4.2 Key Terms Flashcards
(25 cards)
Afferent neurons
Nerve cells that carry impulses towards the central nervous system
Cardiac muscle
Striated muscle fibers (cells) that form the wall of the heart; stimulated by the intrinsic conduction system and autonomic motor neurons
Carpal tunnel syndrome
Condition caused by compression of the median nerve in the carpal tunnel and characterized especially by weakness, pain, and disturbance of sensation in the hands and fingers
Contract
To shorten and thicken
Efferent neurons
Nerve cells that conduct impulses away from the central nervous system
Endomysium
Delicate connective tissue surrounding the individual muscular fibers within the smallest bundles
Epismysium
External connective-tissue sheath of a muscle
Fascicle
Small bundle or cluster, especially of nerve or muscle fibers
Insertion
Attachment of a muscle tendon to a moveable bone or the opposite of the origin
Muscle
Organ composed of one of the three types of muscular tissue (skeletal, cardiac, and smooth), specialized for contraction to produce voluntary and involuntary movements of parts of the body
Myofibril
Threadlike structure, extending longitudinally through a muscle fiber (cell) consisting mainly of think filaments (myosin) and thin filaments (actin, troponin and tropomyosin)
Myosin
Contractile protein that makes up the thick filaments of muscle fibers
Nerve
Cordlike bundle of neuronal axons and/or dendrites and associated connective tissue coursing together outside the central nervous system
Origin
Attachment of a muscle tendon to a stationary bone or the end opposite the insertion
Perimysium
Connective- tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers
Plexus
Network of interlacing blood vessels or nerves
Rigor mortis
Temporary regidity of muscles occurring after death
Sarcomere
Any of the repeating structural units of striated muscle fibrils
Skeletal muscle
Organ specialized for contraction, composed of striated muscle fibers (cells), supported by connective tissue, attached to bone by a tendon or aponeurosis, and stimulated by somatic motor neurons
Sliding filament mechanism
The explanation of how thick and thin filaments slide relative to one another during striated muscle contraction to decrease Sarcomere length
Smooth muscle
Tissue specialized for contraction, composed of smooth muscle fibers (cells), located in the walls of hollow internal organs, and innervated by the automatic motor neurons
Striation
Any of the alternate dark and light cross bands of a myofribil of striated muscle
Tropomyosin
Protein of muscle that forms a complex with troponin regulating the interaction of actin and myosin in muscular contraction
Troponin
Protein of muscle that together with tropomyosin forms a regulatory protein complex controlling the action of actin and myosin and that when combined with calcium ions permits muscular contractions