Human Body: Organs and Bones

Which organ makes insulin?

Pancreas

The pancreas makes insulin, which controls blood sugar.

Which small organ stores bile under the liver?

Gallbladder

Bile is made in the liver and stored in the gallbladder.

Which organ stores urine until you go to the bathroom?

Bladder

The bladder is a stretchy bag that holds urine.

Which organ on your left side filters old red blood cells?

Spleen

The spleen filters blood and helps fight infection.

Which gland in your neck controls how fast your body uses energy?

Thyroid

The thyroid makes hormones that set your metabolism.

Which muscle under your lungs pulls air in?

Diaphragm

The diaphragm flattens as you breathe in, drawing air into the lungs.

How many chambers does the human heart have?

Four

Two atria on top receive blood; two ventricles below pump it out.

Which blood vessels carry blood away from the heart?

Arteries

Arteries carry blood away from the heart; veins bring it back.

Which blood vessels carry blood back to the heart?

Veins

Veins return blood to the heart, helped by one-way valves.

What are the tiniest blood vessels called?

Capillaries

Capillaries pass oxygen and food from blood into the body's cells.

Which blood cells carry oxygen?

Red blood cells

Red blood cells carry oxygen using a protein called hemoglobin.

Which blood cells fight infection?

White blood cells

White blood cells find and destroy germs.

What in your blood helps a cut stop bleeding?

Platelets

Platelets clump at a cut and help form a clot.

Where is blood made in adults?

Bone marrow

Soft marrow inside bones makes new blood cells.

What are the tiny air sacs in your lungs called?

Alveoli

Oxygen passes from alveoli into the blood around them.

Which flap stops food going down your windpipe?

Epiglottis

The epiglottis folds over the windpipe as you swallow.

How many bones does an adult human have?

206

Adults have 206 bones; babies have more that fuse as they grow.

Which bone protects your brain?

Skull

The skull is made of bones joined together around the brain.

Which bones form a cage around your heart and lungs?

Ribs

Twelve pairs of ribs curve around the chest.

How many pairs of ribs do most people have?

12

Most people have 12 pairs of ribs, 24 in all.

What is the column of bones down your back called?

Spine

The spine is a stack of vertebrae that protects the spinal cord.

What is the common name for the patella?

Kneecap

The patella sits in front of the knee joint and protects it.

What is the common name for the clavicle?

Collarbone

The clavicle links your shoulder to your breastbone.

What is the common name for the scapula?

Shoulder blade

The scapula is a flat, triangular bone on the back of the shoulder.

Which bone is in your upper arm?

Humerus

The humerus runs from the shoulder to the elbow.

Which two bones are in your forearm?

Radius and ulna

The radius and ulna run side by side from elbow to wrist.

What is the common name for the tibia?

Shin bone

The tibia is the larger of the two lower-leg bones.

Which ring of bones holds up your belly at the hips?

Pelvis

The pelvis carries your weight to your legs and holds the belly's organs.

What is the common name for the sternum?

Breastbone

Most ribs join the sternum at the front of the chest.

Which bone is your lower jaw?

Mandible

The mandible is the jaw bone that moves when you talk and chew.

What is the smallest bone in the body?

Stapes

The stapes, in the middle ear, is the smallest bone, about 3 mm long.

What joins a muscle to a bone?

Tendon

Tendons are tough cords that pull bones when muscles tighten.

What joins one bone to another at a joint?

Ligament

Ligaments hold the bones of a joint together.

Which kind of joint is your shoulder?

Ball and socket

The rounded top of the upper arm bone sits in a cup at the shoulder.

Which kind of joint is your elbow?

Hinge

The elbow bends and straightens like a door hinge.

Which muscle bends your elbow?

Biceps

The biceps tightens to bend the elbow.

Which muscle straightens your elbow?

Triceps

The triceps works opposite the biceps to straighten the arm.

Which is the largest muscle in your body?

Gluteus maximus

The gluteus maximus, in your buttock, is the largest muscle.

What kind of muscle is the heart made of?

Cardiac muscle

Cardiac muscle is found only in the heart and beats without rest.

Which body system includes the heart, blood and blood vessels?

Circulatory system

The circulatory system carries oxygen and food to every cell.

Which body system includes your lungs and windpipe?

Respiratory system

The respiratory system takes in oxygen and lets out carbon dioxide.

Which body system breaks down the food you eat?

Digestive system

The digestive system turns food into nutrients your body can use.

Which body system carries signals between your brain and body?

Nervous system

Nerves carry messages to and from the brain at high speed.

Which body system uses glands to send hormones?

Endocrine system

Glands such as the thyroid and pancreas release hormones into the blood.

Which body system fights germs?

Immune system

The immune system finds and fights germs.

Which body system makes urine and removes it?

Urinary system

Kidneys filter blood into urine, which the bladder stores.

Which part of the brain helps you balance?

Cerebellum

The cerebellum coordinates movement and balance.

Which part of the eye is colored?

Iris

The iris is the colored ring that changes the size of the pupil.

Which part at the back of the eye senses light?

Retina

The retina turns light into signals for the brain.

Which hard substance covers your teeth?

Enamel

Tooth enamel is the hardest substance in the human body.

What are your hair and nails made of?

Keratin

Keratin is the protein in hair, nails and the skin's outer layer.