Gastrointestinal

Question 1

Components of gastrointestinal system

Answer 1

> Oral cavity/teeth/tongue - mechanical processing
Salivary gland - moisten + CHO enzyme breakdown
pharynx - propulsion to oesophagus
Stomach - chemical + mechanical breakdown
Small intestine - enzyme breakdown
- absorption H2O/substrates/vits/ions
Large intestine - dehydration + compaction - excretion
Pancreas - Hormones/buffers/enzymes to aid digestion
Liver - secretion of bile (lipid digestion)
- store nutrients
Gall bladder - stores bile

Question 2

Functions of gastrointestinal system

Answer 2

> Ingestion
Mechanical processing - solids = torn/mashed
Digestion - chemical breakdown
Secretion - release of water/acids/enzymes/buffers/
salts
Absorption - organic substrates/ electrolytes/vitamins/water
Excretion - removal of waste

Question 3

Stomach

Answer 3

> j shaped organ on left hand side (T7-L3 level)
receives bolus of food from oesophagus
combines bolus with stomach acid to form chyme
4 regions
- Cardia = inlet
- Fundus = very top - under left hemi-diaphragm
- Body = mixing tank
- Pylorus - antrum
- canal - sphincter regulates exit
Function
- store ingested food
- mechanical breakdown
- Absorption - chemical bonds via acids/enzymes
- produces intrinsic factor (glycoprotein for vit. B12 absorption)

Question 4

Small intestine

Answer 4

> ~6m in length
Chemical digestion
products of digestion = reabsorbed (90% of nutrients)
*relies on bile from liver and enzymes from pancreas
Segments
Duodenum (25cm)
- receives chyme from stomach
- receives bile from liver/gall bladder
- receives enzymes from pancreas
Jejunum (2.5m)
- attaches to post. abdominal wall (in peritoneal cavity)
- bulk of chemical digestion + absorption occurs
Ileum (3.5m)
- ends in sphincter - controls exit to large intestine

Question 5

Large intestine

Answer 5

> ~ 1.5m (up to 7.cm width) from end of ileum to anus
> Frames small intestine
Parts:
- Cecum (entry)
- Colon (main)
- Rectum (exit)
Functions
- reabsorb water
- compact waste into feces + store until defecation
- absorption of vitamins

Question 6

Liver

Answer 6

> Largest visceral organ (~1.5kg)
Upper right portion of abdomen - under diaphragm
- above stomach/right kidney/intestines
4 lobes:
- Right
- Left
- Caudate (mid inferior - more anterior)
- Quadrate (mid inferior/posterior surface)
Functions:
Metabolic regulation - receives + stores excess nutrients
Haematological regulation - 25% of cardiac output
Bile production - secreted into common bile duct to duodenum - emulsifies fats

Question 7

Gall bladder

Answer 7

> stores + concentrates bile
sits under right lobe of liver (pear shaped organ)
* If no gall bladder - bile is then stored in liver but less of it is available - lower fat diet

Question 8

Disorders

Answer 8

> Gallstones - small cholesterol stones that can get trapped in duct = cholecystitis (painful)
- treated with meds/ultrasound/surgery
Crohn’s disease = inflammation of parts of digestive system (flare-ups)
- unknown cause - may lead to scar tissue that blocks intestines
- vomiting/diarrhoea/blood in faeces/anaemia
Ulcerative colitis
- inflammation of colon/rectum (similar to crohn’s)
Diverticulitis
- small bulges/pockets in lining of intestines which can cause infection/inflammation
- treated by antibiotics + diet
Ulcers
- gastric/duodenal - lining ulceration - actively bleeding
Gastroenteritis
- bacterial infection
Cancer

Question 9

Surgical incisions

Answer 9

> Laparoscopic - no physio intervention
Laparotomy
- Midline (vertical down midline near belly button)
- Transverse (horizontal under belly button)
- Rooftop (under ribs)
- Paramedian (vertical away from midline)