Brainscape's Knowledge GenomeTM

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


See full index

NME > microscopic anatomy of the gut > Flashcards

microscopic anatomy of the gut Flashcards

1
Q

What type of mucosal epithelium lines the esophagus?

A

The esophagus is lined by non-keratinizing squamous epithelium.

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

What are the features of the mucosal epithelium in the esophagus?

A

he mucosal epithelium in the esophagus is considered a wear and tear epithelium due to its constant exposure to mechanical stress.

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

What type of mucosal epithelium lines the stomach?

A

The stomach is lined by glandular epithelium, which includes columnar and cuboidal cells.

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

What are the features of the mucosal epithelium in the stomach?

A

The glandular epithelium of the stomach secretes mucous, enzymes, and hormones with a variety of functions.

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

What type of mucosal epithelium lines the small bowel?

A

: The small bowel is lined by glandular epithelium, primarily composed of columnar and goblet cells.

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

What are the features of the mucosal epithelium in the small bowel?

A

The mucosal epithelium in the small bowel has a villous architecture, which maximizes the absorptive surface area.

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

What is the function of the large bowel and rectum?

A

The large bowel and rectum are involved in the absorption of water and the formation of feces.

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

What type of mucosal epithelium lines the large bowel and rectum?

A

: The large bowel and rectum are lined by glandular epithelium, primarily composed of columnar and goblet cells.

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

What are the features of the mucosal epithelium in the large bowel and rectum?

A

he mucosal epithelium in the large bowel and rectum has a flat architecture and secretes mucous.

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

What type of mucosal epithelium lines the anus?

A

The anus is lined by a mixture of glandular and squamous epithelium.

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

What are the features of the mucosal epithelium in the anus?

A

The anus has complex anatomy and sphincter functions, involving both glandular and squamous epithelial components.

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

What are the key features of the large bowel and rectum?

A

The large bowel and rectum are the archetypal examples of the gastrointestinal tract. They have the following key features:

Glandular epithelium composed of columnar cells and goblet cells.
Glands in the large bowel and rectum resemble straight test tubes arranged neatly in a rack.
There are some site variations, such as the presence of lymphoid follicles in the appendix.
The anus represents the junction of squamous and glandular mucosa.

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

What does the mucosa of the colon/rectum consist of?

A

The mucosa of the colon/rectum consists of two main components: the epithelium and the lamina propria (LP).

The epithelium is composed of columnar cells and goblet cells.
Glands, also known as crypts of Lieberkühn, open onto the luminal surface of the bowel.
The gland bases rest on the muscularis mucosae (MM).

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

What is the significance of inflammatory cells within the mucosal surface of the colon?

A

Inflammatory cells within the lamina propria of the colon are considered normal. However, the presence of neutrophils in the mucosal surface is always considered pathological and not typically seen in this picture.

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

What can be observed at the base of the crypts in the colon?

A

In the colon, cells appear darker at the base of the crypts. Additionally, scattered neuroendocrine cells can be found in this region.

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

What is the location of the submucosa in the colon/rectum?

A

The submucosa (SM) is located between the muscularis propria (MP) and the mucosa (M) in the colon/rectum.

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

What is the muscular layer responsible for the proper wall of the colon?

A

: The muscularis propria (MP) is considered the “proper” wall of the colon.

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

What is the histological appearance of the appendix?

A

The appendix is a blind-ending tube attached to the base of the cecum. It has the same histological appearance as the large bowel and rectum, with the addition of a variable number of lymphoid follicles.

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

What are the layers observed in the appendix’s tip?

A

The layers observed in the tip of the appendix are the lamina propria (LP), submucosa (SM), muscularis propria (MP), and serosa.

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

What are the layers observed in the appendix’s histology?

A

The layers observed in the histology of the appendix are the lumen, lamina propria (LP), submucosa (SM), muscularis propria (MP), and serosa.

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

What are the key features of the anal canal?

A

The key features of the anal canal include the presence of glandular and non-keratinizing squamous epithelium adjacent to each other, a flat architecture, and the absence of a serosal surface as it lacks peritoneal covering.

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

What types of epithelium are present in the anal canal?

A

The anal canal contains both squamous epithelium and glandular epithelium.

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

What is the transition point between the two types of epithelium in the anal canal?

A

The transition between squamous epithelium and glandular epithelium in the anal canal occurs roughly at the level of the dentate line, although it may not be a perfect correlation.

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

What is the histological appearance of the anal mucosa?

A

The anal mucosa consists of squamous epithelium and glandular epithelium.

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

What are the key features of the small bowel?

A

The key features of the small bowel include the presence of glandular epithelium consisting of columnar cells, goblet cells, and Paneth cells. It has a structural architecture characterized by villi and crypts, which maximize the absorptive area. Minor site variations include the presence of Brunner’s glands in the duodenum and Peyer’s patches in the ileum.

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

What is the histological composition of the small bowel mucosa?

A

The small bowel mucosa consists of epithelium and lamina propria. The epithelium is composed of columnar cells, goblet cells, and Paneth cells.

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

What are the structures present in the small bowel villi and crypts?

A

The small bowel villi are finger-like projections that increase the surface area for absorption. The crypts of Lieberkuhn are invaginations between the villi that contain stem cells for epithelial cell renewal.

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

What are the functions of Paneth cells in the small bowel?

