Uveal Tract

Which is correct about pupillary constriction?

• parasympathetic fibers from Edinger-Westphal nucleus via long ciliary nerves

• parasympathetic fibers from Edinger-Westphal nucleus via short ciliary nerves

• sympathetic fibers via the long ciliary nerves

• sympathetic fibers via the short ciliary nerves

Answer explanation

Pupil constriction - sphincter pupillae, parasympathetic (from the Edinger-Westphal nucleus via the short ciliary nerves)

Pupil dilation - dilator muscle, sympathetic

The ciliary epithelium is made up of 2 layers of cuboidal cells that cover the inner surface of the ciliary body. Which are these layers?

• inner pigmented layer,

  outer nonpigmented layer

• inner nonpigmented layer,

  outer pigmented layer

Answer explanation

From inside to outside, the ciliary body consists of the ciliary epithelium, the ciliary stroma, the ciliary muscle, and the supraciliary layer.

The ciliary epithelium is made up of 2 layers of cuboidal cells that cover the inner surface of the ciliary body. There is an inner nonpigmented layer and outer pigmented layer.

Contraction of the longitudinal and circular ciliary smooth muscle fibers results in accommodation. This is innervated by

• Postganglionic parasympathetic fibers via the long ciliary nerves

• Sympathetic fibers via the long ciliary nerves

• Postganglionic parasympathetic fibers via the short ciliary nerves

• Sympathetic fibers via the short ciliary nerves

Answer explanation

The choroidal stroma consists of vessels, nerves, cells, and connective tissue.

It has 2 vessel layers, namely

• Outer, nonfenestrated large vessel layer (Haller’s layer) and inner nonfenestrated medium vessel layer (Sattler’s layer)

• Outer, nonfenestrated large vessel layer (Sattler’s layer) and inner nonfenestrated medium vessel layer (Haller’s layer)

• Outer, fenestrated large vessel layer (Haller’s layer) and inner fenestrated medium vessel layer (Sattler’s layer)

• Outer, fenestrated large vessel layer (Sattler’s layer) and inner fenestrated medium vessel layer (Haller’s layer)

Answer explanation

True of choriocapillaris (Click all that apply.)

• Single layer of large capillaries with fenestrations in the inner portion of the choroid

• Arranged in segmental pattern (lobular pattern in posterior pole, more parallel in periphery)

• Major source of nutrition for RPE and outer retinal layers

• Choriocapillaris is the only route for metabolic exchange in the retina within the foveal avascular zone