Consists of :1.Brain 2.Spinal Cord

a. Protected by glial cells & meningesb. High metabolic rate that requires

nutrients and oxygenc. Must be isolated from compounds in

blood that could interfere with functioning

3 layers of specialized membranes surrounding brain & spinal cord

A) Dura Mater: 2 fibrous layers; outermost; very tough, holds brain in place Contains fluid, blood vessels & some adipose

tissue Provides stability & shock absorption to CNS tissue

B) Arachnoid: middle; small amt lymphatic fluid (reduces friction) & CSF Cerebrospinal Fluid (CSF): absorbs shock &

transports gases, nutrients, chemical messengers, & wastes

C) Pia Mater: innermost; extensive circulatory supply due to high rate of metabolism

Meningitis: inflammation of meninges due to bacterial or viral infection

Sends sensory info to brain & motor info from brain to rest of body Spinal Reflexes: automatic responses controlled

solely w/in spinal cord (i.e. withdraw from pain) Central Canal: narrow central opening filled

w/ CSF Gray Matter: inside; contains neuron cell

bodies & neuroglia…forms an H or butterfly shape

White Matter: outside; contains axons of neurons

Dorsal Roots: carry sensory info to spinal cord

Ventral Roots: carry motor info to muscles and glands

31 segments designated by letter and number:

C1 C8 Cervical VertebraeT1 T12 Thoracic VertebraeL1 L5Lumbar VertebraeS1 S5 Saccral VertebraeCO1 Coccygeal near tailbone

Each segment has a dorsal root gangliaa. Dorsal Root- axons of sensory neuronb. Ventral Root- Axons of CNS motor neuron

All spinal nerves are mixed because they contain sensory and motor neurons

“Rostral” = anterior (towards nose) “Caudal” = posterior (towards tail)

4 Major Parts: 1) Cerebrum: divided into 2 hemispheres w/ 5 lobes

Corpus Callosum: thick bundles of nerves connecting 2 hemis. 2) Cerebellum: inferior to cerebrum

Sensory perception, motor output, motor control (heart, blood pressure, breathing, etc.)

3) Brain Stem: btwn cerebrum & foramen magnum Attention, arousal, consciousness Composed of midbrain, pons, and medulla oblongata

4) Diencephalon: inner core; btwn cerebral hemisph. sensory processing, emotion, hormone production

1. Cerebrum-

2. Diencephalon (Hypothalamus to pituitary gland)-

3. Midbrain

4. Pons 5. Medulla Oblongata

6. Cerebellum

83% brain volume Gyri: thick folds Sulci: shallow grooves

that separate gyri Central Sulcus: divides

frontal/parietal lobes Lateral Sulcus:

distinguishes temporal lobe

Fissures: deep grooves throughout Longitudinal Fissure:

divides R/L hemispheres

1) Frontal: voluntary (skeletal) muscle control, motivation, memory

2) Parietal: sensory reception, taste, some vision

3) Temporal: hearing, smell, learning, memory, emotional behavior

4) Occipital: main visual center 5) Insula: deep inside; understanding

speech, taste, sensory integration

Most of cerebral volume Transmits signals throughout cerebrum &

to lower brain centers Contains axons of neurons

Neural Integration Contains neuron cell bodies & neuroglia 1) Cerebral Cortex: thin layer covering

hemispheres Stellate Cells: receive sensory input & process

local info Pyramidal Cells: transmit signals to other parts

CNS 2) Basal Nuclei: deep masses w/in white

matter Receive & send signals to midbrain & motor

cortex 3) Limbic System: includes amygdala &

hippocampus Important for emotion & memory