Colon

Colon

1.5-1.8 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

LiverCirrhosis

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