Lecture Notes on Articulations and Muscle Physiology

These flashcards cover key terms and concepts related to articulations and muscle physiology, providing definitions and explanations to aid in exam preparation.

Articulations

Also known as a joint, it is any place where adjacent bones or bone and cartilage come together to form a connection.

Synostosis

A type of joint in which two or more bones fuse together.

Synovial membrane

The membrane lining the joint capsule that secretes synovial fluid.

Bursa

A fluid-filled sac that reduces friction between moving tissues in joints.

Pivot joint

A joint allowing rotational movement around a single axis (e.g., cervical vertebrae).

Hinge joint

A joint allowing movement primarily in one axis (e.g., elbow, knee).

Condyloid joint

A joint allowing movement in two planes (e.g., wrist joint).

Saddle joint

A joint allowing greater freedom of movement than a hinge or a condyloid joint (e.g., thumb).

Ball and socket joint

A joint allowing movement in multiple directions (e.g., shoulder, hip).

Flexion

Movement that decreases the angle between two body parts.

Extension

Movement that increases the angle between two body parts.

Abduction

Movement away from the midline of the body.

Adduction

Movement toward the midline of the body.

Circumduction

Circular movement that involves flexion, extension, abduction, and adduction.

Rotation

Movement around a bone's long axis.

Dorsiflexion

Flexion of the foot at the ankle, raising the toes.

Plantar flexion

Extension of the foot at the ankle, pointing the toes down.

Supination

Rotating the forearm so that the palm faces upward.

Pronation

Rotating the forearm so that the palm faces downward.

Inversion

Turning the sole of the foot inward.

Eversion

Turning the sole of the foot outward.

Opposition

Movement of the thumb to touch the tips of the other fingers.

Bursitis

Inflammation of the bursa, causing pain and limiting movement.

Osteoarthritis

A degenerative joint disease characterized by the breakdown of cartilage.

Gout

A form of arthritis characterized by sudden, severe attacks of pain, redness, and swelling in the joints.

Rheumatoid arthritis

An autoimmune disorder that primarily affects joints, causing inflammation.

Sprain

An injury to a ligament caused by excessive stretching.

Strain

An injury to a muscle or tendon caused by overstretching or overuse.

Excitability

The ability of muscle tissue to respond to stimuli.

Elasticity

The ability of muscle tissue to return to its original shape after being stretched.

Extensibility

The ability of muscle tissue to be stretched.

Contractility

The ability of muscle tissue to contract actively and generate force.

Skeletal muscle

Muscle tissue attached to bones, responsible for voluntary movements.

Smooth muscle

Involuntary muscle tissue found in walls of hollow organs.

Cardiac muscle

Involuntary muscle tissue found in the heart.

Epimysium

The outer connective tissue sheath surrounding a muscle.

Perimysium

The connective tissue surrounding individual fascicles within a muscle.

Endomysium

The connective tissue surrounding each muscle fiber.

Fascicle

A bundle of muscle fibers.

Aponeurosis

A flat sheet of tissue that connects muscles to the parts they act upon.

Sarcolemma

The cell membrane surrounding a muscle fiber.

Sarcoplasm

The cytoplasm of a muscle cell.

Sarcoplasmic reticulum

The organelle that stores calcium ions in muscle cells.

Sarcomere

The basic contractile unit of a muscle fiber.

Myofibril

A long, thread-like structure found in muscle fibers, made up of sarcomeres.

Actin

A protein that forms the thin filaments of muscle fibers.

Myosin

A protein that forms the thick filaments of muscle fibers.

Z disks

The boundaries of each sarcomere.

Troponin

A protein involved in muscle contraction that binds calcium ions.

Tropomyosin

A protein that blocks the binding sites on actin when the muscle is relaxed.

Neuromuscular junction

The synapse where a motor neuron meets a muscle fiber.

Motor unit

A single motor neuron and all the muscle fibers it innervates.

Twitch

A single, quick contraction of muscle fibers.

Graded muscle response

The varying strength of contraction of a muscle based on the frequency of stimulation.

Incomplete tetanus

A state of sustained contraction with partial relaxation between stimuli.

Complete tetanus

A sustained contraction where there is no relaxation between stimuli.

Duchenne muscular dystrophy

A genetic disorder characterized by progressive muscle degeneration.

Hypotonia

Decreased muscle tone leading to reduced muscle strength.

Hypertonia

Increased muscle tone leading to stiff or rigid muscles.

Atrophy

The decrease in muscle mass and strength due to inactivity.

Sarcopenia

Age-related loss of muscle mass.

Hyperplasia

An increase in the number of muscle fibers.

Fibrosis

The thickening and scarring of connective tissue.

Prime mover

The main muscle responsible for a specific movement.

Synergist

A muscle that assists the prime mover in performing its action.

Antagonist

A muscle that opposes the action of another muscle.

Fixator

A muscle that stabilizes one part of the body while another part moves.