Structure of a Skeletal Muscle & Neuromuscular Junction + Basic Types of Joints Study Sheet

These flashcards cover the structure and function of skeletal muscles and neuromuscular junctions, as well as types of joints and their movements, as per the lecture notes.

Muscle Fiber

A muscle cell, which is the basic building block of muscle tissue.

Tendon

The tissue connecting muscle to bone.

Fascicle

A bundle of muscle fibers.

Myofibril

A component within a muscle fiber, composed of a series of sarcomeres.

Sarcomere

The smallest contracting part of a muscle.

Myofilament

The contractile proteins in muscle fibers, consisting of actin and myosin.

Actin

A thin myofilament involved in muscle contraction.

Myosin

A thick myofilament that interacts with actin during muscle contraction.

Epimysium

The connective tissue wrapping around an entire muscle.

Perimysium

The connective tissue that wraps around a fascicle.

Endomysium

The connective tissue surrounding each muscle fiber.

Neuromuscular Junction (NMJ)

The synapse where a motor neuron communicates with a muscle fiber.

Sarcoplasmic Reticulum

The organelle that regulates calcium ion concentrations for muscle contraction.

Acetylcholine (ACh)

The neurotransmitter that triggers muscle contraction at the neuromuscular junction.

Action Potential

An electrical impulse that stimulates muscle contraction.

Synaptic Cleft

The gap between a neuron and a muscle fiber.

Synarthrosis

An immovable joint, such as cranial sutures.

Amphiarthrosis

A joint with limited mobility, such as the pubic symphysis.

Diarthrosis

A freely movable joint, like the knee or hip.

Protraction

The action of sticking out a body part.

Flexion

Decreasing the angle between two body parts.

Extension

Increasing the angle between two body parts.

Elevation

Raising a body part.

Circumduction

Circular motion of a limb.

Adduction

Pulling a limb back toward the midline.

Eversion

Turning the sole of the foot outward.