Human Anatomy: Body Positions, Directions, Planes, Cavities, and Systems

Vocabulary practice flashcards covering human body anatomical positions, regional names, planes, sections, directional terms, body cavities, serous membranes, and body organ systems.

Anatomical position

A standardized method of observing the body where the subject stands erect facing the observer, upper extremities placed at the sides, palms turned forward, and feet flat on the floor.

Prone position

A reclining body position where the body is lying face down.

Supine position

A reclining body position where the body is lying face up.

Planes

Imaginary flat surfaces used to divide the body or organs into definite areas, including sagittal, frontal, transverse, and oblique planes.

Sections

Flat surfaces resulting from cuts made through body structures, named according to the plane on which the cut is made.

Ventral

Toward the front or belly side of the body; in humans, synonymous with anterior.

Dorsal

Toward the back or spine side of the body; in humans, synonymous with posterior.

Anterior

Toward the ventral side of the body.

Posterior

Toward the dorsal side of the body.

Cephalic

Toward the head or superior end.

Rostral

Toward the forehead or nose.

Caudal

Toward the tail or inferior end.

Superior

Located above or toward the head end.

Inferior

Located below or toward the lower end.

Medial

Toward the median plane of the body.

Lateral

Away from the median plane of the body.

Proximal

Closer to the point of attachment or origin of a linear body structure.

Distal

Farther from the point of attachment or origin of a linear body structure.

Ipsilateral

On the same side of the body (right or left).

Contralateral

On opposite sides of the body (right and left).

Superficial

Closer to the body surface.

Deep

Farther from the body surface.

Abdominopelvic quadrants and regions

Divisions of the abdominopelvic cavity into 4 quadrants (RUQ, LUQ, RLQ, LLQ) for clinical study or 9 specific regions for precise anatomical reference.

Cranial cavity

A subdivision of the dorsal body cavity formed by the cranial bones, enclosing and protecting the brain.

Vertebral canal

A subdivision of the dorsal body cavity formed by the bones of the vertebral column, enclosing the spinal cord.

Viscera

The internal organs contained within the thoracic and abdominopelvic body cavities.

Thoracic cavity

The superior portion of the ventral body cavity containing two lateral pleural cavities and the central mediastinum.

Mediastinum

A broad, medial partition between the lungs extending from the sternum to the vertebral column, containing all thoracic contents except the lungs.

Pericardial cavity

The space within the mediastinum surrounding the heart.

Abdominopelvic cavity

The cavity inferior to the diaphragm divided into a superior abdominal cavity and an inferior pelvic cavity.

Serous membrane

A thin, slippery membrane that covers viscera and lines the walls of the thoracic and abdominopelvic cavities.

Parietal layer

The outer layer of a serous membrane that lines the walls of body cavities.

Visceral layer

The inner layer of a serous membrane that covers and adheres directly to organs inside cavities.

Pleura

The double-layered serous membrane surrounding the lungs, consisting of visceral pleura on the lung surface and parietal pleura lining the thoracic wall.

Pericardium

The double-layered serous membrane enclosing the heart, consisting of visceral pericardium covering the heart surface and parietal pericardium lining the pericardial sac.

Peritoneum

The serous membrane of the abdominopelvic cavity, consisting of visceral peritoneum covering viscera and parietal peritoneum lining the cavity wall.

Integumentary system

Organ system comprising skin, hair, nails, and cutaneous glands, responsible for protection, water retention, thermoregulation, vitamin D synthesis, and cutaneous sensation.

Skeletal system

Organ system composed of bones, cartilages, and ligaments that functions in support, movement, protection of viscera, blood formation, mineral storage, and acid-base balance.

Muscular system

Organ system consisting of skeletal muscles responsible for movement, stability, communication, control of body openings, and heat production.

Lymphatic system

Organ system made of lymph nodes, lymphatic vessels, thymus, spleen, and tonsils that recovers excess tissue fluid, detects pathogens, and defends against disease.

Respiratory system

Organ system consisting of the nose, pharynx, larynx, trachea, bronchi, and lungs that facilitates oxygen absorption, carbon dioxide discharge, acid-base balance, and speech.

Urinary system

Organ system consisting of kidneys, ureters, urinary bladder, and urethra, responsible for waste elimination, blood volume/pressure regulation, fluid balance, and detoxification.

Nervous system

Organ system comprising the brain, spinal cord, nerves, and ganglia responsible for rapid internal communication, coordination, motor control, and sensation.

Endocrine system

Organ system composed of hormone-producing glands (pituitary, pineal, thyroid, parathyroid, thymus, adrenal, pancreas, testes, ovaries) for internal chemical communication.

Circulatory system

Organ system consisting of the heart and blood vessels responsible for distributing nutrients, oxygen, wastes, hormones, heat, and antibodies.

Digestive system

Organ system including teeth, tongue, salivary glands, esophagus, stomach, intestines, liver, gallbladder, and pancreas that processes nutrient breakdown and absorption.