Animal tissues, organs and organ systems (green) Flashcards
1
Q
What are multicellular organisms made up of? Put your answers in order of increasing complexity.
A
cells → tissues → organs → organ systems
2
Q
What is a tissue?
A
A group of cells working together to perform a shared function, and often with similar structure
3
Q
How are exchange surfaces, such as alveoli in the lungs and villi in the small intestine, adapted to maximise absorption?
A
- A large surface area
- A short diffusion distance (e.g. one cell thick)
- Good blood supply maintains concentration gradient
4
Q
What is the name for the windpipe?
A
Trachea
5
Q
Where does gas exchange occur?
A
Between the alveoli and blood in the capillaries
6
Q
How do alveoli provide a large surface area for gas exchange?
A
- Small size (around 300 μm in diameter), giving them a large surface area to volume ratio,
- High number - around 700 million alveoli.
7
Q
Describe what happens in the respiratory system when you inhale.
A
- Diaphragm contracts
- Intercostal muscles contract
- Volume in chest cavity increases
- Pressure in chest cavity decreases
- Air rushes in to fill the lungs
8
Q
Describe what happens in the respiratory system when you exhale.
A
- Diaphragm relaxes
- Intercostal muscles relax
- Volume in chest cavity decreases
- Pressure in chest cavity increases
- Air is expelled from the lungs
