Anat 35- Final Exam- Nervous System: General/special Senses

Front 1

what are the flavors of taste?

Back 1

salty

bitter

sweet

sour

water/umami

Front 2

name the common sense receptors found in skin

Back 2

-nociceptors = Pain receptors sensitive to extremes of temperature, mechanical damage, or dissolved chemicals.

-thermoreceptors = change in heat

-mechanoreceptors = physical distortion, contact, or pressure

-chemoreceptors = chemical composition of body fluid

Front 3

referred pain *

Back 3

indicates a different source. For ex. gallstones may create pain radiating up to neck but it's not actually coming from that area.

Front 4

the retina is attached at what locations inside of the eye?

Back 4

Retina - is the neural layer that cover two-thirds of the eye between the choroids and the vitreous humor of the posterior cavity and it extends from the posterior circular edge of the optic disc to the anterior ora serrata.

Front 5

list the structures of the organ of Corti and how they work

Back 5

the hair cells of cochlear duct are found in here. This sensory structure rests on the basilar membrane that separates the cochlear duct from the tympanicmduct.

The hair cells are arranged in inner and outer longitudinal rows. These hair cells lack kinocilia, and their stereocilia are in contact with the overlying tectorial (tek-TOR-ō-al; tectum, roof) membrane. This membrane is firmly attached to the inner wall of the cochlear duct. When a portion of the basilar membrane bounces up and down, the stereocilia of the hair cells are distorted.

Front 6

describe accomodation, hyperopia, myopia, and glaucoma

Back 6

glaucoma: aqueous humor no longer has free access to canal of schlemm. Although drainage is impaired, production of AQ is continued and intraocular pressure rises. The fibrous scleral coat cannot expand enough and the pressure begins to push on and distort nerve fibers, which could affect visual perception and lead to blindness eventually.

accomodation: is the process by which the vertebrate eye changes optical power to maintain a clear image or focus on an object as its distance varies.

hyperopia: farsightedness. Have trouble seeing up close.

myopia: nearsightedness. People have trouble seeing well at a distance.

Front 7

where do you find endolymph?

Back 7

Endolymph is a fluid (high potassium and low sodium ion concentrate) found in the membranous labyrinth of the inner ear.

Front 8

List the structures of the organ of Corti and how they work?

Back 8

Organ of Corti - This is the most important structure in your inner ear that is involved in the sensation of hearing. This is an organ located in the cochlea of the inner ear that converts sound vibrations into nerve impulses, which then travel to the brain for processing and interpretation. The Organ of Corti contains the following structures:

1) Hair Cells - are arranged outer and inner longitudinal rows, which lack kinocilia and the stereocilia are in contact with the tectorial membrane.

2) Basilar Membrane - the organ of corti rest on this structure and it separates the cochlear duct from the tympanic duct.

3) Tectorial Membrane - is firmly attached to the inner wall of the cochlear duct.

4) Nerve Fibers -The nerve fibers that receive a signal from the hair cells are collectively known as the auditory, cochlear or acoustic nerve.

Production of an Auditory Sensation

1) Sound waves arrive at the tympanic membrane.

2) Movement f the tympanic membrane cause displacement of the auditory ossicles.

3) Movement of the stapes at the oval window establishes pressure waves in the perilymph of the vestibular duct.

4) The pressure waves of fluid in cochlea distorts the basilar membrane on their way to the round window of the tympanic duct.

5) Vibration of the basilar membrane causes vibrations of the hair cells against the tectorial duct resulting in hair cell stimulation and neurotransmitter release.6) Information concerning the frequency and intensity of stimulation is relayed to the central nervous system over cochlear branch of vestibulcochlear nerve.

Front 9

Describe accommodation, hyperopia, myopia, and glaucoma?

Back 9

1) Hyperopia - is referred to as “farsightedness” is a common vision condition in which you can see distant objects clearly, but objects nearby may be blurry. Hyperopia develops in eyes that focus images behind the retina instead of on the retina, which can result in blurred vision. This occurs when the eyeball is too short, which prevents incoming light from focusing directly on the retina. It may also be caused by an abnormal shape of the cornea or lens.

2) Myopia - is referred to “nearsightedness”, a common vision condition in which you can see objects near to you clearly, but objects farther away are blurry. Myopia develops in eyes that focus images in front of the retina instead of on the retina, which results in blurred vision. This occurs when the eyeball becomes too long and prevents incoming light from focusing directly on the retina. It may also be caused by an abnormal shape of the cornea or lens.

