Physiology Flashcards
What does the mechanical link between the auditory ossicles prevent?
Incoming sound from being reflected back as well as improving the efficiency in which sound is transferred from the air to the fluid.
Function of the external ear?
To receive sound
What allows the middle ear to amplify sound?
Big ratio of tympanic membrane to oval window- auditory ossicles along it travel between
The inner ear is a _____
receiver/ transducer
What is inertia?
Resistance of an object to change in its velocity
Hair cells contain _________
stereocilia and kinocilium
Defletion of the sterocilia towards the kinocilium leads to _______________
depolarisation > release of a transmitter substance from the base of the hair cell and activation of nerve fibres that convey impulses to the higher centres of the brain
The cochlea comprises of a coiled tube with three tubular canals which are?
scala vestibuli > perilymph
scala tympani > perilymph
scala media > endolymph
The scala vestibuli and tympani are joined at the tip of the coil called the _______
helicotrema
At the base of the scala vestibuli is the ____1___ and at the base of the scala tympani is the ___2_____
1) oval window
2) round window
What is the boundary between the scala media and the scala tympani called?
The basilar membrane
On top of the basilar membrane sits the _____ in which the ______ are situated
organ of corti
hair cells
The hair cells can detect small amounts of movement in the basilar membrane and due to the changing width high frequency sounds displace at the ___1____ and low frequency sounds at the ____2____ end
1) base of the cochlea
2) apical
Lower sounds travel Less distance
At the stimulated point of the basilar membrane what happens?
The organ of corti is depolarised, AP fired stimulating CNVIII then central pathways and information accumulates in the superior temporal gyrus
The semicircular canals are involved in ….
detection of angular movement- tells your body where your head is in space
What are the three semicircular canals and what plane do they detect movement in?
Anterior > sagital plane
Posterior > coronal plane
Lateral > axial plane
Each canal has an _____ with hair cells
ampulla
Explain how the canals detect angular movement?
During acceleration in the plane of a canal the endolymph remains stationary due to inertia. The movement displaces the stereo cilia however so the stimulation of associated fibres occurs. Movement in one direction causes increased during and in another decreased firing
What detects linear movement?
The utricle and saccule
The utricle and saccule have _____ with hair cells
maculas
The utricle detects __1___ movement
The saccule detects ___2_____ movement
1) horizontal
2) vertical
The receptors for taste and smell are _______
chemoreceptors
Sensory receptors for taste are located in ______
the tongue mainly
also the soft palate, pharynx, larynx and epiglottis
Taste buds are associated with …
papillae
Which papillae have taste buds?
fungiform, vallate, foliate
Which papillae doesn’t have taste function? What is its function?
Filiform
Sense touch, temperature and pain
Binding of taste to taste buds provokes __1____ and __2___ generated. Signal are conveyed by cranial nerves ____3_____ via brainstorm and thalamus to the cortical gustatory area
1) receptor cells
2) AP
3) Facial nerve > ant 2/3 tongue
glossopharyngeal > post 1/3 tongue
vagus > epiglottis and pharynx
Olfactory receptors have __1__ that project onto the surface of the olfactory mucosa. __2_____ bind to __1___
1) cilia
2) odorants
Why does sniffing allow deeper smell?
It draws the odourants up to rood of nasal cavity
Word for inability to smell?
Anosmia
Word for reduced ability to smell?
Hyposmia
Word for altered smell?
Dysosmia
Word for inability to taste?
Ageusia
Word for reduced ability to taste?
Hypogeusia
Word for altered taste?
Dysgeusia
Information on hearing is what part of brain?
Superior temporal gyrus
What is the life span of sensory taste receptor cells? Which cells are they renewed from?
10 days
Renewed from basal cells
What is the lifespan of an olfactory epithelium cell?
2 months
