Central nervous system

which two deep grooves run the length of the spinal cord?

• posterior median sulcus

• anterior median fissure

what is the outer region of the spinal cord?

white matter

What is white matter of the spinal cord composed of?

axons 

what do the axons in white matter do?

allow communication between spinal cord and brain

what is the gray matter of the spinal cord shaped as?

the letter H

gray commissure

contains the central canal

Dorsal horns of gray matter

consist of interneurons

Ventral and lateral horns of gray matter

contain cell bodies of motor neurons

What is divided according to somatic and visceral regions?

gray matter

the four somatic and visceral regions

• somatic sensory

• visceral sensory

• visceral motor

• somatic motor

The central nervous system is protected from injury by what 4 things?

• Bones (skull/vertebrae)

• meninges

• cerebrospinal fluid

• blood brain barrier

Dura mater in Meninges

single layer surrounding spinal cord

the strongest layer surrounding the spinal cord

dura mater

Arachnoid mater in Meninges

lies deep to the dura mater

Pia mater in Meninges

innermost layer

What is made of a delicate layer of connective tissue in Meninges?

pia mater

Cerebrospinal fluid

fills the hollow cavities of the brain and spinal cord

what does the cerebrospinal fluid provide for the spinal cord and brain?

a liquid cushion

Blood brain barrier

prevents most blood borne toxins from entering brain

What does the blood brain barrier contain that doesn’t allow fluids to pass through easily?

impermeable capillaries + astrocytes

not an absolute barrier

blood brain barrier

What can pass through the blood brain barrier?

oxygen, CO2, lipids

which 3 other substances can pass through the blood brain barrier?

• alcohol

• nicotine

• anesthetics

Four regions of the brain

• brain stem

• cerebellum

• diencephalon

• cerebral hemispheres

what 3 things does the brain stem include?

• midbrain

• pons

• medulla oblongata

Medulla Oblongata

visceral centers include life support functions

The medulla oblongata helps regulate which 3 things?

• heart

• blood vessels

• respiration

What structure begins in the medulla oblongata and is involved in maintaining consciousness and alertness?

reticular formation

What is the function of the Reticular Activating System (RAS)?

maintain consciousness and alertness

Where does the reticular activating system function?

in sleep and arousal from sleep

Malfunction of the RAS is associated with which disorder?

narcolepsy

The pons

contain motor tracts coming from cerebral cortex

The largest nuclei

corpora quadrigemina

How is the corpora quadrigemina divided?

into the superior and inferior colliculi

Superior colliculi in corpora quadrigemina

nuclei that act in visual reflexes

inferior colliculi in corpora quadrigemina

nuclei that act in reflexive response to sound