Digestive System

lilypoh's version from 2016-04-16 07:38



is the breakdown and transormation of solid and liquid food into microscopic susbtances. Thesesubstances are then transported by the blood into different areas of the body.

Digestive system

Question Answer
Four stages of digestionsMouth -> stomach -> small intestine -> large intestine
Mouthingestion, chewing and swallowing; start of starch digestion
Stomachmixing and protein digestion
small intestinecarbohydrate and fat digestions; absorption
large intestinewaste and excretion
The ball of food that leaves the mouthis also known as a bolus
How many pair of salivary glands?3 pairs, situated below the tongue
What do the salivary glands contain?It contains water, mucus and the Enzyme Salivary Amylase
What is the name of the 3 salivary glands?parotid gland (below the ear), submandibular gland and sublingual gland (below the tongue)
Saliva has 3 functionsto lubricate the food with mucus, making it easier to swallow; contains the enzyme salivary amylase which acts on cooked starch turning it into shorter polysaccharides; to keep the mouth and teeth clean
What is enzyme?Enzyme is like a machine and workers which slowly change whateve is on the belt (digestive system) to make it smaller and smaller so that, eventually, it can be carried around the body in blood.
Tiny projection on the tongueis nown as papillae. Sensory nerve ending in the papillae is known as taste buds.
What is epiglottisis a small flap of cartilage which forms part of the larynx (the windpipe) moves upwards and forwards, blocking the entrance to the larynx. it to prevents choking.
What is Oesophagus?is a muscular tube which leads from the pharynx, at the back of the mouth, to the stomach, the first main organ of digestion.
What is the function of oesophagus?to carry chewed food from the pharynx to the stomach.
What is peristalsis?food moves along it by a muscular contraction. The muscle fibres contract and relax which acts like a wave on the tube, pushing the bolus forward..
What is stomach?it is a j-shaped, elastic organ wich expands and contracts depending on what is in it. Food enters it from the Oesophagus via the cardia sphincter, a valve that stops back flow of the stomach's contents, and leaves t through the pyloric sphincter into the duodenum, the first part of the small intestine.
what is the function of stomach?digests proteins through the action of enzymes; churns food with glastric guices; helps to lubricate the food by producing mucus; absorbs alcohol; kills bacteria by producing hydrochloric acid; storage of food prior to it passing to the small small intestine.
Gastric juices containhydrochloric acid, rennin; persin
Hydrochloric acidneutralises bacteria and activaes pepsin
renninenzyme that curdle milk protein (only in infants)
pepsinenzyme that acts on proteins turning them into polypeptides
Saturated fatscan be found in dairy products and meat.
Monounsaturated fatscan be found in olive oil and avocados
Polyunsaturated fatsfound in sunflower oil, oily fish
How long is the small intestine?7 meter long
Small intestine divided in to 3 sectionsduodenum, jejunum and ileum.
What is the walls contain in the small intestine?1. a muscular layer 2. blood vessels, 3. lymph vessels and nerves, 4. inner mucous membrane.
Inner mucous membranethis wall is covered with villi, tiny finger-like projections which increase the surface area for absrption and contain a nework of blood and lymph vessels.
what does the small intestine do? completion of the chemical digestion of food and the subsequent absorption of nutrients (90% of absorption takes place in the small intestine); to protect the digestive system from infection. It is only section of the system with direct link to the protective lymphatic system.
Peptones are broken down intoPolypeptides
What is the function of bile?to break down fats
How long is large intestine?1.5m long ; it sits draed around the small intestine, in an arch shape.
What is large intestine consists?caecum, appendix, colon, rectum, anal canal and anus
The functions of large intestineto reasbsorb of nutrients vitamins, salt or water left in the digestive waste; secretion of mucus to help passage of faeces; storage of faeces in rectum (short-tem).
Salivary glandssalivary amylase
action of salivar amylaseconverts starch into shorter chain polysaccharides
stomachsecrete Renin, hydrochloric acid, Pepsin
action of Renincoagulates milk into curds (in infants)
Hydrochloric acidneutralises bacteria
Pepsincoagulates proteins into peptones
DuodenumPancreatic juice and bile
Pancreatic juice consiststrypsin, lipase, amylase
Trypsinconverts peptones into shorter chain polypeptides.(is an enzyme involve in protein digestion).
lipaseconverts fats into fatty acid and glycerol
amylaseconverts polysacharides into disaccharides
Bileemuslsifies fats
Small intestine(from the villi) secreteintestinal junice of maltase, sucrase, lactase, enterokinase, peptidases
Maltase,sucrase,lactaseconvert disaccharides into monosaccharides
Enterokinaseactivates trypsin in pancreatic juice, changes trypsinogen into trysin
peptidasesconvert polypeptides into amino acids
LiverIt is the largest gland in the body.
Where is the locaiton of liverit sits at the top of the abdomen, just below the diaphragm and just above and to the right of the medial line.
What is the liver removesit removes toxins from drugs, alcohol and harmful susbtances; nitrogen from amino acids
What is the liver storesvitamins A, B12, D,E,K; glycogen (a compound that stores energy), iron, from the breakdown of read blood cells and food, fats
What is the liver producesheat, Vitamin A (from cartene, found in green-leafed vegetables and carrots), Vitamin D, heparin, plasma protein, bile, uric acid, urea (from breakdown of red blood cells and de-amination of amino acids
What is the liver convertsstored(saturated)fats into other fat products (like cholesterol); glycogen to glucose, when energy is needed; glucose back to glycogen, in presence of insulin, metabolised protein
Gall bladdera pear-shaped sac attached by the cystic and bile ducts to the posterior of the liver.
The function of gall bladderReservoir for bile (from liver); secretes mucus to add to bile, absorbs water from bile, making it more concentrated; contract in order to empty bile into duodenum
Pancreasis a gland situated behind the stomach, between the duodenum and the spleen.
Function of pancreasit delivers pancreatic juices to the duodenum through the pancreatic ducts; It works with both the digestive and endocrine system. it produces enzymes to break down food, the hormone insulin which regulates the blood sugar level after eating
The cells of the pancreasit divided into the inslets of langerhands (which produce insulin and glucagon) and a network of alveoli (small sac-like cavities).
Alveoliare lined with cells that produce enzymes
Pancreative juices containslipase (fat digestion); amylase (starch digestion); trypsin (protein digestion)
The function of the enzyme lipaseto change fats into fatty acids and glycerol
What produce insulin?islets of langerhans
Insulin hormoneis to regulates the blood sugar level after eating by causing the conversion of glucose to glycogen for storage in the liver and muscles.
What is the function of billirubinto give faeces it colour
What is the cardiac sphincter?To control the movement of food into the stomach
What is an enzyme?a chemical catalyst
Food leaves the stomach through thepyloric sphincter