue to depolarize all the way to +30mV. The change is called action potential!
81
Opening of sodium gates can trigger _________
depolarization and action potential if cell reaches -55mV ---> then eventually +30mV
82
Explain repolarization - in other words, how does the cell return to resting membrane potential after being depolarized?
Repolarization starts: After the peak of the action potential, the sodium channels close, and potassium (K⁺) channels open. Potassium ions (K⁺), which are more concentrated inside the cell, now move out of the neuron, driven by both their concentration gradient and the electrical gradient (charge)
Return to negative charge: As K⁺ ions leave the neuron, the inside of the cell becomes more negative again. This outward flow of K⁺ causes the membrane potential to move back toward its resting negative value, a process called repolarization.
Voltage (mV) gated sodium channels close once action potential (+30mV reached), while voltage gated potassium channels continue to diffuse potassium out of the cell, leading to net negative charge inside cell, eventually reaching -70mV resting membrane potential. Potassium ions are driven out of cell by concentration gradient and electrical gradient
83
What is the function of the sodium-potassium pump, which utilizes ATP?
The sodium-potassium pump (Na⁺/K⁺ pump), which actively transports Na⁺ out of the cell and K⁺ back in, helps restore and maintain the resting membrane potential (-70 mV). This pump ensures that Na⁺ and K⁺ are redistributed properly for future action potentials.
84
epinephrine and norepinephrine, adrenaline and noradrenaline are all secreted by ______ neurons
sympathetic
85
What simulates the effects of dopamine? (answer: a specific drug)
methamphetamine, cocaine
86
what neurotransmitter stimulates muscle contraction?
acetylcholine (cholinergic)
87
GABA
gamma amino butyric acid; inhibitory neurotransmitter; plays role in anxiety, pain, sleep and promotes calming effect, decreasing blood pressure
88
Serotonin
inhibitory; plays role in memory, learning, depression
89
How does reuptake of serotonin work?
after signal has been transmitted, it is taken back into the presynaptic neuron through serotonin reuptake transporters.
90
How do SSRIs work?
selective serotonin reuptake inhibitors work by preventing the reuptake of serotonin, resulting in more available serotonin in the synapse
91
Reflexes and how do they work?
involuntary responses to stimuli that occur unconsciously
stimuli to sensory neurons in muscle causes it to stretch > synapses with motor neurons in brain
92
Example of a reflex: Babinski Reflex
this reflex is produced when there's lack of inhibition by the CNS; in newborns, since myelination is incomplete as brain is not fully developed, inhibition is missing.
93
Neurons in higher nervous system INHIBIT reflexes. What happens when inhibition is removed?
Reflex will be exaggerated, which indicate central nervous system damage. Example of Babinski reflex, infants are Babinski positive
94
How do we detect damage to the PNS? What is happening?
Diminished or absent reflexes; there is damage somewhere between spinal cord and muscle
95
Myelin
lipid sheath that wraps around the axon; lipid substance made up of Schwann cells
96
White matter vs gray matter
white matter has myelin and therefore travels faster, gray matter does not have myelin and travels slower compared to white matter
97
Nodes of Ranvier? What do you find there?
gaps in the myelin sheath; voltage gated sodium channels
98
where is the axon potential generated
axon hillock
99
Describe the movement of action potential through a neuron that has a myelinated axon
The action potential moves down the axon and reaches a node of Ranvier, where a large amount of sodium channels open, sodium ions enter the axon, and cause the axon to depolarize, which gives the action potential a boost
100
Action potential jumping from node to node is called ________.
saltatory conduction
101
Saltatory conduction does/doesn't exist in unmyelinated axons (give example)
doesn't; the action potential travels continuously down the axon, instead of skipping between nodes
102
What is it called when myelin is lost? What happens?
demyelination; neurons can't transmit as much information, can cause loss of sensation, motor functions, and reflexes
103
Skeletal muscles' function:
move bones and generate heat
104
Cells in skeletal muscle are called ______ and contain a reddish pigment called _______.
myocytes; myoglobin
105
Functional units in skeletal and cardiac muscle tissue are called _____
sarcomeres
106
Cardiomyocytes have ____ amount of nucleus/nuclei
1
107
What are intercalated discs?
special cell junction; helps cells contract together and move blood through the heart
108
Smooth muscle contain ____ nucleus and _____ striations
1; no striations
109
Where is smooth muscle found? (list 4)
digestive, reproductive, urinary systems, blood vessels
110
What are examples of skeletal muscles?
fascia (length of the muscle), tendons
111
Afferent nerves
carry sensory impulses or stimulus toward the central nervous system.
112
Efferent nerves
carry motor stimulus away from the central nervous system.
113
Spatial summation
114
temporal summation
115
Axon terminal
sends stimulus to another neuron
116
cell body
contains organelles where metabolic activities of the cell occur
117
axon
carries signals away from the cell body and transmits to another neuron through axon terminal
118
dendrites
receives nerve signals from another neuron
119
autonomic/involuntary processes include:
digestion, breathing, heart contractions
120
Another word for voluntary (processes) is:
somatic process
121
Salivation is part of which kind of nervous system? what is this part of nervous system responsible for?
rest-and-digest responses/activities which is under the control of the parasympathetic division of autonomic nervous system.
122
What is the difference between muscle strain and muscle sprain?
strain is injury to the muscle or tendon, sprain is tear or stretching of the ligament
123
what is muscular dystrophy?
progressive reduction in muscle mass that can affect voluntary & involuntary muscles
124
how is ATP involved in muscle relaxation and contraction?
ATP is needed for both relaxation and contraction of muscle.
contraction: ATP is hydrolyzed to facilitate the cross bridge formation which leads to contraction.
relaxation: the binding of another ATP molecule will then facilitate muscle relaxation
125
prostate gland
secretes fluid that contributes to sperm motility & viability
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