NERVOUS SYSTEM

somatic efferent

innervating somatic structures like skeletal muscles and skin; voluntary

visceral efferent

this is the autonomic nervous system; innervates involuntary structures

neurons

the active conducting element; transmits impulses

neuroglia

the supporting elements; do not conduct impulses

astrocyte

blood brain barrier

oligodendrocyte

the one who makes myelin sheaths in CNS

microglia

phagocyte cells

schwann cells

the one who makes myelin sheaths in PNS

ependymal cells

produce and circulate CSF; nourishing the brain

neuron

basic unit of nervous system which conducts electrical impulses from one part of the body to another

dendrites

transmit impulses toward the cell body

axons

conducting impulses away from cell body

synapse

point of connection between neurons

main neurotransmitters

epinephrine (adrenalin); norepinephrine (nor adrenaline); acetylcholine

myelin sheath

insulating material covering axons in CNS/PNS

saltatory conduction of impulses

the electrical impulse jumps from node to node in jyelin sheath instead of traveling continuouslyalong the nerve fiber

nodes of ranvier

gaps in myelin sheath where actiom potentials develop

cns

includes the brain and spinal cord; divided grossly into gray & white matter

gray matter

so called because of its appearance and preponderance of nerve cell bodies & true dendrites

white matter

composed chiefly of myelinated nerve fibers

brain

most complex & largest mass of nervous tissue in the body and contains literally billions of nerve cells

prosencephalon

forebrain

mesencephalon

midbrain

rhombencephalon

hindbrain

telencephalon

cerebrum

diencephalon

thalamus, hypothalamus, epithalamus, subthalamua

mesencephalon

corpora quadrigemina (tectum)

mesencephalon

cerebral peduncles

mesencephalon

cerebral aqueduct of sylvius (iter)

metencephalon

cerebellum, pons

medulla oblongata

myelencephalon

cerebrum

discriminatory identification; integration of sensory information (memory & reasoning)

corpus callosum

hemispheres are connected in the midline by

longitudinal fissure

runs from posterior to anterior aspects almost completely dividing into 2 hemispheres

lateral sylvian fissure

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lateral sylvian fissure

between frontal and parietal lobes above and temporal lobe below

central sulcus

rolandic fissure

central sulcus

between frontal and parietal lobes

transverse fissure

between cefebellum and cerebrum

parieto-occipital fissure

between occipital and parietal lobes

calcarine fissure

found in occipital lobe

calcarine area

visual center

frontal lobe

center for motor functions and personality

frontal lobe

includes cortex lying anterior to central sulcus of rolando and above lateral sulcus Sylvius

parietal lobe

center for sensory functions

temporal lobe

center for hearing and olfaction

occipital lobe

visual center

insula

island of reil

insula

exposed when lips of lateral Sylvian fissure are separated

primary motor area/pre-central gyrus

controls voluntary movements in opposite side of body

primary motor area/pre-central gyrus

brodmann’s area 4

pre-motor area

exerts a controlling influence over the motor area, ensuring an orderly series of movement

pre-frontal area

concerned with foresight, good judgement, abstract thinking

primary sensory/somesthetic area or post-central gyrus

sensations pain, temp, pressure and touch, position and movement sensation from opposite side of body are received and interpreted here

primary sensory/somesthetic area or post-central gyrus

brodmann’s area 3,1,2

motor speech area

broca’s area (broddman’s area 45,44)

sensory speech area

wernicke’s area (brodmann’s area 22)

auditory or hearing area (transverse gyri of heschl)

center for hearing

auditory or hearing area (transverse gyri of heschl)

brodmann’s area 41 & 42

visual area

brodmann’s area 17

olfactory or smell area

brodmann’s area 34

taste area

brodmann’s area 43

basal ganglia

masses of gray matter embedded in white matter of cerebral hemispheres

basal ganglia

include caudate nucleus (medial portion) and putamen and globus pallidus called lentiform nucleus

basal ganglia

constitute corpus striatum

basal ganglia

play role in control of motor function and injury manifest as uncontrolled aimless movements

thalamus

relay center for sensory impulses (except olfactory) from peripheral receptors to cerebral cortex

hypothalamus

involved in regulation of body temperature, feeding activities, biorhythm, emotion… etc.

cerebellum

oval in shape with central constriction and lateral expanded portions

vermis (latin of worm)

the constricted portion of cerebellum

anterior lobe

regulation of muscle tone

posterior lobe

coordination of voluntary motor activity

flocculonodular lobe

concerned with function of equilibrium, posture and balance

midbrain

concerned with motor coordinations

midbrain

connects forebrain and hindbrain

pons

bridge-like structure, consisting almost entirely of white matter linking various parts of brain

hemispheres

the lateral expanded portions of cerebellum

pons

lies anterior to cerebellum and between midbrain and medulla

medulla oblongata

has number of vital regulatory and reflex centers, including those controlling the circulatory system, breathing, swallong, vomiting, coughing, sneezing

medulla oblongata

lies ventral to cerebellum

cerebrospinal fluid

colorless, with a compositiin similar to lymph

cerebrospinal fluid

circulating within ventricles, central canal of spinal cord and also within subarachnoid space

lateral ventricle

found inside cerebral hemispheres; interventricular foramen (foramen of monroe)

third ventricle

between 2 thalamic nuclei, continuous with cerebral aqueduct of Sylvius

fourth ventricle

communicates w subarachnoid space through foramen of luschka and magendie

meninges

protects brain and spinal cord

dura mater

strong protective sheath over entire brain and spinal cord

arachnoid mater

forms loose sac around CNS; between dura and pia

pia mater

surface of the brain

spinal dord

extends from level of foramen magnum to lower border of 1st lumbar vertebra in adult & level of L3 vertebra in children

cervical enlargement

nerve supply of upper extremities arises from

lumbar enlargement

nerve supply of lower extremities arises from

optic

II

olfactory

II

oculomotor

III

trochlear

IV

trigeminal

V

abducens

VI