chapter 12 CNS Flashcards
exam 2
Functions of the CNS
integration/ interpretation of incoming sensory info
sending out a motor response to effector organs
4 regions of brain
cerebral hemispheres
diencephalon
brain stem
cerebellum
gray matter
contains dendrites, cell bodies, and axon terminals
function: all synapses are found in gray matter - allows neurons to communicate
unmyelinated
white matter
contains myelinated axons , mostly in fiber tracts
passes msgs between diff areas of gray matter
allows generatiin of APs and msg relay
in the brain (gray/white)
gray matter is peripheral, white matter is central
outer layer of gray matter - cerebral cortex
in the brain stem (gray/white)
scattered gray matter found within white matter
in spinal cord (gray/white)
gray matter in a butterfly pattern surrounded by white matter
central canal - found at center of gray matter
Ventricles of the CNS
hollow chambers found in the brain that are filled with CSF and lined with ependymal cells
2 lateral ventricles
third ventricle
fourth ventricle
2 lateral ventricles
one in each cerebral hemispheres
look like ram horns
intraventricular foramen : connects lateral to 3rd
third ventricle
found in dienchephalon
cerebral aqueduct connects 3rd to 4th
travels inferiorly
4th ventricle
found in hindbrain
continuous w central canal of spinal cord
cerebral hemishpheres
form the most superior portion of the brain, make up most of the brain by mass
3 regions: cerebral cortex, white matter and basal nuclei
gyri - ridges of cerebral hemispheres
sulci - shallow grooves
fissure separate larger regions of the brain
Longitudinal fissure
separates the left and right hemispheres
transverse cerebral fissure
seperates the cerebral hemiosh[ers from the cerebellum
Lobes of the brain
Central sulcus: seperates frontal lobe and parietal lobe
Parieto-occipital sulcus: separates the occipital lobe from the parietal lobe
lateral sulcus - separates temporal lobe from the frontal and parietal lobes
cerebral cortex
portion of the brain where the conscious mind is found
functions: self-awareness, sensation, communication, memory, understanding/learning, initiation of voluntary movement
3 functional areas of cortex
motor areas: control voluntary movement
sensory areas: conscious awareness of sensations
association areas: integrate diverse information
associate something that has happened w something that is happening
Hemispheres are contralateral
right hemi is concerned info from left side of the body and vice versa
Motor areas of the cerebral cortex
Primary motor cortex
pre motor cortex
Broca’s area
frontal eye field
Primary motor cortex
allows for conscious control of skilled/precise voluntary movements
if u cant move issue w the primary motor cortex
Pyramidal cells
large neurons found in the primary motor cortex
axons of these neurons travel to the spinal cord in corticospinal tracts
synapse with and stimulate motor neurons
Pre motor cortex
- Helps plan movements by selecting and sequencing basic motor movements into more complex tasks
- communicates plan to primary motor cortex - controls voluntary actions that depend on sensory feedback
- if a movement is sloppy issue w pre motor cortex
Brocas area
specialized motor speech area that directs muscles involved in speech production
becomes active as we prepare to speak
usually found on left side of brain
Brocas Aphasia
neurons in Brocas area destroyed/damaged so a person knows what they want to say but are physically incapable of speech
Frontal eye field
controls voluntary movement of the eyes
Sensory areas of the cerebral cortex
primary somatosensory cortex
somatosensory association cortex
visual areas
auditory areas
vestibular cortex
olfactory cortex
gustatory cirtex
visceral sensory area
Primary somatosensory cortex
receive information from the general sensory receptors in the skin
general meaning not localized (scattered throughout the body)
the larger the body part, the more neurons are dedicated to that area of the body - increase sensitivity to sensation in larger body parts
somatosensory association cortex
integrates sensory input relayed to it via the primary somatosensory cortex
produce understanding of what is being felt (size , texture)
reaching into bag and knowing keys vs phone
visual areas
- primary visual cortex: largest cortical area
- receive visual information that originates from the retina in the eye
damage : loss of vision - Visual association area
- uses past visual experiences to interpret visual stimuli: allows us to recognize things
damage: can see clearly but don’t recognize objects