Digestive System Flashcards
Outline the digestive cells, secretions and functions
- Surface mucus cell
Secretes: mucus
Function: Lubrication & protection - Mucus neck cell
Secretes: mucus
Function: Lubrication & protection - Parietal cell
Secretes: Hydrochloric acid & Intrinsic factor
Function:
Hydrochloric acid - kills microbes, converts pepsinogen to pepsin
Intrinsic factor - aids vit B12 absorption which is required for red blood cell production - Chief cell
Secretes: Pepsinogen & Gastric lipase
Functions:
Pepsinogen - converted into pepsin by hydrochloric acid. Pepsin breaks down proteins.
Gastric lipase - digests fats - G Cell
Secretes: Gastrin
Function: Stimulates secretion of gastric juices; increases motility of GI tract; relaxes pyloric sphincter (allowing food out of stomach).
How do the sympathetic and parasympathetic divisions of the NS affect digestion in the stomach?
Parasympathetic & enteric NS: i) stimulates gastric glands to secrete: into the stomach... - pepsinogen - hydrochloric acid - mucus
into the blood…
- gastrin (stimulates gastric juice, makes stomach move, relaxes pyloric sphincter)
ii) once food reaches the stomach:
- it stretches
- becomes more acid
Sympathetic NS:
Stress = above processes slow down
SO more indigestions and other gastric disorders.
What are the components of pancreatic juice and what do they do?
BCTCCPRD - Bicarbonate pancreas trys chewing carby pancakes radiating detox
Bicarbonate ions (bicarbonate)- makes it alkaline, inactive pepsin
Pancreatic amylase (pancreas) - digests carbohydrates
Trypsin (trys) - digest proteins
Chymotrypsin (chewing) - digest proteins
Carboxypeptidase (carby) - digest proteins
Pancreatic lipase (pancakes) - digest fats
Ribonuclease (radiating) - digest nucleic acids
Deoxyribonuclease (detox) - digest nucleic acids
Explain the importance of bile in digestion
Bile allows the emulsification of fat and water molecules which is essential for enzymes to break them down.
Liver makes bile from worn out red blood cells. Bilirubin (one of these) is the emulsifying agent in bile.
Bilirubin (once completed its job) conts down small intestine and is itself digested - one of the products that makes faeces brown.
Name the types of molecules that are broken down in the small intestine.
- carbs
- proteins
- fats
- nucleic acids
What are the types of molecules that are absorbed in the small intestine?
VAMP WIMF
Vitamins
Amino acids
Monosaccharides
Peptides
Water
Ions
Monoglycerides
Fatty acids
Why might a problem in the liver or gallbladder lead to a vitamin deficiency?
Bile salts are needed for absorption of vitamins A, D, E, K. Absorption may therefore be affected if liver or gallbladder aren’t working properly.
What do the enzymes from the bacteria of the large intestine do?
- Ferment any remaining carbs releasing C, H and methane
- Break down any remaining proteins to amino acids
- Decompose bile to simpler pigments (e.g. bilirubin)
- Produce vit K and B
What is a peptic ulcer?
Occur in oesophagus, stomach, small intestine & are most commonly the result of Helicobacter Pylori - bacteria located in gut.
This bacteria (often present in low levels) can multiply (eg. if immunity is low), & castes inflammation to stomach lining. This creates gaps in mucous layer which fill with acid resulting in ulcer.
What are the symptoms of peptic ulcers?
general burning or gnawing abdominal pain between meals thats relieved by antacids or food.
Bloating, burping, gas and vomiting after meals.
How might stress contribute to peptic ulcers?
Stomach produces hydrochloric acid to digest food and mucus protects the stomach from the acid and it’s then neutralised by bicarbonate in the pancreas.
Stress suppresses the blood supply to the digestive tract which slows mucus and acid/pepsin production. This stage is fine as the two are balanced BUT when stress if lifted, the acid & pepsin production recovers much more quickly than the mucus protection meaning the stomach wall is open to attack.
What are the possible complications of peptic ulcers?
- Can erode capillaries causing slow bleeding and anaemea
- If larger arteriole or artery haemorrhaging it can lead quickly to shock and death.
- Can perforate organ walls releasing bacteria and partially digested food into peritoneum (peritonitis).
- Can create combination of scar tissue and inflammation that causes the pyloric valve to spasm
- significantly raises risk of developing stomach cancer
Explain why a person who’s recently been taking antibiotics may complain of patchy, painless white lesions in the mouth.
It is a characteristic of Oral Thrush. Thrush is caused by a yeast like fungus that inhabits the digestive tracts when antibiotics kill harmful bacteria they also kill beneficial bacteria thus giving the thrush an opportunity to reproduce and spread
- What is gingivitis?
2. What are the main signs and symptoms?
- It is gum disease. Not always painful, may be unaware have it.
- Initial symptoms:
- red & swollen gums
- bleeding gums after brushing / flossing
Peridontitis:
Developed gum disease which affects tissues supporting teeth…
- bad taste in mouth
- loose teeth
- gum abscesses (pus collection under gums or teeth)
- What is indigestion?
- What are its common signs and symptoms?
- When might you refer someone to their GP?
- aka dyspepsia - it is pain or discomfort in your chest or stomach. Usually comes on soon after eating or drinking.
- Symptoms include:
- feeling full or bloated
- heartburn
- nausea
- belching
- stomach cramps
- flatulence - Recommend see GP if get recurring indigestion and:
- over 55 yrs
- unintended weight loss
- increased diffuculty swallowing
- persistent vomiting
- iron deficient
- lump in stomach
- blood in vomit or stools