A masticatory muscle whose action is closing the jaws; its posterior portion retracts the mandible.
Muscles arising in the zygomatic arch that close the jaw. Their nerve supply is masseteric from the mandibular division of the trigeminal nerve. (From Stedman, 25th ed)
A masticatory muscle whose action is closing the jaws.
The largest and strongest bone of the FACE constituting the lower jaw. It supports the lower teeth.
The measurement of the dimensions of the HEAD.
Contractile tissue that produces movement in animals.
The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.
Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)
A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.
The nonstriated involuntary muscle tissue of blood vessels.
Injuries to the lower jaw bone.
The dioptric adjustment of the EYE (to attain maximal sharpness of retinal imagery for an object of regard) referring to the ability, to the mechanism, or to the process. Ocular accommodation is the effecting of refractive changes by changes in the shape of the CRYSTALLINE LENS. Loosely, it refers to ocular adjustments for VISION, OCULAR at various distances. (Cline et al., Dictionary of Visual Science, 4th ed)
The top layer of the back muscles whose function is to move the SCAPULA. This group of muscles consists of the trapezius, latissimus dorsi, rhomboid major, rhomboid minor and levator scapulae.
The neck muscles consist of the platysma, splenius cervicis, sternocleidomastoid(eus), longus colli, the anterior, medius, and posterior scalenes, digastric(us), stylohyoid(eus), mylohyoid(eus), geniohyoid(eus), sternohyoid(eus), omohyoid(eus), sternothyroid(eus), and thyrohyoid(eus).
Part of the body in humans and primates where the arms connect to the trunk. The shoulder has five joints; ACROMIOCLAVICULAR joint, CORACOCLAVICULAR joint, GLENOHUMERAL joint, scapulathoracic joint, and STERNOCLAVICULAR joint.
The 11th cranial nerve which originates from NEURONS in the MEDULLA and in the CERVICAL SPINAL CORD. It has a cranial root, which joins the VAGUS NERVE (10th cranial) and sends motor fibers to the muscles of the LARYNX, and a spinal root, which sends motor fibers to the TRAPEZIUS and the sternocleidomastoid muscles.
Traumatic injuries to the ACCESSORY NERVE. Damage to the nerve may produce weakness in head rotation and shoulder elevation.
Four or five slender jointed digits in humans and primates, attached to each HAND.
Elongated, spindle-shaped, quiescent myoblasts lying in close contact with adult skeletal muscle. They are thought to play a role in muscle repair and regeneration.
A paired box transcription factor that is involved in EMBRYONIC DEVELOPMENT of the CENTRAL NERVOUS SYSTEM and SKELETAL MUSCLE.
A family of conserved cell surface receptors that contain EPIDERMAL GROWTH FACTOR repeats in their extracellular domain and ANKYRIN repeats in their cytoplasmic domains. The cytoplasmic domain of notch receptors is released upon ligand binding and translocates to the CELL NUCLEUS where it acts as transcription factor.
Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.
Developmental events leading to the formation of adult muscular system, which includes differentiation of the various types of muscle cell precursors, migration of myoblasts, activation of myogenesis and development of muscle anchorage.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.
An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.
A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.
A protein kinase C subtype that was originally characterized as a CALCIUM-independent, serine-threonine kinase that is activated by PHORBOL ESTERS and DIACYLGLYCEROLS. It is targeted to specific cellular compartments in response to extracellular signals that activate G-PROTEIN-COUPLED RECEPTORS; TYROSINE KINASE RECEPTORS; and intracellular protein tyrosine kinase.
A ubiquitously expressed protein kinase that is involved in a variety of cellular SIGNAL PATHWAYS. Its activity is regulated by a variety of signaling protein tyrosine kinase.
A cytoplasmic serine threonine kinase involved in regulating CELL DIFFERENTIATION and CELLULAR PROLIFERATION. Overexpression of this enzyme has been shown to promote PHOSPHORYLATION of BCL-2 PROTO-ONCOGENE PROTEINS and chemoresistance in human acute leukemia cells.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Arteries arising from the external carotid or the maxillary artery and distributing to the temporal region.
A nonspecific term used to describe transient alterations or loss of consciousness following closed head injuries. The duration of UNCONSCIOUSNESS generally lasts a few seconds, but may persist for several hours. Concussions may be classified as mild, intermediate, and severe. Prolonged periods of unconsciousness (often defined as greater than 6 hours in duration) may be referred to as post-traumatic coma (COMA, POST-HEAD INJURY). (From Rowland, Merritt's Textbook of Neurology, 9th ed, p418)
Acquired and inherited conditions that feature DYSTONIA as a primary manifestation of disease. These disorders are generally divided into generalized dystonias (e.g., dystonia musculorum deformans) and focal dystonias (e.g., writer's cramp). They are also classified by patterns of inheritance and by age of onset.
A condition characterized by focal DYSTONIA that progresses to involuntary spasmodic contractions of the muscles of the legs, trunk, arms, and face. The hands are often spared, however, sustained axial and limb contractions may lead to a state where the body is grossly contorted. Onset is usually in the first or second decade. Familial patterns of inheritance, primarily autosomal dominant with incomplete penetrance, have been identified. (Adams et al., Principles of Neurology, 6th ed, p1078)
A systemic autoimmune disorder that typically affects medium and large ARTERIES, usually leading to occlusive granulomatous vasculitis with transmural infiltrate containing multinucleated GIANT CELLS. The TEMPORAL ARTERY is commonly involved. This disorder appears primarily in people over the age of 50. Symptoms include FEVER; FATIGUE; HEADACHE; visual impairment; pain in the jaw and tongue; and aggravation of pain by cold temperatures. (From Adams et al., Principles of Neurology, 6th ed)
Traumatic injuries involving the cranium and intracranial structures (i.e., BRAIN; CRANIAL NERVES; MENINGES; and other structures). Injuries may be classified by whether or not the skull is penetrated (i.e., penetrating vs. nonpenetrating) or whether there is an associated hemorrhage.
Traumatic injuries to the cranium where the integrity of the skull is not compromised and no bone fragments or other objects penetrate the skull and dura mater. This frequently results in mechanical injury being transmitted to intracranial structures which may produce traumatic brain injuries, hemorrhage, or cranial nerve injury. (From Rowland, Merritt's Textbook of Neurology, 9th ed, p417)