Senses** Flashcards
The sense of smell supplements the sense of ________.
Taste
Epithelial cells; free ends extend between epithelial cells. Sense itching
Free nerve endings
Small oval masses of flattened connective tissue; detects changes in pressure or movement
Meissner’s corpuscles (mechanoreceptors)
Composed of connective tissue and nerve fibers; Found in deep dermal and subcutaneous tissue; responds to pressure
Pacinian corpuscles
Responds to temperature
Temperature Senses
Detects tissue damage
Pain receptors
What is the pathway for smell?
Smell receptor, cilia, axon, olfactory bulb, olfactory tract, limbic senses, thalamus
How does saliva contribute to the perception of taste?
Chemicals must be dissolved in water in order to be tasted
Describe the nerve pathway for taste
Travels on the facial, glossopharyngeal, and vagus nerves. They then travel to the medulla and cerebrum
What is the function of the external ear?
Collect sound waves and produces vibrations of the sound wave
Describe the hearing pathway
Sound waves enter the external auditory meatus, sound waves cause the eardrum to vibrate, vibrations are carried across the middle ear by the malleus, incus, stapes to the oval window. Vibrations cause the stapes to move in and out causing the cochlea to move. Tiny fibers cause a vibration in the hearing receptors which stimulate the nerves. The nerves send messages to the temporal lobe where sounds are interpreted.
Why does it help to chew gum while descending on an airplane?
Makes the pressure in ear at equlibrium
What is the function of the inner ear?
Transfer sound waves/ vibrations and to maintain equlibrium
What are the 4 layers of the eyelid?
Skin, muscle, connective tissue, conjunctiva
Which muscles move the eyelid?
Ocularis oculi and Levator palpebrae
A mucous membrane that lines the inner surfaces of the eyelids and folds back to cover the anterior surface of the eyeball
Conjunctiva
Function is to moisten and lubricate the surface of the eye and lining of the lids
Lacrimal apparatus
What is the lacrimal apparatus consist of?
Lacrimal glands and a series of ducts that carries tears into the nasal cavity
Antibacterial agent which reduces the risk of eye infections
Lysozyme
Rotates eye upwards and toward midline
Superior/inferior rectus
Rotate eye towards midline
Medial/lateral rectus
Rotate eye downward and away from the midline
Superior/inferior oblique
Absorb light (doesn’t differentiate color, only shades of gray)
Rods
Where are rods present?
Peripheral areas of retina
Absorb light of particular wavelength (red, green, blue)
Cones
Where are cones present?
Fovea area
Light absorbing pigment consisting of opsin and retinal
Rhodopsin
Detect light energy
Photoreceptors
Describe the nerve pathway for smell
When olfactory receptors are stimulated, their fibers synapse with neurons in the olfactory lobes. Sensory impulses are first analyzed here and then down the olfactory tract to the limbic system and to the temporal lobe
The whites of the eyes; functions as protective and supportive layer and an area for extrinsic muscle attachment
Sclera
Transparent cover of the eye; function is to focus images onto the lens
Cornea
Dark layer of the eye; function is to prevent backscattering of light
Choroid
The space between the cornea and the iris. Chamber is filled with aqueous humor which is thought to be formed by the ciliary body
Anterior chamber
Clear fluid that nourishes the cornea and lens; helps to maintain shape of the eye
Aqueous humor
Extends forward form the choroid coat and forms an internal ring around the front of the eye
Ciliary body
The colored parts of the eye; a thin diaphragm composed mostly of connective tissue and smooth muscle fibers and contains the pupils
Iris
Circular opening in the center of the iris where light goes through
Pupil
The space between the suspensory ligament and the iris
Posterior chamber
A transparent jelly-like substance that fills the posterior cavity of the eyeball. Functions to distend the sclera, support the retina, and maintain the spherical shape of the eye
Vitreous humor
Transparent, biconvex structure that focuses light on the retina
Lens
Adjusts thickness of lens to focus light
Accomidation
A nearly transparent sheet of tissue that is continuous with the optic nerves and contains photoreceptors
Retina
Often referred to as the blind spot; the spot where nerve fibers and blood vessels make their exit from the eye and does not contain rods or cones
Optic disc
A semicircular area of bright, lustrous tissue occupying a considerable portion of the optic nerve. An adaptation for vision in limited light
Tapetum lucidum
What happens if there is damage before the chiasma?
Damage on the same side
What happens if there is damage after the chiasma?
Damage on the same side
What happens if there is damage in the chiasma?
Damage on both sides
Flattened connective tissue sheaths surrounding two or more nerve fibers and are abundant in hairless areas that are very sensitive to touch
Tactile corpuscles
Large structures of connective tissue and cells that resembles the layers of an onion. Function to detect deep pressure
Lamellated corpuscles
Do temperature receptors adapt quickly?
Yes
Do pain receptors adapt quickly?
No
Do olfactory receptors adapt quickly?
Yes
Do taste receptors adapt quickly?
Yes
Functions to both hold the lens in shape and change the lens size to acommodate for near or far vision
Suspensory ligament
Muscles in the iris that constrict
Circular muscle
Muscles in the iris that dilate
Radial muscle
The ability to sense the position and location and orientation and movement of the body and its parts
Proprioreception
Senses change in the chemical concentration of substances
Chemoreceptors
