Ear Structures
What is the purpose of the tympanic membrane?
Transfers vibrations to the auditory ossicles.
What structure transmits signals about sound to the brain?
Cochlear nerve
What is the relationship between a papilla and a taste bud?
Papillae contain many taste buds
What are somatic senses?
Senses associated with skin, muscles, joints, and visceral organs.
What is the external ear called? Name at least one specific part of the external ear.
Pinna
Helix
Antihelix
Lobule
Concha
Tragus
Which part of the ear transduces sound waves into electrical impulses that are sent to the brain, which creates an interpretation of sound? What type of cells are involved in this process?
Cochlea
Hair cells
Why do some smells trigger emotions and memories?
Olfactory nerves connect directly to the limbic system (hippocampus and amygdala), unlike other sensory nerves that pass through the thalamus first.
As a result, odors can trigger both positive and negative emotions when that aroma is linked to a memory.
What type of receptor cell is responsible for the sense of pain?
Nociceptors
What are the names of the three bones in the ear?
Malleus, incus, stapes
What are the two types of ear infections? How do they differ in location, cause, and treatment?
Swimmer's ear: ear canal, caused by water retention, treatment dries out the ear
Middle ear infection: middle ear structures, caused by bacteria/viruses, treated with antibiotics/pain meds
Explain the process of taste.
Food particles in saliva called tastants travel over the tongue and bind to microvilli in the taste pores of taste buds.
A chemical signal is sent from the microvilli to taste receptor cells. These cells are depolarized.
Depolarization causes the taste cells to release neurotransmitters that stimulate three nerves traveling to the brain.
4. Taste information is sent to the thalamus and finally the gustatory cortex, which allows us to discriminate between different tastes.
What causes referred pain?
Visceral pain (pain in organs) is often felt in other areas of the body because the two regions have a common nerve pathway from the brain.
When the brain sends a signal about pain back to the body, it sometimes sends it to another part of the body within the same nerve pathway.
What is the purpose of the eustachian tube? What is its normal position?
a canal that links the middle ear to the back of the throat. It helps to equalize pressure in the middle ear, which is necessary for proper transfer of sound waves.
It can be opened by coughing or swallowing to equalize pressure, but it normally remains closed.
What is the physiological cause of tinnitus? What is one underlying disorder that can result in this?
Broken hair cells cause false signals to be sent to the brain.
Ear infection, Meniere's disease, otosclerosis, exposure to loud noises
Explain the process of olfaction.
When we sniff, chemicals in the air are dissolved in mucus produced by olfactory epithelium.
Receptor nerve cells in the olfactory epithelium detect these odorants through cilia and and send signals to the olfactory bulb. These signals are caused by depolarization of the receptor neurons.
Signals are sent from the olfactory bulb along the olfactory tract to the olfactory cortex in the brain.
4. The olfactory cortex processes and perceives odors.
Explain how the location of Meissner's corpuscles and Pacinian corpuscles ties to their function.
Meissner’s Corpuscles: detect fine touch; abundant on hairless portion of skin and lips. Found near the surface of the dermis.
Pacinian Corpuscles: found deep in the dermis and detect heavy pressure and vibrations.
What are the two balance organs of the inner ear and their functions?
Vestibule: Sends signals to the brain related to the position of the head when the body isn’t moving. Creates a sense of equilibrium.
Semicircular canals: Filled with a fluid called endolymph, which stimulates hair cells to send signals to the brain about body position and balance. Senses rotation and movement of both head and body.
Thoroughly explain the process of hearing from stimulus to integration in the CNS.
Sound waves enter the external auditory canal and hit the tympanic membrane (eardrum).
Vibrations in the tympanic membrane cause the auditory ossicles (malleus, incus, and stapes) to vibrate.
The stapes vibrates against the oval window in the cochlea, allowing sound waves to enter the bony labyrinth and travel through the perilymph (fluid).
Vibrations exit through the round window.
Within the cochlea, vibrations trigger hair cells to fire.
6. The cochlear nerve transmits signals to the brain to create an interpretation of sound.
What are the four types of papillae? Which doesn't contain taste buds?
Foliate
Circumvallate
Filiform: They don’t contain taste buds.
Fungiform
What are the three types of somatic senses? Define each.
Exteroceptive Senses: senses associated with body surface (touch, pressure, temperature, pain).
Visceroceptive Senses: senses associated with changes in viscera/organs (blood pressure, feeling full after a meal).
3. Proprioceptive Senses: senses associated with positional changes (such as in muscles or tendons).