Lecture 4 : CNS

Question 1

Deficiency of Electrolytes:

Answer 1

:slow impulse conduction (dizzy, confused)

Question 2

EEG “electroencephalogram”

Answer 2

: a way to record brain activity (amount of action potentials of the neurons
- a diagnostic tool to detect brain death, sleep apnea, epilepsy

Question 3

Brain Waves :

Answer 3

• Beta waves: 14-30 Hz/cycle when you are awake/alert
• Alpha wave: 8-13 Hz/cycle when you are calm, eyes closed
• Theta waves: 4-7 Hz/cycle common in children
• Delta waves: 1-4 Hz deep sleep or anesthesia

Brain death = NO waves

Question 4

In what Nervous System can axons regenerate?

Answer 4

In the PNS (peripheral nervous system) axons can regenerate
why…
because Schwann Cells are mitotic and they will secrete growth factor which stimulate axonal growth

Question 5

Coverings of the CNS
(CNS = [brain] + spinal cord)

Answer 5

Coverings of the Brain
1.Skull
2. Meninges
- Dura mater (right under the skull )
> subdural space (contains CSF; cerebrospinal fluid)
- Arachnoid mater (middle layer, web like)
- Pia mater (lies above of brain, many blood vessels

Question 6

Meningitis

Answer 6

inflammation of meninges due to either bacterial infection OR viral infection
- applies a lot of pressure on the brain, can be deadly
- obtain a lumbar puncture + cerebrospinal fluid to detect the bacteria/virus, vaccine needed

Question 7

Coverings of the CNS
(CNS = brain + [spinal cord])

Answer 7

Coverings of the spinal cord (medulla oblongata to L1)
1. Vertebrae
2. Epidural Space: contains adipose tissue of fat
~Epidural injection of anesthesia (during birth,
3. Meninges
- Dura mater
- Arachnoid mater
>subarchnoid mater (contains CSF; lumbar puncture to remove CSF)
- Pia mater

Question 8

Gray matter vs white matter

Answer 8

Gray matter:
- Short unmyelinated neurons/cell body

White matter:
- Myelin axons
- fatty tissue (white color)

Question 9

Ventricles of the Brain:

Answer 9

2 Lateral Ventricle: left and right
3rd Ventricle
4th Ventricle:

• ALL filled with CSF

Question 10

Cerebrospinal Fluid “CSF” :

Answer 10

filled with electrolytes (Na+, K+, water
- lined by ependymal cells

Function:
- protective fluid-filled cushion
- nurtrify neurons by the choroid plexus: specialized capillaries produce CSF (500 mL)

Question 11

CSF in Infants:

Answer 11

have enlarged ventricles (results in a large head):hydrocephalus
- due to an obstruction of CSF by a tumor, blood clot, meningitis, trauma
- occurs in utero due too much pressure causing brain damage

Question 12

Weight of brain:

Answer 12

3-3.5 pounds