The diameter of the pupil changes depending on the contraction of special muscles that act in different ways: the function of the circular muscle is aimed at narrowing the pupil, and the function of the radial muscle is to expand it.
Unconsciously produced and physiologically inappropriate active movements - hyperkinesis - are related to pathologies of nervous regulation of muscles of various localizations and arise as a result of damage to the central and somatic nervous system.
Friedreich's ataxia is an autosomal recessive pathology, when a sick child is born to a visually healthy couple, but one of the parents is the owner of a disease-causing gene.
Cataplexy is a sudden loss of muscle tone caused by emotional stress or a state of affect - from a barely noticeable weakening of the muscles of the face and neck to total short-term atony and loss of the ability to hold the body in a certain position.
Cerebral palsy is one of the most severe neurological diseases, in which the brain is damaged or does not fully develop, and various motor activity disorders occur.
Facial neuralgia, also known as neuritis or Fottergill's syndrome, is a pathological condition in which a person's facial expressions are impaired, and there is paralysis or weakening of the movement of the facial muscles.
The disease, called Duchenne muscular dystrophy, is associated with damage to the gene structures responsible for the production of the large muscle protein dystrophin.
