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Human Physiology Lab- Exam 1
N/A
190
Physiology
Undergraduate 4
09/10/2012

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Term
metabolism
Definition
all of the chemical and energy transformations in an organism
Term
intermediary metabolism or fuel metabolism
Definition
the degradation, synthesis, and transformation of the prinicipal fuels used in the body (fats, carbs, proteins)
Term
anabolism
Definition
the synthesis of larger molecules from smaller molecules and usually requires energy
Term
anabolism involves:
Definition
production of products of importance to the cell or organism or for storage of fuels so that they can serve as a source of energy at a later time
Term
catabolism
Definition
the degradation of molecules into smaller components
Term
catabolism includes:
Definition
mobilization o fuel sources by hydrolysis (breaking bonds with water) and the oxidation of fuel molecules to produce energy
Term
oxidation of fats, carbs, and proteins
Definition
yields carbon dioxide and water
Term

ATP

Adenosine Triphosphate

Definition

biochemical pathways that release this energy are coupled to the production of ATP from Adenosine Diphosphate (ADP)

 

common energy currency in the cell

contains high-energy bonds, which, when broken release energy

Term
energy produced via catabolic processes is used for:
Definition
membrane transport, physical work, digestions and metabolism, maintenance of body temp (thermoregulaton), storage of excess fuels
Term
Aerobic metabolic processes
Definition

require oxygen beause they terminate in the transfer of electrons, ultimately to oxygen, thus forming water, in the ETC

 

beta oxidation, glycolysis and the citric acid cycle

Term
ETC
Definition
coupled to the phosphorylation (addition of phsphate) to ATP from ADP (oxidative phosphorylation)
Term
beta oxidation
Definition
catabolism of fatty acids dow nto acetyl CoA and other substrates for the ETC
Term
Aerobic Glycolysis
Definition

catabolism of carbs ultimately into acetyl CoA and other substrates for ETC

 

doesn't require energy

Term

Citric Acid Cycle

tricarboxylic acid cycle

Kreb's Cycle

Definition
acetyl CoA to create some ATP and to provide more substrates for the ETC
Term
Anaerobic Glycolysis
Definition

catabolism of carbs into some ATP and lactic acid

 

doesn't require oxygen

 

produce ATP faster but can only perform at its maximal rates for short periods of time

Term
whatever energy is used by the subjet, that doesn't end up as physical work will be released as
Definition
heat
Term

ATP can be converted to physical work with

 

Definition

50% resulting in heat and 50% as work

 

20-30 Caolories of work can be performd and 70-80 Calories given off as heat

Term
the approximation of one's overall metabolic rate can be made by measuring
Definition
the total amount of heat (calorimetry) released by the body per unit of time
Term
calorie
Definition

thermal unit of energy

 

amount of heat required to raise the temp of one gram of pure water 1 degree celsius

 

1 C or kCal=1000 small calories

1 c = 4.17 J

Term
Metabolic rate
Definition

the rate wat which energy is expended by the body per unit of time

 

reported relative to the subject's body surface area because diferent size indidivudals expend different amounts of energy

 

kcal/m2/hr

Term
direct calorimetry
Definition
placing the subject in a whole-body calorimeter and measuring the amount of heat given off by the body per unit of time
Term
indirect calorimetry
Definition

determining the subject's oxygen consumption

 

easier and practical

 

used to determine energy expenditure during exercise but only accurate if the subject is exercising at a low/moderate intensity

Term
oxygen consumption
Definition
used as an indirect indicator of the amount of metablism occuring in the subject's body
Term
resting humans derive much of their ATP from
Definition
aerobic metabolic processes
Term

caloric equivalent

 

energy equivalent of oxygen

Definition

the amount of energy expended per liter of oxygen consumed by the subject

 

carbs = 5.05 kcal/L

fats = 4.70 kcal/L

proteins = 4.60 kcal/L

Term
each type of fuel substrate provides a different amount of energy for every gram consumed
Definition

carb/protein = 4 kcal per gram

fat = 9 kcal per gram

alcohol = 7 kcal per gram

Term
average release of energy based on an average oxidation of all three foodstuffs
Definition

