Body Planes, Directions, and Cavities

Vocabulary flashcards covering body planes, directions, cavities, organ regions, and levels of body organization from the lecture notes.

Anatomical position

Standardized body position used in anatomy: standing upright, facing forward, arms at the sides with palms facing forward, feet flat and parallel.

Anatomy

Study of the structure and shape of the body and its parts.

Physiology

Study of how the body and its parts work or function.

Gross anatomy

Large structures that are easily observable without a microscope.

Microanatomy

Very small structures that can only be viewed with a microscope.

Levels of organization

Chemical → atomic → molecular → cellular → tissue → organ → system → organism (from smallest to largest).

Homeostasis

The process by which the body maintains a stable internal environment despite external changes; dynamic equilibrium controlled by the nervous and endocrine systems.

Negative feedback

A feedback loop that reverses a change to maintain homeostasis; the most common type.

Positive feedback

A feedback loop that amplifies a change and is rare; examples include childbirth and blood clotting.

Transverse (horizontal) plane

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

Sagittal plane

Divides the body into right and left sides; midsagittal (equal halves) and parasagittal (unequal halves) are subtypes.

Frontal (coronal) plane

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

Midsagittal plane

Divides the body into equal right and left halves.

Parasagittal plane

Divides the body into unequal right and left halves.

Superior (cranial)

Toward the head end or upper part of the body.

Inferior (caudal)

Away from the head toward the lower part of the body.

Anterior (ventral)

Toward the front of the body; ventral is synonymous with anterior in humans.

Posterior (dorsal)

Toward the back of the body; dorsal is synonymous with posterior in humans.

Medial

Toward the midline of the body.

Lateral

Away from the midline; on the outer side.

Proximal

Near the origin of a body part or the point of attachment.

Distal

Farther from the origin of a body part or the point of attachment.

Superficial

Toward or at the body surface.

Deep

Away from the body surface; more internal.

Dorsal body cavity

Cavity that includes the cranial cavity and vertebral (spinal) cavity.

Ventral body cavity

Cavity that includes the thoracic and abdominopelvic cavities.

Cranial cavity

Cavity that contains the brain.

Vertebral (spinal) cavity

Cavity that contains the spinal cord.

Thoracic cavity

Upper torso; contains heart and lungs; subdivided into mediastinum, pleural cavities, and pericardial cavity.

Mediastinum

Part of the thoracic cavity between the lungs; contains the heart and major vessels.

Pleural cavities

Two cavities surrounding the lungs.

Pericardial cavity

Cavity within the mediastinum that surrounds the heart.

Abdominopelvic cavity

Cavity that contains the abdominal and pelvic regions and their organs.

Abdominopelvic quadrants

Four equal/quadrant divisions used to locate organs: RUQ, LUQ, RLQ, LLQ.

Right upper quadrant (RUQ)

Upper-right quadrant; contains liver, gallbladder, and parts of stomach/intestines.

Left upper quadrant (LUQ)

Upper-left quadrant; contains stomach, spleen, part of liver, and pancreas.

Right lower quadrant (RLQ)

Lower-right quadrant; contains appendix and parts of ileum/ascending colon.

Left lower quadrant (LLQ)

Lower-left quadrant; contains parts of the intestine and sigmoid colon.

Nine abdominal regions

A nine-region grid: Right hypochondriac, Epigastric, Left hypochondriac; Right lumbar, Umbilical, Left lumbar; Right iliac (inguinal), Hypogastric (pubic), Left iliac (inguinal).