Unit 4- The Digestive System Flashcards
Define mastication
Chewing
Describe the structure of the digestive system
One long tube from the mouth to the anus
Which organs are a part of the digestive system?
Mouth, pharynx, oesophagus, stomach, liver, gall bladder, pancreas, small intestine, large intestine, rectum and anus
What is the main function of the digestive system?
Break down molecules which cannot be absorbed intact into smaller molecules that can be absorbed into the blood stream
How is food made easier to swallow in the oral cavity?
Saliva is secreted from the salivary glands
How does the body ensure that food doesn’t go down the trachea?
The epiglottis closes when we swallow, cutting of access to trachea
Define oesophagus
Muscular tube that squeezes food down to stomach
Define peristalsis
Action of food being squeezed down to stomach
Define stomach
Muscular sack that churns food around and begins chemical digestion
What is food called after leaving the stomach?
Chyme
Where does chyme go after leaving the stomach?
Duodenum
Define duodenum
First part of small intestine
What is the function of the duodenum?
Where food mixes with bile from the gallbladder and digestive juices from the pancreas
Where is bile made?
Liver
Where is bile stored?
Gallbladder
Where are the digestive juices produced?
Pancreas
What do the digestive juices contain?
Digestive enzymes and alkaline salts
How do the digestive juices get to the duodenum?
Via the pancreatic duct
Define the pancreatic duct?
Tube from pancreas to gut
What are the three sections to the small intestine?
Duodenum, Jejunum and Ileum
Describe the structure of the ileum
Covered in villi, like a thick carpet
Define villi
Small finger-like projections, containing blood vessels
What happens in the Ileum?
Nutrients are absorbed into the blood
Which substances move onto the large intestine?
Water and food substances that can’t be broken down chemically
What is the large intestine also called?
The colon
What lives in the colon?
Trillions of bacteria
What is the function of the bacteria in the colon?
Feed off undigested food
Produce intestinal gas
What happens in the large intestine?
Food and dead bacteria is dried out to form faeces
Where is faeces stored?
Rectum
Define rectum?
Muscular tube that expels waste
What are the symptoms of IBS?
Bloating Constipation Diarrhoea Abdominal pain Indigestion Flatulence
What does IBS stand for?
Irritable bowel syndrome
What are the believed causes of IBS?
Oversensitive nerves
Stress
Genetics
Slow/fast digestion
What are the common triggers of IBS symptoms?
Alcohol
Caffeine
Fatty/spicy foods
Stress/anxiety
What do doctors advise if an individual is experiencing symptoms of IBS?
Avoiding processed foods
Keeping a food diary to identify triggers
Reduce stress
Try probiotics
What medication is offered to treat the bloating that comes with IBS?
Bus cop an
What medication is used to treat diarrhoea that comes with IBS?
Imodium/Loperamide
What medication is used to treat constipation that comes with IBS?
Fybogel or Celevac
What type of diet is recommend by dieticians to manage symptoms of IBS?
Low FODMAP diet
What does the low FODMAP diet consist of?
Avoiding difficult-to-digest foods such as some types of fruit, milk + wheat product
What type of treatment is offered if stress and anxiety is identified as an IBS trigger?
CBT
What are gall stones made up of?
Cholesterol
What causes gallstones?
Imbalance in bile composition
How are gallstones formed?
High levels of cholesterol + bilirubin result in formation of crystals that clump to form gallstones
What are the risk factors for developing gallstones?
Being female Obesity 40+ Existing liver damage IBS Family history of gallstones
What are the symptoms of gallstones?
Abdominal pain Sweats Nausea/vomiting Jaundice Confusion Loss of appetite
How is an individual diagnosed with gallstones?
Ultrasound, CT scan or cholangiography
What is a cholangiography?
Using a dye to show any abnormalities in the bile/pancreatic systems
What is CT scan?
Many x-rays being taken from many angles
How are gallstones treated if an individual isn’t experiencing any symptoms?
Active monitoring
What is active monitoring?
Letting GP know if and when symptoms are being experienced
What increases the likelihood of an individual needing treatment for gallstones?
Diabetes
Cirrhosis
What treatment is offered for gall stones if an individual is experiencing mild and infrequent pain?
Painkillers
What treatment is offered for gallstones if the pain is severe and frequent?
Surgery
What are the types of surgery offered to treat gallstones?
