A+P Muscular system

Place the layers of connective tissue associated with skeletal muscle in order from deepest (interior) to the most superficial (exterior)

1. Endomysium

2. Perimysium

   1. Epimysium

Short term effects of exercise on muscles

Fatigue, pain, accumulation of lactic acid in the muscle

long term effects of exercise on muscles

Muscular hypertrophy, increased metabolic capacity, more capillaries and mitochondria

prime mover (functional muscle group)

the muscle that has the biggest contribution toward a particular movement. The contractions of the prime mover cause the desired action

Antagonist (functional muscle group)

opposes or reverses a movement that was caused by the prime mover.

Synergist (functional muscle group)

muscles that aid the movement of the prime mover by preventing unwanted shifts at intermediate joints

fixator (functional muscle group)

Their main role is to stabilize the origin of the prime mover and enhance its efficiency. Specialized synergists

6 criteria for naming muscles

Shape

Location

Size

Fiber direction

Number of muscle origins

Action

SLSDNA

Parallel (Fascicle arrangements)

fascicles that are arranged in the same direction as the long axis of the muscle

Circular (Fascicle arrangements)

also called sphincters. When they relax, the sphincters’ concentrically arranged bundles of muscle fibers increase the size of the opening, and when they contract, the size of the opening shrinks to the point of closure

Convergent (Fascicle arrangements)

When a muscle has a widespread expansion over a sizable area and the fascicles come to a single, common attachment point

Pennate (Fascicle arrangements)

muscles (penna = “feathers”) blend into a tendon that runs through the central region of the muscle for its whole lengthFu

Fusiform (Fascicle arrangements)

Other parallel muscles have a larger central region called a muscle belly tapering to tendons on each end. such as the biceps brachii.

Perimysium

the sheath of connective tissue surrounding a bundle of muscle fibers.

Epimysium

1. a sheath of fibrous elastic tissue surrounding a muscle.

Endomysium

a delicate sheath of connective tissue which envelopes each individual skeletal muscle fiber

Sarcolemma

the fine transparent tubular sheath which envelops the fibers of skeletal muscles

Neuromuscular junction

a chemical synapse between a motor neuron and a muscle fiber

Cross-bridges

the globular head of a myosin molecule that projects from a myosin filament in muscle

Complete tetanus

when there is no relaxation of the muscle fibers between stimuli and it occurs during a high rate of stimulation

Flexion

a movement that decreases the angle between two body part

Hypertonia

a condition in which there is too much muscle tone so that arms or legs, for example, are stiff and difficult to move.

All-or-none principle

the principle that if a single nerve fibre is stimulated, it will always give a maximal response and produce an electrical impulse of a single amplitude.

Graded response

the ability of a muscle to exhibit varying levels of contraction strength in response to different levels of stimulation

Thin filaments

essential protein structures found in muscle cells, primarily composed of actin, along with troponin and tropomyosin. composed of different proteins, extending inward toward the center of a sarcomere

Sarcomere

1. a structural unit of a myofibril in striated muscle, consisting of a dark band and the nearer half of each adjacent pale band.

Thick filaments

structures that contain myosin and are essential for movement and motility, functioning through interactions with actin-containing thin filaments.

Sarcoplasmic reticulum

a membrane-bound structure found within muscle cells that is similar to the smooth endoplasmic reticulum in other cells. controls the cytosolic calcium concentrations required for contraction