Examining Resting and Action Potentials: Membrane Potentials & Ion Channels, Exams of Pathophysiology

Download Examining Resting and Action Potentials: Membrane Potentials & Ion Channels and more Exams Pathophysiology in PDF only on Docsity! pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is potential (E)? - correct answer a separation of charge, in this case across a cell membrane (Em) gives ability to do work what is resting membrane potential? - correct answer the difference in charge between the inside and outside of a cell at rest what is depolarization - correct answer a change in the membrane potential so that it is closer to zero what is hyperpolarization - correct answer a change in the membrane potential so that it is farther from zero units for potential - correct answer volts what is a current - correct answer movement of charge, flow of charge units for current - correct answer amperes pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is resistance - correct answer opposition to the flow of charge units for resistance - correct answer Ohms (Ω) what is ohms law? - correct answer V=IR (voltage = current x resistance) what is permeability - correct answer the ease with which a particular ion moves through an open channel or the membrane. Channel open so ion can go through what is conductance - correct answer the ease of current flow through an ion channel. opposite of resistance what is the units for conductance - correct answer Siemens (S) what is the basis of the resting membrane potential - correct answer 1. The Na/K ATPase- direct and indirect roles pathophysiology 3 exam 2024 peoples lectures Questions and Answers intracellular concentration of K - correct answer 145mM intracellular concentration of organic A- - correct answer 140mM intracellular concentration of Cl- - correct answer 10mM relative permeability of K - correct answer 50-75 can cross a lot more readily than Na+ does relative permeability of Na - correct answer 1 explain electroneutrality of the membrane - correct answer -cations and anions in each solution must exactly balance (charges repel!!) -membrane potential is due to a difference in charge at the membrane surface!! what does it mean that membrane potential is due to the difference in charge at the membrane surface - correct answer -immediately by the membrane pathophysiology 3 exam 2024 peoples lectures Questions and Answers -removed from solution because really close to membrane -move really small # of ions to change polarization nanometer amount what is electron potential - correct answer difference in charge (of all charged particles) ions involved doesn't matter electrode in cell --> measuring charge what is chemical potential - correct answer difference in concentration of a given ion (specific) explain equilibrium (reversal) potential - correct answer -the membrane potential at which no net flux of an ion occurs -open Na+ channels --> will always try to get back to - 60Mv -electrical = chemical potential (reversal potential) what is the Nernst equation? - correct answer Ex= (gas constant x temp in K / charge on ion x faraday constant) x ln ( X out / X in) pathophysiology 3 exam 2024 peoples lectures Questions and Answers measures the equilibrium potential at 37 degrees celsius the Nernst equation simplifies to - correct answer Ex = 61/z x log x (Xout/Xin) if Kout = 5mM and K in = 150mM what is Ek? - correct answer Ek = 61/1 x log (5/150) Ek = -90mV if Naout = 150mM and Nain = 15mM what is ENa? - correct answer ENa = 61/1 x log (150/15) ENa = +60mV explain ion permeability - correct answer increasing the membrane permeability of a particular ion will drive the membrane potential toward the equilibrium potential of that ion how can you know which way K will move due to changes in membrane potential? - correct answer More (-) than -90mV -> K moves in More (+) than -90mV -> K moves out pathophysiology 3 exam 2024 peoples lectures Questions and Answers oligodendrocytes function - correct answer form myelin sheaths around axons microglia function - correct answer macrophage system of CNS ependymal cells function - correct answer line the ventricles where is gray matter in a cell - correct answer cell bodies! have no myelin where is white matter in a cell - correct answer axons! have myelin what are the different parts of a neuron - correct answer 1.Cell body 2.Dendrites - receive signals and send it to the body 3.Dendritic Spines - important in signaling. Mushroom shaped. pathophysiology 3 exam 2024 peoples lectures Questions and Answers 4.Axon hillock - important in signaling 5.Myelin Sheath - increases the rate of conduction 6. terminal: release NT's (chemical signals) what is impulse conduction - correct answer Signaling in the nervous system that can be active or passive. - passive could be just like electrons moving in a wire. Electricity. what are graded potentials - correct answer -local changes in membrane potential -graded = amplitude can vary -close to stimulus (2mm) a larger voltage change will occur -far from stimulus a small voltage change will occur what are action potentials - correct answer a way to send a signal a very long distance without having it decline. Happens in excitable cells, neurons, muscles, and heart. Can travel long distances. pathophysiology 3 exam 2024 peoples lectures Questions and Answers explain threshold potential - correct answer Membrane potential at which you would fire an action potential. happens when the sodium conductance is greater than the potassium conduction. what