Special Sense Organs Part 3 Flashcards
Where are the tarsal glands located?
in each eyelid
What kind of gland are the tarsal glands?
sebaceous glands that secrete an oily substance that covers the eyes upon blinking
What is the purpose of the oily substance produced by the tarsal glands?
reduces evaporation of tears
All arteries of the eyeball are branches of what artery?
ophthalmic artery
Where are the long posterior ciliary arteries located?
one on each side of the eye running between the sclera and the choroid
How many short ciliary arteries enter the eyeball on the posterior surface forming a ring around the optic nerve?
six to twelve
How many anterior ciliary arteries arch over or under the eyeball?
six to eight (3 or 4 over and 3 or 4 under)
What artery travels via the optic nerve to the retina where it spreads out into an extensive network? It is the only artery to supply the retina.
Central retina artery
T/F: A thrombus/embolism in the central retinal artery will not result in blindness in that artery.
False; at least some blindness will result in that eye .No redundancy in blood supply to a single retina
What are the 3 sources of venous drainage for the eye?
anterior ciliary, long posterior ciliary, and central retinal veins
T/F: veins of the eye accompany arteries of similar names? i.e. anterior ciliary artery and anterior ciliary vein
True
What branches of the nasociliary nerve of the ophthalmic division of the trigeminal nerve provide nerve supply to the eyeball?
long ciliary nerves and short ciliary nerves
What nerves supply sensory info for the ciliary body, iris, and cornea?
long ciliary nerves
What nerves supply sensory info for the eyeball?
short ciliary nerves
What kind of fibers from the cavernous plexus pass through the ciliary ganglion and reach the ciliaris and dilator pupillae muscles?
postganglionic sympathetic fibers
What fibers from the ciliary ganglion follow a similar path to the ciliaris and sphincter pupillae muscles?
postganglionic parasympathetic fibers
What structure is known as an ectodermal thickening called the placode during embryological development?
ear
After the placode invaginates, it gives rise to the auditory pit which is then called what?
auditory vesicle
What “business part” will the auditory vesicle give rise to?
most of the membranous inner ear
What are the auditory tube and tympanic cavity derived from?
first pharyngeal pouch
What is the malleus derived from?
dorsal end of the ventral mandibular cartilage
What does the incus develop from?
dorsal end of the first pharyngeal arch
What is the stapes derived from?
dorsal end of the second pharyngeal arch
What is the tympanic membrane developed from?
interstitial mesoderm
What does the external acoustic canal develop from?
first pharyngeal groove
What does the auricle develop from?
a groove next to the first pharyngeal groove
What portions make up the ear?
external, middle, and inner portions
What is included in the external ear?
auricle and external acoustic meatus
What horn-like structure funnels sound waves, is composed of cartilage and is also known as pinna?
Auricle
What three extrinsic muscles position the auricle?
anterior, superior, and posterior auricular muscles
What is the smallest extrinsic muscle positioning the auricle? largest
anterior auricular muscle;
superior auricular muscle
What is the extrinsic muscle, which helps position the auricle, that inserts on the lower, posterior aspect of the concha?
posterior auricular muscle
What are the 6 intrinsic muscles of the auricle?
helicis major, helicis minor, tragicus, antitragicus, transverse muscle of the auricle, and oblique muscle of the auricle
