Muscular System Flashcards
Types of muscle tissue
Skeletal muscle, smooth muscle, and cardiac muscle
What does all muscle tissue have in common
The ability to contract and develop tension
Skeletal muscle (striated muscle)
Attaches to the skeleton and, through voluntary contraction, exerts force on the bones to move them; exhibits alternating light and dark bands giving a striated appearance
Smooth muscle
Functions involuntarily to regulate the movement of materials through the body, found in the walls of hollow organs and tubes such as the stomach, intestines, and blood vessels; lacks the striations
Cardiac muscle
Specialized tissue that functions involuntarily to maintain the constant pumping action of the heart; has a striated appearance
Tendon
A specialized form of connective tissue that attaches the muscle to the bones
Tendon of origin
Attaches to the proximal bone of a joint
Tendon of insertion
Attached to the more distal bone of a joint
Agonist (prime mover)
The muscle directly responsible for observed movement
Antagonist
The muscle that acts in opposition to the contraction produced by an agonist (prime mover) muscle
Longitudinal muscle
A muscle in which the fibers run parallel to the long axis of a muscle, forming a long, strap like arrangement; capable of producing considerable movement but is relatively weak compared to other muscle fiber arrangements
Unipennate muscle
Muscles that have a tendon that runs the entire length of the muscle, with muscle fibers inserting diagonally on one side of the tendon
Bipennate muscles
Muscles that have a tendon that runs the entire length of the muscle, with muscle fibers inserting obliquely on each side of the tendon
Mutlipennate muscles
Muscles that have a complex arrangement that involve the convergence of several tendons
General categories of skeletal muscle
Fast-twitch muscle fibers and slow-twitch muscle fibers
Slow-twitch muscle fibers
type I or slow-oxidative fibers
Possess a high volume of capillaries, myoglobin, and mitochondria making them resistant fatigue and capable of sustaining aerobic metabolism
Subtypes of fast-twitch muscle fibers
IIx and IIa muscle fibers
Type IIx muscle fibers (fast-glycolytic fibers)
The largest and fastest type of muscle fiber; possesses a low volume of mitochondria but a high number of glycolytic in enzymes for considerable force-production and anaerobic capacity
Type IIa fibers
fast-oxidative glycolytic fibers
Possess speed, fatigue, and force production capabilities somewhere between type I and type IIx muscle fibers making them highly adaptable
Influences on the percentage of specific muscle fiber types
Genetics, hormones, and exercise habits
Muscle fibers
Tiny individual muscle cells
Fasciae
Thin sheets of connective tissue membranes that hold muscle fibers in place
Epimysium
Fasciae of that incases the entire muscle
Perimysium
Fibrous sheath of fascia that holds bundles of muscle fibers within the epimysium
Endomysium
Fasciae wrapping individual muscle fibers within the perimysium
Mitochondria
The powerplant of the cells where aerobic metabolism occurs
Myoglobin
A compound similar to hemoglobin, which aids in the storage and transport of oxygen in muscle cells
Myofibril
The portion of the muscle containing the thick (myosin) and thin (actin) contractile filaments that give the striated appearance to skeletal muscle
Myosin
Thick contractile protein in a myofibril
Actin
Thin contractile protein in a myofibril
Sacromere
The basic functional unit of the myofibril containing the contractile proteins that generate skeletal muscle movements
Adenosine triphosphate (ATP)
A high-energy phosphate molecule required to provide energy for cellular function; produced both aerobically and anaerobically and stored in the body
Neurotransmitter
A chemical substance that transports nerve impulses across synapses
Acetylcholine
Neurotransmitter released at the end of nerve fibers in the somatic and parasympathetic systems to produce a muscle contract
Criteria in the naming of muscles
Shape, action, location, attachments, number of divisions, and size relationships
Shoulder girdle muscles main function
To fixate the scapula
Muscles that anchor the scapula
There are 6 muscles anchoring the scapula. Four posterior )including the trapezius, rhomboid major, rhomboid minor, and levator scapulae) and two anterior (pectoralis minor and serrartus anterior)
