a substance secreted in a glandular sac under the skin of the abdomen of the male musk deer, having a strong odor, and used in perfumery. 2. an artificial imitation of the substance. 3. a similar secretion of other animals, as the civet, muskrat, and otter. 4. the odor of musk or some similar odor.
Lens: The lens is a clear part of the eye behind the iris that helps to focus light, or an image, on the retina. Macula: The macula is the small, sensitive area of the retina that gives central. vision. It is located in the center of the retina. Optic nerve: The optic nerve is the largest sensory nerve of the eye. It. carries impulses for sight from the retina to the brain. Pupil: The pupil is the opening at the center of the iris. The iris adjusts the size. of the pupil and controls the amount of light that can enter the eye.
The oculomotor nerve is a motor neuron that controls all but two of the extraocular eye muscles, the levator palpebrae superioris and the intrinsic eye muscles. The nerves originate in the mesencephalon and pass through the superior orbital fissure on its way to the eye.he receptors of these neurons are found in the olfactory epithelium and the axons pass through the cribriform plate of the ethmoid bone. These neurons synapse within the olfactory bulb which lies directly above the cribriform plate.