IGCSE Breathing and Gas Exchange

What is the pink?

nasal cavity

What is the red?

pleural cavity

What is the orange?

intercostal muscle

What is the green?

ribs

What is the yellow?

diaphragm

What is the dark blue?

trachea

What is the white?

lung

What is the black?

bronchus

What is the light blue?

bronchiole

What is the grey?

alveoli

What is the pleural cavity filled with?

fluid

What is the function of cartilage in trachea?

incomplete rings of cartilage for expansion when breathing

What is another name for inhalation?

inspiration

What happens to the intercostal muscles in inspiration?

external intercostals contract to elevate ribs

Which intercostal muscles move in inspiration?

external

What happens to the diaphragm in inspiration?

contracts to expand the thoracic cavity

What happens to the air pressure in the lungs in inspiration?

decreases

What happens to lung volume in inspiration?

increases

What is another name for exhalation?

expiration

what happens to the intercostal muscles in expiration?

internal intercostals contract to pull ribs down

Which intercostal muscles are involved in expiration?

internal

What happens to the diaphragm in expiration?

relaxes to reduce thoracic activity

What happens to the air pressure in the lungs in expiration?

increases

What happens to lung volume in expiration?

decreases

Does inhaled or exhaled air have more oxygen content?

inhaled (20-16)

Does inhaled or exhaled air have more carbon dioxide content?

exhaled (0.04-4)

Does inhaled or exhaled air have more nitrogen content?

same

What are the adaptions of an alveolus?

large surface area, moist lining, thin walls, good blood supply

How thin is a wall of an alveolus?

one cell thick

What is the test for carbon dioxide?

limewater

How does physical activity affect breathing?

increases rate and depth

What are three uses of energy in humans?

muscle contraction, growth, cell division

What is respiration?

chemical reactions that break down nutrients molecules in living cells to produce energy

Is respiration endothermic or exothermic?

exothermic

What does respiration involve?

the action of enzymes in cells

How much energy does aerobic respiration produce?

38 ATP

What is aerobic respiration?

using oxygen to break down nutrients for energy

Where does aerobic respiration take place?

mitochondria

What is the word equation for aerobic respiration?

Glucose + oxygen = carbon dioxide and water

What is the chemical formula for aerobic respiration?

C6H12O6 + 6O2 = 6CO2 + 6H2O

How much energy does anaerobic respiration produce?

2 ATP

What is anaerobic respiration?

a reaction in cells that breaks down nutrients without using oxygen

What is the word formula for anaerobic respiration in humans?

glucose = lactic acid + energy

What is the word formula for anaerobic respiration in plants?

glucose = ethanol + CO2

What is the chemical formula for anaerobic respiration in plants?

C6H12O6 = 2C2H5OH + 2CO2

What is another name for anaerobic respiration in plants?

fermentation

Where are two situations that fermentation occurs?

yeast and for wine

Why does anaerobic respiration occur?

if not enough oxygen is reaching muscle, it is an incomplete breakdown of glucose

Why does breathing rate and death increase while exercising?

to supply more oxygen to muscles

Why does heart rate increase when exercising?

it allows oxygen and glucose to reach muscles faster

Why does your body temperature increase when exercising?

respiration is happening faster which causes heat because energy is being created

Why do glycogen stores decrease when exercising?

stored glucose is used for respiration

Why do blood vessels widen during exercise?

more blood to flow to respiring tissues and skin to cool you down

What causes oxygen debt?

lactic acid building up in the muscles and blood during exercise

What is the recovery period?

when oxygen becomes available again after anaerobic exercise you respire aerobically to remove lactic acid

How does aerobic exercise remove lactic acid?

reacting lactic acid with oxygen to provide CO2 and H2O

What is the oxygen debt?

the amount of oxygen needed to completely break down lactic acid