Q.Have you heard about hypoxia? Try to gather information about it, and discuss with your friends.

Hypoxia is best understood as a condition in which the body's tissues do not receive enough oxygen to meet their needs.

• Normally oxygen moves from the alveoli into the blood and from the blood into the tissues, always flowing from higher to lower oxygen pressure.
• If the oxygen available falls — for instance where the surrounding air holds less oxygen, or when the transport and exchange steps are impaired — the tissues can be left short of oxygen. …

To make sense of hypoxia, it helps to recall how oxygen normally reaches the cells. Air is drawn into the alveoli, where oxygen diffuses into the blood; the blood then carries the oxygen — almost all of it bound to haemoglobin — to the tissues, where it diffuses out to the cells. Every step of this journey runs downhill in oxygen pressure, from the alveoli, into the blood, and on into the tissues. The cells use that oxygen to carry out metabolism and generate energy.

Hypoxia is the situation in which this supply falls short, so the tissues are left with too little oxygen. Because so many things must go right for oxygen to arrive — enough oxygen in the air, a healthy exchange surface, and effective transport by the blood — a weakness in any of them can reduce the oxygen that finally reaches the cells.

• Where the surrounding air itself holds less oxygen, the pressure driving oxygen into the blood is lower, so less is delivered onward.
• Where the diffusion surface or the transport of gases is impaired, the tissues can again be left under-supplied. …

Method: Building an Explanation of a Physiological Deficiency Condition

Use this approach for any "condition of shortage/deficiency" question — trace the normal supply chain first, then identify where it can break.

Steps

Step 1: Map the normal supply route

For O2, the route runs alveoli → blood (via haemoglobin) → tissues, always moving down a pressure gradient at every step.

Step 2: Identify possible failure points along the route

List what could interrupt the chain — reduced O2 in the surrounding air, a damaged exchange surface, or impaired transport in the blood — any of these can leave the tissues short. …