Digestive System Flashcards
What does the digestive system do?
Ingestion
Digestion
Absorption
Elimination
Name parts of the digestive system.
Mouth Pharynx Oesophagus Stomach Duodenum Jejunum Ileum Caecum Colon Rectum Anus
Name the accessory organs.
Salivary glands (3 pairs)
Liver
Gall Bladder
Pancreas
What are intestinal secretions?
main constituents are water, mucus and mineral salts. Peptidase breakdown polypeptides into smaller peptides and amino acids. Lipase emulsifies fats to fatty acids and glycerol. Sucrase, maltase and lactase complete digestion of carbohydrates.
What do the accessory organs do?
aid the processes of ingestion, digestion and absorption
Describe the Gall bladder?
Storage of bile produced by the liver. pH of 8. Stores 30-60 mls per day. water, mineral salts, mucous, bile salts, bile pigments, cholesterol. Emulsify fats. Cholesterol, fatty acids, fat soluble vitamins (A, D, E and K) made soluble for absorption. Bilirubin - a waste product from the breakdown of red blood cells. Converted to stercobilin to colour (brown) and deodorise faeces.
Describe Elimination.
Absorption water, mineral salts, vitamins, drugs.
Microbial activity, synthesise vitamin K and folic acid.
Mass movement slow peristalsis (Gastrocolic reflex).
Deification.
Large intestine 1.5 m long.
What is the function of the oesophagus in pregnancy?
Relaxation of lower oesophageal sphincter– regurgitation– heartburn.
What is the function of the stomach in pregnancy?
Gastric secretion Gastric motility slow emptying pulping of food May cause nausea
What is the function of the small intestine in pregnancy?
motility
absorption time
transit time
iron Fe absorption
What is the function of the colon in pregnancy?
motility
water absorption
may cause constipation
Na+ absorption
What are the causes of increased appetite and thirst?
Increased appetite and thirst particularly in the first half of the pregnancy. Appetite may be promoted by several hormones including leptin. Leptin usually suppresses food intake but in pregnancy, leptin levels increase. In advanced pregnancy, both appetite ad capacity for food intake decline owing to upward gastric displacement and pressure from the gravid uterus.
Explain food craving and aversions.
Cravings for fruit and highly flavoured foods such as pickles, kippers and cheese. The sensitivity of taste buds is dulled in pregnancy and so highly seasoned foods are more appreciated. Common aversions such as tea, coffee, meat, fried foods and eggs, alcohol and smoking. Pica, an extreme craving for non- nutritious substance, e.g. soap, toothpaste, ice, coal
What changes does the mouth go through during pregnancy?
The gums become oedematous, soft and spongy during pregnancy. Probably due to the effect of oestrogen, which may lead to bleeding. Gingivitis occurs as food debris and calcified dental plaque collect in the minute space between tooth and the gum, causing irritation and inflammation.
Why do women experience heartburn during pregnancy?
The increased abdominal pressure due to enlarging uterus causes a shift in pressure gradient between abdomen and thorax. The angle of the gastro-oesophageal junction is altered and the lower oesophageal sphincter is displaced into the negative pressure on the intrathorcic cavity. These mechanical changes together with the relaxing effect of the progesterone which reduces gastrointestinal contents into the lower oesophagus leading to heartburn.
