Brainscape's Knowledge GenomeTM

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


See full index

M: DS > Lecture 12 > Flashcards

Lecture 12 Flashcards

1
Q

What is the majority of the small intestine suspended by?

A

Mesentery

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

What are the circular folds in the small intestine called?

A

Plicae circularis

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

What is the evaginating part of the small intestine wall called?

A

Villus

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

What is the invaginating part of the small intestine wall called?

A

Intestinal gland or Crypt of Lieberkuhn

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

What is the function of the smooth muscle found in the core of the villus?

A

Smoth muscle contraction produces rhythmic beating of villi that is enhanced during digestion. Ensures maximal exposure of luminal contents with epithelial cells. Milks lacteal contents along.

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

What can happen to the blood supply to the small intestine in the elderly?

A

Decreased blood circulation leads to decreased absorption, which can lead to malabsorption and malnutrition

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

On which surface of epithelial cells are microvilli found?

A

Apical

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

What is the function of microvilli?

A

Increased SA for absorption and digestion

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

How does contraction of the smooth muscle in the lamina propria lead to mixing at the epithelial cells in the small intestine?

A

Actin filaments are inbedded in the microvilli and are connected to cytoskeleton filaments in the cell. When the smooth muscle contracts, this moves the basement membrane, which moves the epithelial cell above it. This is transferred to the cytoskeleton, which is transferred to the actin filaments, leading to localised mixing of the contents.

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

What is the glycocalyx? What is it made up of?

A

Slippery film made up of many glycoproteins and acidic mucopolysaccharides

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

What is the function of the glycocalyx?

A

Selective gatekeeper: attracts desirable and blocks unwanted molecules.

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

What are the functions of the goblet cells?

A

Help lubricate the surface

May contribute to glycocalyx layer

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

Do goblet cells have microvilli on their apical surfaces?

A

NO

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

Where are enteroendocrine cells found in the small intestine?

A

Deeper in crypts of Lieberkuhn but spread out.

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

Where are undifferentiated cells found in the small intestine?

A

In the gland region. Migrate upwards and downwards to replace cells.

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

Where are Paneth cells found in the small intestine?

A

Cul de sac region

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

What is the function of Paneth cells?

A

Important for antiviral and antibacterial functions

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

What are the 3 substances that Paneth cells produce?

A

TNF-alpha: Produces inflammation in response to bacteria and parasites
Lysozyme: Bactericidal, destroys bacterial membranes
Defensins: Increases ion channels in cell membranes of invading organisms, increasing permeability

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

Where are the enteroendocrine cell hormones released?

A

Liberated through basal lamina into capillaries of lamina propria

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

How long is the duodenum?

A

25 cm

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

What are the distinguishing features of the duodenum?

A

C-shaped

Brunner’s glands in submucosa

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

How long is the jejunum?

A

2.5 m

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

What is the distinguishing feature of the jejunum?

A

Increased plicae and therefore increased villi

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

How long is the ileum?

A

3.5 m

25
Q

What are the distinguishing features of the ileum?

A
  • Massive, macroscopically visible lymphatic aggregates called Peyer’s patches.
  • Plicae not as pronounced
26
Q

Describe Peyer’s patches

A

Centre of B cells surrounded by M cells that are antigen-sensing.

27
Q

How long is the large intestine?

A

1.5 m

28
Q

What are the functions of the large intestine?

A

Major absorptive role

Minor digestive role

29
Q

What is the function of the ileocaecal valve?

A

Regulates passage of materials into caecum

30
Q

What are the functions of the caecum?

A

Collects and stores the arriving materials and begins the process of compaction

31
Q

Describe the appendix

A

Slender, hollow, vermiform, dominated by lymphoid nodules.

32
Q

Describe the mucosal epithelium of the large intestine

A
  • Smooth. No plicae or villi

- Mucosal glands are numerous

33
Q

What is another name for the mucosal glands found in the colon?

A

Crypts of Lieberkuhn

34
Q

What are the two predominant cell types found in the mucosal glands? What are their functions?

A

• Columnar absorptive cells (similar to the enterocytes of the small intestine):
- absorb water & electrolytes
- absorb vitamins produced by bacteria (B & K)
• Goblet cells: secrete mucus for lubrication.

35
Q

What other cells are found in the Crypts of Lieberkuhn of the large intestine?

A
  • Enteroendocrine cells occur, but are not visible in routine sections with the light microscope
  • Undifferentiated cells found at base of glands
36
Q

Describe the lamina propria of the colon

A
  • Contains a dense layer of collagen immediately beneath the surface epithelium
  • Also numerous lymphatic nodules (GALT / MALT - gut or mucosa associated lymphatic tissue) extending down into the submucosa.
37
Q

Why is the rate of metastasis from some colon cancers relatively slow?

A

No lymphatic vessels drain the lamina propria until the level of the muscularis mucosae is reached

38
Q

Describe the muscularis externa of the colon

A

Circular and longitudinal layers present. Outer longitudinal layer forms three distinctbands running along the colon (teniae coli)

39
Q

What is the function of the teniae coli?

A
  • Allow segments of the colon to contract independently

* Contraction pulls the intestinal tube into sac-like pockets (haustra coli)

40
Q

What is the outermost layer of the large intestine?

A

Adventitia occurs on the posterior surface of the large intestine; elsewhere serosa.

41
Q

What is the purpose of the rectum/anus?

A

Temporary storage of faecal matter

42
Q

What triggers the urge to defecate?

A

Movement of material in the rectum

43
Q

What is the final portion of the large intestine called? What does the mucosa of this region contain?

A

Anal canal: mucosa contains longitudinal folds called anal columns

44
Q

What do the transverse folds of the anal canal mark?

A

Boundary between columnar epithelium and stratified squamous

45
Q

Distinguish between the muscle types of the anal sphincters

A

Internal sphincter: smooth muscle

External sphincter: skeletal muscle

46
Q

What is at the end of the anal canal?

A

Anus

47
Q

Where are the stem/germinative cells located in the oes?

A

Basal part of the epithelium

48
Q

What is the replacement rate of cells in the oes?

A

Days - quite frequent due to shearing forces

49
Q

Where are the stem/germinative cells located in the stomach?

A

Near the neck of gastric galnds

50
Q

What is the replacement rate of cells in the stomach?

A

Surface/superficial: days
Deeper: months
Parietal and chief cells cost a lot to replace as they are specialised and are found deep within glands, so are protected from acid

51
Q

Where are the stem/germinative cells located in the small intestine?

A

Lower 1/2 of glands (Crypts of Lieberkuhn)

52
Q

What is the replacement rate of cells in the small intestine?

A

Surface: days
Deeper: months

53
Q

Where are the stem/germinative cells located in the large intestine?

A

Lower 1/3 of glands (Crypts of Lieberkuhn)

54
Q

What is the replacement rate of cells in the large intestine?

A

Days

55
Q

What is the function of columnar absorptive cells?

A

Absorb the small molecules resulting from digestion

56
Q

What is another name for columnar absorptive cell?

A

Enterocytes

57
Q

What is the membrane of columnar absorptive cells studded with?

A

Digestive enzymes such as glycosidase, which is involved with carbohydrate digestion

58
Q

What are the cells found in the mucosa of the SI?

A 
Columnar absorptive
Goblet
Enteroendocrine
Undifferentiated
Paneth

M: DS (29 decks)

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