3) Glaucoma - in this condition the aqueous humor no longer has free access to the canal of Schlemm. Although drainage is impaired, production of aqueous humor continues, and the intra-ocular pressure begins to rise. The fibrous sclera coat cannot expand significantly, so increasing pressures begin to push against the surrounding intra-ocular soft tissues. When they intra-ocular pressures have risen to roughly twice the normal levels, distortion of nerve fibers begin to affect visual perception. If this condition is not corrected, blindness will eventually occur.

Front 10

Explain the function of rods and cones and which function more in the day?

Back 10

1) Rods - are photoreceptors that do not discriminate different colors of light, but provide grainy images of black and white. they are very light sensitive and enable us to see in dimly lit rooms, at twilight, or in a pale moonlight.

2) Cones - are photoreceptors that provide us with color vision. There are three types of cones, and their stimulation in various combinations provides the perception of different colors. Cones give us sharper, clear images, but require more intense light than rods; therefore, function more in day.

Front 11

List the tunics of the eye and what causes the blind spot?

Back 11

Eye Tunics

1) Fibrous Tunic - the outer most layer of the eye, consists of sclera and the cornea.

2) Vascular Tunic - the middle layer of the eye, consist of the ciliary body, iris and choroid, which contains numerous blood vessels, lymphatics, and intrinsic eye muscles.

3) Neural Tunic - Is inner most layer of the eye consists of the “Retina”, which contains two distinct layers, an outer pigmented layer and an inner neural layer called “neural retina”.

Optic Disc - there are no photoreceptors or other retinal structures at the optic disc causing a blind spot because light striking this are goes unnoticed.

Front 12

Describe the arrangement of auditory ossicles and what they attach to?

Back 12

Auditory Ossicles - ear bones (smallest in body) that connect the tympanic membrane with the receptor complex of the inner ear, which acts as levers that transfer sound vibrations from tympanum to a fluid filled chamber called “Chochlea” within the inner ear.

1) Malleus - the hammer shaped bone’s lateral surface attaches to the interior surface of the tympanum a three points.

2) Incus - the anvil shaped bone connects the medial surface of the malleus and to the lateral surface of the stapes

3) Stapes - the stirrup shaped bone connects the medial surface of the incus and it completely fills the oval window of the vestibule of the inner earand held there by the annular ligament.

Tympanic — Malleus — Incus — Stapes — Oval Window of the Vestibule

Front 13

Describe the auditory or Eustachian tube?

Back 13

1) Auditory Tube is referred to as “Eustachian tube” is a tube located in the inner ear that extends from middle ear to the nasopharynx. It penetrates the petrous part of the temporal bone within the musculotubal canal. The connection to the tympanic cavity of the middle ear is relatively narrow and supported by elastic cartilage. The opening into the nasopharynx from the inner ear is relatively broad and funnel shaped. The auditory tube serves to equalize the pressure in the middle ear cavity with the external atmospheric pressure and is to drain any accumulated secretions, infection, or debris from the middle ear space. Pressure must be equal on both sides of the tympanic membrane of the middle ear or there will be painful distortion of the membrane. The auditory tube can allow microorganisms to travel from nasopharynx to tympanic cavity of the middle ear, resulting in an ear infection.

External Ear — Middle Ear (contains Tympanic cavity and membrane) — Inner Ear (contains auditory (Eustachian) tube) — Nasopharynx

Front 14

What are the semicircular ducts?

Back 14

Semicircular Ducts are three small membranous tubes of the vestibular labyrinth within the bony semicircular canals of the bony labyrinth of the inner ear that form loops of about two thirds of a circle. The three semicircular ducts: anterior semicircular duct, lateral semicircular duct, and posterior semicircular duct lie in planes at right angles to each other and open into the vestibule by five openings of which one is common to the anterior and lateral ducts. Each duct has an ampulla at one end within which filaments of the vestibular nerve terminate. The ampulla contains sensory receptors that respond to the rotational movements of the head for purpose of equilibrium.

lateral - 'no'

superior - 'yes'

posterior - 'tilt'

Front 15

Explain location and function of the lacrimal glands?

Back 15

nestles within a depression in the frontal bone, within the orbit and superior lateral to the eyeball. The lacrimal gland normally provides they key ingredients and most of the volume of tears that bathe the conjunctival surfaces. Its secretions are watery and slightly alkaline and contain enzyme lysozyme, which attacks microorganisms.