Lecture 6: 12/1 Flashcards
vascular tunic 3 regions are: (listed posterior to anterior)
choroid, ciliary body, iris
what is a homologous structure to the choroid
pair matter and dura matter in the brain
what are the choroid’s few distinguishing factors
lots of pigment (dark brownish appearance) and extreme vascularity
function of the choroid is to
supply nutrition and oxygen to the outer 1/2 of the retina
what is the extent of choroid (posterior to anterior)
posteriorly from the optic nerve to an area called the ora serrata
what is the thickness of the choroid at its thickest part?
0.22mm thick at the thickest part at the optic disk
thick and thin regions of the choroid are
thickest at optic disc, gets thinner as it goes forward, thin at ora serrata
thickness of the choroid at the ora serrata
0.1 - 0.15 mm thick
what is the parachoroidal space?
between the vascular tunic and fibrous tonic, potential space that runs nerves/vessels from posterior to anterior of the eye
what is the parachoroidal space continuous with
the paraciliary space between the ciliary body and fibrous tunic
list 4 layers of the choroid from most external to most internal
- suprachoroid (most external)
- vascular layer
- choriocapillaris
- bruch’s membrane
how many lamella are in the suprachoroid
10-15 lamella
the suprachoroid blends outward into the _____ ____ of what structure?
lamina fusca in the sclera
what is the lamella structure in the suprachoroid?
delicate mesh of collagen fibers
what is within the mesh of collagen fibers in the lamella of the suprachoroid?
melanocytes and fibroblasts
what are muscle stars in the suprachoroid?
smooth muscle fibers that are found in the tail end of the muscle of the ciliary body, form little “stars” found anterior to the equator
are there melanocytes in the suprachoroid layer?
yes
are there arteries and veins found in the suprachoroid layer?
yes
are there nerves supplying the suprachoroid and what are they?
yes, ciliary nerves that do supply innervation
stroma layer of the choroid can also be called the
vascular layer or vessel layer
what is special about the stroma of the choroid?
essential constituent in branching blood vessels
what are the two layers of the stroma of the choroid?
external (Haller’s Layer)
internal (Satler’s Layer)
what happens to the diameters of the vessels in the stroma of the choroid as you travel inwards?
the diameter gets smaller
the vessels in the stroma of the choroid are surrounded by what type of tissue?
vessels surrounded by collagen loose connective tissue
are there melanocytes in the stroma of the choroid?
yes
why aren’t blood clots as big of a deal in the stroma of the choroid?
there is such a meshwork that the blood can flow around more