is the all-or-none principle? - correct answer Like being pregnant. Either fires or it doesn't. what is active propagation - correct answer -Energy to keep it going is stored along the axon. Like rows of dominos. -Potential energy energy stored in dominos and you are tipping them over and they will keep going. -Energy far from the site is the same as the energy close to the site. -Amplitude is consistent over distance. explain Na+ channels contribution to action potential - correct answer -rapidly opens and closes - If threshold is reached they open and the membrane highly depolarizes pathophysiology 3 exam 2024 peoples lectures Questions and Answers Like with bladder. Tension builds in bladder progressively, until you pee. Peeing is the end-point. what is refractory period? - correct answer - Axon is resistant to firing another action potential. Right after an AP has been fired what is absolute refractory period? - correct answer Cannot fire another AP. System has to reset first. Na channel is inactive. what is relative refractory period? - correct answer can fire AP but have elevated threshold because K+ channels are opened still! explain how AP can only go in one direction - correct answer passive depolarization is very fast. When a wave of passive depolarization occurs, it travels ahead of the action potential and brings area between the two, to threshold so that the action potential can fire. Refractory period behind AP will prevents things from going backwards --> keeps it going in one direction by making it harder for AP to fire pathophysiology 3 exam 2024 peoples lectures Questions and Answers myelinated axons - correct answer wrapping axon wil cell membrane (lipid bilayer). CNS - oligodendrocytes and PNS - Schwann cells ex: insulation nodes of ranvier - correct answer interruptions of myelin with Na+ and K+ channels what is saltatory conduction - correct answer Jumping conduction. Underneath myelin is passive conduction. when it hits a node, another action potential is fired through the node to make sure that another larger amplitude is propagated. Keeps firing at nodes, restoring amplitudes as it goes. Advantage of this is speed. conduction velocity of myelinated axons - correct answer 225 mph conduction velocity of unmyelinated axons - correct answer 25 mph what is the effect of size in conduction velocity - correct answer larger axons are faster pathophysiology 3 exam 2024 peoples lectures Questions and Answers explain electrical synapses? - correct answer gap junctions that interconnect neurons, connexins (Proteins) come together to form a core through the cell membrane what makes up a connexon? - correct answer 6 connexins what do connexons do? - correct answer they form pores which create the gap junction in an electrical synapse, large pathway from one cell to another & transmit ions, nucleotides, etc. (note: always open & in an open state) what are chemical synapses - correct answer most common synapse, specialized for the release and reception of neurotransmitters (NT packaged into vesicles which are released into synaptic cleft via exocytosis), used in conduction of action potentials what are the steps in synaptic transmission? - correct answer 1. the action potential travels down the axon and arrives at the axon terminal pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is an axodendritic synapse - correct answer axon goes on dendrite (typical) what is an axospinous synapse - correct answer axon onto dendritic spine (learning and memory) what is an axosomatic synapse - correct answer axon onto cell body what is an axoaxonic synapse - correct answer terminal comes in and synapses with another terminal -can affect release of NT from cell right before release from cell (enhance or inhibitory_ explain synaptic potentials - correct answer graded potentials in the postsynaptic neuron what are excitatory postsynaptic potentials? (EPSP) - correct answer postsynaptic potentials, increase in probability of action potential firing, these will be depolarizing, can open Na or Ca channel or you could lose the K channel pathophysiology 3 exam 2024 peoples lectures Questions and Answers what are inhibitory postsynaptic potentials? (IPSP) - correct answer decrease probability of action potential firing, usually hyperpolarizing, open a Cl or K channel, every ion is trying to take the membrane to its own reversal potential what is synaptic integration - correct answer neurons integrate/combine the number, amplitude, rate of decay, & timing of EPSPs & IPSPs in "deciding" to fire action potentials what is temporal summation? - correct answer short-duration & rapid decay, fires 2 APs in rapid succession/right in a row down one axon, can get a summation what is spatial summation? - correct answer if both APs fire at the same time from different axons, can get more depolarization & AP triggered what happens when you get an ESPS & ISPS at the same time? - correct answer they will cancel out and an AP will not be sent pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is synaptic plasiticity - correct answer the ability of synapses to strengthen or weaken over time, in response to increases or decreases in their activity -can last for years what is convergence? - correct answer many inputs to one cell ex: purkinje cells , fires AP, >100,000 to one output what is divergence? - correct answer one input to many cells ex: small number of cells going to large portion of brain can divergence and convergence happen at same time - correct answer yes