Respiratory System Flashcards
Purpose of the respiratory system
- Exchange of gases between atmosphere, blood and cells
- Take O2 from air and put it into blood
- Remove CO2 from blood
Function of the Nasal cavity
- Filters, warms and moistens air before it enters the lungs
- Hair and mucus trap dust
- A reasoning chamber for speech sounds
Function of the Pharynx
- Air from nasal cavity passes through here
Function of the Larynx
- Air passes through the larynx, going to and from the lungs
- Contains vocal cords which vibrate to make sound
Function of the trachea
- Carries air to and from the lungs
- Contains cilia that beat to move mucus and trapped particles upward
Function of the bronchi
- Two primary bronchi branch from the trachea
- They then divide into secondary and tertiary bronchi
Function of the bronchioles
- Very fine tubes with walls of smooth muscle
- The finest of them end in groups of air sacks called alveoli
Function of the alveoli
- Tiny air sacks that make up most of the lung
- They occur in clusters and have very thin walls that are well supplied with blood capillaries for the exchange of oxygen and carbon dioxide
Function of the lungs
- Occupy all the chest cavity, except space taken up by the heart
- Covered in a pleural membrane, also lines inside of chest
- pleural fluid holds the lungs against the chest
Function of intercostal muscles
- Move the rib cage upwards and outwards to increase the volume of the chest cavity, and lungs, during breathing in
Function of the diaphragm
- Separates chest from abdomen
- Contracts and flattens downwards, thereby increasing the volume of chest cavity and lungs during breathing
Inspiration
Breathing in
Expiration
Breathing out
Explain how the membranes with the thoracic cavity allow for inspiration and expiration to occur
- membranes within thoracic cavity are separated in a pleural fluid.
- Fluid holds lungs against inside of chest wall and allows the lungs to slide along the wall when breathing
- when chest wall expands outwards lungs move with it . Allows lungs to expand and contract with the chest wall movements
Features of the alveoli
- Moist surface
- Capillary network
- thin walls
How do the features of the alveoli help in their function?
Moist surface - makes it easier for diffusion of gases
Capillary network - Maximise surface area, allows more gases to be exchanged
Thin walls - Faster gas exchange
What muscles expand and contract the ribcage?
Intercostal muscle
What happens to the diaphragm and thorax as we inhale?
- The diaphragm contracts downwards
- Thorax increases in volume and decreases in pressure, sucking in air into the lungs
What happens to the diaphragm and thorax as we exhale?
- Diaphragm relaxes upward
- Thorax decreases in volume and increases in pressure, forcing air out of the lungs
Tiny sack in the lungs
Alveoli
The sheet of muscle between the thorax and abdomen
The diaphragm
What is the process of swapping oxygen and carbon dioxide called?
Gas exchange
Name the process which allows gas exchange across the thin walls of the alveoli
Diffusion
How much of oxygen is in inhaled air and exhaled air
% inhaled air - 21%
% exhaled air - 17%
