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
parkinsons disease
-loss of substantia nigra
-normally: disinhibition of inhibitory output of indirect and inhibition of inhibitory of direct
-loss of indirect and indirect pathway
-reduction in modulation of movements
-tremors at rest
-difficulty stopping when walking
-pill rolling
-mask like face
-slow
-treatment- replacement of dopamine by treatment with I -dopa or dopamine agonists (bromocriptine) -> activation of direct and inactivation of indirect
motor cortex
-primary motor cortex, supplementary motor cortex, and premotor cortex
-supplementary and premotor cortices- plan
-plan sent up to primary motor cortex -> sent down to spinal cord to execute
jacksonian seizures
-epileptic events originating in primary motor cortex
-begins in fingers of one hand and progresses to hand and arms
-eventually spreads over entire body
-jacksonian march
electroencephalogram
-record electrical activity in brain -> on cerebral cortex
-sleep study
-awake- eyes closed -> alpha waves
-beta waves- eyes open
-stage 1- on and off alpha waves
-stage 2- high frequency bursts (sleep spindle) and slow potential (K complexes)
-stage 3- very low frequency delta waves and occasional sleep spindles
-stage 4- large delta waves
-REM sleep (paradoxyl)- desynchronized, low and high frequency, resembles awake, every 90 minutes, deep sleep
cerebellum dysfunction
-ataxia
-delayed onset of movement or poor execution
-overshooting or undershooting targets
-dysdiadochokinesia- unable to perform rapid alternating movements
-intention tremors- occur perpendicular to direction of a voluntary movement, increasing near the end of movement -> during intentional movement
-*rebound phenomenon- inability to stop movement- ex. unable to stop flexion when resistance is removed
REM sleep
-loss of temperature regulation
-pupillary constriction
-penile erection
-fluctuations in HR, BP, respiration
-dreams
-slow wave sleep varies over life
learning
-changes their behavior as a result of their experiences
-non-associative:
-habituation- repeated stimulus -> response that gradually diminishes as it is learned to be unimportant
-sensitization- greater probability of response when it is learned to be important
-associative- consistent relationship in timing of stimuli - classic -> Repetition
-operant condition- response to stimulus is reinforced (+ or -) -> causing response to change
-potentiation- repeated activation -> increase synaptic plasticity -> long term or short
CSF
-80%
-being produced by choroid plexus and reabsorbed at a constant rate
-flows into ventricles and subarachnoid spaces -> surrounds brain/spinal cord
-fluid is transferred from CSF to venous blood by one way bulk flow and returned to systemic circulation
-sample via LP
-Na, Cl, HCO3, osmolarity- same as blood
-K- less than blood (blood absorbs it)
-no large molecules in CSF so it can flow freely (protein, cholesterol)
choroid plexus
-choroid plexus- barrier between cerebral capillary blood and CSF
-BBB- barrier between capillary blood and interstitial fluid
-CSF, interstitial fluid, and brain cells drain into cerebral venous blood
-only allow lipid substances to get through -> very selective
eye
-posterior- vitreous humor
-anterior- aqueous humor
-retina- specialized epithelium -> photoreceptors (rods and cones), interneurons (bipolar, horizontal, amacrine), and ganglion cells
rods
-low threshold for light
-function well in dark
-low acuity
-high sensitivity
-no color
-many rods synapse on single bipolar cells
-single photon of light can activate a rod -> high rhodopsin
-more rods
cones
-higher threshold for light
-best in daylight
-higher visual acuity
-low sensitivity
-color
-only few cones required to synapse on 1 bipolar
-many photons of light required to activate
layers of retina
-pigment- absorb stray light
-photoreceptor- rods and cones
-outer nuclear- nuclei of photoreceptors
-outer plexiform- pre and post synapse with photoreceptor and interneurons
-inner nuclei- cell bodies of interneurons (bipolar, horizontal, amacrine)
-inner plexiform- pre and post of interneuron synapses with ganglion
-ganglion cell- cell bodies of ganglion
-optic nerve- axons of ganglion
interneurons of eye
-bipolar- connect photoreceptors to ganglion cell
-amacrine- improve complexity of vision
-horizontal- improve visual acuity
photoreception
-light strikes photoreceptors -> retinal chemically transforms-> photoisomerization
-when light hits photoreceptors -> ALWAYS hyperpolarized and release decreased amounts of glutamate
-glutamate crosses over synapse on bipolar cell
