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Digestion Syllabus Flashcards
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- 1Define Chemical digestionThe breaking down of food into smaller nutrients that can be absorbed by the body cells
(saliva and stomach acid etc) - 2Define Mechanical digestionPhysically breaking down food into smaller pieces
(teeth and stomach churning etc) - 3Six basic activities of the digestive system1) Ingestion of food and water
2) Mechanical digestion of food
3) Chemical digestion of food
4) Movement of food along the alimentary canal
5) Absorption of digested food and water into the blood & lymph
6) Elimination of material that is not absorbed - 4Label a diagram of the digestive systemSee page 109
- 5Describe Structure and function of each part of the digestive systemSee page 109
- 6Identify the four types of teeth and describe their functionsSee page 110
Incisors - Chisel shaped for biting and cutting (eating and apple)
Canines - Tearing food
Premolars - Two on each side of jaw. Broad crowns for crushing and grinding
Molars - Broad crowns for crushing and grinding food - 7Explain peristalsisFood is pushed along the alimentary canal by peristalsis. One section contracts whilst another relaxes to push food along the tube. Longitudinal and circular muscles work together to cause peristalsis.
(See page 111) - 8Identify and explain the type of digestion occurring in the mouthMechanical:
Chewing - breaking down food with teeth
Bolus - forming food into ball by tongue
Swallowing - tongue pushes bolus into larynx
Chemical:
Salivary amylase - produces Polysaccharides which lead to sugars - 9Identify and explain the type of digestion occurring in the stomachMechanical:
Muscular churning - mixes food with gastric juice and forms chyme
Rennin - (infants only) curdles milk
Chemical:
Hydrochloric acid - activates pepsiongen which leads to pepsin
Pepsin - proteins which leads to polypeptides
(Pepsionogen = inactive form of pepsin)
(Pepsin = only activated when HCL is present in stomach)
Absorption:
Limited absorption of water, glucose, alcohol and some drugs - 10Identify and explain the type of digestion occurring in the small intestineChemical:
Amylases - disaccharides to monosaccharides
Lipase - Fats and oils to fatty acids and glycerol
Peptidases - peptides to amino acids
Absorption:
Absorption of digested material into the blood and lymph though villi - 11Draw and label a diagram of the mucosa wall of the stomachSee page 112
- 12Describe where bile is made, stored, what it is made up of and its functionMade - Secreted by glands in liver
Stored - Gall bladder
Made up of - water, bile salts and cholesterol
Function - bile salts emulsify lipids, forming small globules with large surface area - 13Identify the pancreas and describe each of the enzymes it secretes and its functionLeft side between liver and stomach
Ducts carrying pancreatic juice enter duodenum.
Pancreatic juice - water, sodium hydrogen carbonate, pancreatic amylase, protease, lipase and nucleotides - 14Draw and label a diagram of a villiSee page 114
- 15Explain how each nutrient is absorbed through the villiSimple sugars - (glucose) active transport. Pass through cells on outside of villi and into blood capillaries
Water and water soluble vitamins - Absorbed into blood capillaries by diffusion
Fatty acids and glycerol - simple diffusion. In cells of villi, fatty acids and glycerol recombine to form fats. Tiny fat droplets enter lacteals
Amino acids - absorbed by active transport into blood capillaries. - 16Structure and function of a lactealAbsorbs fat from digested food.
Lymph capillary in villus. Surrounded by network of blood capillaries. - 17Explain where nutrients are taken after they are absorbedBlood capillaries.
Fatty acids recombine in the cells of the villi to form fats and, along with the fat-soluble vitamins, enter the lacteals. Substances absorbed into blood capillaries are carried by the hepatic portal vein to the liver. Here they can be removed for further processing, or remain in blood to be carried to other body cells.
Substances absorbed into lacteals are transported into the lymph system, which eventually empties into the blood through veins in upper chest - 18Distinguish between elimination and exctretionExcretion - removal of metabolic waste = waste that has been produced by chemical activity of the body cells.
Elimination - Except for bile pigments, contents of faeces are not metabolic waste. So defecation is elimination and not excretion - 19Identify parts and functions of the large intestineSee page 116
- 20List each of the digestive enzymes and describe where they are produced, what nutrient each acts on and what nutrient is broken down toSee Table 9.1 on page 117
- 21Describe constipationConstipation - Contents of large intestine remain there for a long time. Water is absorbed and faces become harder and drier.
Caused by lack of roughage in diet (cellulose or insoluble fibre).
No enzymes to digest cellulose but it is important because it stimulates movement of alimentary canal. - 22Describe diarrhoeaFrequent defecation of watery faeces. Caused by irritation of small or large intestine, which increases peristalsis so the contents move through without being absorbed of water etc.
Irritation caused by bacterial or viral infection - 23Describe bowel cancerUncontrollable growth of cells in wall of large intestine. Risks involve: diet, alcohol, smoking, red meat, low fibre (fruit and veg), overweight, physical inactivity
- 24Coeliac diseaseUnable to tolerate protein called gluten, which is found in wheat, rye and barley. If people eat food containing gluten, immune system destroys or damages villi in small intestine. Without villi, nutrients can't be absorbed and person becomes malnourished.
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- Descripción
- Syllabus flashcards for unit 1.4 of digestion and excretion for Human Biology - Year 11
- Creado por
- Hayden McElduff
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