Untitled Flashcards Set

Sclera

The white part of the eye that serves as an anchoring site for extrinsic eye muscles; part of the eye’s fibrous outermost layer.

Cornea

The window that lets light into the eye; part of the eye’s fibrous outermost layer.

Choroid

Supplies all the layers of the eye with blood; part of the eye’s vascular middle layer.

Ciliary body

Ring of muscle tissue around the lens in the eye.

Iris

Ring of smooth muscle between the cornea and lens that contracts and expands to change the size of the pupil; the colored part of the eye.

Pupil

Opening in the center of the iris that allows light into the eye.

Suspensory ligament

A halo of fibers encircling and holding up the lens of the eye.

Retina

The inner layer of the eye that contains the photoreceptors (rods and cones).

Optic nerve

The nerve that transmits visual information from the retina to the brain.

Fovea centralis

Small pit in the eye, packed with cones, that gives us our sharpest and clearest vision.

Optic disc

Where the optic nerve exits the eye.

Rods

Photoreceptors in the retina that register black and white.

Cones

Photoreceptors in the retina that detect fine details and color.

Lens

The convex transparent disc that focuses the light that is allowed in and projects it onto the retina in the inner layer.

Vitreous humor

The clear gel that fills the posterior segment of the eye behind the lens.

Aqueous humor

The clear fluid that fills the anterior segment in front of the lens.

Odor

The gaseous molecules we smell.

Olfactory epithelium

Specialized epithelial tissue in the roof of the nasal cavity that has olfactory sensory neurons.

Taste buds

The sensory organ of taste, mainly located in the papillae.

Papillae

Bumps on the tongue where taste buds are located.

Gustatory epithelial cells

Taste receptor cells.

Basal epithelial cells

Stem cells that make new gustatory epithelial cells.

Hormone

Chemical messengers secreted by cells into extracellular fluids that travel through the blood to regulate cell functions.

Exocrine

Externally secreting structures that release nonhormonal substances, like sweat and saliva, through ducts to the body’s surface.

Endocrine

Internally secreting ductless structures that release hormones into surrounding tissue fluid, like blood.

Humoral stimuli

Hormone release caused by altered levels of critical ions or nutrients.

Neural stimuli

Hormone release caused by neural input.

Hormonal stimuli

Hormone release caused by another hormone.

Permissiveness

When a hormone can’t do its job fully without another hormone present.

Synergism

When more than one hormone produces the same effects at the target cell, causing an amplified combined effect.

Antagonism

When one hormone opposes the action of another.