The Human Respiratory System and Respiration

Comprehensive vocabulary flashcards covering the human respiratory system, the mechanics of breathing, gas exchange, and aerobic cellular respiration.

Respiration

A series of chemical reactions that happens inside every living cell.

Aerobic respiration

The kind of respiration that usually happens inside cells, which uses oxygen to release energy from glucose and produces carbon dioxide and water.

Respiratory system

The group of organs that work together to help take oxygen out of the air and get rid of waste carbon dioxide.

Trachea (Windpipe)

The tube connecting the mouth and nose to the bronchi, which contains strong rings of cartilage to keep it open and prevent it from collapsing.

Rings of cartilage

Strong structures surrounding the trachea and supporting the bronchi that keep airways open and prevent them from collapsing.

Bronchi

The two main branches of the trachea (singular: bronchus) supported by cartilage, each leading into one lung to carry air deep inside.

Bronchioles

Smaller tubes that branch off each bronchus, allowing air to reach deeper into the lungs and ending at the air sacs.

Air sacs (Alveoli)

Tiny structures at the ends of bronchioles with walls made of a single layer of very thin cells, where gas exchange takes place.

Capillaries

Very tiny blood vessels wrapped tightly around the alveoli, each possessing a wall made of a single layer of very thin cells.

Gas exchange

The process inside the air sacs where oxygen from inhaled air moves into the blood, and carbon dioxide from the blood moves out into the air.

Diffusion

The movement of freely moving gas particles from an area where there are a lot of them to an area where there are fewer of them.

Haemoglobin

The substance inside red blood cells that combines with oxygen after the oxygen dissolves into the blood.

Intercostal muscles

Muscles located between the ribs that contract to pull the ribs upwards and outwards during inhalation, and relax during exhalation.

Diaphragm

A sheet of muscle beneath the lungs that contracts and moves downwards during inhalation, and relaxes back into its natural domed shape during exhalation.

Inhalation (Breathing in)

The process where intercostal muscles and the diaphragm contract, increasing the chest cavity's volume, decreasing internal pressure, and causing air to enter the lungs.

Exhalation (Breathing out)

The process where intercostal muscles and the diaphragm relax, decreasing the chest cavity's volume, increasing internal pressure, and squeezing air out of the lungs.

Glucose

A type of sugar broken down from dietary carbohydrates that functions as an energy store and is delivered by blood to every cell.

Mitochondria

Tiny structures found inside most cells that carry out aerobic respiration to release energy from glucose in a controlled manner.

Word equation for aerobic respiration

$$\text{glucose} + \text{oxygen} \rightarrow \text{carbon dioxide} + \text{water}$$