4.825 kcal/L

 

rely more on fats than carbs

Term
oxygen consumption (VO2)
Definition

rate at which oxygen is being consumed and it can be reported as an absolute value (L/min) or relative body mass (ml/kg/min)

 

used for calculation for metabolic rate

 

determined by the amount of air moved in and out of the lungs, and the amount of oxygen extracted from the air

Term

heat production

 

energy expenditure

Definition

amount of energy a person is expending per hour and is usually reported in kcal/hr

 

L/hr x Kcal/L

Term
oxygen consumption measured by closed spirometry
Definition

subject is connected to a closed system respirometer

spirometer bell filled with oxygen

expired carbon dioxide is removed

the bell falls and rises with each inspiration and expiration

movements recored in kymograph

bell gradually lowers as oxygen is consumed and expired carbon dioxide is removed

Term

oxygen consumption measued by open spirometry

 

metabolic chart

Definition
using a one-way breathing valve, a series of tubes, an oxygen and carbon dioxide analyzer, a gas meter or spirometer, and a computer
Term

Standard Temperature, Pressure, Dry conditions

 

STPD

Definition

0 degree Celsius

760mm Hg

no water vapor

 

under these conditions one liter of any ideal gas would contain the same number of gas molecules

the volume of any gas accurately represents the number of gas molecules

Term
respiratory quotient (RQ)
Definition

the ratio of carbon dioxide produced to the oxygen consumed at the cellular level

 

carbs = 1

fat = .7

oxygen and hydrogen are present in carbs in the same proportions as water, whereas in teh various fats extra oxygen is necessary for the formation of water

Term
respiratory exchange ratio
Definition

the ratio of carbon dioxide produced to the oxygen consumed at the whole body level

 

VCO2
VO2

 

need to know what caloric equivalent value to use in our calculation of metabolic rate

Term
average resting RER
Definition

.82 and represents a blend of 40% carbs and 60% fat metabolism

 

4.875 Kcal/L

Term
Non protein RER
Definition

the complete oxidation of proteins can't be completely accounted for by carbon dioxide and water (have nitrogen that must be accounted for)

 

urinary nitrogen excretion

Term
respiratory acidosis
Definition

increase in the amount of CO2 in their circulation and decreases the pH of their blood

 

carbs will produce more CO2

Term
average basal metabolic rate 20-29 years old
Definition

women = 36.8

men = 40.5

Term

standard basal conditions

 

Basal Metabloc Rate

Definition

the subject must not eat at least 12 hours prior to the test

the subject must be mentally and physically relaxed

the subject must not have a fever

the temperature of the room air must be comfortable (65-80 degree F)

 

BMR (+/- %) =measured value - predicted normal value
predicted normal value

Term
Resting Metabolic Rate
Definition
if the subject's metabolic rate is determined at rest, but the subject has recently eaten or has been active during thecourse of the day
Term
body surface area
Definition
correlates well with the metabolic rate since heat exchange occurs at the body surface
Term
factors affecting metabolic rate
Definition
  1. muscular activity (exercise) - metabolic rate also remains elevated for up to several hours after exercise
  2. ingested foods increase metabolic rate because of their specific dynamic action (SDA or thermic effect of food TEF)
  3. environmental temperature - low temps, heat conserving mechanism activated, metabolic rate rises
  4. sex (males have higher)
  5. age (decreases with age)
  6. emotional state (stress increases)
  7. climate (high or low increase)
  8. body temp (higher temp, higher MR)
  9. pregnancy (increase MR)
  10. menstural cycle (increase MR)
  11. lactation (increase MR)
  12. growth hormone (increase MR)
  13. catecholamines (increase MR)
  14. muscle mass (the greater muscle mass the greater heat production)
  15. thyroid hormones (thyroxine) circulating - when one fasts for a prolonged period of time, thyroid hormone secretion decreses reducing metabolic rate
Term

SDA

Specific Dynamic Action

 

