Chapter 7/8: The Cerebrum and Brodmann's Map

what is Brodmann’s map?

• divides brain into 52 areas based on gross anatomy and cellular structure

• areas called Brodmann areas (BA)

BA: Broca’s area

BA 44 and 45

BA: primary auditory cortex

BA 41 and 42

BA: Wernicke’s area

BA 22

BA: primary visual cortex

BA 17

BA: primary motor cortex

BA 4

BA: primary somatosensory cortex

BA 3, 1, 2

frontal lobe functions

reasoning, planning, motor movement, personality, speech production

parietal lobe functions

sensory perception and interpretation, body awareness, spatial processing

occipital lobe function

vision

temporal lobe functions

memory, receptive language, hearing

Identify the frontal lobe

4

Identify the parietal lobe

3

Identify the temporal lobe

1

Identify the occipital lobe

2

right hemisphere function

prosody, emotional interpretation, body language, attention, visuospatial

left hemisphere function

reading, writing, speech, language, comprehension, reasoning

corpus callosum function

band of fibers that connects the right and left hemispheres together

intrahemispheric connections

numerous connections within the cerebral hemispheres

• ex. arcuate fasiculus

Blood brain barrier (BBB) functions

• protects against foreign invaders

• protects against hormones/neurotransmitters in rest of body

• maintains constant environment for brain

BBB problems

can violate the BBB

• hypertension

• developmental problems

• microwaves

• radiation

• infection

• trauma

• stroke

• inflammation

• pressure

meninges

3-layered membrane that surrounds the delicate brain and provides protection

3 layers of the meninges

• dura mater (most outer layer)

• arachnoid mater (middle layer)

• pia mater (inner layer)

cerebral arteries function

provides blood to the brain via the carotid arteries and vertebral arteries; feed the circle of willis

circle of willis

feeds the brain oxygenated blood through the ACA, MCA, PCA

the brain consumes ___% of body’s oxygen

20%

ACA

supplies medial and anterior frontal+parietal lobes

MCA

supplies lateral frontal, temporal, and parietal lobes

• lanaguage regions

• most common cause of stroke

PCA

supplies occipital and inferior temporal lobes

cerebral cortex features

• gyri

• sulci

• fissures (deep sulci)

  • longitudinal

  • central

  • lateral

cerebral cortex layer 1

glia and neurons

cerebral cortex layer 2

small pyramidal cells

cerebral cortex layer 3

large pyramidal cells

cerebral cortex layer 4

nonpyramidal cells

layer 5

betz cells

layer 6

various cells

what area is this?

primary motor cortex in the precentral gyrus

what area is this?

primary sensory cortex in the postcentral gyrus

what area is this?

primary visual cortex in the occipital lobe

what area is this?

primary auditory cortex in heschl’s gyrus in the superior temporal lobe

what area is this?

Broca’s area in the left frontal lobe

what area is this?

Wernicke’s area in the posterior part of the temporal lobe

what is a homunculus?

a distorted model mapping body parts to brain motor/sensory cortex areas

• illustrates sensory perception