Gas Exchange Flashcards
(27 cards)
What is breathing?
Movement of air into and out of the lungs.
What is respiration?
Chemical reaction to release energy in the form of ATP
What is ventilation?
The scientific word for breathing
What is gaseous exchange?
Diffusion of oxygen from the air into the alveoli into the blood and of carbon dioxide from the blood into the air in the alveoli
What happens when the external intercostal muscles contract? (Inhalation)
It pulls the ribcage up and outwards and that provides a bigger volume in the thorax- leads to inhaling
What happens when the internal intercostal muscles contract? (Exhalation)
Pulls the ribcage back in and down to decrease the volume in the thorax- high pressure forcing out air
Where are alveoli found?
At the end of the bronchioles
What are alveoli surrounded by?
Capillaries
Diffusion distance in the alveoli?
Short
What type of cell is the alveoli made up of?
Single layer of cell
What gas exchange process happens in the alveoli?
Diffusion
In the alveoli- what is there a high concentration of?
High conc of CO2- CO2 diffuses out
Oxygen will diffuse from the alveoli across the epithelium and into the blood
How many alveoli are there in each human lung?
300 million in each- creates a very large SA
What does the network of capillaries do?
Remove exchanged gases and therefore maintains a conc gradient- there is a good blood supply
What do the cartilage rings do?
Prevent airways from collapsing due to pressure changes
What do the cartilage rings do?
Allow for swallowing
What does the smooth muscle and elastic tissue do?
Controls the diameter of airways so we can increase ventilation in exercise
How are the lungs specialised to protect the alveoli from damage?
Trachea and bronchi lining
Mucus produced by goblet cells
Mucus trap particles, bacteria and viruses
Cilia move to push mucus up and out of airways
How do elastic fibres in the alveoli help in exhalation?
Provides elastic recoil which helps to force air out (rapid expulsion) from the lungs
Stretch- so the alveoli dont burst.
Describe the pathway taken by a CO2 molecule from the blood to the outside air?
CO2 molecule in the blood diffuses across the epithelium of the capillary
Then across the alveolar epithelium into the alveolar space
Where it travels up the bronchitis
Into the trachea and out of the mouth
How is the trachea adapted to help protect the lungs from infection by bacteria?
Cells produce mucus so bacteria/pathogens are trapped
Cilia beat so mucus moves upwards towards the throat
What does ventilation maintain a concentration gradient mean for the air breathed in?
The air breathed in always has a higher concentration of oxygen compared to the air inside the lungs.
What is pulmonary ventilation?
The total volume of air that is moved into the lungs during one minute
What is the formula for pulmonary ventilation?
Tidal volume x ventilation rate