does axonal transport require energy? - correct answer occurs along microtubules and all requires energy what is anterograde? - correct answer movement away from the cell body (fast: pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is GABA? - correct answer main inhibitory neurotransmitter in the brain what are GABAa receptor/channels - correct answer Cl- channels (fast) ex: sedatives what are GABAb receptors - correct answer -coupled via G proteins to K+ channels -slower they are opening potassium channels; get a high IPSP (hyperpolarizes cell, K+ leaves the cell, a little slower) what is glycine? - correct answer main inhibitory NT in SC -fast -has Cl- channel -lets Cl- in and hyperpolarizes (inhibitory) -strychnine- blocks glycine (lose inhibition in the spinal cord, can result in seizures) pathophysiology 3 exam 2024 peoples lectures Questions and Answers what are the types of monoamines? - correct answer norepinephrine, dopamine, seratonin -small # of cell bodies --> send projection out to brain --> important globally to turn things up or down what is norepinephrine? - correct answer has alpha & beta receptors coupled to g proteins, part of sympathetic nervous system (fight/flight), can regulate wakefulness, attention, and feeding behavior what is dopamine - correct answer receptors: multiple types coupled to G proteins. plays a part in motor control, motivation, and reward (addiction), mood (anxiety) what is serotonin (5-hydroxytryptamine; 5-HT) - correct answer receptors: multiple types; most are coupled to G proteins (antidepressants) plays a role in mood (depression, anxiety), motivation, sleep, and wakefulness what is acetylcholine - correct answer 1: nicotinic receptors: cation channel (ion channel, nicitinic receptors) pathophysiology 3 exam 2024 peoples lectures Questions and Answers 2: muscarinic receptors: coupled to G proteins --both play a role in learning and memory, motivation, and reward (addiction), mood what are neuropeptides? - correct answer substance P (pain transmitter/pain pathway) & enkephalins/ endorphin (endogenous opioids, block release of substance P & therefore blocks pain) examples of unconventional transmitters - correct answer gases, cannabinoids, and retrograde transmission what are gas NT? - correct answer -not nitrous oxide -made in post synaptic membrane -made on demand -small can diffuse out of vesicle why we make on demand what are cannabinoid NT? - correct answer endogenous receptor in the brain, coordination can be inhibited/affected, very lipid soluble, cannot be stored in a vesicle, made on-demand, affects judgement & reward, impairs memory, cognition, stimulates appetite pathophysiology 3 exam 2024 peoples lectures Questions and Answers eg: PCP, ketamine: block NMDA receptors (dissociative procedures can become psychotic in adults so don't usually prescribe because you stay awake) what are examples of receptor agonists that manipulate synaptic function - correct answer eg: morphine: acts at receptors for endogenous opioids ---fetanyl what are examples of receptor modulators that manipulate synaptic function - correct answer eg: valium (benzodiazepines): enhances action of GABA so its a sedative what is the general role of the ANS - correct answer control involuntary bodily movements what specific glands/muscles does the autonomic nervous system control? - correct answer endocrine glands (hormones), exocrine glands (secrete to GI tract/sweating), smooth muscle, cardiac muscle pathophysiology 3 exam 2024 peoples lectures Questions and Answers what are examples of efferent systems? - correct answer away from the CNS (somatic (not part of ANS), autonomic: sympathetic, parasympathetic, enteric) what is the somatic nervous system? - correct answer not part of the ANS, the division of the peripheral nervous system that controls the body's skeletal muscles what has the "2 neuron chain" system? - correct answer sympathetic and parasympathetic explain how the two neuron chain works - correct answer ANS + somatic motor system (spinal motor neurons send axons to muscles & release Ach at neuromuscular junction; In the ANS, there is a ganglion that projects a preganglionic axon & then a postganglionic axon) what are axonal varicosities - correct answer -innervate high amount of tissue in short time frame -swelling in a segment of axon, they are vesicles filled w/ NT (you can have 1 fiber traveling & affect 1 large tissue), makes it more efficient pathophysiology 3 exam 2024 peoples lectures Questions and Answers in the somatic motor system, what is released to the skeletal muscle? - correct answer acetylcholine (Ach) (it is nicotinic- we want speed w/ ion channels to let Na in for muscle contraction) in the ANS, SNS what does preganglionic terminal release to adrenal glands and what does adrenal gland release - correct answer ACh released at preganglionic terminal adrenal gland releases Epi In the ANS, SNS what does preganglionic neuron release and postganglionic neuron release when acting on sweat glands - correct answer ACh released at preganglionic neuron terminal on ganglion --> postganglionic neuron releases ACh on sweat glands muscularinic receptors in the ANS, PNS what does preganglionic neuron release and postganglionic neuronl release when acting on various organs - correct answer ACh release at preganglionic neuron nicotinic receptors on ganglion --> postganglionic neuron will release ACh on various organs in the ANS, SNS what does presganglionic neuron release and postganglionic neuron release when acting