HEENT A&P Flashcards
(36 cards)
What is the location and temperature of the cold Receptors?
- Located in Epidermis
- 50-105 F (10-40 C)
Where are the warm receptors located in the body and what is the temperature range?
- Located Dermis
- 90-118F (32-48C)
What are the special Senses?
- Smell (olfaction)
- Taste (Gustation)
- Vision
- Balance
- Hearing
What are the four primary tastes of the tongue?
- Salt
- Sour
- Bitter
- Umami
How do tears flow?
Lacrimal Gland -> Lacrimal Ducts -> Superior or Inferior Lacrimal Canal -> Lacrimal Sac -> Nasolacrimal duct -> Nasal Cavity
How many cavities make up the eyeball? and what are they made up of?
- Anterior Cavity- Aqueous humor
- Posterior Cavity- Gel-like vitreous humor
What are the four steps of formation of image on the retina?
- Refraction
- Accommodation
- Constriction
- Convergence
RACC
What is RACC?
Steps for forming image on the Retina
1.Refraction
2. Accommodation
3. Constriction
4. Convergence
Describe Refraction
Bending of lights rays as they pass from medium of one density to another of a different density.
Describe Accommodation
Change of lens shape to focus for near vision.
Describe Constriction
Narrowing of pupil to control amount of light entering the eye.
Describe Convergence
Coming together of eyeballs for binocular vision.
Describe vision pathway
Photoreceptor cells (Rods or cones) -> Bipolar layer -> Ganglion cells; their axons form optic nerve.
What is static equilbrium?
Senses position relative to gravity.
What is Dynamic Equilibrium?
Senses position in response to head movement.
How does hearing work?
- Auricle directs sound waves into the external auditory canal
- Sounds strikes the TM and altering between high and low pressure causing it to vibrate slowly, Low frequency sounds vibrate slowly and rapidly to high pitch sounds
- The Central area of the TM is connected to the Malleus. The vibration is then transmitted via this way to the incus and then to the stapes.
- Stapes moves back and forth on the TM and transfers the larger vibrations into a smaller surface (the oval window).
- This movement sets up fluid pressure waves in the perilympth of the cochlea, as the oval window bulges inward, it pushes on the perilymp of the scala vestibuli
- Presssures waves travel from the scala vestibuli to the the scala tympani and into the round window, causing it to buldge in the middle ear.
- Pressure travels through the perilymph of the scala vestibuli, into the vestibular membrane, and then moves into the endolymph inside the cochlear duct
- The pressure waves in the endolymph cause the basilar membrane to vibrate which moves the hair cells of the spiral organ against the tectorial membrane. Leading to the bending of the stereocilia and ultimately the generation of nerve impulses.
What is the ear divided into?
Outer Ear: Auricle, External auditory canal, and the Tympanic Membrance (TM)
Middle Ear: Auditory tube (Eustachian tube), and the Ossicles (bones)
Inner Ear: Bony Labyrinth and Membranous filled with endolymph.
What are some parts of the Outer ear?
The Auricle, External Auditory, Canal and the TM.
Also includes the hairs and the ceruminous glands (The glands that produce ear wax).
What is the middle ear made up of?
Auditory tube (eustachian tube) and ossicles (bones)
* Ossicles include the Malleus, Incus, stapes: attached to the oval window.
What is the inner ear made up of?
Bony Labyrinth and Membranous Labytinth filled with endolymph.
* Also includes the Cochlea and the Vestibule and semicircular canals
What organ is response for the sense of hearing?
Cochlea
What organs are responsible for balance?
Vestibule and Semicircular canals
What is myopia?
Can see near objects (Nearsightedness)
What is hyperopia?
Can see far objects (farsightedness)
