nervous system Flashcards
1
Q
CNS (parts, protection, function)
A
central nervous system
parts-brain and spinal cord
protection-encased by bone
function-processes info and acts as the integrating and command center- interprets sensory info and sends out instructions based on past experiences and current conditions
2
Q
tracts
A
bundles of nerve fibers
3
Q
PNS (parts, protection, function)
A
peripheral nervous system
parts-anything on the perimeter of the CNS- 12 pairs of cranial nerves and 31 pairs of spinal nerves
protection- bundled together by connective tissue
function- afferent and efferent
4
Q
afferent
A
sensory
- transmits action potentials that travel to the CNS
- keeps the brain informed
5
Q
somatic messages
A
from the skin, skeletal muscles, or joints
6
Q
visceral messages
A
from internal organs
7
Q
efferent (branches?)
A
- transmits action potentials that travel away from CNS
- carries out the choice from the brain to body
- 2 branches- somatic and autonomic
8
Q
somatic
A
- voluntary movements
- CNS to skeletal muscles
9
Q
autonomic (branches?)
A
- involuntary movements
- CNS to smooth or cardiac muscle and glands
- regulates automatic events
- 2 branches- sympathetic and parasympathetic
10
Q
sympathetic nervous system
A
- most active during physical activity
- “fight or flight”
11
Q
parasympathetic nervous system
A
- regulates resting functions
- “rest and digest”
12
Q
nervous tissue
A
-made of neuroglia and neurons
13
Q
neuroglia (function)
A
- “nerve glue”
- support and protect neurons
- make up more than half of the brain’s weight
- mitosis (responsible for brain tumors)
14
Q
nerves (functions)
A
- receive stimuli, conduct action potentials, and transmit signals to other neurons
- amitotic
15
Q
resting neurons
A
- polarized (higher concentration of Na+ outside and higher concentration of K+ inside the cell)
- -70 mV charge
16
Q
Na+/ K+ pump
A
-maintain the distribution of Na+ and K+
17
Q
how are nuerons fired
A
- dendrites stimulated
- Na+ gates open to allow Na+ to flood in (depolarization- more positive)
- causes graded potential cause its getting stronger
- graded potential reaches axon hillock at -55mV which causes an action potential (nerve impulse)
- Na+ gates ate opened causing a change from -55 to 30mV
- action potential reaches the terminal and triggers the Ca+ gates to cause the terminal to release neurotransmitters into the synaps through exocytosis
- repolarization is K+ flooding the cell to regain the -70 mV charge
18
Q
axon hillock
A
-where the axon joins the cell body
19
Q
axon terminals
A
- synaptic terminals, synaptic knobs, synaptic boutons.
- play role in communication with another cell
20
Q
dendrites
A
- extend out from the cell body
- intercellular communication.
- receives info
21
Q
synapse
A
- specialized site where the neuron communicates with another cell
- synaptic cleft separates the 2 cells
22
Q
presynaptic cell
A
-sends message and includes axon terminal, typically a neuron
23
Q
three types of neurons
A
- bipolar nuerons
- unipolar nuerons
- multipolar nuerons
24
Q
bipolar nuerons
A
- 2 extensions from cell body
- special sense organs
- small
- optic and auditory sensory
- least common
25
unipolar nuerons
- 1 extension from cell body
- dendrites and axon are continuous
- cell body lays off to the side
- sensory neurons
- long, end at synapses in CNS
26
multipolar nuerons
- 2 or more dendrites
- most common in CNS
- motor and association neurons
27
interneurons
- located between sensory and motor neurons
- most common
- most located within brain and spinal cord
- distribute sensory info and coordinate motor activity
28
resting membrane potential
- -70 in neurons
29
myelin
-protects and electrically insulates axons from one another
30
nodes of ranvier
- gaps between each myelin sheath
| - increases speed of nerve impulse conduction
31
saltatory conduction
-impulses jump from node to node due to myelin
32
how does communication between PNS and CNS occur
- afferent nerves enter the dorsal horn
- message goes up the spinal cord (sensory tracts) to the brain
- brain makes a choice
- efferent nerve tract carries command down the spinal cord
- exits out the ventral horn
33
reflex arc
- rapid, predictable and involuntary response to stimuli
- receptor recieves stimuli
- message goes up the afferent pathway to dorsal horn
- message transferred to ventral horn (help of association neuron)
- travels down efferent pathway and causes a reaction
- afferent message travels to brain but after action
34
cerebrum
- largest part of brain
- surfaces are folded and covered by a neural cortex called the cerebral cortex.
- forms elevated ridges (gyri )
- separated by shallow depressions called sulci or by deeper grooves called fissures
- conscious thoughts and all intellecutal functions originate in the cerebral hemispheres
- processing somatic sensory and motor information
- sends info to oppositie side of body
35
longitudinal fussure
-deep groove down the middle of the cerebral hemispheres
36
corpus callosum
-connection of nerve fibers between the hemispheres
37
frontal lobe
- output center
- functions-problem solving- personality- voluntary motor control
- broca's area
38
broca's area
speaking ability (left hemisphere)
39
parietal lobe
- input lobe
- -functions- recesses and evaluates sensory info, but not smell, hearing, or vision- understand speech- ability to use words
- integrate and interpret sensations
- storage of memories of sensory experiences
40
occipital lobe
- input lobe
- visual area
- functions- recognize objects visually- combine images
41
temporal lobe
- input lobe
- functions- receives and evaluates inpot for smell and hearing
- wernicke's area
42
wernicke's area
- understand oral/ written words
| - in the temporal lobe
43
cerebellum
- second larges part of brain
- attached to brain stem
- functions- controls coordination of muscles- regulates posture and balance
44
arbor vitae
-white matter of the cerebellum
45
diencephalon
- grey matter
| - found between brainstem and cerebrum
46
thalamus
- gateway to the cerebrum
| - relays incoming info to the cerbral cortex and outgoing motor impulses to their destinations
47
hypothalamus
-regulates autonomic functions (sleep, hunger, thirst, etc)
48
brain stem
-pons and medulla oblongata
49
pons
- "bridge"
| - nerve fiber tracts that connect the brain
50
medulla oblongata
- controls bital functions (brathing, heart beat, blood pressure, etc)
- found under the pons and ends at the foramen magnum
51
foramen magnum
- where spinal cord ends
| - injury here could cause quadriple gia
52
spinal cord
- extends from foramen magnum to end of first lumbar vertebrae
- take messages to and from brain
- end of spinal cord is the conus medullaris
53
conus medullaris
- names due to cone shape
| - end of spinal cord
54
meninges
- protects the brain and spinal cord
- dura mater
- arachnoid
- pia matter
55
dura mater
- "tougher mother"
- thickest and toughest
- epidural space- space superficial to the dura mater and deep to the vertebra and skull bones
56
arachnoid mater
- looks like spider web
- subarachnoid space- space between arachnoid mater and pia mater
- blood vessels and cerebral spinal fluid can be located here
57
pia mater
- "gentle mother"
| - lies directly on top of the brain and spinal cord
58
menengitis
- inflammation of the meninges
- a virus or bacteria can cause this
- could be life threatening (spread to CNS)
59
ependymal cells
-lines hollow fluid filled spaces
60
Astrocytes
-regulate the external chemical environment of neurons by removing excess ions
61
Oligodendrocytes
cells that coat axons in the central nervous system (CNS) with their cell membrane, forming a specialized membrane differentiation called myelin
62
Satellite cells
- small cells that surround neurons in sensory, sympathetic, and parasympathetic ganglia
- regulate the external chemical environment
