LO3: The Digestive System Flashcards
What are th Salivary Glands?
Saliav moistens food to make it easier to swallow, contains enzyme amylase, starts chemical digstion of sugars.
What is the Bucal Cavity?
Use our jaws and teeth are usd to make food smaller, makes it easier to digest when the food enters the digestive system, makes food into a bolus.
What does the tongue do?
Moves the food around the mouth
What is the epiglotis?
Flexible lid for windpipe, closes only while swallowing and remains upright at other times, prevents food particles and liquids from entering the larynx or the trachea.
What is the Oesophagus?
A muscular tube which connects the throat with the stomach, food moves down the oesophagus to stomach with the help of peristalsis which are squeezing contractions from the muscles which helps the food move down to the stomach.
What is the Stomach?
Recieves chewed food, tiny glands in stomach secrete gastric juices which contain hydrochloric acid, mucus and enzymes
Mechanical and chemical digestion break down chemicals into smaller, simpler molecules results in soup like substance called chyme
What is the role of the liver?
To process nutrients absorbed from the small intestine
Bile is made in the liver
What is the role of bile?
Made in the liver and stored in the gallbladder, before being screted in the small inestine
Emulsifies fats
Helps chemical digestion in the duodenum, jejunum and ileum
Bitter greenish brown alkaline fluid
What is the role of the bile duct?
Small tube which carries bile from gall bladder to the duodenum
What is the role of the gall bladder?
Small sac shaped organ beneath the liver where bile is stored after secretion by liver
What is the role of the pancreas?
Large gland behind stomach which secretes digestive enzymes into the duodenum
What is the role of the pancreatic duct?
Small tube between pancreas and duodenum
Carried digestive enzymes from the pancreas
Helps chemical digestion in the small intestine
What is th role of the small intestine?
Made up of three sections:
1: Duodenum
2: Jejunum
3: Ileum
Covered in finger like projections called villi which increase surface area of the small intestine to increase rate of absorption of nutrients into the blood
What is the role of the large intestine?
Wider and smaller than the small intestine
Responsible for the reabsorption of water and the formation of faeces
What is the role of the rectum?
Faeces are stord in the rectum until passed out of the body through the anus
What is the role of the anus?
Opening at the end of the digestive tract where faeces leave the body
What is the role of hydrochloric acid?
Acid breaks down protein, absorbing nutrients but also killing off bacteria
What is the role of enzymes?
Breakdowns fats, proteins and carbohydrates
Enzymes are in saliva, pancreas, intestines and stomach
Biological catalyst which speeds up chemical reactions
What is the role of proteins?
Broken down into individual amino acids which are absorbed and used to build other proteins
Used for growth and repair
What is the role of carbohydrates?
Body’s main energy store
Sugar molecules which our body breaks down carbodydrates into glucose
What is the role of fats?
Some used right way for energy, some is stored for later when extra energy is needed your body will break down stored fat
Used for warmth or energy
What is mechanical digestion?
Physically breaking down food substances into small particles to more effectively undergo chemical digestion
What is chemical digestion?
using enzymes to break down nutrients such as carbs, proteins and fats into smaller molecules
What are molecules?
Complex molecules of carbs, proteins and fats are transformed by chemical digestion into smaller molecules that can be absorbed and utilised by cells
What is the meaning of absorb?
To take something in
What is the role of amylase?
Breaks down carbs
What is the role of protease?
Breaks down proteins
What is the role of lipase?
Breaks down fats and lipids
What is the role of pepsin?
Made in stomach, breaks down proteins
What does it meant to emulsify?
Increases surface area of fat which the lipase can act on
Where does mechanical digestion take place?
Buccal cavity and stomach
How does mechanical digestion happen in the buccal cavity?
Grinding of food from the teeth into smaller pieces, the jaw and the tongue work to move food around the mouth
How does mechanical digestion happen in the stomach?
Stomach churns the food with muscular contractions to get to stomach the bolus is squeezed down the oesophagus known as peristalsis
How does chemical digestion happen in the buccal cavity?
Salivary glands produce saliva which moistens food and releases enzymes amylaze to break down carbs
How does chemical digestion happen in the stomach?
Food enters the stomach, dugestive juices are released, enzymes begin to break down food, hydrochloric acid in stomach which creates an acidic environment which generates pepsin which breaks down proteins
How does chemical digestion happen in the small intestine?
Duodenum: food mixed with digestive enzymes and biles, chyme is acidic as it’s been in the stomach, small intestine needs alkaline conditions, bile neutralises acid so enzymes work
What is the role of pepsin in chemical digestion?
Breaks down large protein molecules into smaller polypeptides in the stomach
What is the role of amylase in chemical digestion?
Breaks down starch into maltose in the mouth adn the duodenum
What is th role of protease in chemical digestion?
Break down of protiens into smaller polypeptides or single amino acids in the duodenum
What is the role of lipase in chemical digestion?
Breaks down fats into fatty acids and glycerol in the duodenum
What are villi?
Tiny finger like projections that increase the surface area in the small intestine
What are the 3 key features of the villi?
