Absorption of materials Flashcards
What waste material must be removed from all respiring cells into the blood stream?
carbon dioxide
What two substances must be absorbed into the bloodstream to be delivered to cells for aerobic respiration?
oxygen and glucose
Why is blood arriving in the lung said to be deoxygenated?
the blood contains a low concentration of oxygen
Name the process responsible for the movement of oxygen from the alveoli into the blood stream
diffusion
Explain how carbon dioxide moves from the blood in the capillaries to enter the lungs
carbon dioxide diffuses from the blood into the alveoli where it is exhaled
what is the purpose of alveoli having a large surface area?
Allows maximum absorption of gases
What is the purpose of alveoli having thin walls
allows rapid diffusion of gases
What is the purpose of alveoli having an extensive blood supply
to transport dissolved gases away quickly
What is the type of reaction when food reaches the small intestine the large insoluble molecules have been broken down into small soluble molecules?
degradation reaction
what is the name of the movement of dissolved food through the small intestine walls into the bloodstream?
absorption
How does the small intestine have a large surface area?
because it is covered in a large number of finger like projections on its inside surface called villi
What is the purpose of villi having a large surface area?
Allows maximum absorption of digestion products
What is the purpose of villi having thin walls?
Faster diffusion of digestion products
What is the purpose of villi having an extensive blood supply?
to transport absorbed products away quickly
What are the three main food groups broken down into small soluble products during digestion?
Carbohydrates, proteins, fats
What are carbohydrates broken down into?
glucose
What are proteins broken down into?
amino acids
What are fats broken down into?
fatty acids and glycerol
What molecules are absorbed into the blood capillaries in a villus?
glucose and amino acids
What are the molecules absorbed into the lacteal in a villus?
fatty acids and glycerol
Explain why the structure and number of villi make absorption and efficient process in the small intestine?
The thin walls results in faster diffusion of digestion products, extensive blood supply transports absorbed products away quickly, large number of villi increases the surface area and makes absorption of materials faster
What are the gas exchange organs?
lungs
