B5 - The human body - Staying alive Flashcards
What is a specialised exchange surface
The part of an organism which is specialised to exchange substances with their environment
What are two examples of specialised exchange surfaces in humans
Alveoli
Villi
What is the role of the alveoli
They are small sac like things found in the lungs
They exchange CO2 and O2 between the air and the blood
What is the role of the villi
They are protrusions found on the insides of small intestines, and their role is to absorb nutrients
What is an example of a specialised exchange surface in plants
The root hair cell
What is the role of the root hair cell
To absorb mineral ions and water from the soil
What 5 things do specialised exchange surfaces need
1) large surface area
2) thin surfaces
3) permeable surfaces
4) good supply of external medium
5) good supply of blood (animals only)
What is the trachea
The windpipe
What are the bronchi
The large divide in the windpipe
What are the bronchioles
The many smaller divides in the lungs
How is the inside of the alveoli separated from the blood capillary
By a single layer of thin cells
Why is the barrier between the inside of the alveoli and the blood capillary so thin?
To increase the rate of diffusion
What diffuses in and out of the alveoli
O2 diffuses out, and binds to the hemoglobin, and the CO2 which is dissolved in the bloodstream diffuses into the alveoli
