Chapter 15 Brain and Cranial Nerves

adult brain weight

1.35-1.4 kg (~3 pounds) 1200 cc volume

cranial meninges

3 connective tissue layers - separates soft tissue

meninges

CT membrane, provides protection, support, partition

outer superficial region of gray matter, covers most of adult brain

cerebral cortex

discrete internal clusters of gray matter

cerebral nuclei

what structures protect and isolate the brain

cranium, meninges, CSF, blood-brain barrier

cerebral spinal fluid

cushioning fluid

insula lobe

deep to the lateral sulcus

developing brain growth

disproportionate, different rates depending on different regions

how is neural tissue organized

gray and white matter

motor neuron and interneuron cell bodies, unmyelinated axons

gray matter

where does the brain sit in the head?

in the top half of head, top of eye brows

why are gyrus and sulcus important?

increase surface area in the brain so there are enough neurons to have a properly functioning brain

2 flexures that bend brain toward brainstem

mid brain and cervical flexure

blood-brain barrier

prevents entry of harmful materials from blood stream

bony cranium

provides rigid support and CT membranes

issues in different growth rates

restricted by skull, so growing structure is limited

where does brain development been?

rostral end of neural tube

Lessencephaly

smooth brain, neuron migration disorder - severely mentally retarded, seizures, short lifespan

what determines intelligence?

the number of active synapses and wiring in brain

rostral/anterior

toward the nose

caudal/posterior

toward the tail

open areas in the brain

ventricles

deep to outer gray matter

white matter

myelinated axons

white matter