Thermic Effect of Food

TEF

Definition
expenditure of energy that occurs during the food's assimilation into the body
Term

EPOC

Excess Post-Exercise Oxygen Consumption

Definition
the elevated oxygen consumption following exercise
Term
fractional content of expired oxygen (FEO2)
Definition

the perent of the expired air that is oxygen

 

<20.93%

between 0.15 and 0.18

Term
fractional content of expired carbon dioxide (FECO2)
Definition

percent of expired air that is carbon dioxide

 

>0.03%

 

between 0.025 and 0.06

Term
How did metabolic rate and heat production compare between smaller and larger subjects?
Definition

metabolic rate = roughly the same but the smaller person's was a little higher

 

heat production = larger person's was larger

Term
How did metablic rate and RER, and Blood Glucose compare between fasted and fed states?
Definition
Metabolic rate should increase after eating. Blood Glucose levels should go up after eating, depending on the food
Term
How did metabolic rate and heat production compare between resting and exercise measurements?
Definition
You would have more chemical energy transfer when you're exercising
Term
What are some possible reasons why metabolic rates different to expected values?
Definition
dehydration, thyroid problem, tired, haven't eaten, high temperature in room
Term
what does their blood lactate value suggest regarding our assumptions for using indirect calorimetry
Definition
it assumes the increase in metabolic rate is due to O2 consumption
Term
How does metabolic rate compare across ages? Why?
Definition
MR decreases with increasing age because as you age, people don't tend to maintain a lean body mass
Term
How do acute and chronic exercise influence daily energy expenditure and metabolic rate?
Definition
After exercise, MR remains elevated for several hours. When you exercise, you consume more oxygen. The more oxygen you consume, the higher your energy expenditure and metabolic rate
Term
How does biochemical impedance help us estimate percent body fat?
Definition
A low level electrical current is sent through the body, traveling at different rates depending on the various body tissues. This gives the fat mass and fat free mass. The current passes fairly easy in muscle tissue but slowlying in fat tissue.
Term
Storage form of Carbs
Definition
glucogen which is located in the cytosol/cytoplasm and there is 4Kcal
Term
storage form of fats
Definition
triglycerides which is stored in adipose tissue. there is 9 Kcal
Term
storage form of proteins
Definition
amino acids and they're located in the cytosol and there is 4 kcals
Term
responsible for intracellular communication
Definition

nervous system and endocrine system

 

autocrine, paracrine, gap junctions

Term
neuron
Definition

nerve cell

 

transmit impulses in order to pass info from one point to another

Term
axon
Definition
conducts impulses away from the nerve cell body and connects the nerve to other cells
Term
dendrite
Definition
recieves input from other neurons and conducts impulses towards the cell body
Term
axon hillock
Definition
base of acon when the acon meets the soma
Term
nerve fibers
Definition
axons and dendrites
Term
synapse
Definition

the junction between an axonal ending and another cell

 

where the nerve cell is transferred to the other cell via the release of neurotransmitters by axonal ending

Term

neurotransmitters

 

Definition
binding with specific receptors on the post-synaptoc ce;;
Term
EPSP
Definition
increase the liklihood that an AP will occur in the post-synaptic cell
Term
IPSP
Definition
decrease the liklihood that an AP will occur in the post-synaptic cell
Term
central nervous system
Definition

brain and spinal cord

 

processes, analyzes, integrates and responds to info provided by the sensory neurons

Term
peripheral nervous system
Definition
remaining nervous tissue including autonomic and automatic nerves
Term
sensory (afferent) neurons
Definition
send impulses towards the CNS via the dorsal root
Term
motor (efferent neurons)
Definition

transmit impulses away from the CNS to an effector organ

 

send info out of the spinal cord via the ventral root

Term
Action Potential
Definition

the conduction of an electrical signal over long distances

 

"all or none" because of the either on or off status

 

initiated at an axon hillock or in a dendrite that traels to the soma and then down the axon to the end target

 

cardiac, skeletal and smooth muscle cells all have APs

 

