Human Body Organization and Cell Biology

Vocabulary terms covering anatomy, physiology, cellular organelles, and tissue types based on NCHSE standards.

Anatomy

The study of the form and structure of the human body.

Physiology

The study of the function of the human body.

Levels of Organization

The sequence of complexity in the body: Chemicals → Cells → Tissues → Organs → Systems → Organism.

DNA (Deoxyribonucleic acid)

A nucleic acid that contains genetic information for traits.

Genes

Sections of DNA that contain instructions for molecules.

RNA (Ribonucleic acid)

A nucleic acid that functions as a messenger, transfer, and part of ribosomes.

Proteins

Molecules composed of amino acids; includes enzymes, antibodies, hair, nails, and cell membrane components.

Carbohydrates

Monosaccharides used by the body for energy.

Lipids

Molecules composed of glycerol and fatty acids; used for energy, cell membranes, and insulation.

Cell (Plasma) Membrane

A lipid bilayer that separates internal cellular components from the external environment.

Cholesterol

A component that increases the strength of the cell membrane.

Nucleus

The "Control Center" of the cell that regulates eating, movement, and reproduction.

Chromatin

The thread-like form of genetic material present when the cell is not dividing.

Chromosomes

Short rod-like structures of genetic material visible during cell reproduction.

Nucleolus

A structure within the nucleus made of RNA and protein.

Cytoplasm

The fluid that fills a cell, also known as protoplasm.

Cytoskeleton

Internal framework that provides support and maintains the shape of the cell.

Ribosomes

The sites of protein synthesis made up of ribosomal RNA ($rRNA$).

Endoplasmic Reticulum (ER)

Double membranous channels used for transportation within the cell; split into Rough (with ribosomes) and Smooth (lipid synthesis).

Golgi Complex

A structure that processes, sorts, and delivers proteins and develops transition vesicles to secrete lipids.

Mitochondria

The "Powerhouse" of the cell that produces energy ($ATP$) through cellular respiration.

Lysosomes

Known as "Suicide Packets," these conduct intracellular digestion and can digest organelles for food.

Vacuoles

Vesicles or bags of fluid that store nutrients and remove waste products from the cell.

Centrosomes

Structures containing centrioles that serve as the center of chromosome movement during cell division.

Tissue

A group of cells with a common embryonic origin performing a similar function.

Epithelial Tissues

Tissues that cover body surfaces, line body cavities and ducts, and form glands.

Squamous

Flattened or scale-like epithelial cells.

Cuboidal

Cube-shaped epithelial cells involved with secretion and absorption.

Columnar

Epithelial cells that are taller than they are wide.

Transitional

Epithelial cells with high elasticity that can change shapes, found on structures that expand.

Connective Tissues

The most abundant tissue type; binds organs together, protects, supports, and stores energy.

Osseous Tissue

Bone tissue; divided into honey-comb like Compact Bone and irregular Spongy Bone.

Skeletal Muscle

Voluntary, striated, and multinucleated muscle tissue attached to bones.

Cardiac Muscle

Involuntary, striated muscle forming the heart wall (myocardium) characterized by intercalated disks.

Smooth (Visceral) Muscle

Involuntary, non-striated muscle located in the walls of hollow structures like the stomach and intestines.

Nervous Tissue

Tissue sensitive to stimuli that converts stimulus into nervous impulses (electrical events).

Systems

A level of organization consisting of organs and tissues that work together to perform one or more vital functions.