Anatomical Terminology and Muscular System Overview

These flashcards cover key anatomical terms, muscle properties, and physiological concepts relevant to the understanding of human anatomy and physiology.

Anatomical Terminology

Standard language used to describe the human body and its parts to communicate clearly in anatomy

Anatomical Position

Reference position for the body: standing upright, arms at sides, head facing forward, feet flat and forward, palms facing forward.

Body Cavities

Spaces in the body that house and protect internal organs; function to protect, separate, and support organs.

Cranial Cavity

The cavity that houses the brain.

Thoracic Cavity

The cavity that contains the heart and lungs.

Abdominopelvic Cavity

The cavity that contains digestive, urinary, and reproductive organs.

Sagittal Plane

Divides the body into unequal left and right sides.

Flexion

A joint motion that decreases the angle between body parts.

Extension

A joint motion that increases the angle between body parts.

Homeostasis

The body’s ability to maintain stable internal conditions despite external or internal changes.

Negative Feedback

A response that reverses an original stimulus to maintain homeostasis.

Muscle Origin

The attachment site of a muscle on the stationary bone.

Muscle Insertion

The attachment site of a muscle on the bone that moves.

Excitability (Muscle Tissue Property)

The ability to respond to stimuli and generate electrical signals.

Contractility (Muscle Tissue Property)

The ability of muscle tissue to shorten and produce force.

Skeletal Muscle

Striated, voluntary muscle that is attached to bone, skin, or fascia.

Cardiac Muscle

Striated, involuntary muscle found in the heart that is autorhythmic.

Smooth Muscle

Non-striated, involuntary muscle found in the walls of hollow organs.

Neuromuscular Junction

The synapse or junction between a motor neuron and a skeletal muscle fiber.

Calcium Ion (Ca²⁺) in Muscle Contraction

Triggers contraction by binding to troponin, leading to the exposure of myosin-binding sites.

Rigor Mortis

Postmortem rigidity due to calcium leaks, causing myosin to bind actin without the ability to detach.

Type I Muscle Fiber

Slow oxidative fibers that are red, high in mitochondria, and used for endurance.

Type IIb Muscle Fiber

Fast glycolytic fibers that are white, few in mitochondria, and used for quick bursts of power.

Motor Unit

A motor neuron and all the muscle fibers it innervates.

Muscle Fatigue

Inability to contract after prolonged activity, often caused by ACh depletion or oxygen debt.