Respiratory System Flashcards
What does our diaphragm do when we inhale
It contracts and moves downwards
What do our intercostal muscles do when we inhale?
They contract and move upwards + outwards
What happens to our chest when we inhale?
Volume increases, pressure decreases
What happens to our diaphragm when we exhale?
Relaxes and moves upwards
What happens to our intercostal muscles when we exhale?
They relax and move downwards
What happens to our chest when we exhale?
Volume decreases, pressure increases
What’s the airway called
Trachea
What is at the end of the trachea
Bronchi
What are at the end of the bronchi?
Bronchioles
What are at the end of the bronchioles?
Alveoli (air sacs)
How are alveoli adapted to their function?
Large surface area - more molecules can diffuse across the membrane / increases rate of diffusion
Very thin walls - one cell thick - less space for gases to diffuse through, more efficient
Very close blood supply - shorter diffusion distance + maintains concentration gradient as blood is moving back to the heart / to keep diffusion happening all the time
Moist - gases diffuse easier through a liquid so it speeds up diffusion
What two types of cell line the trachea and what do they do?
Ciliated cells - have tiny hairs called cilia which sweep dirt/bacteria up through the trachea to be coughed out
Mucus-secreting goblet cells - secrete mucus which traps dirt/bacteria, making it easier for cilia to sweep it
Why do we need a breathing system?
• We have a low surface area to volume ratio
• So we need a specialised gas exchange system to get oxygen to cells
What is ventilation?
• Ventilation is the process of inhaling oxygen and exhaling carbon dioxide
