breathing and gas exchange

Respiratory surface

The surface in organisms where gas exchange occurs, such as the lungs in mammals or gills in fish.

Alveoli

Small air sacs at the end of the lungs where gas exchange takes place, surrounded by capillaries.

Ventilation

The process of inhaling and exhaling air to facilitate gas exchange in the lungs.

Goblet cells

Cells in the respiratory system that produce mucus to trap dust, debris, and pathogens.

Epithelial cells

Cells that move mucus in the respiratory system, aiding in the removal of trapped particles.

Pleural cavity

The space between the lungs and ribs filled with fluid to reduce friction during breathing.

Respiration

The breakdown of glucose to produce energy in living organisms.

Emphysema

A condition where the alveoli become damaged, usually due to repeated infections

Alveoli

Air sacs in the lungs where gas exchange (by diffusion) takes place.

Trachea

Allows air to pass to and from lungs.

Bronchioles

Airways in the lungs that lead from the bronchi to the alveoli.

Bronchi

Two short branches located at the lower end of the trachea that carry air into the lungs.

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Gas exchange

The diffusion of oxygen from the lungs into the blood and the diffusion of carbon dioxide from the blood into the lungs.

Diaphragm

Large, flat muscle at the bottom of the chest cavity that helps with breathing.

Ribs

The bones in the chest that protect the heart and lungs.

Asthma

Disorder of the lungs, where the bronchioles narrow.

Intercostal muscles

Muscles between the ribs.

Carbon dioxide

Waste product from respiration process in cells.

Nicotine

The addictive drug found in tobacco.

Cilia

Hair-like projections on the outside of cells that move in a wavelike manner.

Mucus

A slimy substance produced in the nose and throat to trap dust and pathogens and stop them from entering the lungs.

Tar

A dark, sticky substance that forms when tobacco burns.

Respiratory Surface must have

large surface area, thin permeable membrane, moist exchange surface

Large surface area

the larger the SA the quicker the diffusion

Thin permeable surface

the shorter the distances, the better

moist exchange surface

gases usually dissolve in water in order to pass through a membrane

Inspiration 1

intercostal muscles contract, raising the ribcage upwards and outwards

Inspiration 2

The diaphragm contracts and pushes down on the organs in the abdomen

Inspiration 3

both these movement increase the internal volume and decrease the internal pressure

inspiration 4

air enters and inflates the lungs

expiration 1

intercostal muscles relax, lowering the ribcage

expiration 2

the diaphragm relaxes and is pushed upwards by the organs

expiration 3

both these movements result in a decrease in internal volume and an increase in the internal pressure

expiration 4

air is forced out the lungs

Gas exchange in the alveolus

Process where oxygen enters the blood from the alveoli and carbon dioxide is removed for exhalation.