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fnh160
midterm content
| Question | Answer |
|---|---|
| anatomy vs physiology | anatomy is studying body structures, physiology is studying how those structures work together to carry out functions |
| levels of organization in the body | chemical, cellular, tissue, organ, body system, organism |
| chemical organization | atoms combine to form molecules |
| cellular organization | smallest unit that can carry out life processes |
| ribosomes | protein synthesis |
| nucleus | dna |
| smooth er | fat synthesis |
| golgi apparatus | sorts and packages proteins |
| lysosome | digestive enzyme that breaks down waste |
| mitochondria | atp/energy |
| tissues | groups of cells that perform the same function, they're organized into tissues in multicellular organisms |
| types of tissue | epithelial, connective and excitable |
| epithelial tissue types | exchange, transport, ciliated, protective, and secretory |
| connective tissue types | loose, dense, hardened, adipose, and blood |
| loose tissue | under skin and around organs |
| dense tissue | ligaments and tendons |
| hardened tissue | bone |
| adipose tissue | fat/lipids |
| excitable tissue types | muscle and nervous |
| muscle tissue types | skeletal, cardiac, and smooth |
| nervous tissue types | neurons and glial cells |
| glial cells | cells in the brain that aren't neurons, they support neurons |
| organs | two or more types of primary tissue that work together to perform a specific function |
| body system | group of organisms that perform related functions |
| organism | independent living thing, group of body systems that work together |
| types of fluid compartments | intracellular (ICF) and extracellular fluid (ECF) |
| intracellular fluid | inside of the cells, 2/3 total body water |
| extracellular fluid | outside of the cells, 1/3 total body water. this is further divided into two types |
| ECF- plasma fluid | found in the blood, makes up 1/4 of the ECF |
| ECF- interstitial fluid | around cells, 3/4 of ECF |
| negative feedback | response restores equilibrium by opposing the change |
| positive feedback | response enhances the og chance |
| feedback look: receptor | first step, detects the change |
| feedback loop: integrator/integration centre | second step, carries the message (key words are recognizes/releases) |
| feedback look: effector | third and final step, actually makes the adjustments to restore |
| nervous system | body's primary communication centre |
| nervous system: 2 parts | central (CNS) and peripheral (PNS) |
| central nervous system (CNS) | brain and spinal cord |
| peripheral nervous system (PNS) | nervous that extend beyond the CNS (i.e. everything that isn't the brain or spinal cord). maintains homeostasis by monitoring and rapidly responding to internal and external changes in the environment |
| PNS: 2 parts | efferent and afferent |
| PNS: motor/efferent nervous system | brings information away from CNS. carries motor commands to muscles and glands |
| PNS/efferent nervous system: 2 parts | somatic and autonomic |
| autonomic nervous system | involuntary branch of the efferent/peripheral nervous system |
| autonomic nervous system: 2 parts | sympathetic and parasympathetic |
| sympathetic nervous system | flight or flight. preps the body for strenuous activity and dominates in stressful situations |
| parasympathetic nervous system | rest and digest. promotes body maintenance activities and dominates in quiet and relaxed situations |
| PNS: sensory/afferent nervous system | brings information to the CNS. carries sensory information like pain, touch, temperature etc |
| neuron | excitable cell that can product electric signals (ion/charged particle movement) |
| membrane potential | separation of opposite (positive and negative) charges across the plasma membrane |
| resting membrane potential | -70 mV, different between ICF and ECF charges at rest |
| equilibrium potential | membrane potential when the electric gradient = chemical gradient, so there's no net movement across the membrane |
| ECF charge | positive |
| ICF charge | ICF charge |
| K+ electric gradient | K+ wants to move inside of the cell i.e. from ECF to ICF |
| K+ chemical/conc. gradient | higher conc. of K+ in ICF, so it wants to leave the cell (go to ECF) |
| K+ net movement | chemical > electric gradient so K+ wants to move outside of the cell till -90 mV |
| Na+ chemical/conc. gradient | higher conc. of Na+ in ECF, so Na+ wants to move inside of the cell |
| Na+ electric gradient | Na+ wants to move inside the cell i.e. from ECF to ICF |
| Na+ net movement | chemical = electric gradient so Na+ wants to move inside the cell till +60 mV |
| changes in membrane potential | polarization: uneven distribution of electron density, creating regions of partial +ve and partial -ve charge |
| depolarization | decreases the difference between the +ve and -ve charge (e.g. -70 mV to -50 mV) |