on various organs - pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is sensation - correct answer sampling info from the environment and converting it into information in the nervous system what is perception - correct answer integration of sensory information with previously learned information and other sensory inputs what are sensory receptors? - correct answer receptors in biological structures, can be an organ (ex: eye, ear) what is stimulus? - correct answer some factor in the environment that stimulates/activates a sensory receptor (ex: light stimulus in the room activating our eyes) what is modality? - correct answer type of stimulus/kind of sensation (ex: sight, smell, light) what is affect? - correct answer subjective perception (ex: what emotion is associated w/ the stimulus) pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is adequate stimulus? - correct answer the usual & appropriate stimulus (ex: for the eye, the adequate stimulus is light) what is the labeled line principle - correct answer a sensory/neural path conducts one type of signal/modality (ex: eye path only sends light signal, not pain signal; optic nerve handles light) what is transduction? - correct answer the conversion of the stimulus into an action potential /electrical signal (depending on the stimulus, this can be difficult) ex: touch receptors: mechanosensory afferent fiber stretched --> depolarization --> sends signal to brain what are receptor/generator potentials? - correct answer APs are all or none & there is a threshold for firing what happens to action potentials with stronger stimuli? - correct answer increased frequency in APs but remember limited frequency because of refractory potential!! pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is compression? - correct answer there is a logarithmic relationship between frequency & stimulation(bc there is a max frequency [refractory period]). So, the scale needs to becompressed what is the Weber-Fechner principle? - correct answer if stimulus goes from 10 to 100 in frequency, AP goes from 1 to 2 (aka there is a relationship between stimulus intensity & AP) what is adaptation? - correct answer decrease general potential when there is a constant stimulus what is tonic adaptation? - correct answer little or no adaptation ex: Blood pressure, proprioception (anything closely monitored) what is phasic adaptation? - correct answer adaptation can be fast or slow and occurs when we adapt/tune out, regular information, less important things pathophysiology 3 exam 2024 peoples lectures Questions and Answers what do pacinian corpuscles sense and how fast do they adapt - correct answer change in pressure/vibration very rapidly adapting what is the cornea? - correct answer outer layer of the eye, transparent, does ~75% of focusing for the eye what is the iris? - correct answer Colored part of the eye constrict/dilate, regulate light entering eye what is the lens? - correct answer focuses light into the retina does ~25% of the focusing for the eye, allows for variable focus what is the ciliary body? - correct answer smooth muscle attached to lens by suspensary ligaments to allow for focusing what are zonule fibers? - correct answer connect ciliary muscle to the lens, can thicken/thin to focus pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is the retina? - correct answer has photoreceptors innermost layer what is the choroid? - correct answer highly vascular, deeply pigmented layer behind retina what is the sclera? - correct answer tough layer, CT outermost layer of eye what is light adaptation in the eye? - correct answer the process in which the eyes become less sensitive to light in high illumination; can constrict pupil in bright light or dilate pupil in dim light what is lens accommodation for distant vision? - correct answer ciliary body will relax, zonule fibers tighten, & lens flattens so you can focus on distant objects what is lens accommodation for near vision? - correct answer ciliary muscle will contract --> zonule fibers will relax --> lens thickens --> focuses close up pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is presbyopia - correct answer lens --> less flexible as you age not able to thicken or flatten muscle and focus what are parts of the retina? - correct answer rods, cones, neurons, macula lutea, fovea centralis what is the macula lutea? - correct answer small area in center of retina --> most acute vision here 5mm in diameter what is the fovea central's? - correct answer small area 1/2 mm point of direct vision what are pigment epithelial cells? - correct answer has melanin decreases scattering of light ex: albanism --> lack these and have fuzzy vision pathophysiology 3 exam 2024 peoples lectures Questions and Answers what does the stapes do? - correct answer vibrates against the oval window, transmits to inner ear what is the inner ear? - correct answer cochlea and semicircular canals what does the cochlea do? - correct answer transduction, converts signals into action potentials/sound (basilar membrane) what do hair cells do? - correct answer sit on the gelatinous tectorial membrane, sense movement of the basilar membrane & help transduce the movements into electrical signal how does auditory transduction work? - correct answer vibration of basilar membrane is detected, fluid goes back & forth & vibrates the BM, BM has hair cells that touches tectorial membrane, movement moves the stereocilia, which is connected to ion channels (K+ moves into the cell --> depolarization) How