Anatomy and Physiology: Organ Systems, Body Planes, Directional Terms, and Cavities

Comprehensive vocabulary flashcards covering the eleven human organ systems, levels of biological organization, directional terms, anatomical body planes, body cavities, and abdominopelvic regions.

MURDERS LINC

A mnemonic for remembering the eleven organ systems of the human body: Muscular, Urinary, Respiratory, Digestive, Endocrine, Reproductive, Skeletal, Lymphatic, Integumentary, Nervous, and Cardiovascular.

Levels of Organization

The structural hierarchy of the human body, proceeding from simplest to most complex: atoms $\rightarrow$ molecules $\rightarrow$ cells $\rightarrow$ tissues $\rightarrow$ organs $\rightarrow$ organ systems $\rightarrow$ organism.

Molecule

A chemical structure formed by two or more ($2+$) atoms combined together.

Proteins

Molecules that provide the majority of cell functions; utilized by the body to build and repair tissues, as well as synthesize enzymes, hormones, and other vital molecules.

Cell

The fundamental unit of all life on Earth and the structural level at which life begins.

Tissue

A group of similar cells that join together to perform a specific function; exists in four primary types: epithelial, connective, muscle, and nervous.

Organ

A distinct anatomical structure composed of at least two types of tissues coming together to perform a common function.

Muscular System

The organ system consisting of skeletal muscles and tendons that enables movement (with help from the skeletal system) and helps maintain body temperature by generating heat through muscle contractions.

Urinary System

The organ system containing the kidneys and bladder that controls water balance in the body, removes wastes from the blood, and excretes them.

Respiratory System

The organ system containing the nasal cavity, trachea, and lungs that delivers oxygen to the blood and removes carbon dioxide.

Digestive System

The organ system that processes food and removes waste; major organs include the stomach, liver, gallbladder, and the large and small intestines.

Endocrine System

The organ system that secretes hormones to regulate body processes; major organs include the pituitary gland, thyroid gland, pancreas, adrenal glands, testes, and ovaries.

Secrete

The biological action of a cell, gland, or organ producing a substance and releasing it.

Reproductive System

The organ system that produces sex hormones and gametes; the male delivers sperm, while the female supports the embryo/fetus; major organs include the testes, penis, prostate gland, mammary glands, ovaries, uterine tubes, and uterus.

Skeletal System

The organ system composed of bones that supports the body and enables movement.

Lymphatic System

The organ system that returns fluids back to the blood and defends the body against pathogens; major organs include the thymus, lymph nodes, spleen, and lymphatic vessels.

Integumentary System

The organ system consisting of the skin, hair, sweat glands, and nails that encloses and protects internal body structures and serves as the site of many sensory receptors.

Nervous System

The organ system that processes sensory information and activates bodily responses; major organs include the brain, spinal cord, peripheral nerves, and sensory organs such as the eyes.

Central Nervous System (CNS)

The major division of the nervous system consisting of the brain and spinal cord.

Peripheral Nervous System (PNS)

The division of the nervous system composed of nerves located outside the central nervous system.

Cardiovascular System

The organ system consisting of the heart and blood vessels that delivers oxygen and nutrients to tissues, removes wastes, and helps distribute heat around the body.

Anterior

A directional term describing the front or direction toward the front of the body (e.g., the toes are anterior to the foot).

Posterior

A directional term describing the back or direction toward the back of the body (e.g., the scapula is posterior to the clavicles).

Superior

A directional term indicating a position above or higher than another part of the body (e.g., the frontal bone is superior to the mandible).

Inferior

A directional term indicating a position below or lower than another body part, or near/toward the tail (e.g., the pelvis is inferior to the abdomen).

Lateral

A directional term describing the side or toward the side of the body (e.g., the pollex is lateral to the digits).

Medial

A directional term describing the middle or towards the midline of the body (e.g., the hallux is the medial toe).

Proximal

A directional term indicating a position in a limb that is nearer to the point of attachment or the trunk of the body (e.g., the elbow is proximal to the wrist).

Distal

A directional term indicating a position in a limb that is farther from the point of attachment or the trunk of the body (e.g., the ankle is distal to the patella).

Superficial

A directional term indicating a position closer to the surface of the body (e.g., the skin is superficial to the bones).

Deep

A directional term indicating a position farther from the surface of the body (e.g., the brain is deep to the skull).

Pollex

The anatomical term for the thumb, which is positioned lateral to the other digits in standard anatomical position.

Hallux

The anatomical term for the big toe, positioned as the medial toe.

Directional Terms

A standardized set of spatial descriptions used in anatomy to describe the relative locations and orientations of bodily structures.

Coronal Plane (Frontal Plane)

The plane that divides the body or an organ vertically into an anterior (front) portion and a posterior (back) portion.

Sagittal Plane

A plane that divides the body or an organ vertically into right and left sides.

Midsagittal Plane (Median Plane)

A vertical sagittal plane that runs directly down the middle, dividing the body or organ into equal right and left halves.

Parasagittal Plane

A vertical sagittal plane that divides the body or an organ into unequal right and left sides.

Transverse Plane

The plane that divides the body or an organ horizontally into upper and lower portions.

Body Planes

Imaginary two-dimensional geometric surfaces (coronal, sagittal, transverse) passed through the body to section and observe internal organs and structures.

Dorsal Cavity (Posterior Cavity)

One of the two largest body compartments, located posteriorly, which encompasses the cranial cavity and the spinal (vertebral) cavity.

Ventral Cavity (Anterior Cavity)

One of the two largest body compartments, located anteriorly, which encompasses the thoracic cavity and the abdominopelvic cavity.

Cranial Cavity

The posterior (dorsal) cavity subdivision that houses the brain.

Spinal Cavity (Vertebral Cavity)

The posterior (dorsal) cavity subdivision that encloses the spinal cord.

Thoracic Cavity

The anterior (ventral) cavity subdivision enclosed by the rib cage, which contains the mediastinum and the pleural cavities housing the lungs.

Abdominopelvic Cavity

The largest body cavity in the human body, situated within the ventral compartment and subdivided into the abdominal cavity and the pelvic cavity.

Body Cavities

Internal compartments within the body that house and protect vital organs, fundamentally divided into dorsal (posterior) and ventral (anterior) cavities.

Nine Abdominopelvic Regions

A $3 \times 3$ grid system used to locate abdominal organs, consisting of the epigastric, umbilical, hypogastric, right/left hypochondriac, right/left lumbar, and right/left iliac regions.