Special Senses Chap 15

Question 1

Chambers of the cochlea

Answer 1

• Scala vestibuli
• Scala media
• Scala timpani

Question 2

Area next to the Stapes

Answer 2

Oval window

Question 3

Bones of the inner ear

Answer 3

• Malleus (hammer)
• Incus (anvil)
• Stapes (stirrup)

Question 4

auditory tube or pharyngotympanic tube

Answer 4

Eustachian tube

Question 5

Eustachian tube

Answer 5

auditory tube or pharyngotympanic tube

Question 6

tube that links the nasopharynx to the middle ear

Answer 6

Eustachian tube

Question 7

Thin, cone-shaped membrane that separates the external ear from the middle ear

Answer 7

Tympanic membrane

Question 8

Tympanic membrane

Answer 8

thin, cone-shaped membrane that separates the external ear from the middle ear

Question 9

Cochlea

Answer 9

A spiral-shaped cavity of the inner ear that resembles a snail shell and contains nerve endings essential for hearing.

Question 10

A spiral-shaped cavity of the inner ear that resembles a snail shell and contains nerve endings essential for hearing.

Answer 10

Cochlea

Question 11

An oval cavity in the inner ear that together with the semicircular canals makes up the organ that maintains equilibrium

Answer 11

Vestibule

Question 12

Vestibule

Answer 12

An oval cavity in the inner ear that together with the semicircular canals makes up the organ that maintains equilibrium

Question 13

Fluid behind the lens

Answer 13

Vitreous humor

Question 14

Fluid behind the cornea

Answer 14

Aqueous humor

Question 15

Layers of the Retina

Answer 15

1) Pigmented epithelium
2) Photoreceptors (Cones =7.10^6 and Rods =100.10^6)
3) Horizontal cells (lateral integration)
4) Bipolar cells
5) Amacrine cells (lateral integration) = no axon
6) Ganglion cells (their axons form the optic nerve)

Question 16

Rods function

Answer 16

• Detect light.

- Rods handle vision in low light.

Question 17

Cones function

Answer 17

• Acute vision

- Cones handle color vision and detail

Question 18

Blind spot (name, location, characteristics)

Answer 18

• Optic disk
• On the nasal side
• No photoreceptors
• Passage for the optic nerve through the retina

Question 19

Where is the major concentration of Cones (only cones)?

Answer 19

Fovia Centralis

Most acute vision

Question 20

What surrounds the Fovia Centralis?

Answer 20

Macular Lutea (spot + Yellow)

Question 21

What is the spot in the center of the retina called?

Answer 21

Macular Lutea (spot + Yellow) with the Fovia Centralis

Question 22

What would happen to the vision with a tumor in the pituitary gland (Sella turcica of sphenoid bone)

Answer 22

It will press on the optic nerves and cause blindness in the temporal field. 
Bitemporal blindness ( bitemporal hemianopia)

Question 23

Decussation or X-shaped crossing by the crossing of the optic nerves in the brain.

Answer 23

Optic chiasm

Question 24

Name for the nerves after the optic chiasm when enter the brain

Answer 24

Optic tract

Question 25

Meyers loop (importance)

Answer 25

Meyer's loop constitutes the most anterior extension of the optic radiation in the temporal horn. Patients with intractable epilepsy may undergo temporal lobe surgery ( temporal lobectomy), and their optic tract is susceptible to potential injury. Consequently, neurosurgeons must appreciate the surgical implications of this pathway.

Question 26

The vascular layer of the eye,

Answer 26

Choroid

Question 27

Structure that changes the shape of the lens when your eyes focus on something. This process is called accommodation.

Answer 27

Ciliary muscles

Question 28

structure in the eye that releases a transparent liquid (called the aqueous humor) within the eye.

Answer 28

Ciliary body

Question 29

Sclera

Answer 29

The white outer wall of the eye. It is "white fibrous connective tissue" that extends from the cornea (the clear front section of the eye) to the optic nerve at the back of the eye. The sclera gives the eye its white color. - Protects like the dura mater in the CNS

Question 30

Modified sclera (collagenous fibers)

Answer 30

Cornea

Question 31

Iris

Answer 31

+ circular muscle in the eye (constrict eyes), + Radial muscles (dilate the eye) responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina.

Question 32

Lens

Answer 32

epithelium cells that magnify

Question 33

The white outer wall of the eye. It is "white fibrous connective tissue" that extends from the cornea (the clear front section of the eye) to the optic nerve at the back of the eye. It gives the eye its white color.

Answer 33

Sclera

Question 34

Circular channel in the eye that collects aqueous humor from anterior chamber

Answer 34

Sclera venous sinus (canal of Schlemm) is a circular channel in the eye that collects aqueous humor from the anterior chamber and delivers it into the bloodstream via the anterior ciliary veins

Question 35

Too much accumulation of aqueous humor results in ------

Answer 35

Glaucoma associated with elevated pressure in the eye (intraocular pressure). Generally, it is this elevated eye pressure that leads to damage of the eye (optic) nerve.

