Section 8 Vocabulary

• Basilic: royal• Cephalic: head• Serratus: saw• Protract: to draw forth• Retract: draw back• Condyle: knuckle• Collateral: side by

side• Quadratus: squared• Hamate: hooked

• Lunate: moon-shaped• Synovial: with egg• Bursa: purse• Prostate: to stand

before• Ectopic: out of place• Fimbrial: fringe• Gracilis: slender• Malleolus: hammer• Meniscus: crescent

The Central Nervous System

Chapter 12

I. Protection of the CNS

A. Bone- skull & vertebraeB. Meninges- connective tissue

1. Dura mater-outer layer, thick, DWF2. Arachnoid- middle, delicate3. Pia mater- innermost, thin, attached to

brain, vascular

I. Protection of the CNS

• C. Cerebrospinal Fluid (CSF)- clear, watery fluid that fills all cavities within and around nervous system; choroid plexus (capillaries) separate CSF from blood by ependymal cells.

I. Protection of the CNS

C. CSF Functions1. Cushions brain and spinal cord

from mechanical injury2. dissolves and transports

substances filtered from blood3. Medium for exchange of

nutrients and waste products between blood and brain

I. Protection of the CNS

D. Blood- prevents sudden or extreme fluctuations in CSF; provides fluid for CSF

II. Spinal Cord

• Extends from foramen magnum to L1

• Fills the vertebral foramina along with meninges, CSF, adipose, and blood vessels

• Conducts impulses to and from brain

• Serves as integrator or reflex center (ex. Papillary, patellar)

Spinal Cord Protection

By the vertebral column, meninges, cerebrospinal fluid, and vertebral ligaments.

II. Spinal Cord

A. Ascending tracts- sensory impulses up the SC to the brain; named for where it terminates in the brain1. lateral spinothalamic tract2. anterior “ “3. fasciculu gracilis and cuneatus4. spinocerebellar tracts

II. Spinal Cord

B. Descending tracts- from the brain down the SC; motor impulses; names for where it originates in the brain1. lateral corticospinal tracts2. anterior “ “3. lateral reticulospinal tracts4. medial “ “5. rubrospinal tracts

III. Brain

Consists of 100 billion neurons & 900 billion glia; ~ 3 lbs; cell division of neurons only occurs in prenatal development???

III. Brain

A. Brain Stem1. Medulla Oblongata- lower part of brain

stem; attaches to spinal cord; contains reticular formation of gray and white matterA. vital centers- regulate heartbeat,

respiration, bp, diameter of blood vessels

B. Reflex centers- coughing, sneezing, swallowing, vomiting

III. Brain

A. Brain Stem2. Pons- middle part

of brain stem; connects cerebellum to brain stem; relay between upper and lower CNS; affects rate of respiration

III. BrainA. Brain Stem

3. Midbrain (mesencephalon)- above pons; upper part of brain stem; also contains reticular formationA. cerebral peduncles- nerve tracts to and from the cerebral hemispheresB. red nucleus- relay station; coordinates impulses between cerebellum and cerebrum; muscle controlC. corpora quadrigemina- pupil constriction reflex; relay station for auditory impulses

III. Brain

B. Cerebellum- “little brain”; 2nd largest part of brain; below cerebrum; gray matter outside and white matter (arbor vitae) inside

FUNCTIONS:1. Coordinate skel muscle

movt; maintain equil/ balance

2. receive info about touch, vision, sound

3. maintain posture with sk. muscles

III. Brain

C. Diencephalon1. Thalamus- middle below cerebrum;

gray matter; relay station to carry impulses to cerebrum

2. FUNCTIONS-A. pain, temp, touch sensesB. emotions of un/pleasantnessC. Mechanism for arousalD. plays a part in mechanisms that

produce complex reflex movements

III. Brain

C. Diencephalon2. Hypothalamus- beneath the

thalamus; holds pituitary gland and mamillary bodies; links nervous and endocrine systems.

III. Brain

C. Diencephalon2. Hypothalamus- FUNCTIONS-

A. autonomic center- olfactory neurons for smell (in mam bodies)

B. relay station between cerebrum and lower brain centers

C. produce hormones to maintain water balance (ADH), thirst center

D. produce “releasing hormones”- growth hormone, oxytocin, GnRH

E. maintains wake state

C. Diencephalon2. Hypothalamus- FUNCTIONS-

F. Regulates appetite and satiety centerG. Regulates body temperature- blood

vessels/ sweat glandsH. Pleasure center- eating, drinking, sex

III. BrainC. Diencephalon

3. Pineal body- pine cone shape, endocrine gland, aka epiphysis, secretes hormone melatonin for biological clock, daylight vs. sleep

III. Brain

• C. Diencephalon– 4. Optic chiasma- right and left

optic nerves cross here

III. Brain

• D. CerebrumLargest part of the brain; 2

wrinkled hemispheres; axons of neurons may interconnect with same hemisphere, other hemisphere, or other parts of CNS

D. Cerebrum1. Structures

A. Corpus callosum- tissue joins 2 hemispheres; white, curved; surrounds ventricles

B. Cerebral nuclei- gray matter; aka basal ganglia; regulates voluntary motor functions such as walking

D. Cerebrum1. Structures

C. Cerebral Cortex- surface; outer 2-4 mm is gray matter with white matter below

1. white shallow grooves or fissures- sulci (singular- sulcus)

2. wrinkled peaks or convolutions – gyri (singular- gyrus)

D. Lateral Ventricle- cavity in each hemisphere; fluid filled; generally enlarges with age

D. Cerebrum2. Main Lobes or Regions

A. Frontal- personality, voluntary motor controlB. Parietal- processing sensationC. Occipital- visual cortexD. Temporal- auditory cortex, emotions, memoriesE. Insula / Island of Reil- link between emotion and

cognition

III. Brain

D. Cerebrum3. Functions of Cerebral Cortex

A. Sensory- touch, pressure, temperature, body position (proprioception), vision, hearing, taste, smell; sensory speech (Wernicke’s area)

B. Motor- voluntary movements

D. Cerebrum3. Functions of Cerebral Cortex

C. Integrative- all functions between sensation and motor/ effection

1. consciousness- impulses from ret formation; awareness; REM; meditation

2. language- speak, write, hear, see words; motor speech (Broca’s area)

3. emotions-limbic system- anger, fear, sexual feelings, pleasure, sorrow

4. memory- short-term and long-term; use hippocampus

IV. Right vs Left Hemisphere

Right Left creative speechmusical languageartistic hand

movtspatial perception

calculation

Cerebrum

II. Spinal Cord

Extends from foramen magnum to L1; fills the vertebral foramina along with meninges, CSF, adipose, and blood vessels; conducts impulses to and from brain; serves as integrator or reflex center (ex. Papillary, patellar)

II. Spinal Cord

A. Ascending tracts- sensory impulses up the SC to the brain; named for where it terminates in the brain1. lateral spinothalamic tract2. anterior “ “3. fasciculu gracilis and cuneatus4. spinocerebellar tracts

II. Spinal Cord

B. Descending tracts- from the brain down the SC; motor impulses; names for where it originates in the brain1. lateral corticospinal tracts2. anterior “ “3. lateral reticulospinal tracts4. medial “ “5. rubrospinal tracts

V. Electroencephalogram (EEG)

Map out brain waves or impulse activity; measured by frequency (Hz) and amplitude (V)A. Alpha- relaxedB. Beta- busyC. Theta- drowsyD. Delta- deep sleep

V. Electroencephalogram (EEG)

V. Electroencephalogram (EEG)