Colon

meter long Parts Appendix Caecum Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Anal Canal

Function of Large Intestine Absorption of water,salt Microorganism synthesize vit K Stores faeces

Function of Large Intestine Mass movement -20 or more times to propel faeces towards anus Defaecation reflex Involves local and parasympathetic reflex Local reflex - weak contraction Parasympathetic reflex – strong contraction

Effects of aging on the digestive system Wall becomes thin Blood supply decreases Smooth cell decrease Secretion decrease Dental enamel thins Gingiva exposed Healing decrease following injury Liver detoxification decrease Phagocytosis decrease Storage decrease Change in eating habits Increase infection Ulceration Susceptible to cancer Loss of teeth Unable to chew and sensitive teeth

Disorders of the digestive tract Stomach Vomiting Ulcer Liver Cirrhosis Hepatitis A B C Gallstone and jaundice Pancreas Diabetes mellitus Cystic fibrosis Intestine IBD IBS Malabsorption Infection of the digestive tract Staphylococcal Salmonellosis Thyphoid Cholera Giardiasis Pinworm Tapeworm Hookworm Roundworm Diarrhoea Dysentry Constipation

Vomiting Reflex Starts with irritation in the stomach Visceral nerves to the vomiting center in the medulla From the center thru the vagus nerve Deep breath taken – hyoid and larynx is closed by the soft palate – abdominal and diaphragm contracts – stomach contents expelled while the lower oesophagela sphincter is relaxed

Ulcer Causes H.Pylori,stress,diet,smoking,alcohol,excess acid secretion, pain killers Recurrence is common especially those from bacterial infection and poor dietary restriction Peptic Ulcer Duodenal Ulcer Gastric Ulcer - acid base difference

Liver Cirrhosis Hepatitis A – Faeco-oral transmission Hepatitis B – transmitted thru blood or bodily fluids Hepatitis C – transmitted thru injection-drug addicts B AND C leads to cirrhosis and cancer

Pancreas Diabetes mellitus lack of insulin no effect to insulin Cystic Fibrosis Hereditary disorder Defective chloride channel Ducts blocked with viscid fluid Decrease absorption of fat and fat soluble vitamins Night blindness, skin disorders,rickets and bleeding disorder

Intestine IBD Infective,autoimmune or hereditary in origin Crohn or ulcerative collitis Causes inflammation of the intestine Treatment - anti inflammation, surgery IBS Unknown cause Constipation and diarrhoea Psychosomatic disorder Treatment – counseling and stress management, change diet, drugs to modulate motility

Infection of the intestinal tract Malabsorption syndrome Abnormal absorption Types Gluten - protein in grains Tropical – caused by bacteria

Infection of the intestinal tract Bacteria Staphylococcal Salmonella Vibrio cholera Protozoan Giadia lamblia Helminths Pinworm Hookworm Roundworm Tapeworm