| repolarization | making the cell more -ve again i.e. undoing the depolarization, closer to membrane potential (e.g. from -50 mV to -60 mV) |
| hyperpolarization | increasing the difference between charges more than the initial membrane potential (e.g. -70 mV to -90 mV) |
| neuron signalling | electrochemical process where nerve cells (neurons) receive, process, and transmit information |
| graded potenial | initiates electric signal, opens chemical(ligand)/mechanical gated ion channels. depolarizes that specific location of the membrane then dissipates away |
| threshold potential | the membrane potential where an action potential occurs |
| action potential | large change in membrane potential. happens at threshold potential. opens voltage gated ion channels and sends the signal |
| graded potential nature | can vary in size depending on intensity of stimulus, can add together with other graded potentials to increase size, doesn't self propagate i.e. doesn't send a signal |
| action potential nature | goes to the same maximal height every time, self propagates down the axon which sends the signal |
| refractory period | recovery period right after a stimulus occurs, the excitable cell is unable to respond to another stimulus, has two types |
| absolute refractory period | post action potential, membrane cannot be restimulated because the Na+ channels become inactivated and close |
| relative refractory period | post action potential, membrane can only be restimulated with a greater stimulus/stronger graded potential. K+ channels are still open, allowing K+ to move out of the cell as Na+ tries to move in and depolarize the membrane again |
| conduction | nature/how the action potential moves down the axon |
| myelin | fat/lipid that wraps around the axon and acts as an insulator |
| contiguous conduction | happens in unmyelinated fibres. every portion of the axon membrane has to get an action potential |
| saltatory conduction | happens in myelinated fibres. action potential skips through the parts of the axon membrane that have myelin (because the fats don't like ions, so bno charged particles can get in or out so it just skips over) and travels down the axon really fast |
| rate of conduction | speed/how fast the action potential moves down the axon. determined by myelin (with myelin = faster) and diameter of axon (larger = faster) |
| dendrites | receives inputs |
| cell body | has all the organelles |
| axon | sends the outputs/info |
| terminal bulb | communicates with other cells |
| afferent/sensory neurons | brings info from the PNS to the CNS. starts with receptors in the PNS (instead of dendrites, because they detect the signal not only pass it on), cell body is halfway down the axon |
| interneurons | only in the CNS, make up 99% of neurons. in between afferent and efferent, receives signals from afferent, and interprets the data and sends instructions to the efferent neurons |
| efferent/motor neurons | leave the CNS, cell bodies are in the CNS, and they send the message to something e.g. muscle or gland |
| synapses | verb and noun. it's the connection between neurons (neurons don't actually touch each other), but is also the electric signal that gets passed |
| presynaptic neuron | axon terminal |
| synaptic vesicle | in the presynaptic neuron, holds neurotransmitters |
| synaptic cleft | space in between 2 neurons where neurotransmitters diffuse into |
| ion channel receptor | neurotransmitters bond to this on the postsynaptic neuron |
| postsynaptic neuron | dendrites |
| neurotransmitter removal | once they get released into the synaptic cleft, the effect needs to be turned off so they can get removed in three ways |
| NT reuptake | NT go back up into the presynaptic neuron (where they og. came from) or into surrounding cells |
| NT inactivation | when the effect is done, enzymes come and degrade them |
| NT diffusion | once released they move away from the synaptic clef and go into the blood (so it has little to no effect) |
| NT and synapse relationship | different NT for every synapse, and the same NT is always released at the same synapse |
| acetylcholine | prevalent in the brain, used on efferent neurons (the ones that go out to the body) so it controls movement basically |
| glutamate | amino acid that depolarizes the next neuron, so it's a main excitatory NT |
| GABA | amino acid that acts as an off switch, so it's an inhibitory NT. opens Cl- channels to hyperpolarizes the membrane |
| norepinephrine | monoamine thats mainly used in the fight or flight response in the sympathetic nervous system |
| dopamine | monoamine that triggers pleasure and reward |
| seretonin | monoamine used in mood regulation |
| synaptic convergence | each postsynaptic neuron can receive inputs from thousands of presynaptic neurons. basically a bunch of inputs converge onto one cell, and the sum of those inputs determine the output |
| synaptic divergence | single presynaptic neuron branches out and 'synapses' onto many postsynaptic neurons |
