Intestinal pathology (wk 4) Flashcards

1
Q

List the components of the small intestine

A

o Duodenums
o Jejunum
o Ilium

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

List the components of the large intestine

A
o	Caecum
o	Ascending colon
o	Transverse colon
o	Descending colon
o	Sigmoid Colon
o	Rectum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the function of the digestive system?

A

Digestion and absorption

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

What is the function of bile?

A

It is an emulsifier

Further absorption

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

What is the function of pancreatic enzymes?

A

Further breakdown of food into smaller units

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

What is classified as diarrhoea?

A

When faeces is more than 500ml

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

What are some functions of microorganisms?

A

Assist digestion
Produce vitamins
Compete for space/nutrition/oxygen

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

What are the 4 general layers seen in the intestine?

A

Mucosa
Submucosa
Muscle
Serosa

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

T/F:

Mature B and T cells are found in Peyer’s Patches

A

False

They are naive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T/F:

B and T cells in the villi are mature

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T/F:

Intra epithelial lymphocytes are mostly CD4 T cells

A

False

Mostly CD8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

T/F:

Lamina Properia Lymphocytes are mostly CD4 and B cells

A

True

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

Which cranial nerve innervates the gut?

A

Vagus nerve

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

What is the function of the muscular layer?

A

Peristalsis

Makes sure contents move from proximal to distal

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

What predominantly covers villi?

A

Mature absorptive enterocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

T/F:

Villi are long lived

A

False

• Live only for a few days, die and are shed into the lumen to be digested and absorbed

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

What are crypts?

A

moat-like invaginations of the epithelium around the villi, and are lined largely with younger epithelial cells which are involved primarily in secretion

• Toward the base of the crypts are stem cells, which continually divide and provide the source of all the epithelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which part of the villi is most crucial for absorption?

A

Tip ;)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the function of crypts?

A

o Secrete ions and water,
o Delivery IgA
o Anti-microbial peptides to the lumen,
o Serve as the site for cell division and renewal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T/F:

Plasma cells in the intestine are mostly IgM positive

A

False
Mostly IgA positive
Then IgG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

T/F:

Small intestine is mostly involved in reclaiming luminal water and electrolytes

A

False
Large intestine is mostly involved in reclaiming luminal water and electrolytes
Small intestine is more focused on absorption of nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

T/F:

There are villi in the colonic mucosa

A

False
No villi
Flat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

T/F:

The intestinal mucosa is the most vulnerable site for pathogenic invasion

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe what happens when an antigen enters the area

A

Antigen is taken to Peyer’s patch by an antigen presenting cell to activate B and T cells

Drains through lymph nodes and through the blood circulation

Lymphocytes come back to the gut using a homing mechanism (express a molecule that matches the mucosa adhesion molecule ligand in the gut)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why do children experience rotavirus more than adults?

A

Their immune system isn’t as developed as adults

Therefore more susceptible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

T/F:

Rotavirus is a wheel-like virus and is an opportunistic pathogen

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

T/F:

Rota virus is enveloped and unstable in the environment

A

False
no envelope
Stable in environment

dsRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the most common cause of severe diarheoa in children?

A

Rota virus

29
Q

List some symptoms of rota virus

A

Fever
Vomiting
watery poop
Abdominal pain

30
Q

How is rota virus transmitted?

A

Fecal-oral route

Ingestion of contaminated food/water

31
Q

How can you diagnose someone with rota virus?

A

Rapid antigen detection in stool specimens

Enzyme immunoassay

RT-PCR

32
Q

What barrier does rota virus face in the intestine?

A

Inhospitable gastric environment

33
Q

Describe some of the hisopathological changes when someone is infected with rota virus

A

Notable changes in mucosal surfaces
Villi are shortened, blunted, appear atrophic

Enterocytes become cuboidal
Lamina propria is infiltrated with mononuclear cells

34
Q

List some symptoms of inflammatory bowel disease

A
  • Abdominal cramps and pain
  • Diarrhea
  • Weight loss
  • Fecal bleeding
35
Q

T/F:

Irritable bowel syndrome belongs to the Inflammatory Bowel Disease Family

A

False

Not the same

36
Q

What are the two types of inflammatory bowel disease?

A

Ulcerative colitis

Chron’s disease

37
Q

T/F:

Inflammatory bowel disease is a short term disease

A

False
long term
can start as early as 10 years old

38
Q

What are some possible causes of inflammatory bowel disease?

A

• Genetic factors (HLA-DR1/DQw5…)

• Environmental factor
o Pollution, pesticides etc
o Need individual susceptibility
o Ie. Need genetics + environmental factors

• Dysregulated immune response

Not really too sure

39
Q

T/F:

Inflammatory bowel disease consists of too much anti-inflammatory and not enough pro-inflammatory

A

False

Too much pro-inflammatory

40
Q

There are 3 types of possible treatments people use to assist living with inflammatory bowel disease
what are they?

A

• Anti-inflammatory drugs
o Used to decrease the inflammation caused by the disease, e.g. anti-TNF

• Immunosuppressive agents
o To restrain the immune system from attacking the body’s own tissues and causing further inflammation

• Probiotics
o IBD patients have disturbed gut flora
o 10% of patients feel much better after this treatment

41
Q

Describe some macroscopic observations you might see when looking at the colon of a patient suffering chron’s disease

A
Pus
Abcess
Thickened intestinal wall
Narrow lumen
Exudate
Blood
42
Q

Why might people lose weight if they suffer chron’s disease?

A

Inflammation is energy hungry combined with the fact that they aren’t absorbing nutrients efficiently

43
Q

What are some microscopic features of Chron’s disease?

