science of body sounds Flashcards
how do we perceive sound
- through different pressure waves
- amplitude and frequency
what does the tympanic membrane do
- is the signal transduction pathway and vibrates
- needs air movement to change into action potential in the nerves
what do the cochlea and semi-circular canal do
fluid filled with an oval window that vibrates to move the fluid inside
what is the eustachian tube
tube connecting your ear and nasopharynx and affects the pressure in the scala tympani when blocked
how does hearing work in the organ of corti
- scala vestibuli become the cochlea window where vibrations enter
- pressure builds up creating budling
- is a high pressure system changing dynamics of other membranes
- bulging causes tectorial membrane to move across basal membrane attached to the low pressure canal
features of hair cells
- touch the tectorial membrane, embedded in basilar membrane
- cations
- calcium and potassium found in the fluid
- are mechanically sensitive
how do the hair cells work
- when the hair cells bend towards the kinocillum the channels open
- causes influx of ca and K
- cations enter there is depolarisation of membrane potential
- hair cells release neurotransmitter
- primary afferent nerves fire in response to sound
where is sound information recieved
in the auditory cortex
how do we process words
venicers area processes language in the parietal lobe by secondary auditory area
how do we process sounds
cortical processing area makes sense of sounds and tones - in the secondary auditory cortex
where do we process decision
in the frontal lobe deciding to pay attention to the sounds or not
where do we process a response
in the brochasarea
how do we hear body sounds
- stethoscope in ear
- vibration in the ear
- pressure fluctuation in the cochlea canal
- hair cells move, ions enter causing depolarisation
- action potential, nerve signal sent to brain
what do you hear with the bell of the stethescope
high frequency sounds
what do you hear with the diaphragm of the stethoscope
low frequency sounds
what causes amplification from a stethescope
constricting pressure of the tube
what causes vibrations in the body
- opening and closing heart valves
- peristalsis or other contractions
- alveoli snapping open
- membranes rubbing against each other
- turbulent flow
what is laminar flow
clear flow as there are no vibrations detected
what causes turbulent flow
- air flow constriction eg asthma
- air flow obstruction eg obstructed airway
- blood flow constriction eg karotkoff
- blood flow obstruction eg atherosclerosis
what are examples of abnormal lung sounds
- wheezes
- crackles (collapsed alveoli snapping open)
- stridor
- pleural friction rub
- silence
what are examples of abnormal cardiovascular sounds
- murmurs (stenosis and regurgitation)
- bruit
what are some abnormal bowel sounds
- hyperactive
- hypoactive
what are phase I of Korotkoff sounds
- faint, repetitive, clear tapping sounds
- increase in intensity for 2 consecutive beats = systolic BP
what are phase V Korotkoff sounds
all sounds disappears = diastolic
what causes murmurs
- turbulent flow coming from valves not working
- not closing causes backflow or changes in opening and closing times
what causes pericardial friction rub
when the parietal and visceral pericardium rub together and don’t rub smoothly together with fluid
what causes bruit
- turbulent flow from an obstruction in the vessels
- high rate of flow (usually systole)
- high pitcher
what causes bowel sounds
- differing types of contraction
- irregular noises
- need to consider frequency and presence
- can be bubbling, rumbling, gurgling, clicking or silence)
sounds/ changes in sound produced from trauma injuries
- sucking chest wounds
- cracking ribs
- pneumothorax and haemothorax