| postsynaptic potentials | whats happening on the postsynaptic cell when it receives the signal (signal being graded potentials) |
| excitatory post synaptic potential (EPSP) | depolarizes and increases the likelihood of reaching threshold |
| inhibitory post synaptic potential (IPSP) | hyperpolarizes and decreases the likelihood of reaching threshold |
| grand post synaptic potential | because of synaptic convergence, a single neuron is receiving thousands of different inputs at a time. there are different ways to determine whether an action potential will happen or not |
| temporal summation | two EPSPs occur close to each other in time, and add up to achieve a larger membrane depolarization i.e. closer to threshold |
| spatial summation | based on location. EPSPs coming from different neurons converging onto one close to each other generates a larger depolarization |
| EPSP-IPSP | if a neuron gets stimulated with an EPSP and IPSP of the same magnitude, they will cancel out and nothing will happen |
| reflex | automatic, involuntary response to a stimulus that happens without conscious thought |
| botulinum toxin (botox) and NT | prevents the release of acetylcholine (which stimulates muscle movement), preventing muscle contraction |
| tetnus and NT | prevents release of GABA (inhibitory neuron that induces muscle relaxation), meaning the muscle stays contracted |
| SSRI and NT | inhibits reuptake of serotonin, so it binds for longer making you happier/improving mood regulation |
| physiological basis of memory | thoughts, perceptions, and memories are based on neural connections |
| learning process | forms new neural connections |
| memory making process | strengthening connections (breaking habits weakens neural connections). neural pathway is created from input, info is stored in short term (connections are briefly strengthened, then repeated stimulus (retrieval and rehearsal) long term is formed |
| neuroplasticity | ability to change neural connections i.e. strengthen, weaken, or form new ones |
| neurogenesis | formation of new neurons |
| short term memory | temporarily strengthens already existing neural connections. limited capacity and limited duration, hippocampus processes and prefrontal cortex stores them |
| long term memory | involves structural/functional changes to neural connections (e.g. new axon terminal being created). infinite capacity and longer duration. hippocampus processes, stored in cerebral cortex, amygdala, and cerebellum |
| habituation | decreased response to a repetitive presentation of an indifferent stimulus |
| habituation process | action potentials fired often, leading to cumulative and prolonged entry of Ca+ into the presynaptic neuron,. sustained membrane depolarization locks voltage gated Ca+ channels into a non-conducting state, so less Ca+ comes in and less NT gets released |
| sensitization | increases response following a strong or painful stimulus |
| sensitization process | interneuron releases serotonin which blocks K+ channels, preventing K+ or Na+ movement, prolonging the action potential. longer AP means more Ca+ gets let in, so more NT leaves, more NT means bigger response |
| long term potentiation | long lasting strengthening of neural connections that happen after repeated or high frequency stimulation |
| long term potentiation process | glutamate release from presynaptic neuron, binding to AMPA receptors (Na+ channels), Na+ enters, depolarization. more glutamate activates NMDA receptor (Ca+ channel). Ca+ makes more AMPA, so the synapse has more Na+ channels allowing more Na+ in next stim |
| declarative memories (explicit) | facts, events, and spaces. hippocampus helps form, stored in cerebral cortex. hippocampus brings neuron projection together, cerebral cortex does the connecting |
| procedural memories (implicit/autopilot) | procedures and habits. formed and stored in the basal nuclei and cerebellum |
| cerebellum | part of brain involved in motor function |
| retrieve memory | recall long term memories for future use |
| re encoding memories | how your memories change with new information |
| diffuse/decay of memories | neural connections are lost, it gets rid of stuff you don't use |
| interference of memories | new memories interfere with our ability to recall old ones |
| encoding failure of memories | the neural connection wasn't very strong |
| bone: protection of CNS tissue | tissues are enclosed in hard bony structures |
| brain bone protection | cranium |
| spine bone protection | vertebral collum |
| meninges: protection of CNS tissue | protective and nourishing membranes. they have 3 types |
| meninges: dura | 'durable'. toughest, thick and strong outermost layer found under the scalp and skull bone/cranium |
| meninges: arachnoid mater | covers blood vessels (that look like spiders like 'arach') |
| arachnoid mater: subarachnoid space of the brain | actually has the blood vessels |
