EXAM 1 Flashcards
Broca’s Area
-left side of frontal lobe
-damage to this area -> difficulty speaking and writing but still understands and read -> aphasia
parietal lobe
-language, words
-sensory
-memory
-spatial and visual perception
temporal lobe
-understanding language (Wernicke’s area)
-memory
-hearing
-sequencing and organization
-Wernicke’s on left side -> damage causes aphasia
-may speak in long sentences that have no meaning/create new words
-difficulty understanding speech and dont know their own mistakes
hypothalamus
-master control of ANS
-controls behaviors like hunger, thirst, sleep, sexual response
-regulates body temperature, blood pressure, emotions, secretion of hormones
pituitary gland
-connected to hypothalamus by pituitary stalk
-master gland
-controls other endocrine glands in body
-secretes hormones that control sexual development
-promote bones and muscle growth
-responds to stress
thalamus
-early station for almost all information that comes and goes to cortex
-plays role in pain sensation, attention, alertness, memory
-sorting center
brainstem components
-midbrain- eye movement (relays auditory and visual)
-pons- balance, posture, breathing
-medulla- breathing, BP, coughing, vomiting, swallowing
-reflexive control
diencephalon
-thalamus
-hypothalamus
nociceptor mechanism
-thermal/mechanical -> myelinated-> sharp
-polymodal -> unmyelinated -> blunt chronic pain
-hyperalgesia- axons release substances to sensitize nociceptors to recognize stimuli that wasnt previously noxious as noxious -> having a new cut
auditory mechanism
-movement of basilar membrane moves the hair cells on the tectorial membrane (in organ of corti in scala media of cochlea)
-bending of hair cells -> increase conductance of K+ in hair cell membrane -> K depolarizes hair cell -> release glutamate -> glutamate binds to cochlear nerves -> action potential
-goes to the afferent cochlear nerves -> synapse on dorsal and ventral cochlear nuclei -> some cross -> lateral lemniscus -> inferior colliculus -> medial geniculate nucleus of thalamus -> auditory cortex
nystagmus
-limit of lateral eye movement -> rapid eye movement in same direction
-postrotatory-> eyes move opposite of rotation
-Barany test- rotate and watch for normal nystagmus
-caloric test- warm water -> towards; cold water -> away
olfactory mechanism
-activates G protein -> activate adenylyl cyclase -> ATP to cAMP -> opens cation channels (Na, K, Ca) -> depolarized -> action potential
-granule and periglomerular inhibitory interneurons synapse on mitral cells -> lateral inhibition in olfactory bulb -> sharpen CNS
-pathways include:
-lateral olfactory tract -> to primary olfactory tract
-medial olfactory tract -> to anterior commissure and contralateral olfactory bulb
tongue layout
-taste buds:
-circumvallate- base, largest,
-foliate- lateral
-fungiform- everywhere, small
-posterior 1/3 (bitter and sour)- glossopharyngeal (9)
-anterior 2/3 (sweet umami salt)- facial (7)
-throat- vagus (10)
-all ascend as one in the solitary tract -> solitary nucleus of medulla -> ipsilaterally to third order -> leave thalamus -> terminate in taste cortex
taste transduction
-bitter and sweet- G protein activated -> increase in secondary messenger (IP3 and Ca) -> open TRP channels -> depolarize
-sour- H+ ions enter directly through -> depolarization
-salt- Na+ ions enter directly through -> depolarization
intrafusal fibers
-nuclear chain fiber- static gamma
-nuclear bag fiber- dynamic gamma
-group 1 afferent nerve fibers- sense velocity of muscle change
-group 2 afferent- length of muscle fiber
-innervated by sensory and motor
-for fine movement
stretch reflex
-intrafusal senses stretch -> group 1a afferent -> spinal cord -> reinnervates alpha motoneuron -> contraction
-stability
golgi tendon reflex
-clasp knife, inverse myotatic reflex
-intrafusal senses contraction -> group 1b afferent -> spinal cord -> 2 synapse -> contraction of antagonist and relaxation of agonist
polymodal synapse
-flexor withdrawal reflex
-groups 2, 3, 4 afferent nerve fibers
-pain -> stimulate nociceptors -> spinal cord -> contraction of ipsilateral flexor and inhibition of extensor -> contraction of contralateral extensor and inhibition of flexor -> maintains balance
cerebellum division and layers
-3 divisions:
-vestibulcerebellum- input from vestibular system -> balance and eye movement
-spinocerebellum- limb position, touch + pressure sensation input from spinal cord -> reflex
-pontocerebellum- input from pontine nuclei -> preplanned movement
-3 layers:
-granular layer- cell bodies and glomerulus (meeting points for cells)
-purkinje cell layer- purkinje cells
-molecular layer- dendrites, axons, cells, parallel fibers
-ONLY output is purkinje cell -> ALWAYS inhibitory -> prevents overreaction to a movement (smoothes)
-smooths motor movement and controls eyes
basal ganglia
-modulate movement coming from cortex -> sends to thalamus -> feeds back to cortex -> loop
-caudate nucleus, putamen, globus pallidus
-2 pathways:
-direct- excitatory -> stimulate motor movement
-indirect-inhibitory- cortex -> striatum -> globus pallidus -> subthalamic nuclei -> globus pallidus -> substantia nigra -> thalamus
huntingtons disease
-loss of striatal and cortical cholinergic neurons and inhibitory GABAergic neurons
-losing ability to make movements from the cortex
-neurologic symptoms- choreic (writhing) movements and dementia
-no cure