is the ion channels in hair cells different than usual ion channels? - correct answer high K outside not inside!! pathophysiology 3 exam 2024 peoples lectures Questions and Answers K enters the cells and opens Ca channels allowing glutamate to go in synapse and connect to receptors and cause AP what is frequent encoding? - correct answer -hair cells are optimized for increase and decrease in frequency depending on where they are. Being further away from the stapes, makes it harder to increase frequency of AP of hair cells. -hair cells closer to oval window will vibrate at low frequencies what is the purpose of the vestibular system - correct answer allows for maintenance of balance and equilibrium what two parts make up the vestibular system - correct answer saccule and utricle what does the saccule (linear) & utricle detect? - correct answer head position & linear acceleration how are we able to feel linear acceleration - correct answer sterocilia move first and otoliths next (they are resist at first) pathophysiology 3 exam 2024 peoples lectures Questions and Answers what do otolithic (ear stones)/otoliths (Ca carbonate) detects? - correct answer gravity & linear acceleration (roller- coaster makers use this when detecting things) what do semicircular canals do? - correct answer detect rotary acceleration, rotation (cupula moves when fluid moves & hair cells detect it) what 5 types of taste can we detect? - correct answer salty sour (acid) bitter sweet umami what detects salty? - correct answer Na+ channels what detects sour (acid)? - correct answer low pH acid sensing membrane potentials --> proteins pathophysiology 3 exam 2024 peoples lectures Questions and Answers what are nociceptors? - correct answer receptors that detect painful stimuli, most are polymodal (multiple stimuli causes firing: mechanical, pressure, chemicals, temp), high threshold (don't want firing w/o injury), slowly-adapting (don't want adaptation w/ injury) what are Adelta fibers? - correct answer myelinated, fast-conducting, able to detect quick/intense pain, sharp pain (in places like muscles & joints in body surfaces) what are examples of Adelta fibers? - correct answer immediate reflexes! touch hot stove will take away without thinking about it what are C fibers? - correct answer small, unmyelinated, slowly adapting, all over the body, detect dull and aching pain what are examples of C fibers? - correct answer stomach pain, not a huge problem that needs to be immediately brought to attention pathophysiology 3 exam 2024 peoples lectures Questions and Answers what are the 3 ion channels in nociceptors? - correct answer mechanosensitive Na+ channels, voltage- gated Na+ channel subtypes, transient receptor potential (TRP) channels what do mechanosensitive Na+ channels do? - correct answer open when stretched, if you have a drug that blocks these it would be a good local anesthetic (ex: DEG/ENaC) what do voltage-gated Na channel subtypes do? - correct answer NAV 1.7 --> are nociceptors exclusively if nonfunctional can not feel pain what do transient receptor potential channels do? - correct answer -TRP channels -activated by specific things, temperature sensitive & can detect painful temps (menthol & thymol give you a cool sensation) what are spinal & supraspinal pain pathways? - correct answer ascending pathways that go to the somatosensory cortex; there are descending pathways that go down to the spinal cord to modulate pain sensation based on mood/cognition pathophysiology 3 exam 2024 peoples lectures Questions and Answers will release endogenous opioids to decrease sensation of pain where is pain sensed in the brain? - correct answer somatosensory cortex (needed to determine location & duration of pain) what is sensed in the amygdala, insular & cingulate cortices? - correct answer emotional state & attention, fear, unpleasant aspects of pain (aka important for emotional aspect of pain) what is synaptic gating? - correct answer -nociceptors also have inhibitory interneurons that are there to be able to inhibit NT's from sending pain signals to the brain! -This will decrease pain amount -does so by overwhelming touch receptors what is hyperalgesia? - correct answer painful stimuli become increasingly painful & cause more widespread pain ex: inflammation in finger and hit it on something will become even more painful pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is phantom pain? - correct answer neurons still there in brain so you think a place in your body hurts that isn't really there what is neuropathic pain? - correct answer pain due to nerve damage ex: shingles --> told pain is in head so scratch till pain goes away but there isn't actually anything wrong there what is the dura mater? - correct answer tough outer layer what is the arachnoid membrane? - correct answer weblike middle layer CSF, blood vessels within what is the Pia mater? - correct answer delicate inner layer associated with surface of brain How does the circle of willis have collateral circulation? - correct answer -flow through connected arteries ex: atherosclerosis --> can supply blood when other blood vessels within circle of willis can't pathophysiology 3 exam 2024 peoples lectures Questions and Answers do neurons undergo cell division in the adult nervous system? - correct answer no making them susceptible to hypoxia and after more than a few minutes will begin to die what are characteristics of astrocytes? - correct answer principal cells responsible for repair & scar formation, low susceptibility