Wall just one cell thick: ensures there is only a short distance for absorption to happen by diffusion and active transport
Network of blood capillaries: transports glucose and amino acids away from the small intestine in the blood
Internal structure called lacteal: transports fatty acids and glycerol away from the small intestine in the lymph
What is absorption?
Movement of nutrients, water and electrolytes from the lumen of the small intestine into the cell then into the blood
What is assimilation?
Movement of dugested food molecules into the cells of the body where they are used
What is Coeliac disease?
Autoimmune condition, when the immune system attacks the body’s own tissues (the villi) when eating gluten, stops you from taking in nutrients
Causes damage to the villi, causes the surface of the small intestine to become inflamed and the villi are flattened meaning the body’s ability to absorb nutrients is disrupted
What are the symptoms of Coeliac disease?
Abdominal pain
Fatigue
Diarrhoea/ constipation
Weight loss
What are the causes of Coeliac disease?
Abnormal immune system reaction to eating the protein gluten, stressful events or viruses can trigger the immune system to attack gluten
How is Coeliac diagnosed?
Involves having blood tests
May also require biopsys of the small intestine to confirm the diagnosis
While being tested for Coeliac need to eat foods containing gluten to ensure accuracy of tests
What are the treatments for Coeliac disease?
No cure for coeliac, but following a gluten free diet controls the symptoms and prevent long term complications
How does Coealiac disease impact daily life?
Have to stick to a gluten free diet
May have troubles with diarrhoea or constipation which could impact ability to work or socialise
What is IBS?
Wher food moves through the digestion system too quickly or too slowly
Too quickly results in diarrhoea becasue not enough water is absorbed by the intestines
Too slowly results in constipation becasue too much water is absorbed by the intestines
What are the symptoms of IBS?
Stomach pain and cramping
Diarrhoea/ constipation
Bloating and swelling of stomach
Sudden need to go to the toilet
What are the causes of IBS?
Exact cause is unknown
Senstitivity of gut to certain foods
Problems digesting food
Triggered by something that has been eaten or drank
What are the treatments of IBS?
No cure
FODMAP diet
Food diary to track the symptoms compared to what they have eaten to distinguish patterns and what food to avoid
How does IBS impact daily life?
Have to stop what they are doing to go to the toilet
Can affect affection with partner
Difficulty eating
Debilitating and isolating
What are Gallstones?
Can form if:
there are unusually high levels of cholesterol inside the gallbladder
there are unusually high levels of waste product called bilirubin in the gallbladder
Chemical imbalances can cause tiny crystals to develop in the bile, can gradually grow into solid stones that can be as small as a grain of sand or as large as a pebble,
What are the symptoms of Gallstones?
Abdomina pain which can be sudden and severe
Excessive sweating, feeling sick or vomitting
Itchy skin
Loss of appetite
What are the causes of Gallstones?
By an imbalance in the chemical make-up of bile inside the gallbladder
More common if an individual is overweight or obese, aged over 40, has liver cirrhosis, has close family member with gallstones
How to diagnose Gallstones?
Ultrsound: high frequency sound waves to create image of inside the body, if not visibke suggests bile duct may be affected, may need MRI
MRI: uses strong magnetic fields and radio waves to produce detailed images inside the body
Physical exam by GP: check if gallbladder is inflamed, if found painful usually means gallbldder is inflamed and need urgent treatment
How to treat Gallstones?
Removal of gallbladder
Medication
Lithotripsy
What is removal of the gallbladder?
Keyhole surgery, several small cuts mad in the abdomen and small surgical equipment used to remove the gallbladder, faster rcovery and scars are much smaller
Advantages of removing the gallbladder?
Removed if you have small gallstones that cause pain, blockages or inflammation
Stops pain and prevents complications from gallstones
Treat any infection caused by gallstones
Stops gallstones coming back
Disadvantages of removing the gallbladder?
Risk of infection
Could cause bleeding
Bile leakage
Injury to bile duct
Injury to intestine, bowels and blood vessels
Side effects of removing the gallbladder?
Fatty food intolerance
Nausea/ vomitting
Abdominal pain
Heartburn
What is Lithotripsy?
Nonsurgical alternative, can recieve if gallbladder is working normally, uses high energy sound waves to produce shock waves, strong nough to fracture and disintegrate gallstones, tiny endoscope probe used to deliver shock waves
Advantages of Lithotripsy?
Only on day, non-invasive procedure
Quicker recovery time than removal
Nealry 80% of gallstones treated
Disadvantages of Lithotripsy?
Results on larger gallstones aren’t as effective as smaller
Multiple seesion may be required
Passing of stones may cause pain
How does medication treat gallstones?
Need to be taken for at least 2 years, some medications contain bile acids that can break up gallstones, works best to break up small cholesterol stones
Advantags of medication for gallstones?
Easy to carry out
Non-invasive
Doesn’t involve recovery time
Disadvantages of medication for treating gallstones?
Only dissolves small gallstones
Gallstones can reoccur once treatment has stopped
Not prescribed very often becasue they aren’t always that effective
