Lecture 9: Sensory Tracts & Hearing Flashcards
What is hydrocephalus, why is it mostly only present in babies?
Build-up of CSF in ventricles due to stenosis. Usually only present in babies because fontanelles allow for stretching of the skull.
Sound travels through the ________ ear until it hits the ___________ ________.
External, tympanic membrane
Within the external ear, ___ traps foreign bodies and repels _______ through ___________ glands.
Wax, insects, ceruminous.
What is the passageway of the external ear called?
External auditory canal
What are the three ossicles that exit in the ear? What do they do?
Malleus, incus, stapes. Mechanical transmission of auditory sounds.
What is the name of an ear infection that fills puss in the inner ear?
Otitis media
The _____ _______ connects the middle ear to the inner ear.
Oval window.
What are the types of noises heard throughout the cochlea?
Bass = center, mid = middle, treble = outside
What does the tectorial membrane?
When the endolymph vibrates, it stimulates the tectorial membrane. This wiggles hairs inside, and sends a signal to the brain.
After sound hits the tympanic membrane, the sound is transported through the _______.
Ossicles
Ossicles vibrate the ______ ________.
Oval window
When oval windows vibrate, the ________ is vibrated.
Endolymph
Where does sound exit the cochlea?
The round window
Which cranial nerve is responsible for hearing? Where is it sent?
Vestibulocochlear nerve, sent to the auditory cortex.
What occurs during conductive hearing loss?
Reduction in sound amplitude, typically unilateral. Caused by tympanic membrane rupture, wax buildup, damage to ossicles, etc.
What occurs during sensorineural hearing loss?
High tones affected, typically bilateral. Caused by trauma, prolonged nerves, tumors, drugs, etc.
What is contained within the vestibular apparatus?
Utricle, saccule, 3 semi-circular canals (ant, post, lat).
What are the utricle and saccule made of?
Supporting cells, otolith membranes, otolithic crystals, hairs
What two canals make up the semicircular canals?
Ampulla and cupula
The ampula is the _____ region containing ________ and _______.
Dilated, crista, endolymph
The cupula is moved by _______ and bends ______ cells.
Rotation, hair
The __________ and ____________ are responsible for hearing. The ___________ ___________ is responsible for balance.
Cochlea, spiral organ, vestibular apparatus
What are the 5 sensory modalities?
Touch, pressure, proprioception (qual), temperature, pain (quan)
What are dermatomes?
Areas of skin that rely on nerves that connect to spinal cord
How do nerves travel up spine?
Posterior column, lateral spinothalamic tract
What is the thalamus responsible for?
Selective attention, sensory integration/relay
What is the dorsal column responsible for? The spinothalamic system?
Dorsal column = touch, pressure, proprioception. Spinothalamic = pain & temperature
What are the two spinothalamic tracts?
2 synapses: spinal cord and thalamus
What is the reticular formation?
Collection of gray matter within nervous system = pain modulation (oops, don’t do that again!)
Where are the two synapses of the dorsal column?
Medulla, thalamus
Through what does proprioception information travel through?
Ipsilateral cerebellum