to hypoxia (can survive a long time w/o oxygen) what is gliosis? - correct answer benign hyperplasia and hypertrophy; a reaction to all types of injury ex: CNS equivalent of scar what are the two broad categories of cerebral edema? - correct answer cytotoxic and vasogenic what is cytotoxic cerebral edema? - correct answer -swelling of injured cells (neurons, glia, endothelial cells) -hypoxia/ischemia --> decreased ATP --> decreased NA/K ATPase activity --> increased intracellular Na and H2O pathophysiology 3 exam 2024 peoples lectures Questions and Answers -causing swelling in rapid onset but reversible and as time goes on can become vasogenic what is vasogenic cerebral edema? - correct answer -increased interstitial fluid volume due to increased vascular permeability -BBB starting to break down and plasma will escape to extracellular space -takes hours to days -irreversible injury what are the three types of brain herniation? - correct answer subfalcine, transtentorial, and tonsillar what causes brain herniations? - correct answer displacement of brain tissue from increase in inter cranial pressure from things like edema, tumor, and hemorrhage are brain herniations bad? - correct answer yes life threatening what is a subfalcine brain herniation - correct answer -cingulate gyrus is displaced under falx pathophysiology 3 exam 2024 peoples lectures Questions and Answers can happen in elderly or young, children (shaken baby syndrome) cause: traumatic tearing of bridging veins crossing dura what is an epidural hematoma? - correct answer above the dura, rupture of a meningeal artery that causes blood to pool and separate dura from skull increase in arterial pressure --> worry about herniations cause: usually skull fracture aka: talk and die syndrome what are potential spaces? - correct answer epidural and subdural spaces not normally present in brain what is a subarachnoid hemorrhage? - correct answer trauma that causes bleeding in subarachnoid space (can be fatal initially, if you survive you have to worry about reactive vasospasms) (heme irritates vessels --> vasoconstriction --> ischemic stroke) what is an intraparenchymal hemorrhage? - correct answer -bleeding within the brain parenchyma/tissue pathophysiology 3 exam 2024 peoples lectures Questions and Answers -probably due to a small aneurysm (smoking, high BP, more age associated) what is global cerebral ischemia? - correct answer occurs if someone has cardiac arrest (heart stops beating, oxygen not supplied to brain) what is a transient ischemia attack (TIA)? - correct answer -not a stroke and no permanent damage -have stroke like symptoms then recover -can have trouble speaking, slurring words -less than 24 hours in duration what is a stroke (cerebrovascular accident) - correct answer -Blood flow to a specific part of the brain is stopped or interrupted, causing cell death, necrosis -over 24 hour duration -permanent damage signs and symptoms of a stroke? - correct answer confusion, hemiparesis (loss of sensory or motor function on one side of the body); abrupt change in vision, gait, ability to speak or understand; thunderclap headache (for hemorrhagic stroke) pathophysiology 3 exam 2024 peoples lectures Questions and Answers what two types of strokes can someone have? - correct answer ischemic stroke hemorrhagic stroke what is a ischemic stroke - correct answer -85% are these -have infarcts: blocked blood flow to an area, this will have a core (with dead and necrotic tissue) and a penumbra (around the core, that is in danger of ischemia) what is a thrombotic stroke? - correct answer -type of ischemic stroke -due to abnormal clot formation in circle of willis and often from atherosclerosis what is a embolic stroke? - correct answer -type of ischemic stroke -due to a dislodged clot or other material (moves to another bart of brain and causes ischemia) what is a hemorrhagic stroke? - correct answer -15% of strokes -rupture of a BV causes bleeding pathophysiology 3 exam 2024 peoples lectures Questions and Answers -occurs in 4th ventricle -benign even fatal what is a meningioma? - correct answer tumor of the meninges -more treatable and easier to reach -better prognosis explain metastatic tumors of the brain - correct answer -incidence: multiple tumors that come from the body --> brain -primary tissues: lung, colon, breast, melanoma what is meningitis? - correct answer -CNS infection -inflammation of meninges and subarachnoid space what are the signs and symptoms of meningitis? - correct answer fever, headache, neck stiffness, and altered mental state what is acute pyogenic (bacterial) meningitis? - correct answer -caused by a nasopharyngeal infection that spreads to the brain via the circulation pathophysiology 3 exam 2024 peoples lectures Questions and Answers -can be fatal if untreated (ex: herniation, infarction) -perform spinal tap and look at CSF what is acute viral meningitis? - correct answer less severe, bad headache, will resolve on its own (oftentimes we just tell patient to go home & rest) what is encephalitis? - correct answer -inflammation of brain parenchyma -usually viral, can be bacterial or fungal though -signs and symptoms: mild: flu symptoms but severe case: can be in coma, and have brain damage what is neurofibromatosis? (Von Recklinghausen's disease) - correct answer -type 1 = mutation in tumor suppressor gene (@ schwann cells), can be inherited/spontaneous mutation, progressively disfiguring disease; neurofibromas, optic nerve gliomas, café au lait spots, malignant potential