Human Body and Health

How your body works and what keeps it healthy

Human Body and Health is a Bertopia flashcard pack of 61 cards: how your body works and what keeps it healthy. It covers heart, blood and lungs; digestion, kidneys and metabolism; immunity, infection and vaccines; brain, nerves, bones and muscles; health and nutrition.

Sample cards

Why is the wall of the left ventricle thicker than the right?

It pumps blood around the whole body
It only receives blood coming back from the lungs and must stretch more
It pumps blood to the lungs, which need very high pressure
It stores extra blood between beats for use during exercise

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Answer

It pumps blood around the whole body

The right ventricle sends blood a short distance to the lungs at low pressure. The left ventricle must generate much higher pressure to push blood through the systemic circulation.

Why does the stomach produce hydrochloric acid?

It kills microbes and helps protein digestion
It absorbs most nutrients directly into the blood
It neutralises bile that comes up from the liver
It breaks starch down into glucose

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Answer

It kills microbes and helps protein digestion

Stomach acid creates conditions for pepsin to digest proteins and destroys many swallowed microbes. Most absorption happens in the small intestine.

Why does the body raise its temperature during an infection?

The microbes themselves are generating heat as they multiply
The immune system resets the brain's thermostat higher
The muscles are working harder to break down germs
The blood thickens and holds more heat

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Answer

The immune system resets the brain's thermostat higher

Chemicals released during infection raise the hypothalamus set point. A higher temperature can slow some microbes and speed parts of the immune response.

How do nerve cells send signals along their length?

Blood carries the message from one end to the other
Electrical impulses caused by ions crossing the membrane
Tiny hairs pass the message along like a relay
Air bubbles travel through the nerve fibre

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Answer

Electrical impulses caused by ions crossing the membrane

An action potential is a wave of sodium and potassium ions moving across the neuron membrane. Myelin speeds it up.

Why is dietary fibre good for digestion?

It is fully digested into sugar for quick energy
It replaces protein for building muscle
It kills harmful bacteria in the stomach
It adds bulk and helps food move through the gut

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Answer

It adds bulk and helps food move through the gut

Fibre is mostly not digested. It adds bulk, keeps bowel movements regular and feeds helpful gut bacteria.

What do heart valves do?

Produce the electrical signal that starts each beat
Keep blood flowing in one direction
Filter clots and bacteria out of the blood
Add oxygen to blood passing through the heart

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Answer

Keep blood flowing in one direction

The four valves open and close with each beat so blood moves forward and does not flow back. The lub dub sound is valves closing.

Sources

16 sources

OpenStax Anatomy and Physiology 2e, OpenStax, Rice University
NHLBI, How the Heart Works, National Heart, Lung, and Blood Institute, NIH
NHLBI, How the Lungs Work, National Heart, Lung, and Blood Institute, NIH
NIDDK, Your Kidneys and How They Work, National Institute of Diabetes and Digestive and Kidney Diseases, NIH
NIDDK, Your Digestive System and How It Works, National Institute of Diabetes and Digestive and Kidney Diseases, NIH
MedlinePlus, Immune System and Disorders, US National Library of Medicine
NHS, How vaccines work, NHS
NHS, Antibiotics, NHS
WHO fact sheet, Antimicrobial resistance, World Health Organization
NHS, High blood pressure (hypertension), NHS
NHS, Type 2 diabetes, NHS
NHS, Blood groups, NHS
NHS, Stroke, NHS
NHS, Vitamins and minerals, NHS
WHO fact sheet, Healthy diet, World Health Organization
NHS, High temperature (fever) in adults, NHS

Human Body and Health

Sample cards

Sources

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