HA-101_Muscular-System

Skeletal muscle

A type of muscle found in the body that is responsible for voluntary movements.

Cardiac muscle

A type of muscle found in the heart that is responsible for pumping blood.

Smooth muscle

A type of muscle found in the walls of organs and blood vessels that is responsible for involuntary movements.

Electrical excitability

The ability of muscle cells to respond to electrical stimuli.

Contractility

The ability of muscle cells to contract and generate force.

Extensibility

The ability of muscle cells to stretch and lengthen.

Elasticity

The ability of muscle cells to return to their original shape after being stretched.

Endomysium

Connective tissue that surrounds individual muscle fibers.

Perimysium

Connective tissue that surrounds groups of muscle fibers, separating them into bundles called fascicles.

Epimysium

Connective tissue that encircles the entire muscle.

Fascia

Connective tissue that lines the body wall and limbs, supporting and surrounding muscles and other organs.

Tendons

Rope-like structures that attach muscles to bones.

Aponeurosis

Sheet-like structures that attach muscles indirectly.

Fibromyalgia

A chronic, painful disorder characterized by muscle pain, fatigue, poor sleep, and other symptoms.

Sarcolemma

The specialized plasma membrane of a muscle cell.

Transverse (T) tubules

Tiny invaginations of the sarcolemma.

Sarcoplasm

The cytoplasm of a muscle fiber.

Myofibrils

The contractile organelles of skeletal muscle.

Sarcoplasmic reticulum (SR)

A fluid-filled system of membranous sacs that stores calcium ions.

Terminal cisterns

Dilated end sacs of the sarcoplasmic reticulum.

Sarcomeres

The basic functional units of a myofibril, arranged in compartments.

Thick filaments

Protein structures composed of myosin within myofibrils.

Thin filaments

Protein structures composed of actin within myofibrils.

Muscular hypertrophy

Muscle growth that occurs through enlargement of existing muscle fibers.

Muscular hyperplasia

An increase in the number of muscle fibers.

Fibrosis

The replacement of muscle fibers by fibrous scar tissue.

Muscular atrophy

Wasting away of muscles, resulting in a decrease in the size of individual muscle fibers.

Contractile proteins

Proteins involved in muscle contraction, such as myosin and actin.

Regulatory proteins

Proteins that regulate muscle contraction, such as tropomyosin and troponin.

Structural proteins

Proteins that provide structural support to muscle fibers, such as titin and dystrophin.

Sliding filament mechanism

The process by which myosin heads attach to actin filaments and pull them inward, resulting in muscle contraction.

Rigor Mortis

The stiffening of muscles after death due to the inability of cross-bridges to detach from actin.

Somatic motor neurons

Neurons that stimulate skeletal muscle fibers to contract.

Neuromuscular junction

The synapse between a somatic motor neuron and a skeletal muscle fiber.

Synapse

A region where communication occurs between neurons or between a neuron and a target cell.

Synaptic cleft

The gap that separates the somatic motor neuron and the skeletal muscle fiber.

Neurotransmitter

A chemical released from one cell to another, such as acetylcholine.

Acetylcholine

A neurotransmitter that is released at the neuromuscular junction and stimulates muscle contraction.

Motor end plate

The region of the muscle fiber membrane that contains acetylcholine receptors and is stimulated by acetylcholine.1. Muscle action potential:The change in membrane potential that triggers a muscle contraction.

Sarcolemma

The cell membrane of a muscle fiber.

Sarcoplasmic reticulum

A network of tubules within muscle fibers that stores and releases calcium ions.

Acetylcholinesterase (AChE)

An enzyme that breaks down acetylcholine, terminating its activity.

Electromyography (EMG)

A test that measures the electrical activity in muscles.

ATP

Adenosine triphosphate, the energy currency of cells.

Muscle fatigue

The inability of a muscle to maintain force of contraction after prolonged activity.

Oxygen debt

The additional oxygen consumed after exercise to restore metabolic conditions to resting levels.

Isotonic contraction

Muscle contraction where the tension remains constant while the muscle changes length.

Isometric contraction

Muscle contraction where the tension generated is not enough to change the length of the muscle.

Myasthenia gravis

An autoimmune disease that causes damage to the neuromuscular junction, leading to muscle weakness.

Muscular dystrophy

A group of inherited muscle-destroying diseases that cause progressive degeneration of skeletal muscle fibers.1. Duchenne muscular dystrophy:The most common form of muscular dystrophy characterized by the lack of dystrophin, a muscle protein that helps maintain the sarcolemma. It usually becomes apparent between the ages of 2 and 5 and leads to difficulty in movement and eventual respiratory or cardiac failure by age 20.

