Nervous System Flashcards
nervous system
the system that coordinates voluntary and involuntary actions + transmits signals between different parts of the body
Two types of cateogories of the NS
structural and functional
structural organization of the NS
made up of central NS + peripheral NS
what is the cenral nervous system
brain and spinal cord
what is the peripheral NS
cranial nerves, spinal nerves, ganglia
functional categories of the nervous system
collecting information: receptors detect changes in the internal and external environment
processing information: info is collected and determines the appropriate response
responding to the info: initiates nerve impulses to effectors to react to changes in the body’s environment
what does the nervous system collect
receptors detect changes in the internal and external environment
what are the parts of the sensory NS
somatic sensory and the visceral sensory
what does the somatic sensory doe
receives sensory info from touch, smell, etc
what does visceral sensory info do
receives info from viscera
what are the parts of the motor nervous system
somatic motor (voluntary)
autonomic motor (involuntary)
neurons
- nerve cells
- electrically excitable cells that initiate, transmit, and recieve nerve impulses
what are bundles of nerve cells
nerves
neurons are to nerves like
muscle fibers are to muscle
what is the role of neurons
to conduct nerve impulses from one part of the body to another
special characteristics of neurons
high metabolic rate (uses a lot of oxygen)
extreme longevity
nonmitotic
structure of neurons
has the cell body, axon, and dendrites
cell body
contains the nucleus, nucleolus, mitochondria, etc.
dendrites
short processes that branch from the cell body and receive nerve impulses from adjacent nerves
axon
transmits info away from the cell body
axon hillock
collects all info to transmit down to the axon
anaxonic
a neuron that doesnt have an axon
axon colloaterals
side branches of the main axon
telodendria
fine terminal extensions at the end of the axon and its collaterals
synaptic knob
expanded regions of telodendria that store neurotransmitters
what are the two classification types of a neuron
strucutural and function
structural classification of a neuron
unipolar
bipolar
multipolar
unipolar nueron
single short process that branches like a T
- most sesnory neurons
bipolar
two processes, one dendrite, one axon
multipolar
multiple nerve cells processes extend from cell body, one axon, many dendrites
functional classifcation of neurons
sensory
motor
interneuron
sesnory neruon
afferent
- transmits impulses from sensory receptors to the CNS
- mainly unipolar som are bipolar
motor neurons
efferent
- transmit impulses from CNS to muscles or glands (multipolar)
interneurons
facilitate communication between sensory and motor neurons
- multipolar
when stimulus if felt where can the impulses go
to the spinal cord interneurons and motor neurons or to the brain for processing
glial cells
nonexecutive cells that support and protect neurons
what are glial cells also called
neuroglia
can glial cells multiply
yes they are capable of mitosis
how does the size of glial cells compare to the neurons
they are smaller
what are the types of glial cells
oligodendrocytes, ependymal cells, astrocyte, microglial cells
myelination
process of wrapping the axon w myelin sheath
what is the function of myelination
affect the ability of neurons to conduct nerve impulses, serves as insulation
nerves
cable like bundle of parallel axons
what are the connective tissues layers of a nerve
endoneurium
perineurium
epineurium
endoneurium
around each axon
perineurium
around individual fasicles
epineurium
around the entire nerve
where are cell bodies mainly found
the spinal cord or the brain
it is also the gray matter
directional terms from the brain
rostural
caudal
parts of the brain
cerebrum
diencephalon
brainstem
cerebellum
what helps to increase the surface area
gyri and sulci
gyri
humps/mountains of the cortex
sulcui
valleys of the cortex
gray matter
houses the motor neurons + interneruon cell bodies, dendrites, telodendria, unmyelinated axons
cerebral nuclei
the discrete internal clusters of gray matter
white matter
made up of unmyelinated axons
what features support and protect the brain
- bony cranium
- meninges
- cerebrospinal fluid
- blood brain barrier
bony cranium
the skull
- frontal, two parietal, two temporal, occipital, sphenoid, ethmoid bones
meninges
the protective connective tissue of the brain
- dura mater
- arachnoid layer
- pia mater
dura mater
most superficial layer
composed of the periosteal layer and meningial layer
arachnoid layer
middle layer
the spiderweb like layer
pia mater
lines the surface of the cortex
what are the functions of the proctive structures
- to separate sofe tissue of the brain
- enclose and protect blood vessels
- contain and circulate cerebrospinal fluid
cerebrospinal fluid
clear colorless liquid that circulates in the ventricles and subarachnoid space
where is CSF found
in the brain ventricles
brain ventricles
cavities iin the brain that contain cerebral spinal fluid
what are the four ventricles
2 lateral ventricles, 3rd in the diencephalon, 4th in between the pons and cerebellum
functions of the CSF
bouyancy: brain floats in CSF
protection: provides liquid cushion
environmental stability: CSF transports nutrients + removes waster from brain
blood brain barrier
regulates what substances can enter ISF of brain
what occurs in the cerebellum
conscious though, thought processes, intellectual functions
what are the lobes of the cerebellum
frontal lobe
parietal lobe
temporal lobe
occipital lobe
insula
frontal lobe
thinking, function of talking, information processing, executive function
parietall= love
recieving of somatosensory info
somatosensory cortex and association area
temporal love
hearing, smell association
occipital lobe
visual stimuli and associationi
insula
gustatory cortex (taste)