Term
resting membrane potential
Definition

"silent nerve" that is turned off

 

large concentration of Na outside and small concentration of Na inside

 

small concentrationg of K outside the cell and a large concentration of K inside

Term
potential difference
Definition

differences in concentration of charges between the inside and the outside

 

measured in volts (V)

millivolts (mV)

 

Term
resting membrane potential
Definition

 

between -60 and -100 mV

 

the status quo potential of the "off" cell

Term
voltage gated channels
Definition
they will begin opening when there is a change in voltage (potential) across the membrane
Term
change in membrane potential
Definition
initiated by binding of an excitatory neurotransmitter (acetylcholine) with its receptor
Term
depolarization
Definition

Na channel opens, Na rushes into the cell (influx) via simple, passive diffussion

 

When Na moves across the membrane into the cell it causes the electrical potential across the membrane to be more postive (less negative)

Term
repolarization
Definition

K channels open slowly, K leaves the cell (efflux)

 

When K is leaving and Na channels are closed, there is a net movement of positive charges from inside to the outside of the cell, thus the membrane potential starts to become less positive (more negative)

 

brings membrane potential back towards resting potential

Term
hyperpolarization
Definition
because the K channels close somewhat slowly, too much K leaves the cell, and the membrane potential is more polar than normal, during the last portion of the AP
Term
Na/K ATPase
Definition

pump Na from inside to outside of the cell and move K back into the cell from the outside

 

occurring against [ ] graident --> requires energy in the form of ATP

 

3 Na for ever 2 K

Term
Active Transport
Definition

ions against a [ ] gradient requires energy in the form of ATP

 

uneven exchange of positive charges is partly responsible for the relatively negative resting membrane potential

Term
ions move as a result of:
Definition

concentration gradient and electrical gradient

 

ex: K- electrical gradient favor K moving into cell, [ ] gradient favor K moving out of cell

Term
equalibrium potential (Eion)
Definition

the membrane potential wat which there would be no net movement of an ion because the electrical and concentration gradients cause an equal and opposite movement of the ion

 

Na = +60 mV

Term
why is the resting membrane potential so negative?
Definition

the membrane is more permeable to potassium and thus the membrane potential is closer to equilibrium potential for K (-90 mv)

 

When Na channels are open, the membrane is far more permable to Na and now the resting potential will move toward sodium's equalibrium

Term
current
Definition
the movement of electrical charges
Term
resistance
Definition
impedes current
Term
conductors
Definition
allow for significant current because they possess little resistance
Term
insulators
Definition
have minimal current as a result of great resistance
Term
Ohm's Law
Definition

V = IR

 

blood pressure difference, blood flow, and resistance

 

movement of air through the airways of the lungs

Term
refractory period
Definition
brief period following the AP when a second AP either cannot be produced (absolute) or has an increased threshold (relative)
Term
absolute refractory period
Definition
the period of time when no second action potential can be generated (between lines B and C)
Term
relative refractory period
Definition
when a second action potential can occur, but only if an extra strength stimulus is provided
Term
value of refactory period
Definition
it ensures unidirectional propagation of the action potential (the region that has just depolarized can not be depolarized again until the end of the absolute refractory period or the end of the relative refractory period)
Term
impulse propagation
Definition

once an AP is initiated in one region of the neurolemma (nerve cell membrane) it will cause an action potential in a neighboring region of the neurolemma

 

the stimulus will open the Na channels in the immediate area of the stimulus

 

As Na enter the cell the internal voltage of the cell is altered and the Na channels in teh adjacent area are opened

Term

local current flow

 

contiguous conduction

Definition
the current spreads sequentially from one local part of the axon to the next to the next
Term
the speed of impulse propagation or conduction velocity is affected by 2 major characteristics of the nerve fiber
Definition
  1. diameter (affects the resistance of the nerve fiber) - the larger the diamaer, the more quickly the AP travels
  2. presence or absence of a myelin sheath around the axon
  3. temperature - low temps=slow conduction velocity

 

