The word "musculus ciliaria" is spelled using the IPA phonetic transcription as /ˈmʌskjʊləs sɪˈlɛərɪə/. The first part of the word, "musculus," is pronounced as "muh-skyuh-luhs," while the second part, "ciliaria," is pronounced as "sih-lair-ee-uh." This word refers to the ciliary muscle found in the eye, which is responsible for controlling the shape of the lens and ensuring clear vision. Proper spelling and pronunciation of scientific terms like "musculus ciliaria" are crucial in the fields of biology and medicine.
Musculus ciliaris, also known as the ciliary muscle, is a small muscle found within the human eye. It is responsible for controlling the shape and flexibility of the lens in order to facilitate the process of focusing on objects at varying distances.
Located behind the iris, this smooth muscle is part of the ciliary body and is made up of both circularly and radially arranged fibers. The contraction and relaxation of the ciliary muscle play a vital role in adjusting the thickness of the lens, a process called accommodation.
When the ciliary muscle contracts, it causes the circular fibers to tighten, which reduces the tension on the lens capsule and enables the lens to become thicker and more curved. This enables the eye to focus on close objects. Conversely, when the ciliary muscle relaxes, the tension on the lens capsule increases, causing the lens to flatten and focus on distant objects.
Musculus ciliaris is innervated by the parasympathetic nervous system, specifically through the oculomotor nerve (cranial nerve III). The release of acetylcholine from these nerve fibers stimulates the contraction of the ciliary muscle and triggers the accommodation response.
The ability of musculus ciliaris to change the shape of the lens allows for the eye's ability to focus on objects at different distances, contributing to clear vision and visual acuity.
(1) Bowman's muscle, a circular band of non-striated fibers on the outer surface of the chorioid, between that and the iris; it consists of circular fibers (fibrae circulares, or Muller's muscle) and radiating fibers (fibrae meridionales or Brucke's muscle); (2) a separate bundle of the m. orbicularis in the margin of the lids.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "musculus ciliaria" is Latin in origin and can be broken down into its individual components for a better understanding of its etymology.
1. Musculus: This Latin word means "muscle". It is derived from the Greek word "myōsis", which also means "a muscle contraction".
2. Ciliaria: This Latin word refers to the "ciliary body". It is derived from the Latin word "ciliaris", meaning "pertaining to the eyelashes". The term "ciliary" also originated from the Latin word "cilia", which means "eyelashes".
Combining these two words, "musculus ciliaria" would roughly translate to "ciliary muscle" or "muscle of the eyelashes" in English. This term is commonly used in anatomy to refer to the smooth muscle structure in the eye responsible for adjusting the shape of the lens during focusing.