Flexion

Movement that decreases the angle of a joint.

Extension

Movement that increases the angle between two bones.

Rotation

Movement of a bone around its longitudinal axis.

Abduction

Movement of a limb away from the midline of the body.

Adduction

Movement of a limb toward the midline of the body.

Circumduction

Combination of flexion, extension, abduction, and adduction.

Dorsiflexion

Lifting the foot so that the superior surface approaches the shin.

Plantar flexion

Depressing the foot (pointing the toes).

Inversion

Turning the sole of the foot medially.

Eversion

Turning the sole of the foot laterally.

Supination

Forearm rotation laterally so that the palm faces anteriorly.

Pronation

Forearm rotation medially so that the palm faces posteriorly.

Opposition

Movement of the thumb to touch the tips of other fingers on the same hand.

Insertion

The attachment of a muscle's other tendon to the movable bone.

Origin

The attachment of a muscle's tendon to the stationary bone.

Prime mover/agonist

The muscle with the major responsibility for a certain movement.

Antagonist

The muscle that opposes or reverses a prime mover.

Synergist

The muscle that aids a prime mover in a movement and helps prevent rotation.

Fixator

The muscle that stabilizes the origin of a prime mover.

Intramuscular (IM) injections

Injections that penetrate the skin and subcutaneous layer to enter the muscle itself.

Bell's palsy

Unilateral paralysis of the muscles of facial expression due to damage or disease of the facial nerve.

Strabismus

A condition in which the two eyeballs are not properly aligned.

Dysphagia

Difficulty in swallowing.1. Rotator cuff injury:A strain or tear in the rotator cuff muscles, commonly seen in athletes who engage in shoulder movements that involve vigorous circumduction.

Hernia

A protrusion of an organ through a structure that normally contains it, resulting in a visible or palpable lump on the skin's surface.

Inguinal hernia

A rupture or separation of a portion of the inguinal area of the abdominal wall, leading to the protrusion of a part of the small intestine. More common in males due to larger inguinal canals.

Trunk muscles

Muscles located in the torso region, including the abdominal muscles and back muscles.

Golfer's elbow

A condition caused by strain of the flexor muscles, particularly the flexor carpi radialis, due to repetitive movements like swinging a golf club. Can also be caused by other actions such as playing musical instruments or using computers.1. Biceps brachii:A muscle located in the upper arm that flexes the elbow joint and supinates the forearm.

Humerus

The bone of the upper arm or forelimb, extending from the shoulder to the elbow.

Muscle origin

The point of attachment of a muscle to a bone that remains relatively fixed during contraction.

Muscle insertion

The point of attachment of a muscle to a bone that moves during contraction.

Action

The specific movement or function performed by a muscle.

Innervation

The supply of nerves to a specific muscle or region of the body.

Brachialis

A muscle located in the upper arm that flexes the elbow joint.

Deep posterior (extensor) compartment of the forearm

The compartment of the forearm that contains muscles responsible for extending the wrist and fingers.

Abductor pollicis longus

A muscle located in the forearm that abducts and extends the thumb at the carpometacarpal joint.

Bicipital aponeurosis

A flat tendon that connects the biceps brachii muscle to the radius and ulna.

Supinator

A muscle located in the forearm that supinates the forearm and hand.

Brachioradialis

A muscle located in the forearm that flexes the forearm at the elbow joint.

Flexor carpi ulnaris

A muscle located in the forearm that flexes the wrist and adducts the hand.

Flexor digitorum profundus

A muscle located in the forearm that flexes the fingers at the metacarpophalangeal and interphalangeal joints.

Extensor pollicis brevis

A muscle located in the forearm that extends the thumb at the metacarpophalangeal joint.

Profundus extensor carpi radialis

A muscle located in the forearm that extends the wrist and abducts the hand.

Pronator quadratus

A muscle located in the forearm that pronates the forearm.

Extensor indicis

A muscle located in the forearm that extends the index finger at the interphalangeal joint.

Triceps brachii

A muscle located in the upper arm that extends the elbow joint.

Anconeus

A muscle located in the forearm that assists in extending the elbow joint.

Carpal tunnel syndrome

A condition characterized by compression of the median nerve within the carpal tunnel, resulting in pain, numbness, and tingling in the hand and fingers.

Median nerve

A nerve that innervates the muscles of the forearm and hand, as well as provides sensory innervation to the palm and fingers.

Thenar eminence

The fleshy area at the base of the thumb.

Flexor retinaculum

A band of connective tissue that forms the roof of the carpal tunnel.