grey mater
unmylinated matter that surrounds fluid space
white mater
mylinated matter that surrounds grey mater
Grey mater cortex
grey mater that covers the surface cerebral hemispheres
grey and white mater organization
Central fluid filled space(ventricles, central canal)
Grey mater
white mater
then grey mater cortex surrounding everything
supportive structures
Meniges
-dura mater-outermost, tough membrane, right beneath the skull
-arachnoid- spider web filamentous layer
-pia mater- thin vascular layer adherent to contours of brain
Cerebrospinal fluid
-within brain and surrounds brain
-protects brain via buoyanc
Bld-brain barrier
is endothelium
-permeable to lipid-soluble materials(02 c02, nicotine anesthetics alcohol)
-circumventricular organs-in 3rd and 4th ventricles are breaks in bld-brain barrier where bld has direct access
great route for HIV to invade brain.
Bld-CSF barrier
is at choroid plexus
is ependymal cells joined by tight junctions
Brain stem includes?
Medulla oblongata, pons, midbrain, diencephalon
medulla-pyramids
cortiocospinal motor tracts, on the anterior surface side and are descending, carry motor signals to muscles
most tracts cross over(decussate)
medulla-dorsal nuclei
sensory tracts on posterior side also cross over
two of them , cuneate nucleus and gracile nucleus
medulla-cardiac and vasomotor centers
regs bld pressure, heart reate, blood flow
respiratory center
regs breathing rate, and depth
medulla-reflex centers
coughing sneezing gagging swallowing vomiting salivation sweating movement of tongue and head
medulla-inferior olivary nucleus
relay center for signals to cerebellum
reticular formation
loose network of nuclei extending throughout the medulla pons and midbrain
reulates muscle tone, balance, cardiovascular function(cardiac and vasomotor centers part of RF) pain pathway impulses to brain, sleep and consciousness, filter out repetitve stimu
pons-longitudinal fibers
these go to higher brain functions
pons-transverse fibers
go to cerebellum or more specifically the cerebellar peduncles
midbrain- cerebral peduncles
join brainstem to cerebrum
contains sensory and corticospinal tracts
midbrain-corpa quadrigemina
visual auditory relfexes
midbrain-tegmentum(red nucleus)
fibers to cerebellum
fine motor control
midbrain-substantia nigra
very important place for us humans
were motor center skills are located and where dopamine secreting neurons which inhibit excitatory neurons in the basal ganglia and thalamus. Parkinsons disease is when this area fails to secrete its dopamine (tremors oc
Cerebellum-vermis
joins the left and right cerebellar hemispheres
cerebellum-cerebellar peduncles
fiber tracts that join cerebellum to brainstem
cerebellum
corordinates smooth, voluntary limb movement, learned motor skills
thalamus
relay center for sensory info and some motor info, directs sensory input to appropriate sensory cortex,interconnected with limbic system
diencephalon-hypothalamus
joined to pituitary gland, maintains homeostasis regulates autonomic/endocrine systems, autonomic pathways regulating cardiovascular/digestive functions , thermoregulation, hunger, sleep, memory, emotional responses basically does everything!!!
corpus callosum
what joins the left and right hemispheres of brain
frontal cerebrum lobe
vol motor func, mem, planning, judgement, emotion, mood,aggreesion
parietal cerebrum lobe
sensory input and integration of general senses taste vision
central sulcus
separates frontal and parietal lobes
precentral gyrus
primary motor cetner
postcentral gyrus
somesthetic cortex, EX for senses
occitpal lobe of cerebrum
visual center
temporal lobe of cerebrum
hearing smell visual recognition memory learning emtional behavior
cerebrum
cerebral cortex is 3mm deep layer of grey matter with extensive folds to increase surface area- divided into lobes
Cerebral cortex tracts
3 of them...
projection tracts - ascending/descending tracts joining cerebrum to rest of CNS
commissural tracts - join two cerebral hemispheres
association tracts - join regions of one hemisphere
two types of grey matter neurons in cerebral cortex?
stellate cells- sensory input local integration have dendrites projecting in all direction
pyramidal cells-cortical output to rest of CNS-have axons that passes out of the area
functional cortical areas in cerebral cortex?
sensory cortex-termination point of sensory input
postcentral gyrus- general senses
association areas- access memory, intents other stims
motor cortex- initiates voluntary movement
basal nuclei-grey matter helps cordinate muscle movement, inhibits tremors
amygdala- limbic system
emotion
hippocampus-limbic system
memory
EEG(electroencehalogram)
records voltage changes from post synaptic potentials in cerebral cortex, finds any abnormailities
brain wave types?
alpha waves- awake eyes closed
beta waves- eyes open doing mental tasks
theta waves- sleep or emotional stress
delta waves- deep sleep in adults or being awake in infants
REM sleep
occurs 5 times a night may help or strenghen info from memory, allows nervous tissur to recover from fatigue.
Memory
response comprised of facilitated synapses
short term mem
lost after hrs if not converted to long term
reverberating circuits
long term mem
may or may not be accessible
declarative memory- facts events limbic system associated with forming accessing these mems
hippocampus processes new mems for LTM
amygdala associates sensroy input with emotional state which makes emo
procedural mem-behaviors
wenickes area
association area
brocas area
controls muscles for speech
lension to brocas area??
nonfluent aphasia, slow speech cant choose words, entire vocab might be 2 or 3 words
lension to wernickes area??
speech normal and excessive but makes little sense
anomic aphasia
speech and understand are normal but text and pics make no sense
left hemisphere of brain
analytical thought logic numerical ability speech center
right hemisphere of brain
musical artistic
imagination recognition of patterns spatial relationships
C10 nerve vagus nerve
cardiovascular, respiratory and digestive system MAIN NERVE