| meninges: pia mater | innermost layer. follows the grooves of the brain, making it hard to separate because they're very closely attached. |
| cerebrospinal fluid: protection of CNS tissue | surrounds and cushions the brain and spinal cord. they're basically floating in this fluid |
| cerebrospinal fluid process | fluid filled spaces of the brain have specialized cells that make the fluid. it travels from these spaces into the subarachnoid space around the brain and spinal cord |
| blood brain barrier: protection of CNS tissue | brain blood vessels are not porous/leaky (like normal blood capillaries are) because they're tightly linked together and wrapped in another layer of cells. nutrients and gases are allowed in, but not things like viruses, which can normally spread |
| glial cells of CNS | cells in the brain that are not neurons (they support neurons) |
| glial cells: astrocytes | have a bunch of projections that make it look like a star (astro). most abundant, holds neurons in place (spatial arrangement), makes up the blood brain barrier (wraps around blood vessels) and maintains ECF |
| glial cells: ependymal cells | lines the brain cavities (spaces) and forms cerebrospinal fluid |
| glial cells: microglia | immune cells of the brain, attacks things that are foreign or damaged |
| glial cells: oligodendrocytes | make myelin that wrap around axons to insulate them and speed up electric signals |
| spinal cord location | goes from base of brain to lumbar/lower back |
| spinal cord job | link between the brain and body, manages reflex activity (involuntary automatic movement) |
| spinal cord protection | same as brain (same meninges and cerebrospinal fluid, but has blood spine barrier and vertebral column instead of cranium) |
| grey matter in spinal cord | found in the middle, is the neuron cell bodies |
| white matter in spinal cord | surrounds the grey matter, made up of tracts that are bundles of axons that are wrapped in myelin (the white is the fat because fat is white) |
| spinal nerves | allow info to come in and out of the spinal cord. has two types of 'roots'. all of the nerves start inside the spinal cord then extend beyond. the nerves are made up of a bunch of neruons |
| spinal nerve: dorsal root | afferent neurons bring info into the spinal cord from PNS to CNS (come from behind, dorsal = back/behind) |
| spinal nerve: ventral root | efferent neurons send messages out into the body from CNS to PNS (the cell starts in the spinal cord) |
| cervical nerves | neck area |
| thoracic nerves | trunk/chest |
| lumbar nerves | lower back |
| sacral nerves | tailbone |
| coccogeal nerves | basically legs |
| brain's functions | homeostasis, perception, voluntary movement, emotions, higher cognitive processes (thoughts and memories) |
| brain stem | vital link. controls digestive, cardiovascular, and respiratory function. starts at base of brain and is continuous with the spinal cord. cranial nerves start here. |
| reticular activating system (RAS) | controls degree of awareness, collection of neurons in the brain stem that activate when we're awake (tells the cerebellum to be awake and alert) |
| hypothalamus | homeostasis, controls body temp, sleep, thirst, controls autonomic nervous system (para and sympathetic nervous system) |
| pituitary gland | found in hypothalamus, produces pituitary hormones which manage metabolism, stress response, growth etc) |
| thalamus | middle of the brain above the hypothalamus. sensory input goes through the thalamus, then the message gets sent to the cerebrum |
| cerebellum | controls balance, muscle movement and tone (degree of contraction/tension of the muscle at rest). stores procedural memories |
| basal nuclei | groups of neurons deeply embedded into the brain, controls posture and smooth voluntary movements (impairment would cause parkinsons's) |
| cerebrum | outerlayer of the brain, has a lot of folds, has a left and right side (which uses the corpus collosum to communicate with each other) |
| cerebral cortex composition | outerlayer = grey matter (cell bodies and dendrites). core = white matter (axons that connect the dif areas of the brain). this is opposite to the spinal cord/ divided into different cortical lobes. |
| occipital lobe: cerebral cortex | at the back, vision |
| temporal lobes: cerebral cortex | at the sides, hearing |
| parietal lobe: cerebral cortex | top back of head, somatosensation. different sections correspond to different areas of the body |
| frontal lobe: cerebral cortex | front of head, voluntary movement |
| prefrontal cortex: frontal lobe | at the very very front, does higher level thinking |
| primary somatosensory cortex | behind central sulus. perceives sensations in the body |
| wernicke's area: primary somatosensory cortex | understands written and spoken language |
| broca's area: primary somatosensory cortex | produces sound, coordinates the motor commands needed to shape words using the mouth |
| limbic system | network of structures in the brain that control emotions and behaviours, survival and perception of species, motivation and sexual behaviours |
