Iris and Ciliary Body Flashcards
All exocrine glands have what type of tissue?
Secretory epithelium
Ora Seratta is what?
transition point between anterior and posterior uvea
Ciliary muscle is located where?
Ciliary body
Pupilary margin also called? is it pigmented? what does it rest on?
pupilary ruff, YES, lens.
Iris stroma is continuous with which other stroma?
ciliary body stroma
Sclera and cornea are what types of connective tissue?
Dense regular CT
what two chambers does the iris separate?
anterior and posterior
Iris is attached by what? and that is where?
root at angle of anterior chamber.
is the iris root thinner or thicker compared to central? therefore?
thinner therefore more susceptible to damage.
What type of tissue is on the posterior iris? Which section of this tissue is continuous with the ciiary processes (pars plicata) and pars plana?
bilayer epithelium (anterior= lighter pigment, posterior= darker pigment) Posterior is continuous.
What is the avg pupilary diameter (range)? what muscle is this controlled by?
1-8mm sphincter muscles (circular)
What separates the pupilary region and ciliary region in the pupil? which region is bigger?
collarette
ciliary region
furrows are what type of muscle? when are they more noticeable?
circular muscles allow for contraction, in dark iris.
What are crypts?
holes in the anterior iris, allowing fluid to move from anterior chamber to iris stroma.
the cells in the posterior bilayer epithelium of the iris are arranged how?
apex to apex therefore basal on either side of that.
which layer of the bilayer epithelium in the posterior iris has processes? what are they? which holds what muscle? innervated by?
anterior portion, myoepithelial portion which holds the dilator muscle (innervated by symp)
which layer of the iris is the sphincter muscle located in?
stroma
What are the four layers of the iris?
- Anterior border: has crypts!
- stroma: loose CT, also has crypts
- Bilayered epithelium which is broken into anterior myoepithelium and posterior pigmented epithlium.
which cell types are present in the iris stroma?
fibroblasts, melanocytes, collagen, macros and mast cells.
are there crypts in the posterior chamber? where are they?
NO (it has tight junctions, fluid cant get through) they are in anterior chamber.
the posterior pigmneted layer of bilayer epithelium in posterior iris continuous to become? does anterior layer continue up?
pupilary margin.
NO
the anterior lens capsule has what kind of epithelium tissue?
simple cuboid epithelium
dilator muscle located where? innervated by?
anterior myoepithelium of bilayer in posterior iris. innervated by sympathetic.
sphincter contractile muscle located where? innervated by?
stroma, smooth muscle, parasymp.
REMEMBER ANTERIOR BILAYER IN POSTERIOR IRIS MEANS WHAT?
most inner layer, closest to inner eye!
Iris stroma is what kind of CT? what types of cells here?
Loose CT. fibroblasts, melanocytes and collagen fibres, elastin.
where is the minor arterial circle located?
where collarette is
is there leakage between blood and stroma? why?
NO. due to tight junctions
what types of cells are located in posterior part of bilayer in posterior iris? how many layers?
cuboid or high columnar
single layer
is the myoepithelium pigmented?
NO
Ciliary body is made up of?
ciliary processes (pars plicata) and ciliary muscle. PARS PLANA OUTSIDE OF THIS
“spur” of sclera is located where?
at limbus. (where it becomes cornea)
What is the distance from the pars plicata to the ora seratta? pars plicata are how wide? how many of them usually? pars plana how long?
6mm
2mm long (70-80 normally), 0.5mm wide
4mm
zonules originate how far from ora seratta?
1.5mm
valleys of khunt located where?
between pars plicata
Where are zonules made?
pars plana secretes them
Describe pathway of aqeous humor? this pathway is called which?
goes from posterior chamber to between iris and lens (pupilary margin) to through pupil to anterior chamber to trabecular meshwork to schlemms canal to venous system (through episcleral vein).
conventional pathway
CIliary bilayer epithelium (continuation of iris bilayer) orientation of cells? which layer is pigmented which is not?
apex to apex
Posterior becomes non pigmented by the anterior layer remains pigmented (by anterior I mean most inner to eye)
where are Schwalbe folds and furrows located?
posterior epithelium of iris.
what are the three different ciliary fibres going from inner to outer (closest to sclera)?
- circular
- radial
- longitudinal
the non pigmented tissue in the ciliary epithelium becomes what? the pigmented becomes what?
neural retina.
RPE.
fornix is the point where what transitions into what?
palpebral (more folded) becomes bulbar conjunctiva.
trabecular meshwork is a series of canals lined with what?
endothelium (simple squamous epithelium)
Anterior chamber angel is formed by what posteriorly? what anteriorly? this gets smaller in what disease causing what affect?
posteriorly: iris, anteriorly: trabecular meshwork. gets smaller in glaucoma which increases IOP.
aqeous humor is continuously formed by what?
non pigmented epithelium
How fast is aqeous humor made?
2-4microlitres a min.
aqeous humor brings what to the lens and cornea?
metabolites, O2, also maintains IOP.
is aqeous humor also made in posterior chamber?
YES (and anterior)
what is the non conventional pathway of aqeous humor? what percent of humor does this?
through ciliary muscle, choroid and then sclera.
10-30%
what makes up trabeculae in trabecular meshwork?
collagen fibres
Glaucoma due to what changes? the most common type of glaucoma? whats another type called?
changes in trabecular meshwork and schlemms canal. increased IOP. open angle glaucoma (due to reasons above) closed angle (where the anterior chamber angle literally closes in, iris moves toward TM)
