Anatomical Terms Review

Anatomy

The study of body structures and their physical relationships.

Physiology

The study of how body structures function and carry out life-sustaining activities.

Sagittal Plane

Divides the body vertically into left and right sides.

Mid-sagittal Plane

Passes directly down the exact centerline, dividing the body into equal left and right halves.

Coronal (Frontal) Plane

Divides the body vertically into anterior (front) and posterior (back) portions.

Transverse Plane

Divides the body horizontally into superior (top) and inferior (bottom) portions.

Superior (Cranial)

Toward the head or upper part of a structure; above.

Inferior (Caudal)

Away from the head or toward the lower part of a structure; below.

Anterior (Ventral)

Toward the front of the body.

Posterior (Dorsal)

Toward the back of the body.

Medial

Toward the midline of the body.

Lateral

Away from the midline of the body.

Proximal

Nearer to the point of attachment or trunk of the body (used for limbs).

Distal

Farther from the point of attachment or trunk of the body (used for limbs).

Superficial

Toward or at the body surface.

Deep

Away from the body surface; more internal.

Dorsal Cavity

Body cavity located on the posterior side; contains the cranial and spinal cavities.

Cranial Cavity

Enclosed by the skull; houses the brain.

Spinal Cavity

Enclosed by the vertebral column; houses the spinal cord.

Thoracic Cavity

Upper chest cavity containing the heart and lungs.

Abdominal Cavity

Contains the stomach, liver, gallbladder, spleen, and most of the intestines.

Pelvic Cavity

Contains the urinary bladder, reproductive organs, and rectum.

Right Upper Quadrant (RUQ)

Abdominopelvic quadrant containing the liver, gallbladder, and right kidney.

Left Upper Quadrant (LUQ)

Abdominopelvic quadrant containing the stomach, spleen, pancreas, and left kidney.

Right Lower Quadrant (RLQ)

Abdominopelvic quadrant containing the appendix, cecum, and right ovary/spermatic cord.

Left Lower Quadrant (LLQ)

Abdominopelvic quadrant containing the colon and left ovary/spermatic cord.

Femoral Region

Refers to the thigh area of the body.

Cervical Region

Refers to the neck area of the body.

Brachial Region

Refers to the upper arm region of the body.

Orbital Region

Refers to the eye area of the head.

Homeostasis

The maintenance of a stable, balanced internal environment despite external changes.

Receptor (Sensor)

Homeostatic component that detects changes in the environment (stimuli).

Control Center

Homeostatic component that receives sensor input and sets the reference set point (e.g., brain).

Effector

Homeostatic component that carries out the response to adjust the system back to baseline.

Negative Feedback Loop

Mechanism where the response opposes or reverses the initial stimulus to maintain homeostasis (e.g., thermoregulation).

Positive Feedback Loop

Mechanism where the response amplifies or intensifies the initial stimulus until a specific goal is achieved (e.g., labor contractions, blood clotting).

Cellular Level

The basic structural and functional unit of living organisms.

Tissue Level

A group of similar cells working together to perform a specific function.

Organ Level

A structure composed of two or more tissue types working together for a specific task.

Organ System Level

A group of organs collaborating to perform major complex life functions.

Epithelial Tissue

Tissue that covers body surfaces, lines cavities/organs, and forms glands for protection and absorption.

Connective Tissue

Tissue that supports, protects, and binds body structures together; characterized by cells in an extracellular matrix.

Muscle Tissue

Tissue specialized for contraction and producing physical movement (skeletal, cardiac, smooth).

Nervous Tissue

Tissue specialized for sensing stimuli, processing information, and transmitting electrical impulses.

Integumentary System

Forms the external body covering, protecting deeper tissues, regulating temperature, and sensing environment.

Skeletal System

Protects and supports body organs, provides a framework for muscle movement, and stores minerals.

Muscular System

Allows manipulation of the environment, locomotion, facial expression, maintains posture, and produces heat.

Nervous System

Fast-acting control system that responds to internal and external changes by activating appropriate muscles and glands.

Endocrine System

Glands that secrete hormones into the bloodstream to regulate long-term processes like growth, metabolism, and reproduction.

Cardiovascular System

Transports blood throughout the body, carrying oxygen, carbon dioxide, nutrients, and wastes.

Lymphatic / Immune System

Picks up leaked fluid from blood vessels, returns it to blood, and defends against foreign pathogens.

Respiratory System

Keeps blood constantly supplied with oxygen and removes carbon dioxide via gas exchange in lungs.

Digestive System

Breaks down food into absorbable nutrients and eliminates solid indigestible wastes.

Urinary System

Eliminates nitrogenous wastes from the body and regulates water, electrolyte, and acid-base balance in blood.

System Interdependence

The concept that body systems rely on one another to function and maintain overall homeostasis.