Transcript The CNS * Brain - Mr. Haan`s Science

THE CNS
– BRAIN
CHAPTER 8-1
A. CEREBRAL HEMISPHERES
1. Superior part of the brain
2. Gyri – ridges of the brain
3. Sulci – shallow grooves
and divide brain into
lobes
4. Lobes
a. Frontal
b. Parietal
c. Temporal
d. Occipital
5. Cerebral cortex
a. Gray matter
1) Outside hemispheres
2) Controls movements,
balance, and senses
b. Each hemisphere controls
opposite side of the body
c. Functions
1) Communication
2) Sensations
3) Remembering
4) Understanding
5) Initiate voluntary movements
d. White matter
1) Communication
2) Deeper in brain
B. THALAMUS, HYPOTHALAMUS, EPITHALAMUS
1. Thalamus
a. Information is sorted and edited
b. Most impulses are sent to the thalamus
c. Sensory impulses (not smell)
2. Hypothalamus
a. Below the thalamus (hypo – below)
b. Helps mostly with homeostasis
1) Cardiac functions – heart beat, blood pressure
2) Smooth muscles
3) Emotional response – pleasure, fear, anger
4) Body temp – controls sweating or shivering
5) Regulates food – hungry and satisfied
6) Water balance and thirst
7) Sleep and wake cycles
8) Endocrine system – hormones
3. Epithalamus – helps with sleep/wake cycles
C. BRAIN STEM
1. Superior to inferior – midbrain, pons, medulla oblongata
2. Midbrain
a. Pain suppression
b. Fight or flight response
3. Pons
a. Rounded bulge
b. Completes path from spinal cord to brain
4. Medulla oblongata
http://www.youtube.com/watch?v=VF5PyeMG8Lo
a. Cardiac center – force and rate of heart contractions
b. Respiratory center – rate and depth of breathing
c. Others
1) Vomiting and swallowing
2) Hiccups
3) Coughing and sneezing
D. CEREBELLUM
1. Under the occipital lobes
2. Provide timing for muscle
contractions
3. Smooth coordinated
movements
4. Agility
5. Works in subconscious
6. White matter in the center
7. How it works
a. Motor areas notify cerebellum to move voluntary muscles
b. At the same time cerebellum gets info about muscle tension,
tendons, joint position from visual and equilibrium pathways
1) Info evaluates body position and momentum
2) Determines where it is and where it is going
c. Calculates best way to coordinate force, direction, & extent of
muscle contraction
1) Prevents overshoot
2) Maintains posture
3) Ensures smooth coordinated movements
d. Info sent to motor nerves of brain and spinal cord
8. Constantly taking in info
9. Stops working = clumsy, unsure movements, loss of muscle
tone
10. Predicts sequences of events: adjusts for mult. forces on a
limb involving several joints
11. Word association and puzzle solving
E. PROTECTION
1. Cerebrospinal fluid
a. CSF
b. Provides liquid cushion for brain and spinal cord
c. Secreted from choroid plexuses
d. Maintains stable ionic concentration
2. Blood-brain barrier
a. Bound by tight junctions
b. Least permeable capillaries in the body
c. Injury in brain could break this down
d. Prevents some drugs to enter the brain