Histology II: the eyes Flashcards
Main purpose of the sense organs?
provide the connection between central nervous system and outer and inner environment.
What basic components do sense organs consist of?
receptors,
pathways and
center in the central nervous system.
Receptors contain?
sensory cells
Sense organs are divided into what three groups, depending on the nature of the sensory cells?
- sense organs with primary sensory cells with central processes (axon)
- sense organs with only secondary sensory cells (dendrites)
- sense organs with nerve endings are located diffusedly in the tissues
Name 2 sensory systems.
external (exteroception) and internal (interoception) sensory systems
Give an example of a sense organ with primary sensory cells.
eyes and nose
Give an example of sense organs with only secondary sensory cells.
hearing organ, vestibular organ, and gustatory receptors
Give an example of a sense organ with nerve endings diffused throughout.
skin
What layers does the wall of the eye consist of?
The outer fibrous layer or corneoscleral coat,
The middle uvea (layer) or vascular coat,
The inner layer or retina
Another name for the outer fibrous layer of the eye.
corneoscleral coat
Another name for the uveal layer of the eye.
vascular coat
What 3 main structures does the uveal layer contain?
choroid, ciliary body and iris
What is the choroid?
is the vascular layer that provides nutrients to the retina.
What is the ciliary body?
is a circular structure that is an extension of the iris, it produces the aqueous humor. It also contains the ciliary muscle
Difference between vitreous- and aqueous humor?
Vitreous humor is the fluid which is between the lens and retina, the aqueous humor is the fluid between the cornea and lens.
Purpose of the ciliary muscle?
changes the shape of the lens/ controls accommodation for viewing objects and regulates the flow of aqueous humor into Schlemm’s canal.
What is the iris?
The iris is a contractive diaphragm that extends over the anterior surface of the lens.
What is the canal of Schlemm?
also known as the scleral venous sinus
is a circular canal found within the posterior part of the corneoscleral junction.
What is the function of Schlemm’s canal?
The function of Schlemm’s canal is to collect the aqueous humor from the anterior chamber of the eyeball and deliver it to the veins of the eyeball.
What main two parts can we describe the retina as consisting of?
the neural retina and the pigment epithelium
What is the neural retina?
an inner layer the contains light sensitive receptors and a complex of neuronal networks.
What is the retinal pigment epithelium?
an outer layer composed of simple cuboidal melanin-containing cells.
Name the chambers of the eye.
anterior chamber
posterior chamber
vitreous chamber