Chapter 14-Cranial Nerves Flashcards
rostral
toward the forehead
caudal
toward the feet
3 major regions of the brain
cerebrum
cerebellum
brainstem
cerebrum
83% of brain volume
cerebellum
50% of neurons
longitidunal fissure
separates the 2 cerebral hemispheres
cortex
surface layer of grey matter
gyri
folds, increase the surface area for gray matter
sulci
grooves
nuclei
bundles of grey matter in CNS
tracts
bundles of axons (white matter) in CNS
What are the meninges of the brain?
dura mater
arachnoid mater
pita mater
dura mater
outermost tough membrane, 2 layers
-outer periosteal layer
-inner meningeal layer
falx cerebr.
separates left and right halves of cerebrum
falx cerebelli
separates left and right halves of cerebellum
tentorium cerebelli
separates cerebellum from cerebrum
meningitis
inflammation of the meninges
bacterial and viral invasion of the CNS
high fevers, stiff neck, drowsiness, intense headache
lateral ventricles
found inside cerebral hemispheres
2
-interventricular foramen
third ventricle
single vertical space under corpus callosum
-cerebral aqueduct
fourth ventricle
cerebrospinal fluid
clear liquid that fills ventricles, forms by filtration of blood through choroid plexus
-functions include buoyancy, protection, chemical stability
hydrocephalus
abnormal accumulation of CSF
blood brain barrier
tightly joined endothelium of blood capillaries
blood CSF barrier
at choroid plexus, ependymal cells joined by tight junctions
What materials can pass through the blood brain barrier?
lipid soluble materials
Hindbrain: Medulla oblongata
primitive brain, spinal cord
1. cardiac center-adjusts rate and force of heartbeat
2. vasomotor center- adjusts blood vessel diameter
3. respiratory centers
4. reflex centers
pons
ascending sensory tracts
descending motor tracts
nuclei concerned w/ sleep, hearing, balance, respiration
midbrain
eye movement
cerebral aqueduct
Major regions of the midbrain
- cerebral peduncles
- tegmentum- connects to cerebellum and helps control fine movement
- substantia nigra- motor center relays inhibitory signals to the thalamus and basal ganglia (degeneration can lead to tremors and Parkinson)
- central gray matter
- tectum- nuclei that track moving objects, reflex turning of head to sound
reticular formation
scattered throughout all areas of the brainstem
1. motor control-balance and posture
2. central pattern generators
3. cardiovascular control
4. pain
5. regulates sleep and conscious attention
cerebellum
muscular coordination
equilibrium
connected to brainstem through peduncles
granule cells
thalamus
apart of diencephalon
gateway to cerebral cortex
-receives nearly all sensory information
-emotional and memory functions
hypothalamus “i feel”
major control center for ANS and endocrine
- hormone secretion
-food and water intake
-emotional behavior
-thermoregulation
epithalamus
pineal gland-secretes melatonin
habenula- connects limbic system to midbrain
cerebrum
contains the lobes
frontal lobe
planning
mood
personality
parietal lobe
sensory reception
occipital lobe
visual center of brain
temporal lobe
hearing, learning, emotional behavior
projection tracts
from brain to spinal cord
association tracts
connect different regions of the same hemisphere
commisural tracts
cross one hemisphere to another
-in cerebrum
cerebral cortex
40% of brain
-stellate cells receive sensory info and process info, have dendrites projecting in all directions
-pyramid cells have an axon that passes out of the area
limbic system
contain amgydala which is responsible for emotions
and hippocampus which is responsible for memory
EEG
monitors electrical activity of brain waves
alpha waves
awake and resting with eyes closed, mind wandering
8-13 hz
beta waves
14-30 hz
eyes open and performing mental tasks
theta wave
4-7 hz
drowsy or sleeping adults
delta waves
<3.5 hz
deep sleep in adults
can indicate serious brain damage in awake adults
sleep
cycle of circadian rhythms
suprachiasmatic nucleus
biological clock to set our circadian rhythm of sleep and waking
non rem
stage 1- drifting sensation, claim to not be sleeping
stage 2- still easily aroused, EEG is more irregular
stage 3- vital signs change, bp and breathing rates drop
stage 4- deep sleep
REM sleep
rapid eye movements under the eyelids
occurs about 5 times a night
cognition
mental processes such as awareness, perception, thinking, and knowledge
anterograde amnesia
can not store new data
retrograde amnesia
can not remember old data
hippocampus
organizes info into a memory
cerebellum
helps learn motor skills
What controls how emotions are expressed?
prefrontal cortex formed by hypothalamus and amygdala
somesthetic
receptors for pain, touch, pressure, heat
special senses
vision, hearing
wernickes area
permits recognition of spoken and written language
brocas area
-generates motor program for larynx, tongue, cheeks, lips
aphasia
language deficit resulting from lesion in wernickes area