Term
myelin sheath
Definition
lipid coating that insulates teh axon
Term
glial cells
Definition
specialized cells form the myelin sheath
Term
Schwann Cells
Definition
forms the myelin sheath in the peripheral nervous system
Term
oligodendrocytes
Definition
forms myelin sheath in the CNS
Term
nodes of Ranvier
Definition
at intervals along the axon, there are areas where there are gaps in the myelin sheath
Term
myelinated axons
Definition
the electrical events of the AP spread from one node to the next, and these skipping effect provides for a more rapid propagation of the AP
Term
saltatory conduction
Definition
AP propagation down the axon
Term
Multiple Sclerosis
Definition

autoimmune disease characterized by destruction myelin in the CNS and eventually may damage the underlying nerves

 

slower AP propagation and wide range of symptoms related to neuronal dysfunction

Term
quanta
Definition

the amount of neurotransmitter released by an axon terminal as a result of one AP

 

result in either a EPSP or an IPSP

Term
to release more quanta:
Definition
  1. increasing the frequency of neurotransmitter release by a given axon terminal
  2. increasing the number of axon terminals that are releasing neurotransmitters
Term
summation
Definition
when quantas are released with increased frequency or from multiple locations, many EPSPs can be created. the depolarization caused by each EPSP can sum together to bring the membrane potential to threshold (AP created)
Term
temporal summation
Definition
if summation is caused by one axon terminal releasing quanta more frequently
Term
spatial summation
Definition
if summation is caused by multiple axon terminals releasing quanta (spatial means referring to location)
Term
stimulator
Definition
allows one to deliver varying intensities of voltage to the neuron
Term
controls on the stimulator allow to vary:
Definition
  1. voltage (strength)
  2. duration (length of time the voltage is delivered)
  3. frequency (the number of times per second the pulse is delivered)
Term
delay control
Definition
allows for twin pulses to be delivered at varying intervals
Term
oscilloscope
Definition

instrument that can record the potential changes by plotting variations in electrical potential against time

 

click "O" then enter to stimulate the neuron

Term
subthreshold stimuli
Definition
combinations of strength and duration of stimulus produce no response in the axon
Term
threshold
Definition
stimuli of sufficient strength and duration to produce a response
Term
graded potential
Definition
subthreshold stimuli may result slight depolarization of the cell membrane
Term
all or none principal
Definition
once above the threshold strength the magnitude of the response will remain the same even when stimulus strength is far above threshold
Term
utilization time
Definition
the minimum duration necessary to produce an action potential for a given voltage
Term
rheobase voltage
Definition
the minimum strength below which no action potential is produce
Term
chronaxie time
Definition
the duration that corresponds to 2 times the voltage rheobase
Term
stimulus artifact
Definition
represents the voltage and duration of the stimulus
Term
conduction velocity
Definition
(m/sec) = Distance (m)
            T (sec)
Term
end of the relative refractory period
Definition
the maximal delay setting between impulses that fails to produce a second action potential
Term

the end of the absolute refractory period

 

and

 

the beginning of the absolute refractory period

Definition

the longest delay setting where no second action potential can occur, even with an extra strong voltage

 

and

 

begins as soon as the action potential begins to occur

Term
sensory receptors
Definition

specialized structures at the ends of afferent nerves and they recieve stimuli

 

receptors detectm the nerves transmit the info, and the CNS is responsible for the snesing or perception of this info

Term
exteroceptors
Definition
detect outside the body stimuli
Term
interoceptors
Definition

receptors detecting changes within the bodty

 

subdivides into visceroceptors and proprioceptors

Term
visceroceptors
Definition
found within the viscera (body organs) and recieve info regarding visceral pain, pressure, blood pressure, osmotic pressure, partial pressures of gases, pH and temp
Term
proprioceptors
Definition
detect changes in body position such as: body balance, position and acceleration
Term
types of sensory receptors
Definition

mechanoreceptors

thermoreceptors

nocioceptors

electromagnetic receptors

chemoreceptors

osmoceptor

Term
adequate stimulus
Definition
the type of stimulus to which the receptor is most sensitive to
Term
law of specific nerve energies
Definition

regardless of the type and strrength of stimulus applied to a given receptor, the sensation perceived when the receptor responds is always the same

