Chapter 17: The Special Senses Flashcards
Where are the receptors for the sense of smell located?
located in the olfactory epithelium of the nose
The olfactory epithelium consists of three kinds of cells, what are they?
olfactory receptor cells
supporting cells
basal cells
What are olfactory receptor cells?
the first-order neurons of the olfactory pathway
Extending from the dendrite of an olfactory sensory neuron are several ________ _____________ ________
nonmotile olfactory cilia
What is the role of olfactory cilia?
responsible for perception of smell.
Within the plasma membranes of the
olfactory cilia are what kind of receptors?
olfactory receptors
What are olfactory receptors?
Proteins that detect inhaled chemicals
Chemicals that bind to and stimulate the olfactory sensory neurons in the olfactory cilia are called?
Odorants
What are supporting epithelial cells?
columnar epithelial cells of the mucous membrane lining the nose.
What do supporting epithelial cells provide?
They provide physical support, nourishment, and electrical insulation for the olfactory sensory neurons and help detoxify chemicals that come in contact with the olfactory epithelium.
_________ epithelial cells are stem cells located between the bases of the supporting epithelial cells
Basal epithelial cells
Within the connective tissue that supports the olfactory epithelium are ________ glands
olfactory glands
What is the role of olfactory glands?
They produce mucus that is carried to the surface of the epithelium by ducts
What is the role of the mucus produced by the olfactory glands?
The secretion moistens the surface of the olfactory epithelium and dissolves odorants so that transduction can occur
What is olfactory transduction?
A series of events in which cells in the nose bind to scent-bearing molecules and send electrical signals to the brain where they are perceived as smells
What is olfactory adaptation?
Nose blindness or adaptation to the smell in an area
What is gustation?
The sense of taste
TRUE or FALSE
gustation is much simpler than olfaction
TRUE
How many primary tastes are there?
There are 5
What are the 5 primary tastes?
Salty, sour, sweet, bitter, and umam
Where are the receptors for taste located?
On the taste buds
What is a taste bud?
sensory organs that are found on your tongue and allow you to experience tastes
Taste buds consist of three kinds of epithelial cells, what are they?
Supporting epithelial cells
Gustatory epithelial cells
Basal epithelial cells
What are gustatory microvilli
are responsible for sensing taste stimulus
What are the three types of papillae?
Vallate papillae
Fungiform papillae
Foliate papillae
What are the chemicals that stimulate gustatory receptor cells called?
Tastants
What is the muscle called that is in the upper eyelid?
levator palpebrae superioris
The space between the upper and lower eyelids that exposes the eyeball is the ________ fissure
palpebral fissure
The space between the upper and lower eyelids that expose the eyeball is the palpebral fissure. Its angles are known as the _____
lateral commissure
What is the lacrimal caruncle?
The small, pink, globular spot at the inner corner, or the medial canthus, of the eye.
The _______ plate is a thick fold of connective tissue that gives form and support to the eyelids.
tarsal
What are the glands called that secrete a fluid that helps keep the eyelids from adhering to each other?
Tarsal Glands
Infection of the tarsal glands produces a tumor or cyst on the eyelid called a ___________
chalazion
The ________ is a thin, protective mucous membrane composed of nonkeratinized stratified squamous epithelium with numerous goblet cells that is supported by areolar connective tissue.
conjunctiva
The _______ conjunctiva lines the inner aspect of the eyelids
palpebral
the ______ conjunctiva passes from the eyelids onto the surface of the eyeball
bulbar
Dilation and congestion of the blood vessels of the ________conjunctiva due to local irritation or infection are the cause of bloodshot eyes.
bulbar
Sebaceous glands at the base of the hair follicles of the eyelashes called
Sebaceous Ciliary Glands
Sebaceous ciliary glands release a lubricating fluid into the ______
follicles
Infection of ________ glands, usually by bacteria, causes a painful, pus-filled swelling called a sty.
sebaceous ciliary glands
The ________ apparatus is a group of structures that produces and drains what type of fluid?
Lacrimal
Tears
The ______ glands, each about the size and shape of an almond, secrete lacrimal fluid
lacrimal
Tears then pass into two ducts, the superior and inferior _________ _________
lacrimal canaliculi
The lacrimal glands are supplied by parasympathetic fibres of the ______ nerves.
Facial (VII)
What is lysozyme?
a protective bactericidal enzyme within lacrimal glands
what is structural fat/ periorbital?
is the padding of the eye inside the orbit
How many extrinsic eye muscles move each eye?
six
Anatomically, the wall of the eyeball consists of three layers, what are they called?
(1) fibrous layer
(2) vascular layer
(3) inner layer (retina)
What is the fibrous layer of the eyeball?
the superficial layer of the eye- ball and consists of the anterior cornea and posterior sclera
What is the cornea?
A transparent coat that covers the coloured iris
What is the sclera?
the “white” of the eye is a layer of dense connective tissue made up mostly of collagen fibres and fibroblasts
At the junction of the sclera and cornea is an opening
known as the _______ __________ __________
scleral venous sinus
What is the vascular layer of the eye?
is the middle layer of the eyeball
What is a choroid?
A thin layer of tissue that is part of the middle layer of the wall of the eye, between the sclera and the retina
What is the ciliary body of the eye?
A part of the middle layer of the wall of the eye
What is the ora serrata?
the transition site between the single, nonpigmented layer of ciliary epithelium and the multilayered retina
What are the ciliary processes?
protrusions or folds on the internal surface of the ciliary body
What is another name for zonular fibres?
suspensory ligaments
What are zonular fibres?
they are ligaments that attach to the lens of the eye
What are the ciliary muscles, and what do they do?
Circular bands of smooth muscle that contract or relax changing the shape of the lens to switch from seeing far and seeing close
What is the iris?
the coloured portion of the eye ball
What is the purpose of the pupil?
regulate the amount of light entering the eye
what is sphincter pupillae?
a muscle located in the colored part of the eye called the iris
What is the dilator pupillae?
A ring of contractile cells within the iris.
The third and inner layer of the eyeball, the ________?
retina
What is the optic disc or blind spot?
is the site where the optic (II) nerve exits the eyeball
What is the central retinal artery and what does it do?
Is the first branch of the ophthalmic artery, and it supplies nerve fibres in the optic nerve as well as the inner layers of the retina
What is the central retinal vein?
a vein that drains the retina of the eye.
The retina consists of a ______layer and a _____ layer
pigmented
&
neural
What is the pigmented layer of the retina?
a sheet of melanin-containing epithelial cells located between the choroid and the neural part of the retina