| amygdala: limbic system | controls emotions |
| hypothalamus: limbic system | activates autonomic nervous system (para or sympathetic system) |
| hippocampus: limbic system | learning and memory |
| afferent/sensory nervous system: visceral stimuli | internal changes that are not usually consciously perceived |
| afferent/sensory nervous system: sensory stimuli | external stimuli that are consciously perceived. have two types |
| sensory stimuli: somatic sensation | touch, pain, hot/cold, proprioception i.e. physical awareness |
| sensory stimuli: special senses | visual, auditory, olfactory, taste, equilibrium |
| afferent/sensory nervous system: perception | conscious awareness/interpretation of the external world. derived from sensory input (doesn't give true reality) |
| receptor physiology | receptors at the nervous system are structures at the end of afferent neurons (found in CNS). they don't have dendrites because they start with a receptor, they start the signal. turn various stimuli into electrical energy i.e. graded or action potentials |
| transduction process | stimulus, mechanically gated ion channels open, Na+ enters, depolarization, graded potential, more Na+ leads to threshold, voltage gated channels open, threshold reached, action potential |
| coding of sensory info: type of stimulus | processed by a specific receptor, then sent to a particular area in the cerebral cortex |
| coding of sensory info: location of stimulus | where the receptors are (receptive field), and which area of the somatosensory cortex gets activated (which corresponds to an area in the body) |
| coding of sensory info: intensity of stimulus | frequency of action potentials initiated after the neuron is activated/amount of receptors/afferent neurons activated |
| somatosensation | sensations that arise from the body/skin |
| proprioceptions | sensations from muscles, tendons, and joints showing you the position of your limbs |
| primary somatosensory area | located in parietal lobe of the cerebral cortex |
| somatosensation detection process | stimulus, ion channels open, Na+ enters, enough Na+ threshold leads to action potential, info goes to the CNS |
| ascending pathways | transports somatosensation info/signals to the cerebral cortex in the brain (where we have conscious awareness), and uses 3 different neurons |
| ascending pathways: first order neuron | receptor to the CNS. detects and sends info via the dorsal root ganglion (type of afferent neuron) |
| ascending pathways: second order neuron | CNS to thalamus, type of interneuron because it's inside the CNS |
| ascending pathways: third order neuron | thalamus to cerebral cortex, the sensation then gets interpreted, type of interneuron |
| pain | protective mechanism meant to bring conscious awareness that tissue damage is going to happen. helps to prevent/avoid potentially harmful events in the future |
| nociceptors | receptors that detect pain. has 3 different types |
| mechanical nociceptors | detect mechanical damage e.g. cutting, crushing, pinching etc |
| thermal nociceptors | detect temperature extremes |
| chemical nociceptors | detect irritating chemicals |
| pain transmission process | same as other somatosensations (i.e. ascending pathways): nociceptors to brain stem to thalamus to somatosensory cortex (localization of pain). also goes from brain stem to reticular formation (makes u alert), then limbic system (relating emotion to pain) |
| opiates | peptide neurotransmitters in the body that bind to opioid receptors which regulate pain and mood |
| endorphins | endogenous opiates that block pain transmission to the brain |
| endorphin process | pain detected, brain sends message to release endorphins, bc it's an opiate it blocks the first neuron from sending the message to release of substance P, pain subsides |
| exogenous opiates | substances you can take to mimic the effect of opiates. stimulates the release of dopamine. if you take them consistently you can build a tolerance (i.e. need more to get same effect) |
| exogenous opiate tolerance process | GABA released to stop dopamine release, opioids stop GABA, dopamine keeps getting released, GABA gets used to the opioids stopping it, more opioids are need to stop GABA (continue dopamine release) |
| when on exogenous opiates | pain is dulled and dopamine is released |
| when off exogenous opiates | GABA goes full force, completely stopped dopamine release, causing intense pain and a crash |
| chemical senses | taste and smell |
| taste detection process | tastants (chemicals) dissolved in water/saliva to go into taste pores and bind to taste receptors, chemically gated ion channels open, Na+ enters, taste receptors synapse with afferent neurons, action potential, signal travels to brain |
| salty | chemical salts like NaCl |
| sour | acids that have free H+ |
| sweet | configurations of glucose |
