GASTROINTESTINAL SYSTEM Flashcards
11 components and what they do
ORAL CAVITY, TEETH AND TONGUE- Food or liquid ingested and mechanical processing to moisten and mix with saliva
Salivary glands- Secrete lubricating fluid with enzymes to break down carbs
Pharynx- muscular propulsion to pass through oesophagus
Oesophagus- Transport materials to stomach
Liver- Produces bile for lipid digestion, stores nutrients etc
Gallbladder- Stores and concentrates bile
Pancreas- Exocrine cells secrete digestive enzymes and buffers , endocrine secretes hormones
Stomach- Chemical breakdown of materials via acid and enzymes and is mechanical process through muscular contractions
Large intestine- dehydration and compaction of materials into faeces
Small intestine- Enzymatic digestion, absorption of water, ions, organic subtrates and vitamins
Anus- eliminates faeces
6 functions of digestive system
I Must Digest So Alice Eats
INGESTION- Via mouth and active decision making
MECHANICAL PROCESSING- Solids need mashing and tearing (preliminary mechanical processing) + swirling and churning of mixture
DIGESTION- Chemical breakdown of food into small substances ; molecules disassembled by enzymes before absorption
SECRETION- Release of water, enzymes, buffers, acids and salts (glandular organs)
ABSORPTION- Movement of organic substrates, electrolytes, vitamins and water from digestive epithelium into tract
EXCRETION - Removal of wastes
STOMACH
J Shaped organ
Left hand side at T7-L3
Receives masticated food (chewed) in form of BOLUS (round mass) from oesophagus
Ingested food + stomach acid = CHYME
Chyme is highly acidic and viscous substance
4 Functions of stomach
SMAP
Storage of ingested food
Mechanical breakdown of ingested food (swirling to breakdown food with stomach acid)
Absorption of chemical bonds of food via acids and enzymes
Production of intrinsic factors (B12 absorption functions with this, so lack of intrinsic factor is B12 deficiency)
4 sections of stomach
CARDIA
FUNDUS
BODY
PYLORUS (Made of pyloric antrum and pyloric canal)
CARDIA or inlet
Accepts bolus of food from oesophagus
Placed between oesophagus and body of stomach
FUNDUS
Most superior
Under left hemi diaphragm
Patient having FUNDUS removed may have respiratory issues as surgery impacts diaphragm sometimes
BODY OF STOMACH
Where food and stomach acids make chyme
PYLORUS
Pyloric antrum
Pyloric canal with sphincter to pass chyme into duodenum of small intestine
Small intestine
Where chemical digestion finished and products of digestion absorbed
Relies on bile release from liver and pancreas enzymes for finishing digestion (then absorption)
90% of nutrients absorbed here
6m in length
3 segments of small intestine
DUODENUM
JEJUNUM
ILEUM
More about small intestine
Between L1-L4
Duodenum is 25cm long.
Receives chyme and digestive enzymes from liver and pancreas
Curved shape and near the pancreas
JEJUNUM - in peritoneal cavity
2.5m long
Most chemical digestion happens here
ILEUM- 3.5m long
Ends in sphincter for fluid into large intestine
LARGE INTESTINE
Begins at end of ileum and ends at anus
Frames the small intestine
1.5 metres long and up to 7.5cm sometimes
Functions of large intestine
RAS
Reabsorption of water and compaction into faeces
Absorption of vitamins from bacterial action
Storages of faeces prior to removal
3 parts large intestine
CECUM
COLON
RECTUM
4 parts of colon:
Ascending, transverse, descending and sigmoid
About the large intestine
Cecum is extended puch of ileum
Colon=
Ascending up right side , bends at hepatic / colic flexure
Transverse from R to L, bends at splenic flexure
Descending down left side , curves into
Sigmoid colon is C shaped and empties into rectum
Rectum is 15cm long and end of digestion- Voluntary and involuntary sphincters
Liver
Largest visceral organ
Weighs 1.5kg
Upper right of abdominal cavity, beneath diaphragm and stretches to top of stomach, right kidney and intestines
Secretes bile into duodenum by common bile duct
Liver lobes
Right
Left
Caudate
Quadrate
3 liver functions
Metabolic regulation- remove and store nutrients
Haematological regulation- receives 25% full cardiac output and is large so stores some blood
Bile production- secrete bile into duodenum and emulsified chyme
Gallbladder
Pear shaped
Stores and concentrates biles
Under right lobe of liver
If you have gallbladder removed , bile stored in liver and produced in smaller amounts . Struggle to digest fatty foods.
GALLSTONES
Small cholesterol stones Too many or too large Stuck in bile duct excruciating pain Inflammatory process and infection Cholecystitis
Treatment = Breakdown using ultra sonic equipment
Pain relief
Cholecystectomy can remove them
Chrons
Lifelong Inflammation of digestive system parts May be linked to R arthritis or ankylosing Flare ups Can pass blood in faeces Loss of blood can cause anaemia Scarring Constipation fromntightening if bowel
Treatments- to reduce inflammation
Immunosuppressants
Surgery to remove damaged cells
Iliostomy bags
Ulcerative colitis
Lifelong
Colon and rectum inflamed
Small ulcers on colon linin and can bleed and pus
Symptoms - abdominal pain, diarrhoea, blood I’m faeces , fatigue and weight loss and loss of appetite
Flare ups
Managed like chrons
Diverticulitis
Bulges in lining of large intestines
Inflammation and infection
Pain, loss of appetite, vomit and diarrhoea
Get it in bouts
Treatment - diet control like fibre and antibiotics
Not seen as lifelong
Ulcers
Gastric or duodenal ulcers
Pain and vomiting blood
So it is actively bleeding
Surgery and meds
Cancer common
Gastroenteritis
Bacterial infection
Affects any age
Projectile vomiting, watery diarrhoea , nausea and mild fever
Treatments - drink fluids, paracetamol , rest and plain diet , anti diarrhoea and anti emetics
Laparotomy
Where narrow tubes in the abdomen via incisions
Incisions may be Midline Transverse Rooftop Paramedian Subcostal
