Human Body Glossary for Kids – Simple Anatomy Explanations

Learn anatomy words with simple, kid-friendly definitions!

Find a word by its first letter

A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
R
S
T
U
V
W

A

  • ABDOMEN – This part of your body is commonly called the belly. It is located between the chest and waist and contains most of the digestive system.
  • ADRENALINE (EPINEPHRINE) – A hormone released by the adrenal glands during stressful or exciting experiences. Also, a medication that treats food allergies.
  • ALLERGY – A condition when the immune system overreacts to something harmless to most people, like plants, food, or insects.
  • ALVEOLUS (plural: alveoli) – Tiny air sacs at the end of bronchioles that exchange oxygen and carbon dioxide. Under a microscope, alveoli look like miniature balloons.
  • ANTIBODY – A Y-shaped protein that remembers antigens on germs and other substances.
  • ANTIGEN – A substance that looks toxic to your body and triggers your immune system to make antibodies.
  • AORTA – The large artery that delivers fresh oxygen from the left ventricle to the rest of the body. Also the largest artery in the human body.
  • ARTERY – A blood vessel that carries blood with oxygen from the heart to tissues and organs.
  • ATRIUM (plural: atria) – A room at the top of the heart that collects blood. Examples: The right atrium collects blood from the vena cava. The left atrium collects blood from the lungs.

B

  • BACTERIUM (plural: bacteria) – A type of germ that can either be normal in the body or can invade and make people sick. Examples: Streptococcus pyogenes, Staphylococcus aureus.
  • BLADDER – A stretchy muscle that collects and stores urine (pee).
  • BLIND SPOT – A pinpoint-sized area of the retina where the optic nerve joins the eye. The eye cannot detect light here because this spot has no cone or rod cells.
  • BLOOD – Red fluid containing plasma, blood cells, platelets, nutrients, waste, hormones, oxygen, carbon dioxide, and other substances.
  • BLOOD PRESSURE – A measure of the force on the blood vessels as blood flows through.
  • BLOOD VESSEL – A tube that carries blood to different organs and tissues. Examples: arteries, capillaries, veins.
  • BONE – A rigid organ that gives structure to the body and contains bone marrow.
  • BRAILLE – A reading system with little bumps on paper designed for people who are blind.
  • BRAINSTEM – The part of the brain that controls breathing, heart rate, and blood pressure.
  • BRONCHUS (plural: bronchi) – The airway tube that connects the trachea to the bronchioles.
  • BRONCHIOLE – The smallest branch of the airway that connects to an alveoli.

C

  • CAPILLARY (plural: capillaries) – The tiny blood vessel that connects arteries and veins.
  • CAPILLARY REFILL TIME – The amount of time it takes for the pink color to return to the fingertip after it is squeezed.
  • CARBOHYDRATE (“CARB”) – One of the 3 main nutrients that the body takes in to make energy. Examples: sugar, starch, fiber.
  • CARBON DIOXIDE – An invisible gas made by the body as a waste product. Lungs breathe out carbon dioxide.
  • CARDIAC MUSCLE – The heart muscle that pumps blood around the body.
  • CARTILAGE – A special connective tissue similar to bone but softer and more flexible. It also cushions the joints.
  • CARDIOVASCULAR SYSTEM – The heart and blood vessel system that carries blood around the body.
  • CELL – The smallest living unit of the body.
  • CEREBELLUM – The part of the brain that controls balance and coordination.
  • CEREBRUM – The largest part of the brain that plans your body’s movements and actions and processes what you see, hear, smell, taste, and touch. Also known as the “thinking cap”!
  • CERVIX – The bottom part of the uterus connects to the vagina.
  • CHROMOSOME – A thread-like structure that contains DNA.
  • COCCYX (TAILBONE) – The bottom end of the vertebrae.
  • COCHLEAR IMPLANT – A small electronic device that electrically stimulates the nerves for hearing.
  • COLOR BLINDNESS (COLOR DEFICIENCY) – A condition where one cannot see the difference between certain colors, like red, green, and blue.
  • CONSTIPATION – When the poop is hard and dry, and the body has a hard time pushing it out. 
  • CYTOPLASM – The jelly-like fluid inside of a cell.