A
Architecture destroyed
Thickened
Reduced epithelial cells (ulceration) 
Vascularisation 
Leukocyte accumulation
Loose connective becomes solid 
Granuloma forms 
Fissure/splitting due to chronic inflammation
No cryps
Neutrophil infiltration
44
Q

Which parts of the digestive system does Ulcerative collitis affect?

A

Descending colon and sigmoid colon

45
Q

What are some macroscopic observations you can make about ulcerative collitis?

A
Diffuse
Hemorrhage
Lack of intestinal folds= bad absorption, causes diarrhea
Ulceration
Pseduopolyps
46
Q

What are some microscopic features of ulcerative collitis?

A

No cryps
Chronic inflammation
New vascularization particularly in sub mucosa (it should be loose connective)
Only really affects 2 layers (chron’s affects 4 layers)
Lymphoid aggregates
Submucosa gradually becomes solid
Plasma cells, neutrophils, macrophages
Muscle and serosa layers are not affected

47
Q

T/F:

Ulcerative collitis is transmural

A

False

Only affects mucosa and submucosa

48
Q

T/F:

Granulomas are seen in ulcerative collitis

A

False

They are seen in Chron’s disease

49
Q

What is an issue with surfically removing parts of the intestine in patients suffering ulcerative collitis?

A

The disease affects descending colon and sigmoid colon so you lose a direct link to the anus

50
Q

T/F:

You can survive without eating foods with fat in them

A

False

Need in moderation

51
Q

What is malansorption?

A

• Malabsorption is difficulty in the digestion or absorption of nutrients from food substances from the small intestine

52
Q

What is gastritis?

A

struggle to digest the food

53
Q

If you cant digest food you can’t ____ food

A

absorb

54
Q

What are the two common forms of malabsorption?

A

• Protein-energy malnutrition
o Inadequate availability or absorption of energy and proteins in the body
o Not often seen in Australia
o Seen more in rural areas, Africa

• Micronutrient malnutrition
o Inadequate availability of some essential nutrients (vitamins & trace elements) that are required by the body in small quantities
o People on ships travelling long distances= lack of vitamin c, noticed they were bleeding a lot

55
Q

List some of the main causes of malabsorption

A

• Celiac disease (next slide)
• Liver disease
o Cirrhosis, hepatitis, and gallstones
o Cirrhosis from alcohol abuse or viral (makes it nodule)
o Gallstone: compromises your absorption, disturbs bile production (this is needed for absorption)
• Cystic fibrosis
• Lactose intolerance
o Primary and Secondary forms
o Lack lactase and can’t break down lactose
• Chronic pancreatitis
o Need pancreatic enzymes for digestion
o Enzymes break things down into smaller constituents
• Inflammatory bowel disease (previous lecture)
• Intestinal infections (Bacterial or parasitic)
o You are competing with the microorganism
o They’ve already inflamed your digestive system
o They absorb nutrients before you get a chance to
• Specific medications that affect the intestines
• Surgery of the stomach or bowels
o Removal of parts of the stomach/bowels/pancreas may compromise digestion/absorption

56
Q

How may a gall stone contribute to malabsorption?

A

Disrupts bile production which is needed for absorption

57
Q

A patient is diagnosed with coeliac disease. What kinds of symptoms may they be experiencing?

A

loose stools, flatulence, abdominal discomfort and distensionstools are bulky, malodorous and often difficult to flush
villous atrophy

58
Q

If you take a histological sample and the sample appears quite dark (H and E stain) what does this mean?

A

Lots of nuclei are being stained

Cellular infiltration

59
Q

What happens when villi are ‘flat tip’

A

‘flat tip’= reduce surface area, decreases absorption efficiency

60
Q

What is B12 essential for and what is its main source?

A

• Essential for normal nervous system function and blood cell production (RBCs)
• The main sources of vitamin B12
o Eggs & dairy products

61
Q

T/F:

B12 can be absorbed without any additional factors

A

False

Needs an intrinsic factor to be absorbed by the body

62
Q

Pernicious anemia is caused by ______ deficiency

A

Vitamin B12

  • It would show up on a blood test because of the large immature red blood cells that are present.
  • These large red blood cells are very inefficient at carrying oxygen
63
Q

R-binder is produced by ____

A

saliva

64
Q

Explain how B12 is absorbed

A

B12 enters the body bound to a protein
In the stomach, pepsin separates B12 from the protein and now the R-binder (produced by the saliva) can bind to B12
In the duodenum, the pancreas will secrete enzymes and R-binder will release from B12
The stomach produces an intrinsic factor and it binds to B12
The terminal ilieum has receptors for the intrinsic factor
B12 can now be absorbed

65
Q

T/F:

R Binder is produced by the stomach

A

False

Produced by the saliva

66
Q

T/F:

The pancreas produces an intrinsic factor that binds to B12 to allow for its absorption

A

False

the stomach produces the intrinsic factor

67
Q

How would pancreatitis affect the absorption of B12?

A

don’t have enzymes to break down R-binder and B12, then B12 can’t bind to intrinsic factor produced by the stomach

68
Q

What does the stomach produce in terms of B12 absorption?

A

Produces pepsin to break apart B-12 from the protein

Produces an intrinsic factor to bind to B12

69
Q

What are some symptoms of B12 deficiency?

A
•	Anemia
•	Fatigue
•	Weakness
•	Constipation 
o	Nerve deficiency/nerve development deficiency
o	Don’t send good messages to the gut

• Loss of appetite
o When you’re sick you don’t feel like eating
o Can be psychological

• Weight loss
o Don’t have an appetite
o Struggle to absorb nutrients