Chapter 13 & 14 Flashcards
Cerebral hemispheres
83% of total brain mass, mushroom cap
gryi
the wrinkles
elevated ridges, “twisters”
sulci
shallow grooves “furrows”
medial longitudinal fissure
separates hemispheres
3 regions of hemisphere
cortex- outer, gray matter
white matter- internal
basal nuclei- islands of gray matter in white matter
Cerebral cortex
enables perception, communication, comprehension, voluntary movements = consciousness
consists of gray matter (neuron cell bodies, dendrites, unmyelinated axons)
primary motor cortex
precentral gyrus of frontal lobe
motor homunculus (representative body regions where motor control is generated)
contralateral control- left motor cortex controls right side of body
motor homonculus
motor homunculus- representative body regions where motor control is generated (more control then more area) ex: fingers and mouth have the most control so they have the biggest motor homonculus
contralateral control
left motor cortex controls right side of body
stroke
contralateral loss of voluntary control
premotor cortex
behind precentral gyrus of frontal lobe
controls learned motor skills (repetitious like typing)
Broca’s area
anterior to inferior portion of premotor cortex
motor speech area- directs muscles of tongue, throat, lips
frontal eye field
anterior to premotor cortex, superior to Broca’s
controls voluntary movement of eyes
sensory areas
conscious awareness of sensation located in parietal, temporal, occipital lobes
primary somatosensory cortex
postcentral gyrus of parietal lobe
receives general sensory info and IDs body region = spatial discrimination
somatosensory homunculus- body represented by part, more sensitive then more area
somatosensory association area
posterior to primary somatosensory cortex
integrate and analyze different sensory inputs for evaluation
ex: reach in pocket and recognize quarter
visual area
primary visual cortex- extreme posterior tip of occipital lobe
largest of cortical areas
receives visual info from retinas
Visual association area
interprets stimuli using past visual experiences (recognition of face)
functional blindness
damage to primary visual cortex
comphrension blindness
damage to association area, can see but don’t understand
auditory areas
primary auditory cortex- temporal lobe
receives info from inner ear related to sound
auditory association area
perception of sound (talk, music), memory
olfactory cortex
receives info from smell receptors in nasal cavity, travels to olfactory tracts (bulb)
gustatory cortex
receives info from taste receptors of tongue
prefrontal cortex
anterior portion of frontal lobes
intellect, cognition (learning), personality, judgement, reasoning
slowly develops in children (environment feedback)
gnostic area
‘common intelligence’
parts of temporal, parietal, and occipital lobes
receives input from all association areas - integrates to understanding
“imbecile” - damage here, inability to interpret situation
language areas
Wernicke’s area- posterior temporal lobes, speech area
Parts of the Diencephalon
thalamus and hypothalamus
Thalamus
80% of diencephalon
relay station for sensory information/sends to appropriate area of sensory cortex or association area, “gateway”
hypothalamus
“master gland”
below thalamus, caps brainstem, infundibulum and pituitary attached
main visceral control center
What does the hypothalamus control?
autonomic control center, emotional response and behavior, body temperature regulation, water balance and thirst, sleep cycles
autonomic control center
heart rate, blood pressure, GI motility, pupil size
emotional response and behavior
center of limbic system (pain, pleasure, fear)
psychosomatic illnesses and “emotion vs logic” here
ex: fear -> heightened rate rate, sweat
body temperature regulation
thermoreceptors -> thermostat -> shiver (heat) / sweat (cool)
water balance and thirst
osmoreceptors sense concentration of body fluid and release antidiuretic hormone (ADH)
sleep cycles
suprachiasmatic nucleus = biological clock, adjust to light/dark cycles (epithalamus secretes melatonin = sleep inducer)
Parts of the Brainstem
Midbrain, Pons, Medulla Oblongata
Midbrain
reflexes!
between diencephalon and pons
contain superior and inferior colliculi (corpora quadrigemina)
visual (tracking) and hearing (startle) reflex respectively
part of reticular formation which controls consciousness and serves as a sensory filter (99%) for cortex
Pons
between midbrain and medulla oblongata = bridge
several cranial nerves exit to body from here
pneumotaxic center-helps regulate breathing rhythm
medulla oblongata
most inferior part of brainstem
decussation - crossover of nerve tracts occurs here (contralateral)
rest of cranial nerves exit here
autonomic reflex centers include: cardiovascular and respiratory centers and reflexes such as vomiting, coughing, sneezing
Cerebellum
“little brain” 11% of brain mass
coordinates voluntary movements by processing info from cerebral motor cortex, sensory receptors, visual and equilibrium pathways
“autonomic pilot” constantly comparing settings with actual course
ataxia
lack coordination due to cerebellar damage (appear drunk)
Blood Brain Barrier
must maintain close to constant environment, no fluctuations
ependymal cells of choroid plexus associated with each ventricle
BBB capillaries have _______ = least permeable of body, most selective
tight junction
Why is blood brain barrier “super” filtered”?
blood is “super filtered” to make cerebrospinal fluid (CSF)
ex: keeps metabolic wastes out but alcohol, nicotine, anesthesia can cross
Name 2 problems you may experience with the brain
Cerebrovascular accidents or stroke
Alzheimer’s Disease
Cerebrovascular accidents (strokes)
blood route to brain blocked due to thrombus (clot) and brain tissue dies
Alzheimer’s Disease
progressive degenerative disease of brain leads to dementia(mental deterioration) due to formation of senile plaques (aggregates of neurons/protein) and neurofibrillary tangles (twisted fibrils within cell bodies)