D

  • DEOXYRIBONUCLEIC ACID (DNA) – The tiny blood vessel that connects arteries and veins.
  • DIABETES MELLITUS – A medical condition where the pancreas cells do not produce enough or respond normally to insulin.
  • DIAPHRAGM – Muscle between the chest and abdomen that helps with breathing.
  • DIARRHEA – Watery stool with no solid pieces.
  • DIGESTION – The body’s way of breaking down food.
  • DIGESTIVE SYSTEM – A group of organs involved with breaking down food.
  • DISEASE – An abnormal condition that negatively affects a person.

E

  • ENDOCRINE SYSTEM – A group of organs involved with sending messages throughout the body as hormones.
  • ENZYME – Chemicals that speed up reactions in the body.
  • EPIDIDYMIS – Muscle between the chest and abdomen that helps with breathing.
  • EPIGLOTTIS – A piece of cartilage that covers the trachea during eating and drinking and opens during breathing.
  • ESOPHAGUS – A tube that carries food from the throat to the stomach.

F

  • FALLOPIAN TUBE – The tube that carries eggs from the ovary to the uterus.
  • FAT – A nutrient we eat so our body can store it for energy.
  • FECES – The waste created by the large intestines. Also called stool or poop.
  • FEMUR (THIGH BONE) – The largest bone in the human body.
  • FIBULA – The calf bone in the lower leg.
  • FRACTURE – A broken bone.
  • FUNGUS (plural: fungi) – A type of organism that is a natural part of the environment; some fungi are germs that can make people sick. Example: Aspergillus Fumigatus.

G

  • GASTROINTESTINAL SYSTEM – A group of organs involved with breaking down food.
  • GENE – A section of DNA.
  • GLAND – An organ that releases hormones, enzymes, or other substances into the blood.
  • GLUCOSE – A type of sugar people can eat which gives us energy. This is the main type of sugar in the blood.
  • GLUCAGON – A hormone made by the pancreas that causes the body’s blood sugar levels to be higher.
  • GROWTH PLATE – The special “growing zone” in children’s bones is where new bone cells are made so kids can grow taller.

H

  • HEARING AID – A device worn on the ear that makes sounds louder.
  • HEART RATE (PULSE) – How fast your heart pumps blood in a minute.
  • HICCUP – A sudden spasm in the diaphragm muscle.
  • HORMONE – A chemical that tells organs what to do.

I

  • IMMUNE SYSTEM – A team of organs, tissues, and cells that work together to fight infection.
  • INFECTION – A disease caused by germs growing and invading the body.
  • INSULIN – A hormone made by the pancreas to lower the body’s blood sugar levels.
  • INTEGUMENTARY SYSTEM – The organs covering everything outside the body: skin, hair, and nails.
  • IRIS – The colored part of the eye that makes the pupil smaller in bright light or bigger when it is dark.

J

  • JOINT – A moveable part of the skeleton where ligaments connect two bones.

K

L

  • LARGE INTESTINE – The part of the digestive system that makes poop.
  • LIGAMENT – A band of connective tissue that connects bones.
  • LIVER – This big organ has 3 important jobs: It makes bile, cleans up your blood, and stores sugar to give your body energy.
  • LUNGS – The organs in your chest that help you breathe.
  • LYSOSOME – A small organelle in the cell that breaks down dying cells and takes out waste.

M

  • MANDIBLE – The jawbone.
  • MARROW – The substance inside bones.
  • MELANOCYTE – A skin cell that makes melanin.
  • MELANIN – A substance that gives your skin its color.
  • MELATONIN – A hormone that helps your body sleep at night.
  • MENISCUS– The pad of cartilage that cushions the knee joint.
  • MICROTUBULE – Tube-shaped organelle that gives movement and shape to cells. It also acts like a highway, transporting vesicles throughout the cell.
  • MITOCHONDRIA – The part of a cell that makes energy.
  • MUCUS – A slimy substance that covers and protects the inside of your organs.
  • MUSCLE – A type of organ that moves other organs, tissues, and cells in the body.
  • MYOCYTE – Another name for a muscle cell.

N

  • NAIL – The hard tissue at the top of a fingertip.
  • NASAL CAVITY– The space behind the nose with many sensory (smell) nerves and hairs that protect the upper airway.
  • NEURON – Another name for a nerve cell.
  • NERVE – A group of nerve cells arranged like a wire that sends signals to and from the brain.
  • NUCLEUS – The control center of a cell.
  • NUTRIENT – A substance that helps the body grow, develop, and work.

