nervous system

sensory function

detect internal/external stimuli

integrative function

process information to make appropriate response

motor function

activates effectors (muscle contraction/gland secretion)

parts of central nervous system

brain & spinal cord

peripheral nervous system

all parts outside cns

sensory (afferent) division

convey impulses to CNS

motor (efferent) division

carry impulses from cns

somatic nervous system

voluntary control of skeletal muscle

autonomic nervous system

involuntary effect (smooth & cardiac muscles, glands) automatic

spinal nerves

carry impulses to and from the spinal cord

cranial nerves

carry impulses to and from the brain

astrocyte

largest, most numerous neuroglia

astrocyte

maintains blood-brain barrier and maintain appropriate chemical environment for generation of nerve impulses

oligodendrocytes

form and maintain myelin sheath around CNS axons, and myelinates several axons

microglia

phagocytes, derived from macrophages, remove cellular debris

microglia

phagocytize microbes and damaged nervous tissue

ependymal cells

line the ventricles of the brain and central canal of the spinal cord, also produce cerebrospinal fluid

schwann cells

form myelin sheath around PNS axons and myelinates a single axon

satellite cells

surround the cell bodies of PNS neurons and provide structural support

satellite cells

regulate exchange of materials between neuronal cell bodies and interstitial fluid

neurons

transmit impulses from one part of the body to another

nissl bodies

granular structures found in the neuron's cell body and dendrites that consist of rough endoplasmic reticulum studded with ribosomes

neurofibrils

found within nerve cells that form a network in the cell body and extend into processes, consisting of aggregations of smaller neurofilaments resembling microtubules.

dendrites

receive and collect information from other neurons at junctions called synapses

axons

electrical impulses from the neuron travel away to be received by other neurons

axon hillock

long thin cylindrical/cone-like region of a neuron where the axon originates, playing a crucial role in initiating action potentials

axon terminals

the specialized endings of an axon that transmit signals to other cells, such as neurons, muscles, or glands

synaptic end bulb

small, swelling structures at the very end of an axon terminal that contain neurotransmitters within synaptic vesicles

myelin sheath

a fatty, whitish layer that covers and wraps around the axons of nerve cells, allowing electrical impulses to travel quickly and efficiently

nuclei

cell bodies in the CNS

tracts

nerve fibers in the CNS

ganglia

cell bodies in the PNS / group of neurons outside the CNS

white matter

component of the CNS that is a collection of myelinated fibers

grey matter

component of CNS that is a collection of unmyelinated fibers and cell bodies

synaptic cleft

gap between two neurons where they communicate

saltatory conduction

the rapid "jumping" of nerve impulses along a myelinated axon from one uninsulated gap, or node of Ranvier, to the next

nodes of ranvier

gap between the myelin sheath formed by schwann cells

interneuron

connect sensory and motor neurons

multipolar

structural classification of neurons that has several dendrites + 1 axon

bipolar

structural classification of neurons that has 1 axon + 1 dendrite

structural classification of neurons that is a single process (fused dendrites + 1 axon)

resting membrane potential

a nerve impulse; plasma membrane of resting inactive neuron is polarized, fewer positive ions inside the neurons (K+), more positive ions outside the nuron (Na+)

resting state

a process where there are negative chargers inside the membrane, and build up of positive charges outside

depolarizing phase

process where build up of positive charges form inside the membrane and it becomes depolarized

cerebrum

most superior and largest part of the cerebral hemisphere

gyrus

elevated ridges of tissue

sulcus

shallow grooves

fissures

deep grooves

cerebral cortex

superficial,outermost layer of the cerebrum, made of gray matter,

white matter

nerve tissue in CNS that contains bundles of myelinated axons

basal nuclei

islands of gray matter in white matter

thalamus, hypothalamus, epithalamus

3 diancephalons/interbrains

primary somatosensory area

posterior to the central sulcus, parietal lobe

primary motor area

anterior to the central sulcus, frontal lobe

visual area

posterior part of occipital lobe (function/area)

auditory area

temporal lobe bordering the lateral sulcus (function/area)

olfactory area

deep temporal lobe (function/area)

broca’s area

motor speech area and base of precentral gyrus

anterior association area

for higher intellectual reasoning (area/function)

posterior association area

for recognition of patterns/faces (area/function)

thalamus

encloses the 3rd ventricle

hypothalamus

‘under the thalamus’. regulates body temp, water balance, metabolism

mamillary bodies

reflex centers involved in olfaction

epithalamus

forms the roof of the 3rd ventricle

choroid plexus

forms the cerebrospinal fluid

brain stem

control breathing and blood pressure

cerebral aqueduct, cerebral peduncles, corpora quadrigemina

3 structures of midbrain

cerebral aqueduct

connects 3rd to 4th ventricle

cerebral peduncles

two bulging fiber tracts

corpora quadrigemina

four rounded protrusions located dorsally, involved in vision and hearing

pons

rounded structure below the midbrain

medulla oblongata

most inferior part of the brainstem that merges into the spinal cord

medulla oblongata

control heart rate, bp, breathing, swallowing, vomiting

cerebellum

controls balance and coordinates body movement

gray matter

outer cortex of cerebellum

white matter

inner region of cerebellum

cerebral hemispheres

the two symmetrical halves of the brain, the left and right, and acts in intellectual/emotional processing

hypothalamus

chief integration center of autonomic nervous system

limbic system

includes cerebral and diancephalon structures, and mediates emotional response and memory processing

midbrain

visual and auditory reflex centers

pons

relays information from cerebrum to cerebellum

reticular formation

maintain cerebral cortical alertness

dura mater

meninges; outer layer “tough mother”

arachnoid mater

meninges; ‘spider’, looks like cobweb

pia mater

meninges; “gentle mother”, innermost, delicate, clings tightly to the surface of the brain

subarachnoid space

space between the arachnoid mater and the pia mater

arachnoid granulations

absorbs cerebrospinal fluid (CSF) into the venous system

choroid plexus

cerebrospinal fluid is formed by

lumbar puncture

procedure to obtain CSF for testing

17 inches (42cm)

how long is the spinal cord?

31

how many pairs are the spinal nerves?

ventral horn

send axons out the ventral root of the cord

central canal

a fluid-filled tunnel in the center of the spinal cord

endoneurium

surrounds each nerve fiber

perineurium

surrounds group of fibers forming fascicles

epimysium

binds all fascicles together, forms the coldlike nerve

12

how many pairs of cranial nerves?