Digestive System

Question 1

Outline the digestive cells, secretions and functions

Answer 1

1. Surface mucus cell
   Secretes: mucus
   Function: Lubrication & protection
2. Mucus neck cell
   Secretes: mucus
   Function: Lubrication & protection
3. 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
4. Chief cell
   Secretes: Pepsinogen & Gastric lipase
   Functions:
   Pepsinogen - converted into pepsin by hydrochloric acid. Pepsin breaks down proteins.
   Gastric lipase - digests fats
5. G Cell
   Secretes: Gastrin
   Function: Stimulates secretion of gastric juices; increases motility of GI tract; relaxes pyloric sphincter (allowing food out of stomach).

Question 2

How do the sympathetic and parasympathetic divisions of the NS affect digestion in the stomach?

Answer 2

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.

Question 3

What are the components of pancreatic juice and what do they do?

Answer 3

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

Question 4

Explain the importance of bile in digestion

Answer 4

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.

Question 5

Name the types of molecules that are broken down in the small intestine.

Answer 5

1. carbs
2. proteins
3. fats
4. nucleic acids

Question 6

What are the types of molecules that are absorbed in the small intestine?

Answer 6

VAMP WIMF

Vitamins
Amino acids
Monosaccharides
Peptides

Water
Ions
Monoglycerides
Fatty acids

Question 7

Why might a problem in the liver or gallbladder lead to a vitamin deficiency?

Answer 7

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.

Question 8

What do the enzymes from the bacteria of the large intestine do?

Answer 8

1. Ferment any remaining carbs releasing C, H and methane
2. Break down any remaining proteins to amino acids
3. Decompose bile to simpler pigments (e.g. bilirubin)
4. Produce vit K and B

Question 9

What is a peptic ulcer?

Answer 9

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.

Question 10

What are the symptoms of peptic ulcers?

Answer 10

general burning or gnawing abdominal pain between meals thats relieved by antacids or food.

Bloating, burping, gas and vomiting after meals.

Question 11

How might stress contribute to peptic ulcers?

Answer 11

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.

Question 12

What are the possible complications of peptic ulcers?

Answer 12

1. Can erode capillaries causing slow bleeding and anaemea
2. If larger arteriole or artery haemorrhaging it can lead quickly to shock and death.
3. Can perforate organ walls releasing bacteria and partially digested food into peritoneum (peritonitis).
4. Can create combination of scar tissue and inflammation that causes the pyloric valve to spasm
5. significantly raises risk of developing stomach cancer

Question 13

Explain why a person who’s recently been taking antibiotics may complain of patchy, painless white lesions in the mouth.

Answer 13

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

Question 14

1. What is gingivitis?

2. What are the main signs and symptoms?

Answer 14

1. It is gum disease. Not always painful, may be unaware have it.
2. 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)

Question 15

1. What is indigestion?
2. What are its common signs and symptoms?
3. When might you refer someone to their GP?

Answer 15

1. aka dyspepsia - it is pain or discomfort in your chest or stomach. Usually comes on soon after eating or drinking.
2. Symptoms include:
   - feeling full or bloated
   - heartburn
   - nausea
   - belching
   - stomach cramps
   - flatulence
3. 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

Question 16

When would you advise a patient with nausea and vomiting to see their GP?

Answer 16

• have been vomiting uncontrollably for 24hrs+
• have not been able to keep fluids down for 12hrs+
• vomit is green (likely to be bile and suggests blockage in bowel)
• blood in vomit or what looks like coffee granules (sign of peptic ulcer)
• also have severe stomach pain

Question 17

What factors associated with diarrhoea may give more cause for concern?

Answer 17

• D lasting longer than 2 wks can be sign of bowel cancer, Crohn’s disease or IBS.
• blood or pus in faeces
• baby or child has 6+ episodes of D in 24hrs
• also if feeling unwell in addition to D

Question 18

1. What factors can contribute to constipation?

2. Name 3 common complications from constipation

Answer 18

1. • not eating enough fibre
     - change in routine or lifestyle
     - ignoring urge to pass stools
     - side effects of medication
     - not drinking enough fluids
     - anxiety or depression
2. haemorrhoids, faecal impaction (dry, hard stools collect in rectum) or faecal incontinence (leakage of liquid stools)

Question 19

1. What are the symptoms of IBS?
2. Why should a patient who appears to exhibit symptoms of IBS contact their GP if develop a fever or have blood in stools?

Answer 19

1. • Recurrent abdominal pain at least 3 days per month
   • pain with defecation
   • changes in stool frequency
   • changes in stool appearance
   • gas, bloating
   • headaches
   • general malaise
2. symptoms are not related to IBS

Question 20

What are the signs and symptoms of Crohns Disease?

Answer 20

• periods of flare and remission
• abdominal pain (esp lower right)
• cramping diarrhea (often with blood)
• bloating
• weight loss
• fever
• joint pain
• small ulcers in mouth and throat
• lesions on skin
• severe pain around anus, anal fissures and abscesses

Question 21

Ulcerative colitis is a disease involving inflammation and shallow ulcers of the colon, but other systems can be affected. Describe the possible effects on other systems.

Answer 21

• inflammation of liver or gallbladder ducts
• arthritis
• osteoporosis
• anaemia from blood loss
• kidney stones
• loss of vision
• skin disruptions

Question 22

1. What is diverticular disease?
2. What are the signs and symptoms?
3. What are the possible complications?

Answer 22

1. Small bulges develop on the lining of the intestine that become inflamed or infected.
2. May be no signs but can include:
   - bloating
   - nausea
   - fever
   - cramping
   - severe pain (usually lower left side)
3. Complications include:
   - bleeding
   - abscess
   - perforation and rupture
   - blocking
   - fistula

Question 23

1. What happens in cirrhosis of the liver?

2. Why is early identification so important?

Answer 23

It is the result of long term liver damage. Healthy liver cells are replaced by non functioning scar tissue. This interferes with virtually every function of the liver which includes:

• bile production
• enzyme production
• clotting factors
• toxin neutralisation
• hormone production

2. By the time signs and symptoms become apparent the damage is often too extensive to remedy.

Question 24

1. What is hepatitis?
2. Why do the severity of hepatitis symptoms vary so widely?
3. What are the typical symptoms of hepatitis?

Answer 24

1. It means inflamed liver. It can be caused by drug reactions, autoimmune diseases, exposure to toxins but usually viral infections.
2. Severity depends on:
   - the phase of infection
   - general health of the patient
   - type of virus involved
3. • general malaise
     - weakness
     - fever
     - nausea
     - food aversion
     - jaundice

Question 25

1. What are gallstones? | 2. What factors are likely to increase chances of gallstones?

Answer 25

1. Concentrated deposits formed in the gallbladder. 2 types: - cholesterol stones (light yellow, dark green, at least 80% cholesterol) - pigment stones (small & dark, made from bilirubin & calcium salts. Less than 20% cholesterol) 2. Obesity - increases amount of cholesterol made by liver and stored in gallbladder Oestrogen - increases amount of cholesterol in bile and gallbladder. Can be increased with pregnancy, birth control pills or HRT. Race - Native Americans and Mexican Americans have higher gallstone incidence Gender - women are aged 16-60 are twice as likely as men to develop Diabetes - high levels of triglycerides Rapid weight loss - causes liver to metabolise fat for energy and increases cholesterol in bile. Other diseases: Crohns, cirrhosis