| bitter | chemically diverse group of alkaloids, toxic plant derivates, poisonous substances |
| umami | meaty/savoury taste evoked by amino acids, especially glutamate |
| taste perception | same process as somatosensation (3 neuron path). taste receptor detect tastants, signal is sent via cranial nerves to the brain stem, brain stem to thalamus, thalamus to glustartory cortex in the cerebral cortex |
| smell detection process | detected by olfactory receptors (at top of nasal cavity), the receptor is afferent neuron, Na+ opens, action potential travels from olfactory bulb to olfactory nerve, scent gets organized in olfactory bulb, interneurons pass the signal to cerebral cortex |
| olfactory receptors | are the only neuron that can be replaced (the other ones cant) because they're renewable and replaceable |
| how we sense smell | have to volatile (vaporized) to reach the olfactory mucosa. when u eat, these scent fumes travel there via pharynx |
| flavour | taste + smell + what you're expecting + vision |
| pupil | round opening in the centre of the iris where light enters |
| iris | thin, pigmented (your eye colour) smooth muscle that forms a ring like structure |
| iris: sphincter pupillae | circular muscles, constrict the pupil, controlled by parasympathetic, protect the retina from bright light by reducing the amount of light that enters the eyes |
| iris: dilator pupillae | radial muscles, dilate the pupil, controlled by sympathetic, helps you see better in the dark by increasing the amount of light that enters the pupil |
| cornea | outermost layer that protects the pupil and iris |
| sclera | outermost layer that covers and protects the rest of the eye (is continuous with the cornea) |
| retina | covers the very back of the eye. has photoreceptors that detect light (this info gets sent to the brain via optic nerve) |
| fovea | at the centre back of the eye, vision is the most clear because it has the most photoreceptors |
| vision perception process | light enters pupil (front of eye), hits retina (back of eye), detected by photoreceptors (rods/cones), message gets passed to bipolar cells, leaves via optic nerve to ganglia cells |
| photoreceptors | layers of membrane embedded with light absorbing pigments. these proteins absorb light, get activated, and undergo chemical alterations to change shape. chemical pathways alter ion channels, then light becomes electric signal |
| photoreceptor: rods' job | for low light bc they're sensitive and get overstimulated in bright light. less activity bc they can't see detail, or colour |
| photoreceptor: rods' ratio | multiple rod cells converge onto one bipolar cell, so less stimulation is needed to generate the signal, but the image is less clear |
| photoreceptor: cones' job | for bright light, they aren't sensitive enough to see in the dark. respond to different wavelengths of light so can see colour. when they get burnt out they see complimentary colours |
| photoreceptor: cone' ratio | 1:1 cone:bipolar cell, so images are very clear |
| seeing dark process | rod don't change shape, ion channels stay open, cell depolarizes, Ca+ opens, NT gets released and blocks the next bipolar cell from sending signals to another |
| seeing light process | photoreceptors absorb, retinal becomes trans retinal (hyper polarizes and changes shape), starts signal that closes Na+ (so Ca+ stay closed), no NT gets released, bipolar cells depolarize, signal to ganglia, optic nerve to visual cortex to get perceived |
| when photoreceptor cells are stimulated... | ...no NT gets released |
| dark adaptation | vision gradually improving when entering a dark environment after being in a light one. photopigment in rods take 20-30min to regenerate and become active (because in bright: rods=off and cones=on) |
| light adaptation | feeling 'blinded' after going from dark to bright. in bright light, rods=bleached/oversaturated and shut down. cones only take a minute to reactivate tho |
| outer ear | pinna, ear canal, and ear drum |
| pinna | floppy part, funnel shaped to funnel sound waves into the ear canal |
| ear canal | external auditory meatus. sound waves travel via this to enter ear drum |
| ear drum | aka tympanic membrane, separates outer ear from middle ear |
| middle ear | auditory ossicles which are 3 different bones |
| auditory ossicles | malleus, incus, and stapes. they amplify and transmit sound waves (so the waves can move through the fluid in the inner ear after easily moving through air within the ear canal/drum) |
| inner ear | oval window, cochlea, organ of corti, basilar membrane, hair cells, tectorial membrane, auditory nerve |
| oval window | start of cochlea/inner ear. sound waves hit the window and get transferred into the cochlea |
| cochlea | fluid-filled and spiral-shaped. basically the entire inner ear |
| organ of corti | where sound waves get transducted into electric signals. sits on the fluid on top of the basilar membrane |
| hair cells | attached to the basilar membrane, they move/bend as the fluid moves and detect movement caused by sound |