O

  • OLFACTORY NERVE – The nerves at the top of the nasal cavity that detect smell.
  • ORGAN – A body part made of a group of different tissues that work together for the same purpose. Examples: brain, eye, heart, stomach, kidney.
  • ORGANELLE – The different types of mini-organs inside of a cell. Examples: mitochondria, microtubules, vesicles.
  • OPTIC NERVE – The nerve that connects the eye and the brain.
  • OVARY – The female reproductive organ that stores eggs.

P

  • PANCREAS – A gland that works for both two different organ systems. For the endocrine system, the pancreas makes insulin and glucagon to control blood sugar. In the digestive system, it makes enzymes that break down food.
  • PATELLA – The bone that covers the knee. Also known as the knee-cap.
  • PHARYNX (THROAT) – The tube that connects the back of the nose, back of the mouth, and top of the esophagus.
  • PLATELET – A little cell that makes clots by clumping together to stop bleeding. They are your body’s natural bandages.
  • PLASMA – The liquid part of your blood.
  • PULSE – The type of heart rate that you can feel in different parts of your body. It tells you how many times your heart beats in one minute.
  • PUPIL – The hole in your eye that lets light enter.

R

  • RECTUM – This is the bottom end of the large intestines. It holds and pushes out poop of the body.
  • RED BLOOD CELL – A disc-shaped cell that carries oxygen to organs around the body.
  • RETINA – The thin layer of cells at the back of the eyeball that detects light.
  • RIB CAGE – This group of bones creates a protective shield around your heart, lungs, liver, and kidneys.

S

  • SCLERA – The tough white layer that covers most of the eye.
  • SCROTUM – This soft bag of skin contains and protects the testicles. It also controls the temperature to keep sperm safe.
  • SENSES – The 5 main ways people observe and learn from their surroundings: seeing, hearing, smelling, tasting, and touching.
  • SINUS – Spaces in the bone around the nose that are normally filled with air.
  • SKELETAL MUSCLE – A muscle attached to bone that controls how you move and exercise.
  • SMOOTH MUSCLE – A muscle inside your organs that automatically moves things inside your body.
  • SPHINCTER – A ring-shaped muscle that opens (relaxes) and closes (contracts) to let a substance in or out.
  • SPINAL CORD – The long bundle of nerves that connects the brainstem to other nerves in the body.
  • STEM CELL – A unique cell that can develop into any human cell.
  • STERNUM – The flat vertical bone in the middle of the rib cage. Also called the breastbone.
  • STOMACH – This organ acts like a blender, mixing, churning, and breaking up food that you just ate. It’s located between the end of the esophagus and the beginning of the small intestines.
  • STOOL (FECES, POOP) – Solid waste removed by the body.

T

  • TASTE BUD – A sensory organ in the tongue that detects flavor.
  • TENDON – A tough strap of tissue that connects muscle to bone.
  • THYROID – A small gland in your neck that makes thyroid hormone to help you grow and develop.
  • TISSUE – A group of similar cells that work together.
  • TIBIA (SHIN BONE) – A long bone in the lower leg between the patella (knee cap) and ankle.
  • TONGUE – A muscular organ in the mouth that moves to help you talk. It also has thousands of taste buds to help you eat.
  • TOXIN – A substance that can hurt the body.
  • TRACHEA (WINDPIPE) – The main airway in the neck.

U

  • UMAMI – A savory, meaty flavor found in seaweed, meats, aged cheeses, soy, mushrooms, and tomatoes.
  • URETER – A tube that connects the kidney and bladder.
  • URETHRA – A tube that carries urine out of the body from the bladder.
  • URINARY SYSTEM (RENAL SYSTEM) – The team of kidneys, ureters, bladder, and urethra that remove liquid waste from the body.
  • URINE (PEE) – Liquid waste that is filtered by the kidneys.
  • UTERUS – A muscular organ where a baby grows when a person is pregnant.

V

  • VACCINE – A safe and simple tool that protects your body from a harmful disease.
  • VEIN – A blood vessel that carries waste-containing blood from tissues and organs to the heart.
  • VALVE – A flap of tissue that acts like doors for bodily fluid. Examples: Mitral valve and tricuspid valve in the heart.
  • VENTRICLE – A room at the bottom of the heart. Examples: Right ventricle and left ventricle.
  • VERTEBRA (plural: vertebrae) – The backbone.
  • VESICLE – An organelle that carries protein and other things around a cell.
  • VIRUS – A type of germ that can make people sick. Examples: Coronavirus, Influenza virus, Measles Virus.
  • VULVA – The outside part of the female reproductive system.

W

  • WHITE BLOOD CELL – A blood cell that fights infection.