Central Nervous System(CNS)

BSCI201 final exam review

what are the 4 protective structure of the brain

1) cranium

2)meninges

3) Cerebrospinal fluid(CSF)

4) Blood brain barrier

cranium

bony helment composed of 8 cranial bones

meninges of brain- what are the three layers and description

3 connective membrane surrounded by the bone

1) Dura mater- outermost menix

• outer perisoteal layer- lines internal surface of cranium

• inner meningeal layer- SUBdural space separate from arachnoid mater

2) Arachnoid mater- middle menix sepeated from pia mater by SUBARACHNOID space

• web like extensions from arachnoid mater to subarachnoid space

3) pia mater- innermost menix cling to surface of the brain

cerebrospinal fluid- location and actions

located in ventricle and subarachnoid space

• act as liquid cushion

• filtered from blood

• provide buoyancy to brain

• provide nutrient

• remoce metabolic waste

Blood brain barrier

selective chemical barrier that prevent harmful, toxic substance in blood from crossing to neuron in brain

what are the three ventricle

lateral ventricle, 3rd ventricle, 4th ventricle

lateral ventricle

2 lateral ventricle connected by septum pellucidium

connect to 3rd ventricle by channel called interventricuar forearm

3rd ventricle

located in diencephalon and connect to 4th ventricle via cereal aqueduct

4th ventricle

located in brain stem

hydrocephaly

excessive buildup of CSF in ventricles

• cause increase rate of CSF production or blockage in CSF drainage

• increase pressure and damage neuron in adult because suture are synarthrotic joint and resist pressure

what are the 4 major regions of an adult brain

cerebrum, diencephalon, brainstem, and cerebellum

cerebrum

• superior region of the brain

• gyri- elevated ridges on suface

• sulci- shallow grove

• fissure- deeper groves

what are the two cerebral hemisphere held together by?

medially held together by corpus callosum.

longitudinal fissure

separate the left and right cerebral hemisphere

What are the three sucli in the cerebral hemisphere

1) central sulcus

2) lateral sulcus

3) parieto-occipital sulcus

central sulcus

seperate the frontal and parietal lobe

• precentral gyrus- motor control area

• postcentral gyrus-somatosensory area

precentral gyrus

motor control area

postcentral gyrus

somatosensory area

lateral sulcus

separate temporal from parietal lobe and frontal

parieto-occipital sulucs

separate parietal lobe from the occipital lobe

what are the three region of each cerebral hemisphere

cerebral cortex, cerebral white mater, basal nuclei

cerebral cortex and the three functional areas

highly convulated and composed of gray matter= cell bodies, dentries

conscious mind

• motor area

• sensory area

• association area

motor area

control voluntary movement

• consist of primary motor cortex, premotor cortex, brocas area, front eye field

• all in frontal lobe

sensory area

for conscious awareness of sensation

• primary somatosensory cortex, primary visual cortex, primary auditory cortex, primary olfactory cortex, primary gustatory cortex

association areas

integrate and interpet sensory input from sensory area

• each primary sensory area has its own association area

what are the three motor areas in the cerebral cortex

primary motor cortex, premotor cortex, croca area, frontal eye field

primary motor cortex

control voluntary movment of skeletal muscle

• located in precentral gyrus of frontal lobe

• pyramidal cell located

• bundle of pyramidal cell called pyramidal or corticospinal tract cross over in medualla obongata

• decussation of the pyramid

decussation of the pyramid

voluntary movement on left side of body are controlled by the right cerebral hemisphere

voluntary movement on the right side of body controlled by left cerebral hemisphere

premotor cortex

control learned motor skill such as typing, driving, playing instrument

broca area

skeletal movement involved in speech production

'“motor speech area”

present in frontal lobe in the left cebrebral hemisphere

arcuate fasciculus

connect the broca area to wernkle area located in temprotal lobe

frontal eye field

control voluntary movement of skeletal muscle that postion eye( extrinsic eye muscle)

wernicke area

udernstanding speech and using correct word to express our thoughts

brocas aphasia

partial or complete loss of ability to speak but lanuage comprehension is intact

wernicke aphasia

loss of lanuage comprehnsion and incoherent speechto question refered to as word salad

what are the three types of tract based on direction in teh cerebral white mater

commisural tract

projection tract

association tract

commisural tract

connect corresponding areas in teh two cerebral hemisphere

projection tract

connect cerebrum to lower brain area and spinal cord

two types:

• descending projection- send information to cerebral cortex

• ascending projection- send senesory information to cerebral cortex

asssociation tract

connect areas within the same cerebral cortex

example: arcuate fasciculus

what are three major major basal nuclei

caudate nucleus, putamen, globus pallidus

putamen + globus pallidus=

lentiform nucleus

all three nuclei: putamen + globus pallidus + caudate nucleus

corpus striatum

what does the substantia nigra in the basal nuclei is involved in…

inhibiting and stopping unnecessary voluntary skeletal muscle movement

diencephalon and the three parts

consist of the third ventricle

• thalamus

• hypothalamus

• epithalamus

thalamus and what is it referred to as?

relay station for sensory input to cerebral cortex

contains the the ventricle

• referred to as gateway to the cerebral cortex

• visual relay center in talamus is lateral geniculate nucleus(LGN)

• auditory relay center is the medial geniculate nucleus(MGN)

hypthalamus

located below the thalamus

• emotional response

• activities of the autonomic nervous system

• core body temperature

• food intake- satiety center

• water intake- thirst center

• endocrine function- produce 9 hormone

epitalamus

form root of third ventricle

contain pineal gland

endocrine gland that secrete hormone, melatonin

brain stem and its three areas

cell bodies of 10 out of 12 cranial nerve

control autonomic function requried for survival

• mid brain

• pons

• medulla obogata

midbrain

• contain cerebral aquaduct which connect 3rd and 4th ventricle

• 2 superior nuclei= superior colliculi act as visual reflex center

• 2 inferior nuclei= inferior colliculi which as act as auditory reflex center

• contain two pigment:

• red nuclei regulate limb flextion

• substantial nigra contain dopamine release neuron0 modulate activites of the basal nuclei- degeneration of dopaminergic neuron from subtantia nigra to basal nuclei causes parkinson disease

substantial nigra

substantial nigra contain dopamine release neuron0 modulate activites of the basal nuclei- degeneration of dopaminergic neuron from subtantia nigra to basal nuclei causes parkinson disease

pons

located between midbrain and medulla oblongata connect motor cortex and cerebellum

contain respitory center

medulla oblongata

most inferior region that blend with spinal cord

decussation of pyramid occur on ventricle surface

contain autonomic reflex center, cardiovascular control center, respitory center, emetic center

cerebellum seperates

transverse fissure separate the cerebellum and cerebrum

separated into two cerebellar hemisphere which held together medially by vermis

vermis

holds the two parts of the cerebellum togther

three lobes of the cerebellum

• anterior lobe

• posterior lobe

• flocculonodular lobe

the cross section of the cerebellum

outer gray cortex

inner white matter with arbor vitae- pattern resembling branching tree

function of the cerebellum

process information from cerebral motor area, visual and equilibrium input, smooth and coordinated skilled voluntary skeletal movement

what is the function of the cerebellum affected by

alcohol intoxication

the spinel cord

• extend from medulla obligate to second lumbar vertebre

• conus medullaris- ends in a cone shaped structure

• filum terminale- fibrous extention of pia mater from conus medullaris which anchor the spinal cord vertically on coccyx

• denticulate ligament- what anchors the spinal cord laterally and formed by pia mater

what is the spinal cord composed of?

• outer white mater and inner gray mater

conus medullaris

end in a cone shaped structure

filum terminale

fibrous extension of pia mater from conus medullaris

anchors the spinal cord verically to coccyx

denticulate ligament

anchors spinal cord and formed by pia mater

what are the three protective structure of the spinal cord

1) vertebral column

2) meninges

3)cerebrospinal fluid(CSF)

vertebral column

bony protective structrue of spinal cord connected by amphiarthrotic intervertebral disc( flexaible)

meninges of spinal cord

dura mater- outer most meninx and is singe layered called spinal dural sheath

• epindural space- space between spinal dural sheth and internal surface

• contain vein and fat

arachnoid mater- in middle menix- space between arachnoid and pia mater called subarachnoid space

pia mater- innermost menix which forms two extentions- dentiualte ligament and the filum terminale

CSF of spinal cord

in the central canal in the core of the spinal cord and inside subarachnoid space

CSF act as liquid cushion

provide nutrient and remove metabolic waste

what are the three types of spina bifida

occulta

mengocele

myeomeningocele

occulta

least serious and most common

usually discovered in only x ray or scan

most people never aware

meningocele

2nd most serious

meningocele cover spinal cord pass back through the opening in the spine and form cyst like swelling

myelomeningocele

if spinal cord enclosed in cyst

most serious type of spinal bifida

white mater of the spinal cord and its three tracts

ascending tract- sensory input

descending tract- motor output

transverse tract- commissural fiber

inner gray matter in the spinal cord and the three types

dorsal( posterior) horns

ventral(anterior) horns

lateral horns

dorsal( posterior) horn of inner gray mater if spinal cord

house of cell bodies of afferent fiber carrying sensory information from sensory receptor

ventral( anterior) horns of inner gray mater of spine

house mainly cell bodies of somatic neurons and there axons innervate skeletal muscle

amount of gray mater at level of spinal cord reflect extent of innervation of skeletal muscle

• ventral horn largest in cervical and lumbar enlargements that innervate upper limbs and lower limbs

lateral horms of inner gray mater of spinal cord

present only in thoracic and upper lumbar segment of spinal cord with cell bodies of sympathetic neurons whoes axon innervate visceral organ

what are the two types of spinal enlargment

cervical enlargment and lumbar enlargment

cervical enlargment

nerve that innervate and control voluntary motor function and sensation in the upper limbs

lumbar enlargements

nerves that innervate and control voluntary motor function and sensation in lower limbs

quadriplegia

transection of spinal cord above the cervical enlargment

flaccid paralysis of all four limbs

paraplegia

transection of the spinal cord below teh cervical enlargment but above lumbar

flaccid paralysis of the two lower limbs