Bones and muscles
Bones and muscles: a chapter of The Human Body Book, with the facts about your own body that are worth knowing.
10 cards · Science
Each Zap teaches up to 5 new cards, so you learn the deck a few at a time.
Checked by the Brain Zap team · reviewed 26 Oct 2026
Sources: Human body (Encyclopaedia Britannica), Health A to Z (NHS)
Preview
Number of bones in an adult
Show answerHide answer: Number of bones in an adult
206
Learn more: Many of a baby's bones fuse as it grows, such as those of the skull and the base of the spine.
The longest bone in the body
Show answerHide answer: The longest bone in the body
Femur
Learn more: It is about a quarter of your height and can bear several times your body weight.
The smallest bone in the body
Show answerHide answer: The smallest bone in the body
Stapes
Learn more: About 3 mm long, it passes sound vibrations from the eardrum to the inner ear.
The bones that make up the spine
Show answerHide answer: The bones that make up the spine
Vertebrae
Learn more: Rubbery discs between them absorb shocks, and a tunnel through them protects the spinal cord.
Pairs of ribs in most people
Show answerHide answer: Pairs of ribs in most people
12
Learn more: They form a cage that protects the heart and lungs and moves with every breath.
About this topic
Your skeleton holds you up, protects your organs and makes your blood cells. Muscles move it: they can only pull, so they work in pairs, joined to the bones by tendons. Bone is living tissue: it is constantly broken down and rebuilt, it heals after a break, and it grows stronger when you load it, which is why walking, running and lifting keep it healthy as you age.
This is a chapter of The Human Body Book. Each card asks one question, with a hint before you answer and a short reason after. Once you know most of this chapter, the next one starts arriving in your Daily Zap.
All 10 cards
Number of bones in an adult
206
Learn more: Many of a baby's bones fuse as it grows, such as those of the skull and the base of the spine.
The longest bone in the body
Femur
Learn more: It is about a quarter of your height and can bear several times your body weight.
The smallest bone in the body
Stapes
Learn more: About 3 mm long, it passes sound vibrations from the eardrum to the inner ear.
The bones that make up the spine
Vertebrae
Learn more: Rubbery discs between them absorb shocks, and a tunnel through them protects the spinal cord.
Pairs of ribs in most people
12
Learn more: They form a cage that protects the heart and lungs and moves with every breath.
The muscle type found only in the heart
Cardiac muscle
Learn more: It beats about 100,000 times a day, and you can't move it at will, unlike the muscles of your arms.
The body's largest muscle
Gluteus maximus
Learn more: It straightens the hip, powering climbing, running and standing up from a chair.
Tissue that joins a muscle to a bone
Tendon
Learn more: Muscles can only pull, so tendons carry that pull to the bone; ligaments join bone to bone.
Where blood cells are made
Bone marrow
Learn more: It makes billions of new blood cells every day to replace the ones that wear out.
The mineral that makes bones hard
Calcium
Learn more: Bones hold about 99% of the body's calcium and act as a store the blood can draw on.
More science decks
Each deck takes about 1 min a day.
Bleeding, burns and breaks
Bleeding, burns and breaks: a chapter of the First Aid Book, with the steps that help in the first minutes of an emergency.
10 cards · meet them all in 2 days
Brain, nerves and senses
Brain, nerves and senses: a chapter of The Human Body Book, with the facts about your own body that are worth knowing.
10 cards · meet them all in 2 days
Calling for help and CPR
Calling for help and CPR: a chapter of the First Aid Book, with the steps that help in the first minutes of an emergency.
10 cards · meet them all in 2 days