HESI A2 - General Terminology - Key Terms and Concepts

Anatomy

The scientific study focused on the physical structure and organization of body components.

Physiology

The branch of biology concerned with understanding how the body's organs and systems operate and interact.

Homeostasis

The capacity of the body to keep its internal environment stable.

Cell

The smallest living unit that makes up all organisms, capable of performing life processes.

Tissue

A collection of related cells cooperating to perform a specific task.

Organ

A structure with a particular function that is composed of several tissues.

Organ System

A set of organs that collaborate to achieve specific physiological goals.

Metabolism

The total of all bodily chemical reactions.

Catabolism

Energy is released when complex molecules break down into simpler ones.

Anabolism

The building up of complex molecules from simpler ones, requiring energy.

Superior

Above or toward the head.

Inferior

Below or toward the feet.

Anterior (Ventral)

Toward the body's front.

Posterior (Dorsal)

Refers to the back side or rear of the body.

Medial

Closer to the body's midline.

Lateral

Positioned away from the body’s central (midline) axis.

Proximal

Closer to the point of attachment (e.g., shoulder or hip).

Distal

Located farther from the origin or point of attachment of a limb to the trunk.

Superficial

Situated close to or on the exterior surface of the body.

Deep

Positioned further within the body, away from the external surface.

Sagittal Plane

Separates the left and right parts of the body.

Midsagittal Plane

Separates the body into equal left and right halves.

Frontal (Coronal) Plane

Separates the anterior and posterior halves of the body.

Transverse Plane

Separates the superior and inferior parts of the body.

Dorsal Cavity

Comprises the spinal and cranial cavities.

Ventral Cavity

Includes the abdominopelvic and thoracic cavities.

Thoracic Cavity

Contains the heart and lungs.

Abdominal Cavity

Contains digestive organs like the stomach and intestines.

Pelvic Cavity

Contains reproductive and some urinary organs.

Diaphragm

The muscular structure that separates the thoracic cavity from the abdominal cavity.

Neurons

Nerve cells that transmit signals.

Hormones

Chemical substances produced by glands that influence or regulate the activities of organs and tissues.

Blood Pressure

The force of blood on arterial walls.

Alveoli

The lungs' tiny air sacs for gas exchange.

Osmosis

The passive movement of water molecules through a selectively permeable membrane toward an area of higher solute concentration.

Enzymes

Specialized proteins that speed up bodily chemical reactions by acting as catalysts.

ATP (Adenosine Triphosphate)

The main energy carrier of cells.

DNA (Deoxyribonucleic Acid)

Cells' genetic material.

Hemoglobin

Red blood cells' oxygen-carrying protein.

Synapse

The point where two nerve cells meet and communicate.

Diffusion

The transfer of molecules between a region with a greater concentration and one with a lower concentration.

Active Transport

Moving chemicals across a cell membrane against their concentration gradient is an energy-dependent operation.

pH

An indicator of alkalinity or acidity, with a range of 0 (very acidic) to 14 (extremely alkaline).

Isotonic solution

A solution that has no net water movement and has the same solute concentration as a cell.

Hypertonic solution

Water exits the cell when the concentration of the solute in the solution is higher than that of the cell.

Hypotonic solution

Water enters the cell as a result of a solution having a lower solute concentration than the cell.

Mitochondrion

An organelle that produces energy (ATP) through cellular respiration.

Ribosome

A cellular structure that synthesizes proteins from amino acids.

Endocytosis

A cellular process in which the cell membrane wraps around external substances, forming a vesicle to bring them into the cell.

Exocytosis

The process of a cell releasing substances by fusing a vesicle with the cell membrane.

Body Plane

It is an imaginary two-dimensional surface used in anatomy to describe locations and relationships between body structures.

RUQ

It refers to the "right upper quadrant" of the abdomen.

LUQ

It refers to the "left upper quadrant" of the abdomen.

RLQ

It refers to the "right lower quadrant" of the abdomen.

LLQ

It refers to the 'left lower quadrant" of the abdomen.

Body Cavities

These are internal spaces within the body that house and protect organs.

Peritoneal Cavity

A space within the abdomen that houses the digestive organs such as the stomach, liver, and intestine.

Abdominopelvic Cavity

A part of the ventral cavity that includes both the abdominal and pelvic cavities, housing organs like the gastrointestinal tract and reproductive organs.

Cranial Cavity

It is also known as the "intracranial space," a space within the skull that houses the brain.

Spinal Cavity

Also called the "vertebral cavity" or "vertebral canal," it houses the spinal cord and spinal nerve roots.

Abdominal Regions (Abdominal areas divided into nine (9) regions)

Right hypochondriac

Epigastric

Left hypochondriac

Right lumbar

Umbilical

Left lumbar

Right iliac

Hypogastric

Left iliac

Right Hypochondriac Region

It is an abdominal region associated with the right lobe of the liver and gallbladder.

Epigastric Region

It is an abdominal region associated with the stomach, liver, pancreas, adrenal glands, and duodenum.

Left Hypochondriac Region

It is an abdominal region associated with the spleen and parts of the stomach, colon, and pancreas.

Right Lumbar Region

It is an abdominal region associated with the ascending colon and right kidney.

Umbilical Region

It is an abdominal region associated with the navel and small intestines.

Left Lumbar Region

It is an abdominal region associated with the descending colon and left kidney.

Right Iliac Region

It is an abdominal region associated with the appendix and cecum.

Hypogastric Region

It is an abdominal region associated with the bladder, sigmoid colon, and female reproductive organs.

Left Iliac Region

It is an abdominal region associated with the sigmoid colon and descending colon.