The iris and the ciliary muscle
intrinsic eye muscles are controlled by the autonomic nervous system
Extrinsic eye muscles move the eyeball in relation to the rest of the body, whereas intrinsic muscles move structures within the eyeball.A: The extrinsic muscles control the movement of the eyes.The extrinsic muscles are controlled by the somatic nervous system(voluntary) The intrinsicmuscles control the lens and pupil. The intrinsiceye muscles, (including the iris sphincter, radial pupilodilator muscles and the ciliarymuscle), are under the control of the autonomic nervous system(involuntary)
The intrinsic muscles of the eye are the dilator (radial), the sphincter pupillae (circular) constrictor muscle and the ciliary muscle. The iris contains the dilator pupillae and the constrictor pupillae with antagonist effects on the diameter of the pupil. The ciliary muscle is a smooth muscle that, when contracted relaxes the suspensory ligament of the lens. Contraction of this muscle is part of the accommodation reflex and under the control of parasympathetic fibers that travel with cranial nerve 3.
The medial rectus muscles are primarily responsible for the convergence reflex. When focusing on a near object, these muscles contract to rotate both eyes inward, allowing them to converge and maintain single binocular vision.
extrinsic muscles are strained
No, most cardiac muscles are not directly controlled by the nervous system. The cardiac muscles have their own intrinsic pacemaker called the sinoatrial (SA) node that generates electrical impulses and coordinates the contraction of the heart. While the nervous system can influence the rate and strength of the heart's contractions, it does not have direct control over the cardiac muscles.
many muscle fibers are controlled by a single motor neuron
Your eye muscles are controlled ultimately by your brain, so when you think "look over there" ... the muscles move your eyes to look. Obviously the thought doesn't have to be a conscious decision though. It is lightning fast... as soon as you think that you want to look someplace, you do.
The deep muscles of the human body are generally called intrinsic muscles. The muscles that are closer to the skin are called superficial muscles.
The deep muscles of the human body are generally called intrinsic muscles. The muscles that are closer to the skin are called superficial muscles.
The term intrinsic means essential in nature. They are necessary and needed.
The lateral rectus muscle is controlled by cranial nerve VI, also known as the abducens nerve. This muscle is responsible for moving the eye outward, away from the nose.