Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Gastro-intestinal System > The Intestines And Inflammatory Bowel Disease > Flashcards

The Intestines And Inflammatory Bowel Disease Flashcards

(84 cards)

Start Studying
1
Q

What are the main roles of the intestines?

A

Absorb nutrients
Water
Electrolytes

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

What are the basic cells of the intestine?

A

Enterocytes

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

What are plicae circulares?

A

Valvular flaps projecting into the lumen of the small intestine

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

Why is mucus in the gut important?

A

Keeps the bacteria away from the cells

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

How often is mucosa shed in the gut?

A

3-6 days

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

Describe the cells in intestinal glands

A

Stem cells at the base - migrate to surface as they mature
Enteroendocrine - release hormones
Paneth cells - protection against infection

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

What types of carbohydrates can be absorbed?

A

Monosaccharides

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

Where does the final breakdown of carbohydrates occur?

A

In the brush border of the gut

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

What are the monosaccharides?

A

Fructose
Galactose
Glucose

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

What are the common dietary carbohydrates?

A

Starch
Lactose
Sucrose

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

What are the 2 parts of starch?

A

Amylose (20%)

Amylopectin (80%)

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

What type of bonds make the straight chains in starch?

A

Alpha 1, 4 glycosidic

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

What type of bonds make the branching chains in starch?

A

Alpha 1, 6 glycosidic

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

Which bonds does amylase break?

A

Alpha 1, 4 glycosidic

Usually cleaves at the ends of straight chains

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

What are alpha dextrins?

A

Smaller units from starch that still contain branches

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

Which enzyme breaks alpha 1,6 glycosidic bonds?

A

Isomaltase

This enzyme has many different names

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

Which enzymes are found in the brush border?

A

Maltase
Isomaltase
Lactase
Sucrase

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

Describe SGLT-1

A

Sodium glucose transporter
Na/K/ATPase sets up the gradient
On apical membrane
Cotransports glucose or galactose with Na+ into enterocyte

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

Describe GLUT-5

A

On the apical membrane

Transports fructose into the enterocytes

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

Describe GLUT-2

A

Basolateral membrane
All the monosaccharides pass through this into the blood
Down their concentration gradients

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

Describe the idea behind oral rehydration methods

A

Uptake of Na+ generates osmotic gradient so water follows
Glucose uptake stimulates Na+ uptake
A mixture of glucose and salt will stimulate maximum water uptake

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

What kinds of peptides can be absorbed in the gut?

A

Amino acids
Dipeptides
Tripeptides

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

Describe the first part of protein digestion

A

In the stomach, acid unravels proteins
Pepsinogen secreted from chief cells
Converted to pepsin by HCl
Pepsin breaks down proteins