| tectorial membrane | stable membrane above the hair cells |
| auditory nerve | where action potentials travel, carry info from the cochlea to the brain |
| sound transduction | sound wave enters cochlea via oval window, cochlear fluid moves, basilar membrane moves, hair cells bend, mechanically gated ion channels open, graded/action potential |
| sound wave discrimination | by different properties of the sound waves, timbre, intensity and pitch |
| timbre/quality | overtones (i.e. different types of sounds like voices and instruments) |
| intensity/loudness | amplitude. greater tympanic membrane movement means great basilar membrane movement, hair cells produce more frequent action potentials, CNS interprets louder sound |
| pitch | frequency of the wave. determined by location (on basilar membrane) of the hair cells that have been activated |
| high pitch/frequency gets detected | at narrow/stuff end of basilar membrane close to the oval window |
| low pitch/frequency gets detected | near the helicotrema |
| vestibular apparatus | sensory system in the inner ear that controls balance, spatial orientation, and movement coordination |
| semicircular canals | 3 tiny, fluid filled tubes (with different orientations) that detect rotational acceleration/deceleration of the head. at the bottom, there's cupola with hair cells |
| otolith organs | in the vestibular apparatus, detects linear acceleration and position of head relative to gravity. their hair cells have gelatinous layer on top, which has a layer of tiny crystals call otoliths |
| otolith organs: utricle | detects horizontal movement |
| otolith organs: saccule | detects vertical movement |
| otolith organs process | movement, hair cells and attached gel moves, otolith crystals don't move bc they're heavier, hairs get pulled back, this bending creates electric signal that gets sent to the CNS |
| autonomic nerve pathway | has two efferent neurons: preganglionic and postganglionic fibre |
| autonomic nerve pathway process | signal travels down preganglionic axon (goes into PNS) of the first neuron (cell body in CNS). synapses with autonomic ganglion/2nd neuron, releasing preganglionic neurotransmitters. signal travels down 2nd neurons axon to the effector organ |
| parasympathetic preganglionic neuron | starts at cranial (brainstem) or sacral (spinal cord/lowerback) and releases acetylcholine which binds to nicotinic receptors |
| parasympathetic postganglionic neuron | releases acetylcholine that binds to muscarinic receptors on the effector organ |
| sympathetic preganglionic neuron | starts at thoracic (spinal cord/middle-upper back) or lumbar (spinal cord/lowerback above sacral), releases acetylcholine that binds to nicotinic receptors on postganglionic fibres |
| sympathetic postganglionic neuron | releases norepinephrine and binds to adrenergic receptors on the effector organ |
| acetylcholine released by both presynaptic neurons binds onto this | nicotinic receptors |
| acetylcholine released by parasympathetic postganglionic binds onto this | muscarinic receptors |
| norepinephrine binds and released... | binds to adregenic receptors on effector organ and is released by the sympathetic postganglionic |
| autonomic agonist | binds to the same receptor as a NT and mimics NT's effect (has the same effect) |
| autonomic antagonist | binds to the same receptor of the NT and blocks the response |
| control of autonomic activities | whether you set off sympathetic or parasympathetic nerves. involves hypothalamus (homeostasis), brainstem/medulla (life processes control centre), and prefrontal cortex (personality |
| somatic nerve pathway | one neuron path. starts in CNS, motor/efferent neurons that control skeletal movement come out of ventral root and go to skeletal muscle |
| cell bodies of somatic motor neurons are found in... | spinal cord grey matter (called spinal nerves) |
| cell bodies of somatic motor neurons that control face and neck movement are found in... | brainstem (called cranial nerves) |
| voluntary body movement process (somatic nervous system) | stimulus, efferent neuron gets action potential, propagates to skeletal muscle along efferent fibres, axon branches out, forming multiple neuromuscular junctions with muscle fibres at the muscle |
| neuromuscular junctions | neuron to muscle. 1 neuron : 1 muscle cell fibre. always excitatory, always action potential. |
| control of motor neurons | motor cortex, basal nuclei, and cerebellum |
| control of motor neurons: motor cortex | sends info to spinal cord (where the nerve is) then the motor neuron takes it to the muscle |
| control of motor neurons: basal nuclei | refines movements and controls posture |
| control of motor neurons: cerebellum | manages balance, muscle done and procedural memories. e.g. if you want to walk, the cerebellum sends program to the motor cortex, motor cortex to neuron, then neuron to muscle |
Created by:
kaiashea