 

the sensation evoked is that for which the receptor is specialized no matter how or where along the pathway the activity is initiated

Term
modality
Definition

each principle type of sensation

 

pain, touch, sight and sound

 

each has a discrete pathway to the brain

 

 

Term
the sensation percieved as well as the part of the body to which it is localized is determined by
Definition
the particular part of the brain stimualted
Term
threshold stimulus
Definition

in order for a receptor to be activated, the stimulus must be higher than a certain minimal level

 

the threshold strength is lowest for the adequate stimulus and higher for the other types of stimulus

Term
receptor potential may be caused by:
Definition

a change in potential

 

  1. mechanical deformation
  2. application of chemical to the membrane
  3. change in the temp of the membrane
  4. the effects of electromagnetic radiation on the receptor
Term

differences in intensity of a given sensation are communicated in two ways:

 

Definition
  1. frequency coding- changes in frequency at which action potentials are generated
  2. population coding - changes in the number of receptors activated
Term
sensory cortex
Definition
more space is dedicated to the areas of finer sense
Term
sensory homunculus
Definition

a graphic presentation of the area in the sensory cortex dedicated to each part of the body

 

clearly displays the location and size of each site

Term
somatic sensory site
Definition

located on the parietal cerebrum, just posterior to the central sulcus

 

info starting at the receptor and passing by way of an afferent nerve to the spinal cord or brain stem is recieved and where sensing or perception of the stimulus occurs

Term
primary somatic sensory cortex
Definition

all areas of the body surface

 

Term
localization of the stimulus depends on:
Definition

 

  1. the magnitude of cortical representation of the area on the body surface
  2. overlapping sensory fields in the skin
Term
law of projection
Definition

the principle that connects the receptor site to its perception on the cortex

 

no matter where a particular sensory pathway is stimulated along its course to the cortex, the conscious sensation produced is referred to the location of the receptor

Term
dermatome
Definition

a segmental field of skin where each spinal nerve innervates at

 

maps used clinically to locate nerve lesions

Term
referred pain
Definition
one may feel pain in a part of their body that is considerably removed from the actual site causing the pain
Term
explanation for referred pain
Definition

branches of visceral pain fibers synapse with some of the same second order neurons that receive pain fibers from the skin.

when pain fibers of an organ are stimulated, action potentials signaling pain from the organ are conducted through some of the same neurons that conduct pain impulses from the skin

Term
Sensory interpretation
Definition

cutaneous receptors are rarely stimulated singularly

 

several different receptors are stimulated at the same time

Term
adaptation
Definition

if the stimulus strength remains constant and the stimulus is not removed, the receptor becomes increasingly less sensitive to the presence of the stimulus

 

the receptors at first responds at a very high impulse rate, then at a lower rate, until many of them no longer respond at all

Term
phasic receptors
Definition
some receptors adapt rapidly to the presence of stimuli
Term
tonic receptors
Definition

receptors adapt very slowly and incompletely

 

ex: carotid sinus, muscle spindle, organs for cold, pain and lung inflation

Term
afterimage
Definition

the sensation percieved after removal of the stimulus

 

due to the receptor again discharging with removal of the stimulus

Term
thermal receptors
Definition

respond to changes in temp

cold receptors increase their discharge of impulses as their temp decreases, while warm receptors increase their firing rate as their temp increases

Term
Weber - Fechner Law
Definition

one's ability to discriminate the intensity of a stimulus is far greater at the low intensity level than at the high intensity level

 

gradations of stimulus strength are discriminated approximately in proportion to the logarithm of the stimulus strength

 

 

Term
Weber - Fechner Law explanation
Definition

how the nervous system is able to discern stimulus strength over a tremendous range of intensities

 

emphasizes that the greater the background sensory stimulus, the greater the stimulus strength is in order for the brain to detect the change

Term
Weber's Fraction
Definition

Delta I/I

.

 

Term
Power law
Definition
perceieved intensity is related to the power (exponent) of the actual stimulus intensity
Term

After sensory info enter the spinal cord via the dorsal roots, they may ascend the spinal cord through one of two alternate pathways located in the cord's white matter columns:

 

Definition
  1. the dorsal-lemniscal system
  2. anterolateral system

They come together at the level of the thalamus

Term
dorsal column - lemniscal system
Definition

a sensation that must be transmitted rapidly or that has fine gradations of intensity levels

 

limited to mechanoreceptive sensations (esp. joint sense, proprioreception, localized touch sensation, vibration)

Term
anterolateral system
Definition

includes the lateral and anterior spinothalamic tracts, transmits info more slowly than the tracts in the dorsal columns and allows for a less fine ability to discriminate the intensity of the stimulus

 

transmit a broad range of sensory modalities

Term
neuropathy
Definition

inability to perceive peripheral sensory info as a result of nerve damage

 

ex: diabetic sensory neuropathy

Term
outer ear
Definition

pinna, the external auditory meatus (ear canal), and the outer surface of the tympanic membrane (ear drum)

 

collecting and transferring sound waves to the middle ear

Term
middle ear
Definition

contains 3 auditory ossicles:

malleus (hammer), incus (anvil), and stapes (stirrup)

 

function to transfer vibrations of the tympanic membrane to the inner ear

Term
inner ear
Definition

consists of 2 sensory receptors:

cochlea

vestibular apparatus

Term
cochlea
Definition
contains receptors for the conversion of sound waves into nerve impulses
Term
vestibular apparatus
Definition
transduces info about equilibrium
Term
cochlea duct
Definition
the middle compartment
Term
upper compartment of the cochlea
Definition
seperated from the middle ear by the oval window
Term
round window
Definition
seals the lower compartment from the middle ear
Term
helicotrema
Definition
the area beyond the tip of the cochlear duct where the fluid of the upper and lower compartments is continuous
Term
basilar membrane
Definition
the floor of the cochlear duct which houses the organ of Corti
Term
organ of corti
Definition

the sense organ for hearing

 

contains hair cells

Term
what causes air waves?
Definition

compression and rarefaction

 

They are conducted and focused by the outer ear and cause the tympanic membrane to vibrate, which foreces the malleus to move. The malleus directly moves the inclus, which in turn moves the stapes. The stapes creates vibration on the oval window causing the generation of waves within the fluid of the upper compartment of the cochlea. The result in the vibration of the basilar membrane, causing the hair cells of the organ of Corti to move back and forth. The back and forth motion causes graded potential changes in the receptors at the same frequency as the transmitted sound waves. As the hair cells are depolarized, the auditory nerve is excited, sending receptor info along the auditory pathway to the auditory cortex in the temporal lobe of the brain.

Term
Pitch
Definition
determined by the location of hair cells stimulated
Term
high frequency sound waves
Definition
detected by hair cells near the base of the cochlea
Term
low frequency sound waves
Definition
detected near the cochlea's apex
Term
loudness
Definition
interpretted by the number of nerve impulses per unit time sent by the cochlea
Term
Hearing Impairment categories
Definition
  1. conductive hearing loss
  2. sensorineural hearing loss
  3. central hearing loss
Term
conductive hearing loss
Definition
deafness due to inadequate transmission of sound in the internal or middle ear
Term
sensorineural hearing loss
Definition
deafness may be due to damage of the cochlea, organ of Corti, degeneration of the hair cells, a lesion in teh coclea nerves of CN VIII, degenerative bone disease, and functional derangement of the organ of Corti
Term
presbycusis
Definition

a loss of hearing acuity due to aging

 

caused by a loss of hair cells and decreased elasticity

Term
central hearing loss
Definition
defects in the auditory pathways or auditory portion of the temporal lobe
Term
What caused the green-purplish image in your eye?
Definition
stimulation of the rods and cones of the receptors for vision by mechanical pressure against the eyeball
Term
audiogram
Definition
a graphic representation of one's hearing thresholds at the selected test frequencies
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