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

Trypsinogen is converted to trypsin by …

A

Enteropeptidase (on brush border)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Which pancreatic protease activates all the other proteases?
Trypsin
26
How do exopeptidases work?
Break bonds at ends of polypeptides | Produces dipeptides/amino acids
27
How do endopeptidases work?
Break bonds in middle of polypeptides | Produce shorter polypeptides
28
Name an exopeptidase
Carboxypeptidase
29
Name 3 endopeptidases
Trypsin Chymotrypsin Elastase
30
Why can newborns absorb whole proteins?
Needed to help immunity etc when breast feeding
31
How are amino acids transported into cells?
Na+ amino acid transporter
32
How are most protein products absorbed?
As dipeptides or tripeptides Via H+ co-transporter (PepT 1) Inside the cells, further broken down into amino acids
33
Which hormone induces the Na+ channels in the large intestine?
Aldosterone
34
What is the difference in absorption when calcium is normal/high and when it is low?
``` Normal/high = calcium absorbed passively paracellular Low = active transcellular absorption (facilitated diffusion apical and pumped out of basolateral by Ca-ATPase) ```
35
How is iron absorbed?
Haem/Fe2+ | Cotransported with H+ (why gastric acid is important to this)
36
What happens to iron when iron levels are low?
Binds to transferrin | Transported to stores
37
What happens to iron when levels are high?
Contained in ferritin complexes Trapped inside enterocyte Can be transported out if we need it Lost when enterocyte is shed
38
How is iron stored in the body?
Approx 1/2 is in Hb | Approx 1/2 stored in ferritin complexes in bone marrow, liver and spleen
39
How are water soluble vitamins absorbed?
Via Na+ cotransport
40
How is vitamin B12 absorbed?
In the terminal ileum | Bound to intrinsic factor (secreted by parietal cells)
41
B12 deficiency leads to ...
Megaloblastic anaemia
42
How does the small intestine ensure caudal drive of contents?
Intestinal pacemakers have higher frequencies proximally Intestinal gradient set up Drives the contents caudally Peristaltic contractions
43
What is segmentation?
Contents move back and forth on a particular area Shuttling to increase the contact time Aid absorption
44
What is mass movement?
Occurs 1-3 times a day Contents move rapidly from transverse colon to rectum Often triggered by eating (gastro-colic reflex)
45
What are haustra?
In the large intestine Formed because the longitudinal muscle (taenia coli) is not the complete length Forms pouches
46
When do we get the urge to defaecate?
Stretch receptors activated | When rectum is 25% full
47
Describe the internal and external anal sphincters
Internal - smooth muscle, PNS control | External - striated/skeletal muscle, voluntary control
48
How do we defaecate?
Relax both the internal and external anal sphincters | Increase intra-abdominal pressure
49
What are inflammatory bowel diseases?
A group of conditions characterised by idiopathic inflammation of the GI tract (affecting the function of the gut)
50
What are the 2 most common IBDs?
Crohn's disease | Ulcerative colitis
51
What are the peak ages for Crohn's disease?
15-30 years | 60 years
52
What is the peak age for UC?
Young adults
53
What is diversion colitis?
Inflammation distal to a surgical cut through the bowel
54
What is microscopic colitis?
Can only see the inflammatory changes on histology
55
Where does Crohn's affect?
Anywhere in the GI tract | Ileum involved in most cases
56
Which IBD is more likely to be transmural?
Crohn's | Through all layers of bowel wall
57
Which IBD presents with skip lesions?
Crohn's
58
Where does UC commonly affect?
Begins in rectum | Can extend to involve entire colon
59
Which IBD is found in a continuous pattern?
UC
60
Which IBD usually just has mucosal (superifical) inflammation?
UC
61
Name some extra-intestinal problems linked to IBDs
MSK pain - arthritis Erythemanodosum, pyoderma gangrenosum, psoriasis Primary sclerosing cholangitis Eye problems
62
What things can trigger the start of an IBD?
Antibiotics Infections Smoking Diet
63
Describe Crohn's and the affect on the body
Inflammation in area that would normally absorb nutrients More water left in the gut lumen - diarrhoea Weight loss due to not absorbing enough Terminal ileum involvement - vita B12 deficiency - megaloblastic anaemia Hyperaemia Mucosal oedema
64
Which IBD is more likely to present with strictures?
Crohn's
65
Which IBD can give a cobblestone appearance?
Crohn's
66
What is a cobblestone appearance?
Areas of oedema surrounded by ulceration
67
Where can the bowel form fistulae to?
Other parts of bowel Bladder Vagina Skin
68
What microscopic evidence signifies Crohn's disease?
Granulomata
69
How would we investigate for Crohn's disease?
Bloods - anaemia CT/MRI - bowel wall thickness, obstruction, extramural problems Barium enema (less likely) and xray Colonoscopy - biopsy - histology
70
Is UC more common in males or females?
Females
71
Describe some general features of UC
Pain tends to be less localised than Crohn's Always in rectum Inflammatory infiltrate of lamina propria Crypt abscesses and distortion Decreased goblet cells - less mucus so loss of protection Loss of haustra
72
Which IBD is more likely to have crypt distortion?
UC
73
Which IBD has a decreased production of mucus?
UC
74
Describe the investigations for UC
``` Bloods - anaemia, serum markers Stool cultures Plain abdominal x-ray CT/MRI Colonoscopy Barium enema ```
75
What do we call cases that cannot be classed as either Crohn's or UC?
Indeterminate colitis
76
In which IBD is bleeding more common?
UC
77
Which IBD is more likely to present with perianal disease?
Crohn's
78
In which IBD is fibrosis more common?
Crohn's
79
In which IBD is the mucosa friable? (Delicate)
UC
80
What would you see using radiology for Crohn's?
Lots of narrowing in the lumen of gut Lots of distortion due to inflammation and healing 'String sign of Cantour'
81
What would you see in the radiology for UC?
Lead pipe colon (featureless bowel - no haustra) | Contrast medium may adhere to walls of bowel - see the continuous ulceration
82
What are the treatment options for IBDs?
Stepwise 1. Aminosalicylates for flares and remission 2. Corticosteroids for flares only (avoid long term) 3. Immunomodulators for extreme cases, fistulae and maintenance of remission 4. Surgery
83
Describe the surgery for Crohn's
Not curative Fix strictures/fistulae Remove as little bowel as possible
84
Describe the surgery for UC
Can be curable Colectomy usually Dramatically reduces/eradicates disease process

Gastro-intestinal System (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions