Topic B - Breathing and Gas exchange Flashcards
Name the 15 parts of the human respiratory system (starting from the top)
- Nasal cavity
- Pharynx
- Epiglottis
- Larynx
- Oesophagus
- Trachea
- Cartilage
- Rib
- Intercostal muscle
- Bronchus
- Bronchiole
- Pleural Cavity
- Lung
- Heart
- Diaphragm
Definition of breathing?
Physical process
Allows fresh air to be brought into he lungs
Allows used air to move out of the lungs
Definition of gas exchange?
Diffusion of oxygen from the alveolar air space into the blood.
Diffusion of carbon dioxide from the blood to alveolar air space
Definition of respiration?
It is a chemical reaction
Occurs in ALL cells
Release of energy from food
Glucose + oxygen ——> carbon dioxide+ water+’energy’
Explain gas exchange at the alveolus
- Blood (from heart + lungs ) with low oxygen and high
carbon dioxide passes through capillaries
surrounding alveoli - The air in the alveoli has low concentration of
carbon dioxide and high concentration of oxygen - Therefore there is a concentration gradient which
allows - carbon dioxide to diffuse out of the blood
across wall of alveolus and into the alveolar
air. - Vies Versa for oxygen
Explain INhalation ( 6 steps)
- External intercostal muscles CONTRACT make ribs
move UP and OUT - Diaphragm CONTRACTS and FLATTENS
- Volume of thorax INCREASE
- Air pressure in thorax DECREASE
5.Air pressure in lung now LOWER than air pressure
outside body
6.Causes air to ENTER LUNGS
Explain EXhalation ( 6 steps )
- External intercostal muscles RELAX make ribs
move DOWN - Diaphragm RELAXES and goes back to DOME
SHAPE - Volume of thorax DECREASE
- Air pressure in thorax INCREASE
5.Air pressure in lung now HIGHER than air pressure
outside body
6.Causes air to LEAVES LUNGS
What is the 4 contents of air?
- Oxygen
- Carbon dioxide
- Nitrogen
- Water Vapour
How much oxygen in- inspired air
- expired air
inspired= 21%
expired =16%
How much carbon dioxide in- inspired air
- expired air
inspired=0.04%
expired=4%
How much nitrogen in- inspired air
- expired air
inspired=78%
expired=78%
How much water vapour in- inspired air
- expired air
inspired= variable
expired=saturated
Definition of Trachea (windpipe)
1st part of breathing system
Treats air before it reaches lungs
Air is warmed, moistened, filtered + cleaned
Definition bronchus
2 short tubes that split from trachea
1 bronchus enters each lung
Definition of bronchiole
Smaller branches divided from the bronchus