Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gastrointestinal pathophysiology > Malabsorption and malnutrition > Flashcards

Malabsorption and malnutrition Flashcards

1
Q

What is malnutrition?

A

Insufficient dietary intake to meet metabolic requirements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is malabsorption?

A

Disorder of the digestive tract resulting in the inability to utilise an appropriate dietary intake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Explain the process of carbohydrate digestion

A
  1. Begins in mouth with salivary amylase
  2. Acidic pH of stomach destroys salivary amylase
  3. Starches not already broken down are cleaved by pancreatic amylase in pancreatic juice
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where are sucrose, lactose and maltose digested?

A

In the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Maltose is digested by which enzyme?

A

Maltase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sucrose is digested by which enzyme?

A

Sucrase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Lactose is digested by which enzyme?

A

Lactase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do monosaccharides pass from the lumen of the SI through the apical membrane?

A

Via facilitated diffusion (fructose) or active transport coupled with Na+ (glucose and galactose)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain the process of protein digestion

A
  1. Begins in stomach with pepsin
  2. Enzymes in pancreatic juice (trypsin, chymotrypsin, carboxypeptidase and elastase) continue to break down proteins into peptides
  3. Protein digestion is completed by two peptidases in the brush border into amino acids
    - Amino acids are absorbed by active transport in the duodenum and jejunum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain the process of fat digestion

A
  1. Lipids combine with bile salts to form emulsification droplets
  2. These are digested by lipase to form FFAs (monoglycerides) and bile salts
  3. These combine to form micelles
  4. Micelles transport poorly soluble monoglycerides to the surface of enterocytes to be absorbed
  5. Monoglycerides are absorbed once freely dissolved (micelles are not absorbed)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the three types of exocrine cells in the stomach glands?

A
  1. Mucous neck cells: secrete mucous
  2. Parietal cells: produce intrinsic factor and HCl
  3. Chief cells: secrete pepsinogen and gastric lipase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

G cells secrete what?

A

Gastrin which stimulates gastric acid secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the role of cholecystokinin?

A

IT is released from the duodenum and stimulates secretion of pancreatic juice, contraction of the gall bladder, relaxed sphincter of Oddi and contraction of pyloric sphincter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the role of secretin?

A

Secreted from S cells in the glands of the small intestine, it stimulates the flow of pancreatic juice rich in HCO3- to buffer acidic chyme
- It inhibits secretion of gastric juice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which enzymes are released from the pancreas (exocrine function)?

A
  1. Amylase
  2. Lipase
  3. Proteolytic enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Role of bile?

A

Emulsifies fats

Micelle formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is absorbed in the jejunum?

A

Macronutrients

- Absorb sugars, amino acids, and fatty acids

18
Q

What is absorbed in the ileum

A

Bile acids and vitamin B12

19
Q

Give an example of a luminal disease of the SI

A
  • Infections

- Bacterial overgrowth

20
Q

Give examples of mucosal diseases of the SI

A

Loss of absorptive surface area

  • Crohn’s
  • Surgery
  • Lymphoma

Degradation of absorptive surface area
- Coeliac

21
Q

Major causes of malabsorption: luminal - infections?

A
  • Giardiasis - Bloat, steatorrhoea
  • TB 
  • Ancylostoma - Fe deficient
  • Tripheryma whippelii - Subtotal villous atrophy
  • Cryptosporidium, microsporidium, isospera (AIDS)
22
Q

Major causes of malabsorption: luminal - bacterial overgrowth?

A

 - High folate, low B12
 - Jejunal diverticulosis
 - Blind loop syndrome - Surgical, fistulation
 - Obstruction
 - Motility disorders - Autonomic neuropathy (diabetes), scleroderma
 - Hypochlorhydria in the elderly
 - Miscellaenous

23
Q

Major causes of malabsorption: mucosal - coeliac?

A
  • Gluten enteropathy
  • Immune mediated
  • Subtotal villous atrophy
  • Crypt hyperplasia
  • Intraepithelial lymphocytes
  • Loss of surface area and villus maturation
  • Autoantibodies
24
Q

Substrate deficiency in coeliac disease?

A
  1. Fe deficiency
  2. Folate deficiency
  3. Osteomalacia
25
Q

Cause of malabsorption: Mucosal: terminal ileal surgery

A 
Bile salt malabsorption
Bile salt catharsis
B12 malabsorption
Megaloblastic anaemia
Peripheral neuropathy
Optic atrophy
Dementia
SACD
26
Q

Causes of malabsoprtion: biliary disease

A
  1. Obstructed biliary drainage - intrahepatic and extrahepatic
  2. ADEK malabsorption - coagulopathy, osteomalacia, ataxia, night blindness, xerophthalmia
27
Q

Causes of malabsorption: pancreatic disease

A
  1. Chronic pancreatitis - alcohol

2. Tumours - obstructing the pancreatic duct, Zollinger-Ellison syndrome

28
Q

What are the different types of malnutrition?

A
  1. Protein-energy malnutrition (PEM)
    - Developing world
    - Developed world
  2. Specific nutrient malnutrition
    - Vitamin deficiency
29
Q

Explain the different types of PEM in the developing world (Kwashiorkor vs Marasmus)

A
  1. Predominantly protein lack = KWASHIORKOR

2. Total dietary lack (caloric) = MARASMUS

30
Q

Explain the different clinical manifestations for marasmus PEM

A
  1. Growth failure
  2. Apathy
  3. Diarrhoea
  4. Hepatomegaly
  5. Muscle wasting
  6. Oedema
  7. Anaemia
  8. Stomititis
31
Q

What are different causes of PEM in the developed world

A
  1. Anorexia - suppression of appetite
  2. Neglect
  3. Dysphagia
  4. Increased metabolic demands - thyrotoxicosis
31
Q

What are different causes of anorexia in the developed world?

A
  1. Malignancy (cytokines)
  2. Infection/inflammation - TB, AIDS
  3. Anorexia nervosa
32
Q

What are different causes of neglect in the developed world?

A
  1. Elderly
  2. Hospitalised
  3. Neurological disease
33
Q

What are different types of vitamins seen in specific malnutrition deficiencies?

A
  1. Iron
  2. Vitamin B
  3. Folic acid
  4. Vitamin D
  5. B12
  6. Vitamin C
  7. Vitamin K
34
Q

Clinical manifestations and causes for iron deficiency

A

Microcytic, hypochromic anaemia

  • Menses
  • Vegetarians
35
Q

Clinical manifestations and causes for Vitamin B deficiency

A

Neuropathy (B6)
Cardiomyopathy and encephalopathy (B1)
Stomatitis (B2)
Pellagra (niacin)

  • Alcoholics
36
Q

Clinical manifestations and causes for folic acid deficiency

A

Megaloblastic anaemia

  • Pregnancy
  • Neural tube defects (NTD)
37
Q

Clinical manifestations and causes for vitamin D deficiency

A

Osteomalacia

  • Indian sub-continent
  • lack of UV
38
Q

Clinical manifestations and causes for B12 deficiency

A 
Megaloblastic anaemia
Neuropathy
SACD
Ataxia
Dementia
39
Q

Clinical manifestations and causes for vitamin C deficiency

A

Scurvy

40
Q

Clinical manifestations and causes for vitamin K deficiency

A

Coagulopathy

Gastrointestinal pathophysiology (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions