Nervoussy System Pt2

2 Parts of the CNS

Brain and Spinal Cord

Four major divisions of the brain

Cerebrum (2 cerebral hemispheres)
Diencephalon
Brain Stem
Cerebellum

Surface anatomy of the cerebrum (cerebral hemispheres)

The surface is covered w gyri
Gyri - (gyrus, bumps)
Sulci - (sulcus, creases)
Longitudinal tissue - divides the brain into L and R cerebral hemispheres
Lobes - frontal, parietal, temporal, occipital

Function of the Corpus Callosum

Connects Left and Right hemispheres to allow communication

Location and function of the Primary Motor Cortex

Located on the precentral gyrus on the frontal lobe
Voluntary movements of the body
Anterior to central sulcus

Location and function of the Primary Somatosensory Cortex

Located on the postcentral gyrus on the parietal lobe
Processes body sensations
Posterior to central sulcus

Location of the Diencephalon

Deep structure in the center

Cerebellum parts and functions

Controls skeletal muscle activity
Balance
Equilibrium
Results in smooth, coordinated body movement

CSF production and functions

The Choroid Pllexus
Network of capillaries inside ventricles, produce CSF by filtering blood
Watery cushion

Spinal tap -- location and diagnostic value

L1, L2, changes forms solid to cauda equina
Stringy and not solid, nerves
Below the spinal cord is not solid and if someone bends over the needle can break the meninges, then get into the sac, between the nerves instead of hitting a solid spot

Hydrocephalus

CSF build up causes pressure on the brain
Pushes skull bone up in children creating larger head
Most adults just get large build up, some fluid can be removed

Brain injuries - concussion, contusion, hemorrhage

Concussion- no permanent damage

Contusion- bleeding (hematoma), tissue destruction, if in brain stem often coma because of damage to RAS

Hemorrhage- intracranial (bleeding causes compression) and cerebral edema (swelling causes compression)

Cerebrovascular Accident (Stroke) - ischemic & hemorrhagic - similarities & differences

Ischemic Stroke (block) lack 02
Hemorrhagic stroke (bleed) lack 02
Brain tissue dies
If occurring on left cerebral hemisphere, APHASIAS are common

Motor Phasia (Brocas area) difficulty speaking
Sensory Aphasia (Weinickes area) difficulty with understanding written or spoken language

Transient Ischemic Attack (TIA)

“Mini-stroke”
Temporary brain ischemia
Usualy 5-50 mins
24 hrs for symptoms to clear
Numbness, impaired speech, temporary paralysis

Thalamus function

Thalamus - relay station for sensory impulses

Hypothalamus functions

Hypothalamus - autonomic nervous system center (body temp, water balance)
- emotions and drives (thirst, appetite)
-secretes melatonin

epithalamus location and functions

Pineal Gland - regulates seasonal and daily activities (day-night)
-affected by light and dark cycles
-secretes melatonin

Meringues

protection of CNS and covers CSF

1st merengue

DURA MATER (thickest) - outer covering of brain and spinal cord

2nd merengue

ARACHNOID MATER (weblike) threadlike extensions in subarachnoid space (CSF)
Attached to pia mater

3rd merengue

PIA MATER (innermost) - clings to surface of brain
Fibrous, thin, and delicate

brainstem system (parts and functions)

Brainstem-reticular activating system (RAS)

-reticular formation along the length of the brainstem
-consciousness and wake/sleep cycles
Damage = coma

PONS (brains parts and functions)

controls breathing

MIDBRAIN (brain parts and functions)

cerebral peduncles ( ascending sensory and descending motor impulses)

CORPORA QUADRIGEMINA (brain parts and functions)

(4 bumps) vision and hearing

MEDULLA OBLONGATA

controls heart rate, breathing, and blood pressure