Keyhole surgery
Open surgery
ERCP
What is keyhole surgery? (In relation to gallstones)
A laparoscope is inserted into the body via small incisions on the abdomen, and removes the gallstones
What is open surgery? (In relation to gallstones)
If a keyhole is unsuccessful, a larger incision is made to remove the gallbladder completely
What is an ECRP? (In relation to gallstones)
Endoscope passed down mouth to the bile duct and is widened using a hot wire or small incision, to allow gallstones into small intestine
What is a laparoscope?
Long thin tube with camera and light at the end
Used in laparoscopy
What is an endoscope?
Long, thin, flexible tube with a light and camera at the end
Used in endoscopy
What does ERCP stand for?
Endoscopic retrograde cholangio-pancreatography
What medication is sometimes offered to dissolve gallstones?
Ursodeoxycholic acid tablets
How are gallstones prevented?
Avoid saturated fat
Drinking small amounts of alcohol
Regularly eating nuts
Losing weight
What is coeliac disease?
Autoimmune disease where immune system attacks own tissues when gluten is consumed, damaging small intestine and hindering digestion
What is gluten?
Dietary protein found in wheat, barley and rye
What are the symptoms of coeliac disease?
Stomach ache Bloating Constipation/diarrhoea Infertility Fatigue Ataxia
What is ataxia?
Disorder that affects co-ordination, balance and speech
What is the primary treatment of coeliac disease?
Following a gluten-free diet
What are the complications of coeliac disease?
Osteoporosis
Anaemia
Vitamin deficiency
What happens in the body of someone with coeliac disease whe gluten is consumed?
Immune system mistakes gliadin as threat and the antibodies produced cause inflammation of the intestine, flattening villi and reducing ability to digest food
How is coeliac disease diagnosed?
Blood test + biopsy
What is mechanical digestion?
Food being physically broken down into molecules small enough to be used by enzymes
Where is mechanical digestion carried out?
The mouth and the stomach
What is food called once it reaches the stomach?
Chyme
What is chemical digestion?
Enzymes chemically changing nutrients into smaller, soluble units
Name the 4 types of digestive juice
Saliva
Gastric juice
Pancreatic juice
Intestinal juice
Where is saliva produced?
Salivary glands in the mouth
Where is gastric juice produced?
Gastric glands in stomach
Where is pancreatic juice produced?
Pancreas
Where is intestinal juice produced?
Intestinal glands in small intestine
Which digestive enzymes are contained in saliva?
Ptyalin
Mucin
Amylase
Which digestive enzymes are contained within gastric juice?
Pepsin
Which digestive enzymes are contained within Pancreatic juice?
Pancreatic amylase
Trypsin
Lipase
Which digestive enzymes are contained within intestinal juice?
Lactase, maltase and sucrase
Peptidase
Lipase
What does Ptyalin, Mucin
+ Amylase work on?
Changing starch into complex sugar
What does Pepsin work on?
Changing proteins into simpler proteins
What does pancreatic amylase work on?
Turning starch into complex sugar
What does trypsin work on?
Turing proteins into simpler proteins
What does lipase work on?
Turning fats into fatty acids and glycerol
Where is hydrochloric acid produced?
Pits in the stomach walls
What enzyme does the hydrochloric acid in the stomach activate?
Pepsin
What does pepsin do?
Breaks down proteins into polypeptides
How is chyme neutralised as it enters the duodenum?
Adding alkali salts to make it slightly alkaline
Where do the alkali salts in the duodenum come from?
Bile+pancreatic juice
Why does water in the gut present a problem for the digestion of fat?
Fat and water don’t mix
How is fat digested in the gut?
Salts in the bile act as a detergent, breaking up fat into globules that form an emulsion, allowing enzymes to reach the molecules
What is the function of the liver?
Produce bile and send it to the gallbladder
What is the function of bile?
Break down fats in the duodenum
Where does all blood pass through after leaving the stomach?
Liver
Describe the structure of the gallbladder
hollow, muscular and pear-shaped
3x1.5 inches
Where does the tapered end of the gall bladder connect to?
The cystic duct, which connects to the common hepatic duct. Both merge to form common bile duct
Describe the structure of the pancreas
6 inches long
What is the function of the pancreas in the endocrine system?
Secrete insulin and glucagon
What is the function of insulin?
Lower blood glucose when levels are too high
What is the function of glucagon?
Increases blood glucouse when levels are too low