-bipolar cell can be ionotropic -> decrease glutamate -> hyperpolarization of center of bipolar cell -> inhibit bipolar cell
-bipolar cells can be metabotropic-> decreasing glutamate -> depolarization of center of bipolar cell -> excitation
-surround of bipolar cells receives input from horizontal photoreceptors -> shows opposite response of center bc horizontal cells are inhibitory
-relay to ganglion cells
visual discrimination
-visual cortex
-3 cells:
-simple- receptive fields similar to ganglion cells and lateral geniculate cells (on-center or off-center) -> although patterns are elongated rods rather than concentric circles
-simple cells response best to bars of light that have “correct” position and orientation
-complex- respond best to moving bars of light or edges -> identifies edges of objects
-hypercomplex- respond best to lines of particular length and to curves and angles -> structure objects
hemianopia
-loss of vision in half the visual field of one or both eyes
-cutting optic nerve causes blindness in ipsilateral eye
-cutting optic chiasm causes heteronymous (both eyes) bitemporal (both temporal visual fields) hemianopia -> all information is lost from fibers that cross -> information from temporal visual fields from both eyes is lost because these fibers cross at optic chiasm
-cutting the optic tract causes homonymous contralateral hemianopia -> cutting left optic tract results in loss of temporal visual field from right eye (crossed) and loss of nasal visual field from left eye (uncrossed)
damage to spinal cord
-paralysis to areas inferior to injury, difficulty breathing, muscle spasms, nerve damage
brain stem damage
-basic life function impacted
-brain dead
-can cause coma
-decreased motor function
dopamine
-excites direct pathway
-inhibits indirect -> inhibition of inhibitory output -> increases thalamic activity
-in parkinsons loss of dopaminergic neurons -> reduces activation of direct and indirect pathways -> inhibition of thalamic neurons
-greater suppression of movements initiated by cortex
CSF
-choroid plexus- barrier between arterial blood and CSF
-BBB- barrier between arteries and interstitial fluid
-CSF, interstitial fluid, and brain cells drain into cerebral venous blood
-only allow lipid substances to get through -> very selective
beta blockers and lack of insulin
-causes K to be pushed outside the cell
-hyperkalemia
-no potassium gradient
-muscles weakness
-Na is able to go into cell though
-cell cant hyperpolarize bc there is no K gradient
nernst equation
-equilibrium potential
-how much electrical gradient is needed to prevent movement of a solute down its concentration gradient
Na-K ATPase pump
-primary active transport
-3 Na out and 2K in
-allows for secondary active transport of other molecules
-cardiac glycosides inhibit Na-K pump ->decreases contractility of heart
SGLT1 (Na Glucose transport protein)
-intestinal epithelial cells
-Na-K pump pumps Na out of cell and K in the cell against gradient
-Na can enter the cell down its gradient now and bring glucose with it
-cotransport
H-K ATP pump
-primary active transport
-H+ out and K in
-parietal cells of gastric mucosa and alpha intercalating renal collecting duct
-acidifies gastric content
-omeprazole inhibits
Ca2 + ATPase (SERCA)
-primary active transport
-pumps Ca2+ out
-creates a concentration gradient for muscle contraction
-SR and ER
Ca+ and Na+ exchanger
-secondary active
-counter transporter
-2Ca2+ out and 3 Na in
-creates Ca concentration gradient for muscle contraction
skeletal muscle contraction
-action potential opens presynaptic Ca channels -> induces Ach release
-ACh binding to postsynaptic -> depolarization of motor end plate
-travels to T tubules
-conformational change in voltage sensitive DHPR -> mechanically coupled RR releases Ca from SR into cytoplasm
-tropomyosin is blocking myosin binding sites on actin filament
-Ca binds to troponin C (TnC) -> moves tropomyosin and exposes myosin binding site
-myosin head binds strongly to actin forming cross bridge and power stroke
-force is produced as myosin pulls on thin filament -> muscle shortening
-binding of new ATP causes detachment of myosin head from actin filament
-Ca is re sequestered
skeletal muscle bands
-Z to Z is sarcomere
-sarcomere shorten when muscle contraction occur
-M line is center
-H band contains only thick filament myosin
-A band contains both actin and myosin -> never shortens
-I band contains only thin filament actin
total body water
-50-70% weight
-intracellular fluid- 2/3
-extracellular fluid- 1/3 ->
1/3 plasma and 2/3 interstitial fluid
sodium glucose blocker
-jardiance
-block reabsorption of glucose in diabetics
-causes increase secretion of glucose