Question 36

Cloudy lens results in ----

Answer 36

Cataract. occur when there is a buildup of protein in the lens that makes it cloudy. This prevents light from passing clearly through the lens, causing some loss of vision. Since new lens cells form on the outside of the lens, all the older cells are compacted into the center of the lens resulting in the cataract. Lens replacement.

Question 37

Pupil

Answer 37

The pupil is a hole located in the center of the iris of the eye that allows light to enter the retina. It appears black because light rays entering the pupil are either absorbed by the tissues inside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil.

Question 38

sensorineural hearing loss

Answer 38

Damage to cochlear hairs, irreversible and cannot be cured. This type of hearing loss is sometimes referred to as sensory, cochlear, neural or inner ear hearing loss. A permanent sensorineural hearing loss is the result of damage to the hair cells within the cochlea or the hearing nerve (or both). Damage to the cochlea occurs naturally as part of the ageing process (age-related hearing loss is known as presbycusis) – but there are many things that cause sensorineural hearing loss, or add to it, such as: + Regular and prolonged exposure to loud sounds. + Ototoxic drugs – some medicines are harmful to the cochlea and/or hearing nerve. These include drugs that are used in the treatment of seriouc diseases such as cancer but also include certain types of antibiotics. + Certain infectious diseases, including Rubella + Complications at birth + Injury to the head + Benign tumours on the auditory nerve - although rare, these can cause hearing loss Genetic predisposition – some people are especially prone to hearing loss. Sensorineural hearing loss not only changes our ability to hear quiet sounds, but it also reduces the quality of the sound that is heard, meaning that individuals with this type of hearing loss will often struggle to understand speech.

Question 39

Conductive hearing loss

Answer 39

Conductive hearing loss is the result of sounds not being able to pass freely to the inner ear. This usually results from a blockage in the outer or middle ear, such as a build-up of excess ear wax or fluid from an ear infection (especially common in children). It can also happen as a result of some abnormality in the structure of the outer ear, ear canal or middle ear – or be due to a ruptured eardrum. A condition known as otosclerosis (which results in the abnormal growth of bone in the middle ear) can cause severe conductive hearing loss. The excess bone prevents the ossicles in the middle ear from moving freely. The result of this type of hearing loss is that sounds become quieter, although not usually distorted. Depending on its cause, a conductive hearing loss can either be temporary or permanent. Conductive hearing losses can often be corrected with medical management, or minor surgery.

Question 40

Gustatory pathway

Answer 40

1) The afferent fibers of the cranial nerves collect in the rostral solitary nucleus 2) Axons ascend ipsilaterally in the central tegmental tract of the brain stem and terminate in the parvocellular division of the ventral posterior medial nucleus of the thalamus 3) From the thalamus, neurons project to the insular cortex, the posterior limb of the internal capsule, and the operculum (primary gustatory areas)

Question 41

Cranial nerves for Taste

Answer 41

1) Taste buds on the anterior tongue and palate innervated by Facial nerve (VII). 2) Posterior tongue and pharynx innervated by glossopharyngeal nerve (IX) 3) Epiglottis and larynx innervated by vagus nerve (X) 4) The afferent fibers of these cranial nerves synapse with many taste cells between single or multiple taste buds Intermediate nerve afferents enter the brain stem at the pontomedullary junction Glossopharyngeal and vagus nerve afferents enter the brain stem in the rostral medulla

Question 42

Hair cells in gustatory apparatus

Answer 42

+ Projections from gustatory epithelial cells + Extend to the taste pore + Bathed by saliva + Sensitive portion of epithelial cells

Question 43

Kinds of papillae

Answer 43

1) Foliate papillae - a series of folds on the sides of the tongue in the back (located on the folds) 2) Circumvallate papillae - are organized in an inverted V at the back of the tongue (tasted buds tasted buds located deep in the trenches) 3) Fungiform papillae - are found scattered across the top front and middle of the tongue (tasted buds located on the surface) 4) Filiform papillae - are found across the top of the tongue

Question 44

Basic taste sensations 1) Sweet 2) Sour (acids) 3) Salty 4) Bitter 5) Umami

Answer 44

1) Sweet: (OH) 2) Sour (acids): (H+) 3) Salty: Na+, K+ Ca++ 4) Bitter: alkaloids (caffeine, nicotine, morphine) 5) Umami: MSG mono-sodium glutamte

Question 45

• Region that contains part of the system that helps maintain cerebral alertness and regulates skeletal and visceral muscle activity. (location)

Answer 45

Reticular Formation (medulla oblongata, pons)

Question 46

Reticular Formation (location, function)

Answer 46

o medulla oblongata, pons, midbrain o Region that contains part of the system that helps maintain cerebral alertness and regulates skeletal and visceral muscle activity.