what are neurofibromas? - correct answer -genetic disorder -multiple rubbery, painless nodular skin lesions pathophysiology 3 exam 2024 peoples lectures Questions and Answers -benign tumors of peripheral nerves composed of Schwann cells and fibroblasts what are gliomas in neurofibromatosis - correct answer glial cell tumors of the optic nerve what are cafe au last spots in neurofibromatosis - correct answer small, flat, hyperpigments skin lesions does neurofibromatosis have malignant potential? - correct answer fibromas may become malignant fibrosarcomas, other gliomas (astrocytomas) may develop what are some neurodegenerative disorders? - correct answer -multiple sclerosis, alzheimers disease, Parkinson's disease, levy body dementia, amyotrophic lateral sclerosis etiology of multiple sclerosis - correct answer -autoimmune disease involving myelin- specific autoantibodies pathophysiology 3 exam 2024 peoples lectures Questions and Answers 2. cognitive impairment, anxiety, depression, sleep disturbances, pain 3. clinical course: steady progression what is Lewy body dementia? - correct answer has many types but may occur with parkinsons pathological features in Lewy body dementia? - correct answer Lewy bodies throughout brain signs and symptoms of Lewy body dementia - correct answer -include REM disorder, visual hallucinations, fluctuating cognitive ability and attention etiology of amyotrophic lateral sclerosis - correct answer unknown, probably genetic and occurs often in late 50s pathological features in ALS - correct answer 1. loss of upper (cortical) and lower (brain stem and SC) motor neurons 2. muscle atrophy: secondary to loss of innervation pathophysiology 3 exam 2024 peoples lectures Questions and Answers signs and symptoms in ALS - correct answer 1. upper motor neurons: spasticity, uncontrolled reflexes 2. lower motor neurons: weakness and paralysis. atrophy of muscle defining feature: loss of motor neurons clinical course in ALS - correct answer relentlessly progressive death in 3-5 years what is mild traumatic brain injury & neurodegeneration? - correct answer dementia pugilistica ("punch drunk" syndome), pugilistic parkinsonism, CTE, intracellular neurofibrillary tangles containing tau protein & axonal shearing (seen in NFL players & boxers what is severe traumatic brain injury & neurodegeneration? - correct answer risk factor for Alzheimer's & Parkinson's; Abeta & tau pathology what is myopia? - correct answer 1. nearsightedness 2. focusing on distant objects becomes difficult pathophysiology 3 exam 2024 peoples lectures Questions and Answers 3. problem with eyeball being longer than usual what is hyperopia? - correct answer 1. farsightedness 2. close up out of focus, eye to short 3. focusing on point past retina what is colorblindness or color deficiency? - correct answer impairment (anomaly) or inability (anomia) to detect color due to a problem with one or more types of cone cells (proteins: red, deuter: green, trit: blue) eg: deutanopia what is conjunctivitis? - correct answer -bacteria/virus --> highly contagious -pink eye!! what is keratitis? - correct answer -inflammation of cornea -increase in nerve ending in cornea -irritation --> painful -many causes: bacteria/virus pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is dry type macular degeneration? - correct answer 85% cases -drusen: cellular debris accumulates, not abnormal to have some, a lot will be bad -macular things -VEGF: vascular epithelial growth factor: problem if occurs what are the 2 primary eye malignancies? - correct answer malignant melanoma, retinoblastoma what is malignant melanoma? - correct answer most common malignancy in adults UV radiation exposure over time treatment: radiation, chemo, denucleation (remove eye) what is retinoblastoma? - correct answer malignancy in children letukochoria --> clinical sign --> white pupil treatment: radiation, chemo, remove eye what is hypertensive retinopathy? - correct answer hypertension damages retina pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is diabetic retinopathy? - correct answer neurovascularization, leading cause of blindness in adults increase in VEGF what is glaucoma? - correct answer problem w/ normal flow of aqueous humor (thin fluid) --> pressure builds up --> open in optic disc -- > loose axons --> blindness; can be primary open angled (fluid can still reach trabeculae) or primary closed angled (fluid cannot reach network --> increased BP) what is conductive hearing loss? - correct answer its a mechanical problem and the vibrations aren't being conductive to the cochlea (ex: ossicles problems) what is sensorineural hearing loss? - correct answer there's a problem with the cochlea. The mechanical signals are making it there, but they aren't being converted into action potentials. This is a neurology issue. what is mixed hearing loss? - correct answer conductive and sensorineural issue pathophysiology 3 exam 2024 peoples lectures Questions and Answers types of cancer that can occur in external ear - correct answer basal cell carcinoma squamous cell carcinoma explain BCC on the external ear - correct answer on the pinna caused by UV rays often in elderly people and more common in men can be surgically removed unlikely to metastasize explain SCC on the external ear - correct answer on the pinna caused by UV rays often in elderly people and more common in men. can be surgically removed and LIKELY TO METASTASIZE what are risk factors for cancer on ear? - correct answer moles fair skin blue/green eyes