50 free Human Body Trivia for Seniors trivia questions with answers — science & nature quiz, new questions added Aug 2026.
This human body trivia for seniors quiz is written for a senior centre, a retirement community social or a family game night with grandparents. It covers the body facts most of us half-remember from school and from a lifetime of doctor's visits: how many bones an adult has, how fast the heart beats at rest, which organ is the largest, why blood is red, how many teeth we grow, what the kidneys and liver actually do, and which parts of the ear keep us balanced. There are also a few gentle surprises, like the bone that touches no other bone and the muscle that is barely a millimetre long. The questions are pitched to be answerable from general knowledge and life experience, with a handful that will start a conversation. Nothing here is alarming or medical advice, and each answer comes with a short, interesting fact. Every answer was checked against Wikipedia and standard anatomy references, and each question shows its source. All 50 questions are free with no sign-up. For a tougher round, try our Hard Human Body trivia page or the main Human Body quiz.
30 of 50 questions with answers and explanations. Play the quiz
Q 01How many bones does an adult human normally have?
About 206
Babies start with around 270; many fuse together as we grow, especially in the skull and spine.
Q 02Which is the longest in the human skeleton?
The thigh (femur)
It is also the largest and thickest, and the only bone in the upper leg.
Q 03The smallest bone in the body is shaped like a stirrup. Where is it?
In the ear
It is called the stapes and passes sound vibrations to the inner ear. It is one of three tiny bones there.
Q 04Which is the only bone in the body not connected to any other bone?
The hyoid, in the throat
It sits above the voice box, held by muscles, and helps anchor the tongue for swallowing and speech.
Q 05Roughly how big is the human heart usually said to be?
The size of a closed fist
It sits between the lungs, slightly to the left, with the atria on top and the ventricles below.
Q 06Roughly how many times a minute does a healthy adult heart beat at rest?
72
The American Heart Association counts anything from 60 to 100 as normal. Ultra-trained athletes can be down in the high 30s.
Q 07How many chambers does the human heart have?
Four
Blood comes back to the right side, goes to the lungs for oxygen, returns to the left side and is pumped out to the body.
Q 08Which is the largest artery in the body, carrying blood out of the heart?
The aorta
It rises from the left ventricle, arches over and runs down to the abdomen, where it splits into the two iliac arteries for the legs.
Q 09Which iron-containing protein carries oxygen in red blood cells and gives blood its colour?
Haemoglobin
Blood is bright red when it is loaded with oxygen and dark red when it has given the oxygen up.
Q 10Roughly how long does a red blood cell live before the body recycles it?
About four months
They are made in the bone marrow, at a rate of about 2.4 million a second, and the spleen clears out the old ones.
Q 11Which Austrian doctor discovered blood groups A, B and O in 1901?
Karl Landsteiner
He first called the third group C. Matching ABO and Rh types made blood transfusion safe.
Q 12Which is the largest organ of the human body?
The skin
It makes up roughly 16 percent of body weight and covers 1.5 to 2 square metres on an adult.
Q 13Which pigment gives skin its colour and helps protect it from the sun's ultraviolet rays?
Melanin
It is made by cells called melanocytes and absorbs some of the harmful UV radiation.
Which is the heaviest internal organ and the body's largest gland?
Q 21Which is the last part of the digestive tract, where water is absorbed and waste is stored?
The large intestine
Its colon runs up, across and down the abdomen before reaching the rectum.
Q 22How many adult teeth does a person usually have, wisdom teeth included?
32
Children have 20 baby teeth, which usually start appearing at about six months old.
Q 23Which type of teeth do the cutting at the front of the mouth?
Incisors
Canines tear food, and the molars and premolars at the back crush it.
Q 24What is the hardest substance in the human body?
The liver
It is dark reddish-brown with two unequal lobes, and it can regrow lost tissue better than any other organ.
Q 15What fluid does the body's largest gland make to help digest fats?
Bile
It is stored and concentrated in the pear-shaped gallbladder until a meal arrives.
Q 16The kidneys are often described as being shaped like which food?
A bean
Each one contains around a million tiny filters called nephrons that clean the blood.
Q 17Which small organs sit on top of the kidneys and produce adrenaline?
The adrenal glands
They also make the steroid hormones cortisol and aldosterone. Their other name, suprarenal, just means 'above the kidney'.
Q 18Which hormone, made in the pancreas, controls the level of sugar in the blood?
Insulin
Its name comes from the Latin for island, because it is made in little islands of cells inside the pancreas.
Q 19Which butterfly-shaped gland in the neck controls how fast the body burns energy?
The thyroid
It sits just below the Adam's apple. The commonest cause of an underactive one worldwide is too little iodine.
Q 20Roughly how long is the small intestine, folded up inside the abdomen?
About 6.5 metres (21 feet)
Despite the name, it is much longer than the colon, just narrower. It has three parts: duodenum, jejunum and ileum.
Tooth enamel
It is 96 percent mineral, but acids from food and drink can still wear it away, and it does not grow back.
Q 25Wisdom teeth are the last to come through. When does that usually happen?
Late teens to early twenties
If there is no room they can get stuck, or impacted, which is why so many are removed.
Q 26Which is the coloured part of the eye that controls how much light gets in?
The iris
The pupil is the opening in its middle. The white part is called the sclera.
Q 27Which cells in the eye let us see colour in good light?
Cones
Rods handle dim light and give only grey, low-detail vision, which is why colours fade at dusk.
Q 28Besides hearing, what else does the human ear look after?
Balance
Fluid-filled canals in the inner ear tell the brain which way the head is moving.
Q 29Which spiral part of the inner ear does the actual hearing?
The cochlea
Its name is Latin for snail shell. The semicircular canals sit next to it.
Q 30Which is the fifth basic taste, alongside sweet, sour, salty and bitter?
Umami (savoury)
The tongue has 2,000 to 8,000 taste buds, and each one is replaced about every ten days.