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Details Title: Human Physiology Description: Membranes/Membrane Potentials, Nervous System Total Flash Cards: 139 Created: 02/01/2007 12:56:57	To study from this set of flash cards, or to create your own your own study flash cards, register HERE. If you are already a registered user, CLICK HERE.
Cards Term 2 properties of a molecule that influence its movement across a cell membrane? Definition size, and lipid solubility Term diffusion is caused by what? Definition molecular motion Term t/f the rate of diffusion increases as temp increases Definition true Term fick's law of diffusion says that rate of diffusion is equal to... Definition SA*[] gradient*membrane perm./membrane thickness Term flux= Definition []gradient*membrane perm. Term facilitated diff. Definition is passive, and moves molecules down concentration gradient until equal concentrations on both sides Term channel proteins Definition create water-filled passageways that directly link ICF and ECF Term carrier proetins Definition bind substrates and transport them across membrane but the ICF and ECF are not in dirrect contatct Term compare channel vs. carrier proteins Definition channel proteins are faster at transport but less selective. Carriers can also move larger molecules than channels Term What determines the selectivity of a channel? Definition the diameter of the pore and the electrical charge of the pore residues Term 3 types of gating are ... Definition mechanical, voltage, chemical gating Term GLUT1 Definition glucoses and other hexoses in most tissues Term GLUT2 Definition glucose and hexoses in liver and epithelium of intestine and kidney Term GLUT3 Definition glucose and hexoses in neurons Term GLUT4 Definition glucose in adipose tissue and skeletal muscle Term GLUT5 Definition Fructose in intestinal epithelium Term name a saturable transporter Definition GLUT Term name the 3 kinds of tranport proteins in the transport of glucose Definition Na+-glucose symporter GLUT transporter Na+K+ ATPase Term equilibirum potential Eion= Definition 61/z log [ion]out/[ion]in Term afferent neurons Definition bring sensory info to the CNS Term Efferent neuronsd are divided into 2 classes... Definition somatic and autonomic neurons Term the autonomic nerurons or visceral neurons are divided into Definition sympathetic and parasympathetic branches Term Neurons are classified as ... Definition sensory (afferent), interneurons, and efferent(somatic and autonomic) Term long axons budled together with connective tissue in the peripheral NS are known as Definition NERVES Term the area where an axon begins is known as a Definition axon hilcock Term two ways that proteins are moved to the axon terminal from the call body Definition slowaxonal transport (diffusion), and fast axonal transport (microtubles transport) Term PNS glial cell that secretes myelin Definition Schwann Cell Term CNS glial cell that secretes myelin Definition oligodendrocytes Term How do schwann cells create myelin Definition they wrap around the axon many times forming multiple insulating layers of cell membrane Term difference b/t oligodendrocytes and Schwann cells Definition oligo's can form myelin around portions of several axons while Schwann is 1:1 Term Goldman Hodgkin Katz (GHK) eqn. Definition Vm=61log the combined effects of each ions permeabilty and conc. gradient Term movement into the cell Definition influx Term movement out of the cell Definition efflux Term this channel has 2 gates Definition Na+ activation and innactivation Term why cant action potentials travel backwards? Definition refractory periods prevent it Term why is a stronger than normal graded potential needed to create a new action potential during the relative refractory period? Definition because the K+ channels are still open and any movement of Na+ into the cell is offset by the loss of K+ Term 2 factors that influence the rate of conduction of neurons Definition 1)diameter of axon 2) resistance of the axon memb rane to ion leaekage Term Why is saltatory conduction of action potentials faster? Definition opening of channels slos conduction slightly Term name two demylenating diseases? what is the affect? Definition Guillain-Barre, and MS The action potentials may be subthreshold due to ion leak Term Some neurotoxins and local anesthetics like procaine work by.... Definition altering the conduction of ions by binding to Na, K, and Ca channels Term What happens in the Na channel is made unfunctional Definition Na can't enter cell, so the depolarization loses strength down the axon like a graded potential and may be subthreshold Term hyperkalemia Definition hjigher than normal extracellular [K], shifts the resting mem potential closer to threshold and subthreshold AP's are fired Term hypokalemia Definition lower than normal extracellular [K] and moves resting potential away from threshold' potentials that should be suprathreshold may become subthreshold, muscle weakness Term two toxins that block excytosis of neurotransmitters Definition botulinum and tetanus toxins Term initiates the release of NT into synapse when axon terminal depolarized Definition Ca++ Term 3 types of acetylcholine receptors Definition cholinergic, nicotinic, muscarinic Term muscarinic ACh is what kind of receptor? Definition GPCR Term NIcotinic ACh recep. is what kind? Definition Ion channel receptor (Na, K) Term What are the receptors for Norepinephrine? what kind of receptors? Definition (alpha, beta) adrenergic GPCR Term what is the name/ type of receptor for dopamine? Definition Dopamine GPCR Term Serotonin receptors? Definition Serotoneric Ion channel receptors (Na, K) and GPCR Term Histamine receptors? Definition Histamine GPCR Term Glutamate receptors? Definition AMPA ion channel (Na, K) and NMDA ICR (NA,K,Ca) Term Glutamate is inhib or excit? Definition excitory Term GABA receptors? inhib/excit? Definition GABA ICR (Cl) and GPCR. It is inhibitory Term Is glycine inhib or excit? Definition inhibitory most times Term Adenosine receptors? Definition Purine GPCR Term Myasthenia Gravis Definition an autoimmune disease that destorys ACh receptor and produces skeletal muscle weakness Term Receptors that alter ion channel function are called Definition ionotropic Term Receptors that exert action through a second messenger system is called Definition metabotropic Term EPSP Definition excitatory depolarization Term IPSP Definition Inhibitory hyperpolarization Term AMPA receptors Definition are ligand gated channels similar to nicotinic ACh channels; glutamate binds, Na influx, depolarization Term NMDA receptors Definition channel opening requires gulutamate binding and a change in membrane potential to move Mg out of the way Term creates a fast synaptic potential Definition opening of an ion channel to allow the movement of ions thus changing the mebrane potential Term create a slow synaptic membrane potential Definition GPCR acting thru scond messengers to effect a change in mem pot. Term 3 ways neurotransmitter activity is terminated Definition diffusion,inactivation by enzymes, or reuptake of NT to presynaptic axon Term Name two enzymes that destroy NT Definition acetylcholinestarase (AChE) acts on ACh and MAO destroys norepinephrine Term what is a divergent pathway? Definition one presynaptic neuron branches to affect many post synatpic neurons Term what is a convergent pathway? Definition many presynaptic neurons converge to influence a smaller number of post synaptic neurons Term what is spatial summation Definition the initiation of an action potential from several simultaneous subthrshold graded potentials Term what is temporal summation? Definition SUMMATION THAT OCCURS FROM GRADED POTENTIALS OVERLAPPING IN TIME TO CREATE A SINGLE ACTION POTENTIAL Term long term potentiation Definition process in which activity at a synapse induceces sustained changes in the quality or quantity of synaptic connections Term What is a key compnent of long term potentiation? Definition the NT glutamate Term how does Glutamate cause LTP? Definition because the NMDA causes intake of Ca which activates a second messenger to produce paracrine signal which enhances NT release from presyn, and greater synsitivity to NT in post synapt. Term what is plasticity? Definition the ability to change circuit connections and functions un repsonse to sensory input Term These reflexes do not require integration in the brain but can occur in the ganglion Definition spinal reflexes Term what are ventricles? where are they located? Definition hollow areas of the brain, there are four, two lateral and two descending Term what is diff bt white and grey matter? Definition white matter has myelinated axons, and grey isnt Term clusters of cell bodies clustes of axons? Definition nuclei (CNS), galglia (PNS) Nerves (PNS) and tract (CNS) Term 3 layers of meninges moving from brain to cranium Definition pia mater, arachnoid membrane, dura mater Term specialized region on the walls of ventricles that secrete CSF Definition choroid plexus, helps regulate the material entering the CSF Term What is the blood brain barrier Definition AStrocytes foot processes help create tight junctions between the capillary cells to make a highly selective endothelial layer Term Specialized part of spinal nerve to bring incoming sensory info Definition dorsal root (has dorsal root ganglia) Term carries info from CNS to muscles and glands Definition ventral root Term ascending tract descending tracts propiospinal tracts Definition info from cord to CNS info from CNS to cord tracts that remain within the cord Term parts of the brain stem and functions Definition medulla= white matte has somatosensory tracts and corticospinal tracts greymatter controls involuntary functions like BP, breating, swallowing, vomitting Pons=relay station between cerebellum and cerebrum Midbrain= controls eye movements and auditory and visual reflexes Term what is the cerebellums function? Definition coordinate movement and balance Term the 4 parts of the diencephalation and their fxns Definition thalamus=relay station bt lower brain to cerebrum hypothalamus=center for homeostasis and behaviors like sex, hunger, and thirst pituitary gland= secrete endocrine hormones pineal gland=secretes melatonin Term part of cerebrum that connects the two hemispheres Definition corpus callosum Term the three major regions of the cerebrum Definition cerebral cortex, basal ganglia, and the limbic system Term fxn. of cerebral cortex Definition higher brain fxns. Term fxn. of basal ganglia Definition grey matter controls the control of movement Term parts/fxn of limbic system Definition Cingulate gyrus=plays role in emotion Hippocampus=is involved in learning and memory Amygdala=involved in emotion and memory Term lobes of cerbral cortex and fxns. Definition frontal= coordinates info from other areas, behavior, taste parietal=sensory association Ociipital=vision Temporal= Hearing and smell Term A role of