biology lesson8.3

The Brain – Lesson 8.3

Three Major Parts of the Brain

1. Cerebrum2. Cerebellum3. Brain stem

Brain stem

1. CerebrumoDivided into two hemispheresoRight – creative, big pictureoLeft – logical, mathematical

oRight side of brain controls the left side of the body

oLeft side of the brain controls the right side of the body

Longitudinal fissuredivides two halves of cerebrum

oTwo sides connected by the corpus callosum a nerve bundle

oCerebrum consist of both gray matter and white matter

oGray matter on the outside called cerebral cortex

o and white matter on the insideoPage 171 in text

Note: Brain is convoluted or folded to get more in a tight space.

So well designed equivalent all phone cable of world into a thimble – WOW!

Four division or pairs of lobes of the cerebrum

Frontal lobes (right and left)Parietal lobes (right and left)Occipital lobes (right and left)Temporal lobe (right and left)

Frontal lobe: location of personality, judgment

and self control

Motor area of frontal lobe – part of frontal lobe in the rear portion controls the voluntary movement

of the skeletal muscles.

Parietal lobes: analyzes the senses

Specific areas in lobe for specificareas of the body.

Occipital lobe: sense of vision

Temporal lobes: sense of hearing, smell and taste, also long term memory

Three Major Parts of the Brain1. Cerebrum

2. Cerebellumsecond largest brain region;

means little brain

right and left hemispheres

white and gray matter

tightly packed, convoluted

2. Cerebellum

Function:To take over the skeletal muscle control from the cerebrum so it is free to think about biology!

Cerebrum slowly gives up as practice (ex. Basketball layup, bike riding)

Three Major Parts of the Brain1. Cerebrum 2. Cerebellum

3. Brain stem

located between cerebrum and spinal cord

3 parts to brain stem:

a. medulla oblongata • lowest section of brain stem

•regulates breathing, blood pressure, and other vital functions

•crossover occurs in medulla oblongate

3 parts to brain stem:a. medulla oblongata

b. Pons links cerebrum and

cerebellum assist medulla in regulating

breathing coordinates eye movement

3 parts to brain stem:a. medulla oblongata b. Pons

c. Midbrainlocated above the ponscoordinates eye movements and

pupil dilationcontains reticular formation

Reticular Formation:

On/off switch of cerebrum

Switches cerebral cortex on you wake and are conscious/off you go to sleep, adjust level of alertness

Damage = coma

Reticular formation nuclei are located throughout the brain stem.

Limbic System

a number of complex brain structures

around the brain stem.

Limbic system includes:

thalamus – switch board – sends pulses to right place in brainhypothalamus – control unit for autonomic and endocrine systems (adrenaline)