PSIO 241 CH 5

including the brain and spinal cord

including the peripheral nerves connecting target cells/organs to the CNS

the nerve network of the digestive tract

carries sensory information from skin, skeletal muscles

carries sensory information from smooth muscle, glands and organs – aka autonomic

• somatic

• visceral

shares information about an organ into the system

• somatic nervous system

• autonomic nervous system

motor neurons that supply skeletal muscles

motor neurons that innervate smooth muscle, cardiac muscle, and glands (involuntary)

• sympathetic

• parasympathetic

fight or flight response

resting/digesting

• physical support neurons in proper spatial (3d space) relationships

• induce formation of blood-brain barrier

• take up excess K+ to help maintain proper brain ECF ion concentration and normal neural excitability

• form myelin sheaths in CNS

  - get attacked in MS

play a role in defense of brain as phagocytic scavengers

contribute to formation of cerebrospinal fluid

_ covers CNS

tough outer coat

blood vessels

filled with cerebral spinal fluid (blood)

on brain surface

_ limits access of blood-borne material into brain tissue

cushioning fluid that surrounds brain and spinal chord (CNS)

- is produced inside ventricles in the brain and flows out into the subarachnoid space

• Serves as a shock-absorber to prevent brain from hitting skull.

• Exchange of materials between neural cells and interstitial fluid surrounding brain.

• Constant production and flow out of CNS and into venous system; carries wastes out of CNS.

• Brain depends on a constant blood supply.

• Unlike most tissues the brain cannot produce ATP without O2.

• Brain normally uses only glucose but does not store any.

Under resting conditions the brain uses 20% of the O2 and 50% of the glucose consumed in the body

the lower the part of the brain the _

• makes up about 80% of total brain weight.

• Largest unit in the brain

deep groove that separates cerebrum into right and left cerebral hemispheres

• each hemisphere divided into lobes

thick fold

shallow grove

• Outer surface of each hemisphere composed of gray matter and is the complex integrating area of the brain

• caps core of white matter

• organized into 6 well defined layers

• primarily neuronal cell bodies, dendrites, and glial cells

• integration of neural input and ignition of neural output

• contains all axons, surrounded in myelin

• consists of bundles of nerve fibers that interconnect brain areas

houses the visual cortex

houses the auditory cortex

responsible for reception and perception of somatosensory input - somatic

responsible for voluntary motor movement

Site for processing and perception of both somesthetic (sensation from surface) and proprioceptive (awareness of position) input

• Located in each parietal lobe as the post-central gyrus.

from the surface of the body (touch, pressure, heat, cold, and pain)

awareness of body position

• The somatosensory cortex receives input from the _ side of the body.

• Regions of the somatosensory cortex receives input from a specific areas of the body.

the distribution map

• the size of each body part in the homunculus is proportional to the level of sensory perception associated each body part

• Located in the frontal lobe as the pre-central gyrus.

• Controls voluntary movement produced by skeletal muscles

• Sends information to theventral portions of the spinal cord to activate motor neurons

_ on each side of the brain primarily controls muscles on the opposite side of the body

Body parts needing fine control of movement occupy _ area of motor homunculus