Nutrition Flashcards
What is the oesophagus?
a muscular tube that takes food from the mouth to the stomach
What is the alimentary canal?
the digestive tract running from the mouth to the anus
What is peristalsis?
the contraction of muscles along the alimentary canal that pushes the food along
What is amylase?
an enzyme produced in the salivary glands and pancreas that specialises in the break of starch into maltose in the mouth and the duodenum
What is the duodenum?
the first part of the small intestine where food is broken down
What enzymes are produced in the pancreas work in the duodenum?
amylase, lipase, trypsin
What is the ileum?
second part of the small intestine where the products of digestion are absorbed and adapted
What are the adaptations of the ileum?
one cell wall thick -> short diffusion distance
villi and microvilli -> high surface area
capillaries -> high concentration gradient
What is ingestion?
taking food in through mouth and swallowing
What is digestion?
breaking down large insoluble molecules into smaller soluble molecules
What is absorption?
movement of small soluble molecules out of the gut and into the blood by diffusion and active transport
What is assimilation?
forming larger biological molecules from small soluble molecules
What is egestion?
passing out undigested food via anus
What are the functions of bile?
neutralise stomach acid and emulsify lipids
Where is bile made, store and used?
made in liver, stored in gall bladder and used in duodenum
What is mechanical digestion?
chewing
What is chemical digestion?
use of enzymes such as amylase
What is the colon?
the first part of the large intestine where the water is reabsorbed
What is lipase?
an enzyme produced in the pancreas and used in the duodenum to speed up the breakdown of lipids into fatty acids and glycerol
What is maltase?
an enzyme produced and used in the duodenum to breakdown maltose into glucose
What is the pancreas?
an organ that produces and secretes enzymes
What is the rectum?
the final part of the large intestine where faeces is stored
What happens in the stomach?
food enters via the oesophagus and is exposed to stomach acid which is the optimum pH for pepsin (pH2). the acid also kills any bacteria on the food. muscular walls contract to move food around to increase chance of food coming into contact with digestive enzymes.
What are villi?
small projections on the surface area of the ileum that increase surface area for maximum absorption (by diffusion). The walls of the villi are folded which further increases the total surface area.
