Lecture 32 RH Flashcards
What bone forms the supraorbital margin?
Supraorbital margin is formed by the frontal bone.
What is the function of the supraorbital notch?
Passage of blood vessels and nerves to the forehead
What bones form the infraorbital margin?
Infraorbital margin is formed by the zygomatic bone laterally and maxilla medially
What bones form the orbit?
Roof: Frontal bone and lesser wing of sphenoid
Floor: Maxilla, zygomatic, and palatine
Lateral wall: Zygomatic, greater wing of the sphenoid
Medial wall Maxilla, lacrimal bone, ethmoid (papyrus region), body of sphenoid
What are the fissures and foramina found in the posterior eye?
Optic canal
Superior orbital fissure
Inferior orbital fissure
What nerves go through the optic canal?
Optic nerve + opthalmic artery
What goes through the superior orbital fissure?
opthalmic division of the trigeminal nerve.
Which holes in the orbit are most relevant for the eye?
Superior orbital fissure
Optic canal
What is the outer layer of the eye called?
Outer coat is formed by the cornea and the sclera (strength)
What is the middle layer of the eye called?
Uvea (important for nutrition) (includes coroid, ciliary body, and the iris)
What is the inner layer of the eye called?
Retina
What is the sclera?
forms 5/6 of the eyeball
Made up of collagen and layed down in a series of whirls to maintain the shape of the globe offering resistence to internal and external forces.
What is the cornea?
It is a continuous transparent structure.
What is the cornea made up of?
Corneal epithelium
What is corneal stroma made up of?
Corneal stroma is made up of collagen
What is the function of corneal endothelial cells?
Endothelial cells control thickness and water balance of the cornea.
Why is maintaining endothelial cell number important?
Endothelial cell number is determined at birth.
Why is the cornea transparent and not the sclera despite both being made of collagen?
The way the collagen is arranged. In the cornea they are more organized and arranged in an evenly spaced way.
What would happen if eye is poked and the epithelium is damaged?
Epithelium can repair itself so he would recover completely soon after.
Where is the anterior chamber and angle located?
Anterior chamber and angle is the region just behind the cornea between the cornea and the iris
What happens at the anterior chamber and angle?
Aqueous humour drains out of the eye.
Why is it important to drain the aqueous humour of the eye?
Fluid formed in the eye continuously and so the fluid of the eye is removed via the anterior chamber and angle
What are the functions of the ciliary body?
Forms the aqueous humour
Important region to tehter the lens to the wall of the eyeball
It is important for accomodation (ciliary muscle)
What is the function of the aqueous humour produced by the ciliary body?
It is important for maintaining health of the lens.
Creates intraocular pressure
Passes through the pupil and drains via anterior achamber and angle
What is accomodation and how is it carried out?
Accomodation is the ability to adapt the eyes to looking at something close or far depending on what is required and this is done by ciliary muscle.
What does contraction of the ciliary muscle do?
Ciliary muscle contraction means you read. (focusing on something close)
What is the iris?
Iris is the colour part of the eye.
What muscles control the iris?
Sphincter pupillae: Constricts pupil: Innervated by Parasympathetic NS.
Dilator pupillae: Dilates pupil: Innervated by sympathetic nervous system
