Human Body Trivia for Seniors
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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
About 206. A baby is born with dozens more, somewhere between 270 and 300, because many bones start out as separate pieces that fuse together as the child grows.
Q 02Which is the longest bone in the human body?
The thigh (femur)
The thigh (femur). It makes up about a quarter of a person's height, which is why forensic scientists can estimate how tall someone was from a single thigh bone.
Q 03Where in the body is its smallest bone, which is shaped like a stirrup?
In the ear
In the ear. Called the stapes, Latin for stirrup, it is the last in a chain of three tiny bones that carry sound vibrations from the eardrum to the inner ear.
Q 04Which is the only bone in the body that is joined to no other bone?
The hyoid, in the throat
The hyoid, in the throat. This U-shaped bone hangs from muscles and ligaments alone, and it anchors the tongue, which is what lets us swallow and speak.
Q 05Roughly how big is the human heart usually said to be?
The size of a closed fist
The size of a closed fist. It sits slightly left of centre, which is why the left lung is the smaller of the two, with a notch in it to make room.
Q 06A resting adult heart beats 60 to 100 times a minute; whose normally beats just 40 to 60?
Athletes
Athletes. Years of training enlarge and strengthen the heart, so it shifts more blood with every beat and can get by on far fewer of them.
Q 07Which heart chamber pumps blood around the body?
Left ventricle
Left ventricle. Its wall is about three times as thick as the right ventricle's, which only has to push blood the short distance to the lungs and back.
Q 08Which is the largest artery in the body, carrying blood out of the heart?
The aorta
The aorta. Its elastic wall stretches with every heartbeat and springs back between beats, which keeps blood moving even while the heart is refilling.
Q 09Which iron-containing protein carries oxygen in red blood cells and gives blood its colour?
Haemoglobin
Haemoglobin. It is bright red when loaded with oxygen and dark red without it, never blue, whatever the colour of the veins on the back of your hand.
Q 10Roughly how long does a red blood cell live before the body recycles it?
About four months
About four months. A red cell has no nucleus, so it cannot repair itself, and after roughly 120 days of squeezing through tiny vessels it is filtered out and broken down in the spleen.
Q 11Which 1901 discovery by Austrian doctor Karl Landsteiner finally made blood transfusions safe?
Blood groups
Blood groups. Landsteiner noticed that mixing blood from two people often made the red cells clump together, worked out why, and won a Nobel Prize for it in 1930.
Q 12Which is the largest organ of the human body?
The skin
The skin. As well as keeping water in and germs out, it works as a chemical factory, making vitamin D whenever sunlight falls on it.
Q 13Which pigment gives skin its colour and helps protect it from the sun's ultraviolet rays?
Melanin
Melanin. A suntan is this defence in action: when sunlight starts to damage them, cells called melanocytes make extra pigment and the skin darkens.
Q 21Which is the last part of the digestive tract, where water is absorbed and waste is stored?
The large intestine
The large intestine. It is also home to vast numbers of bacteria, which feed on what we cannot digest and make vitamin K for us in return.
Q 22How many adult teeth does a person usually have, wisdom teeth included?
32
32. A child gets by with only 20 baby teeth, and the extra adult ones replace nothing: they grow in at the back as the jaw gets longer.
Q 23Which type of teeth do the cutting at the front of the mouth?
Incisors
Incisors. Standing at the very front, the upper middle pair are also the teeth most often chipped or knocked out in accidents.
Q 14Which is the heaviest internal organ and the body's largest gland?
The liver
The liver. It can regrow lost tissue, which is why a living donor can give part of a liver to someone else and have the rest grow back.
Q 15What fluid does the body's largest gland make to help digest fats?
Bile
Bile. It works like a detergent, breaking fat into tiny droplets that digestive juices can attack, and it waits in the pear-shaped gallbladder until a meal arrives.
Q 16The kidneys are often described as being shaped like which food?
A bean
A bean. The kidney bean is in fact named after the organ, not the other way round, and each kidney packs in about a million tiny filters called nephrons.
Q 17What releases the 'fight or flight' hormone when we are frightened?
The adrenals
The adrenals. These two small glands sit on top of the kidneys, and their name says so: 'adrenal' is built from the Latin for 'near the kidneys'.
Q 18Which hormone, made in the pancreas, controls the level of sugar in the blood?
Insulin
Insulin. Its name comes from the Latin for island, because it is made in little islands of cells scattered through the pancreas.
Q 19Which butterfly-shaped gland in the neck controls how fast the body burns energy?
The thyroid
The thyroid. It needs iodine to make its hormones, and without enough it swells into a goitre, which is why iodine is added to table salt.
Q 20The small intestine is the longest part of the gut, so what does the 'small' in its name describe?
Its width
Its width. The tube is only two or three centimetres across, yet it runs for several metres and takes in most of the nutrients we get from food.
Q 24What is the hardest substance in the human body?
Tooth enamel
Tooth enamel. It is 96 percent mineral, yet acids from food and drink can still wear it away, and because it contains no living cells it never grows back.
Q 25Wisdom teeth are the last to arrive; at about what age do they usually come through?
Around 20
Around 20. They turn up so long after the other teeth, when a person has reached adulthood, that they were named for wisdom.
Q 26Which is the coloured part of the eye that controls the amount of light getting in?
The iris
The iris. One ring of muscle in it tightens the pupil in bright light, and a second set, arranged like the spokes of a wheel, pulls it wide in the dark.
Q 27Which cells in the eye let us see colour in good light?
Cones
Cones. Rods take over in dim light but play little part in telling colours apart, which is why the world fades towards grey at dusk.
Q 28Besides hearing, what else does the human ear look after?
Balance
Balance. Three fluid-filled loops in the inner ear work as motion sensors: whenever the head turns, the fluid sloshes and tells the brain which way it moved.
Q 29Which spiral part of the inner ear does the actual hearing?
The cochlea
The cochlea. Its name is Latin for snail shell, and the thousands of tiny sensory cells inside it never grow back once loud noise has killed them.
Q 30Which is the fifth basic taste, alongside sweet, sour, salty and bitter?
Umami (savoury)
Umami (savoury). Japanese chemist Kikunae Ikeda pinned it down in 1908 while asking what made seaweed broth so tasty, then turned his answer into the seasoning MSG.