age (older more likely) pathophysiology 3 exam 2024 peoples lectures Questions and Answers cochlea ear drum labyrinth or surrounding bone eardrum perforation brain abscesses what is otosclerosis? - correct answer -ankylosis of stapes to oval window: the stapes will not move. -conductive hearing loss -not clear on cause -treatment: surgical freeing up of the stapes or placement of prosthetic stapes/ossicles what does the labyrinth? - correct answer cochlea and vestibular organs what is labyrinthitis? - correct answer both branches of the 8th cranial nerve is affected (vestibular and auditory branches) so you lose hearing and balance pathophysiology 3 exam 2024 peoples lectures Questions and Answers what is vestibular neuritis? - correct answer lose only the vestibular part of the 8th CN so you will have balance issues and vertigo only explain what a serous bacterial infection of inner ear is? - correct answer a middle ear infection is present and the bacteria itself doesn't move into the inner ear but the toxins they create move there explain what a suppurative bacterial inner ear infection is - correct answer there is bacteria in inner ear (from inner ear) explain how noise-induced hearing loss occurs? - correct answer 1. common in places with loud noises (factory floors, music) 2. causes the loss of hair cells overtime. often found with increased age, but can occur from one single traumatic event 2. sensorineural loss of hearing what is presbycusis? - correct answer most common type of sensorineural hearing loss caused by the natural aging of the auditory pathophysiology 3 exam 2024 peoples lectures Questions and Answers system. It occurs gradually and initially affects the ability to hear higher pitched (higher frequency) sounds --companies make noise machines presenting high pitched noises to deter young people from being in certain areas How does a basic hearing aid work? - correct answer amplifies outside noise in the ear. Pretty much useless How does bone conduction hearing aids work? - correct answer titanium implant into the bone that picks up sound waves and transmits it to the bone to reach the cochlea, bypassing the entire conductive system how does a cochlear implant hearing aid work? - correct answer implant an electrode into the cochlea to bypass the hair cells. allows for direct stimulation to create action potentials. will not restore normal hearing but it is functional what is Menieres disease? - correct answer -middle aged and old people -progressive disease, gets worse over time -unknown etiology pathophysiology 3 exam 2024 peoples lectures Questions and Answers How does the cerebellum work with movement? - correct answer will receive sensory input and input from the cortex to store learned movements. Also is involved in postural reflexes (not thinking about) by taking in information and adjusting it How controls a reflex at the neuromuscular junction? - correct answer sensory neurons that will synapse on efferent alpha motor neurons without having to go to the brain to cause movement (reflex) what happens at the neuromuscular junction? - correct answer 1. depolarization at the axon terminal will cause voltage gated Ca++ channels to open 2. rush of calcium comes into the axon terminal 3. causing vesicles to fuse & release NTs- ACh into the synapse 4. ACh will binds to nicotinic ACh receptor 5.opening of non-selective cation channel) allowing K out and Na into the muscle fiber which moves more after opening of cation channel, Na or K, at neuromuscular junction - correct answer more Na+ coming in because has greater driving force. Na+ electrical and chemical gradient is in pathophysiology 3 exam 2024 peoples lectures Questions and Answers after the depolarization at the motor end plate what occurs? - correct answer spreads to the adjacent membrane which has voltage gated Na+ channels where an action potential is initiated which spreads along the skeletal muscle membrane if there an action potential at the motor end plate - correct answer no what is the role of acteylcholinesterase? - correct answer 1. cleaves ACh to cholinę and acetate 2. choline is brought back to nerve terminal to make more explain the electrical events that occur at the neuromuscular junction - correct answer Once the nicotinic receptor opens, the channel will have equal permeability to Na and K. So the potential will go equally between the two at -15mV ==> EPP depolarization explain how summation isn't required at the neuromuscular junction - correct answer takes only 1 AP in alpha motor neuron --> 1 EPP in skeletal muscle --> 1 AP in skeletal muscle pathophysiology 3 exam 2024 peoples lectures Questions and Answers How does the EPP have a safety factor? - correct answer depolarizes to -15mV that is over -55mV (threshold) therefore holding a safety net that helps if you have a disease, you will still be able to send AP's and move skeletal muscle what occurs to the synapse if you are exposed to nerve gas and pesticides - correct answer acetylcholinesterase will be blocked leading to ACh build up in the synapse!! what does nerve gas and pesticides do to your skeletal muscle and therefore AP's? - correct answer 1. causes paralysis because muscles aren't able to contract due to membrane staying depolarized at -15mm ---> prevents more contraction because we have to depolarize to remove inactivation gates of VG Na channels Explain how a myotonic (stretch) reflex causes muscle contraction - correct answer hit knee --> stretch tendon --> stretch muscle --> muscle contracts