Sensory (*) Flashcards
what are the 3 main function of the eye?
- Capture the light, regulate the amount of light entering eye
- Focus the image on the retina
- Transform the image into neural
what is a snellen chart?
eye chartthat can be used to measure visualacuity.
Acuity means?
sharpness
what does the sagittal section of the eye show?
the interrelationships among the major ocular structures, the three major layers or tunics of the wall, important regions within those layers, and the refractive elements (cornea, lens, and vitreous)
describe the stroma
comprises approximately 90% of the cornea’s thickness, consisting of some 60 layers of long type I collagen fibers arranged in a precise orthogonal array and alternating with flattened cells called keratocytes. Also lined with endothelium internally
what does the aqueous humor do?
continuously flowing liquid that carries metabolites to and from cells and helps maintain an optimal microenvironment within the anterior cavity of the eye
the aqueous humour is secreted from __________ processes into the posterior chamber of the anterior cavity, flows into the anterior chamber through the ________, and drains into the_____ _________ ________
ciliar, pupil, scleral venous sinus (canal of Schlemm)
what is located at the circumfrence of the cornea?
limbus or corneoscleral junction
what is the function of the iris?
regulates the amount of light to which the retina is exposed
the intraocular lens consists of which 4 parts?
- lens capsule
- lens epithelium
- differentiating lens fibers
- mature lens fibers
The lens is a _________, _________ tissue that focuses light on the retina
transparent, elastic
Surrounding the entire lens is a thick, homogenous external lamina called the _______ ________
lens capsule
Differentiating lens fibers still have their nuclei but are greatly elongating and filling their cytoplasm with proteins called ________
crystallins
mature lens fibers have lost their _________ and become densely packed to produce a unique transparent structure
nuclei
To see closer objects, the ciliary muscle fibers _________, changing the shape of the ciliary body, relaxing tension on the ciliary zonule, and allowing the lens to assume the more rounded shape.
contract
The retina is the thick layer of the eye inside the ________
choroid
what is the sclera?
lateral wall of an eyes dense connective tissue
what is the choroid?
lateral wall of an eyes loose, vascular connective -tissue
_________ are prominent in the choroid, especially in its outer region, the suprachoroidal lamina
Melanocytes
choroidocapillary lamina does what?
has a rich microvasculature that helps provide O2 and nutrients to the adjacent retina
what is Bruch’s layer?
Between the choroid and the retina is a thin layer of extracellular material
The _______ layer of the retina is the pigmented layer
outer
what are the general layers of the retina?
- Photosensitive (neural retina)
- Non-sensitive (pigmented layer) RPE retinal pigmented epithelium:
cuboial; blood-nerve barrier
what are the types cells in the retina?
- pigmented cells
- Photoreceptors
- Conducing neurons
- Association neurons
- Supporting glial cells
what are the 10 specific layers of the retina?
- inner limiting layer
- nerve fiber layer
- ganglionic layer
- inner plexiform layer
- inner nuclear layer
- outer plexiform layer
- outer nuclear layer
- outer limiting layer
- rod and cone layer
- non-neural pigmented layer
what is the difference between rod and cone cells?
The outer limiting layer is the line of adherent junctions that attach the rod and cone inner segments to the distal ends of the Müller glial cells (not shown). The membranous discs of the cone outer segments are continuous with the cell membrane; those of the rods are not
the eyelid has _______ covering the inner surface?
conjunctiva
what do lacrimal glands do?
secrete most components of the tear film that moisturizes, lubricates, and helps protect the eyes
what are the 3 parts to the ear?
The external, middle, and internal regions
what is located in the internal ear?
consists of a cavity in the temporal bone, the bony labyrinth, which houses a fluid-filled membranous labyrinth. The membranous labyrinth includes the vestibular organs for the sense of equilibrium and balance (the saccule, utricle, and semicircular ducts) and the cochlea for the sense of hearing.
what are the two sensory areas called in the ear, where do they occur? and describe the function
maculae occur in the membranous labyrinth of the vestibular utricle and saccule, both specialized for detecting gravity and endolymph movements.
_____ cells and _______cells are part of an epithelium with tight junctions
Hair, supporting
Each of the semicircular ducts has an expanded end called the _________ (ear)
ampulla
The wall of each ampulla is raised as a ridge called the ________ __________ (ear)
crista ampullaris
what is the auditory part of the inner ear?
cochlea