the reticular formation Definition keeping the conscious brain awake Term Damage to Wernicke's area causes Definition a person is unable to understand spoken or visual info, speech from person is nonsense (receptive anaphasia) Term Damage to Broca's area Definition person is unable to speak or write in normal syntax; speech consists of appropriate words strung together in random order; patients are aware of their mistakes but anable to fix them Term Proprioception is Definition the awareness of body movement and position in space Term TOnic Recpetor Phasic Receptor Definition are slowly adapting receptors that respond rapidly for the druation of the stimulus ex-pain rapidly adapt to a constant stimulus then turn off ex-smell Term Nociceptors Definition are receptors that respond to stimuli that could harm or destroy tissue Term Nociceptive pain Definition is mediated by free nerve endings that repond to chem, mech, and thermal stimulil with the help of membrane ion channels Term 2 ways that nociceptors may act Definition 1) a reflexive protective response integrated at spinal cord 2) a consious sensation through ascending pathways to the cerebral cortex (pain and itch) Term 3 types of primary sensory fibers that carry afferent signals to CNS Definition alpha beta, alpha delta, and C fibers Term Fast pain Slow Pain Definition sharp and localized; transmitted on alpha delta fibers dull and diffuse; transmitted on slower C fibers Term Where are nicotinic ACh receptors located? Where are muscarinic ACh receptors located? Definition Skeletal Muscle, CNS Smoot and cardiac muscle, glands, CNS Term Region of the brain where glutamate signaling has been studyied? Definition Hippocampus Term Fine touch, proprioception, and vibration cross midline where? Nociception, temperature, and course touch cross where? Definition medulla spinal cord Term lateral spinothalamic tract of spinal cord does what?? Definition temperature and pain sensations from body Term what does basal ganglia do? Definition muscle coordination, movement Term lateral horns of spinal cord do what? Definition anatomic regulation of internal organs and vessels Term spinothalamic Definition ascending tract Term corticospinal Definition descending tract Term Iion= Definition Gion(Vm-Eion) Term What is COMT? how does it work? Definition It degrades a NT by methylating it Term is adenosine inhib/or exhit? Definition inhib in CNS and vasodialator Term muscarinic ACh is EPSP and IPSP where Definition IPSP in heart and EPSP in smooth muscle Term gives a clinical assesment of the enviroment of the brain Definition spinal tap Term this type of afferent fiber is what causes fast pain Definition alpha delta Term what accounts for rubbing an injury to make the pain go away? Definition the gate control theoy: mechanical stimuli carried on alpha beta fibers can accivate an inhibitory neron that diminshes the pain signal carried on c-fibers (slow, dull pain) Term these afferent neurons are conducted contralaterally to the dorsoventral horns Definition fine pain, temperature, coarse touch;;;; dull pain, virbration, and proprioception are ipsilatertal Term Parasympathetic nervous system is for... Sympathetic for.... Definition PSNS=Rest and digest,,, SNS=for f's fight flight fright fuck Term these neurons have long pre-ganglionic fibers and short post-gang. fibers (ganglia lie close to organ) Definition parasympathetic autonomic neurons Term positions of para and sympathetic innervations along spinal cord Definition para=cranio-sacral sympathetic=thoracolumbar Term main NT of each autonomic division Definition para= ACh onto muscarinic receptors and symp= norepinephrin onto adrenergic receptors Term alpha 1 symp. receptor Definition stimulatory, activate PLC and IP3 opens Ca channels leading to contraction Term alpha 2 sympatecic receptor Definition inhibitory, decrease cAMP to cause smooth muscle relaxation in GI Term beta 1 symp. receptor Definition stimulatory, increase cAMP cause smooth muscle and cardiac contraction Term beta 2 symp. receptor Definition inhibitory, decrease cAMP to cause vasodilation and bronchodilation Term beta 3 symp. receptor Definition increase cAMP in adipose tissue Term alpha sympathetic receptors respond strongly to which NT? Definition norepinephrine Term muscle spindles are.... Definition embedded between skeletal muscle fibers to detect stretch on a muslce Term what aare the roles of various fibers in the muscle spindle Definition alpha fibers synapse onto extrafusal skeletla muscle and the gamma fibers synapse on contractile portion of intrafusal fibers Term how do muslce fibers work Definition these are tonically active sensory neurons that connect to spinal cord. When length in muscle stretches the spindle increasing the frequency of AP's to cord Term what are golgi tnedons? Definition sense stretching in tnedon and prevent muscle from damage caused by excessive contraction Term how do golgi tendon organs work? Definition stretching of colllagen fibers compress nerves which excite inhibitory neruons that synapse on alpha motor neurons to decrease contraction or cause it to stop altogether Term two types of lipid soluble hormones and where they are made Definition steroids=adrenal cortex and thyroid=thyroid gland Term what is the level of hormone neede to cause an effect? Definition small levels of hormone are needed to create an effect Term which hormones have the shortest/longest action? Definition steroids=longest and peptides=shortest