A

Paneth cells, present throughout the small bowel, secrete antimicrobial peptides and enzymes involved in the digestion of proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are lacteals in the small bowel?

A

Lacteals are blind-ending lymphatic vessels located within each villus of the small bowel. They play a role in the absorption of dietary fats.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are plicae circularis in the small bowel?

A

Plicae circularis, also known as valvulae conniventes, are macroscopic mucosal folds in the small bowel. They increase the surface area for absorption but are not directly related to individual villi seen microscopically.

31
Q

What are the components of the small bowel villus?

A

The small bowel villus consists of enterocytes (columnar absorptive cells) and goblet cells. These cells are supported by the lamina propria.

32
Q

: What is the role of mucin in the small bowel?

A

Mucin is a glycosylated protein produced by epithelial tissues. Mucin stains can show the presence of goblet cells and the brush border, which is composed of microvilli on the surface of enterocytes.

33
Q

What is the brush border in the small bowel?

A

The brush border refers to the microvilli-covered surface of enterocytes in the small bowel. It increases the surface area for absorption and enzymatic activity.

34
Q

What is the function of Paneth cells in the small bowel crypts?

A

Paneth cells are secretory epithelial cells located at the base of the crypts throughout the small bowel. They contain granules that contain α-defensins, lectins, and lysozyme. Paneth cells have various functions, including their role in innate immunity and maintaining stem cell renewal.

35
Q

What is the composition of the small bowel submucosa?

A

The small bowel submucosa is composed of loose connective tissue. It contains structures such as blood vessels, lymphatics, and fat.

36
Q

What is the outermost layer of the small bowel wall?

A

The outermost layer of the small bowel wall is the serosa. It provides a protective covering for the underlying structures.

37
Q

What is the unique feature of the duodenum compared to the rest of the small bowel?

A

The duodenum, in addition to having the same overall structure as the rest of the small bowel, contains Brunner’s glands.

38
Q

Where are Brunner’s glands located?

A

Brunner’s glands are located in the submucosa of the duodenum.

39
Q

Describe the histology of Brunner’s glands.

A

Brunner’s glands are a collection of glands in the submucosa of the duodenum. They are composed of cuboidal to columnar cells with clear cytoplasm and basal nuclei. The glands open into the crypts of Lieberkuhn. Scattered endocrine cells can also be found within Brunner’s glands.

40
Q

What is the function of Brunner’s glands?

A

Brunner’s glands secrete an alkaline fluid and mucin. This alkaline fluid helps neutralize the acidic content coming from the stomach, providing protection to the small bowel mucosa.

41
Q

What is a Peyer’s patch?

A

A Peyer’s patch is a lymphoid aggregate or follicle found within the mucosa and submucosa of the ileum.

42
Q

What is the function of Peyer’s patches?

A

Peyer’s patches are part of the Mucosal Associated Lymphoid Tissue (MALT) and play a role in immune defense. They contain lymphoid tissue that helps monitor and respond to antigens within the intestinal lumen.

43
Q

What is the parenchyma of the liver composed of?

A

The parenchyma of the liver is formed from hepatocytes arranged in cords or plates.

44
Q

What are the components of the portal tract (triad)?

A

The portal tract, also known as the triad, contains a branch of the portal vein (PV), a branch of the hepatic artery (HA), and a bile duct (BD).

45
Q

What are the basic units of the liver?

A

The basic units of the liver are lobules and acini. Lobules are formed from hepatocyte cords and are interconnected to form the liver structure.

46
Q

What is zonal heterogeneity in the liver?

A

Zonal heterogeneity refers to the fact that different zones within the liver perform different metabolic functions. These zones, often referred to as Zone 1, Zone 2, and Zone 3, have varying metabolic activities and oxygen supply.

47
Q

What does a reticulin stain of the liver highlight?

A

A reticulin stain of the liver highlights the liver cords, central veins (CV), and portal tracts (PT) by highlighting the delicate connective tissue that supports the liver cords.

48
Q

What is the normal staining pattern of reticulin in the liver?

A

: The normal staining pattern of reticulin in the liver shows well-defined cords or plates surrounded by reticulin fibers. This staining pattern helps visualize the normal structure and organization of the liver tissue.

49
Q

What is the ultrastructure of the liver?

A

The ultrastructure of the liver includes various components such as hepatocytes, sinusoids, central veins (CV), portal tracts (PT), spaces of Disse, stellate cells, Kupffer cells, endothelial cells, and the canal of Herring. Blood flows from the portal tract to the central vein in the sinusoids, and bile is formed by hepatocytes and flows towards the portal tract in bile canaliculi between hepatocytes.

50
Q

What is the oxygen tension difference between Zone 1 and Zone 3 of the liver?

A

Zone 1 of the liver has a high oxygen tension, while Zone 3 has a low oxygen tension. This zonal heterogeneity in oxygen supply contributes to the metabolic functions and characteristics of different liver zones.

51
Q

What is the Space of Disse in the liver?

A

The Space of Disse is a small space or gap between hepatocytes and sinusoidal endothelial cells in the liver. It contains reticulin fibers and is involved in the exchange of substances between hepatocytes and the blood.

52
Q

What is the role of hepatocytes in the liver parenchyma?

A

Hepatocytes are the main functional cells of the liver parenchyma. They perform various metabolic functions, including synthesis and storage of glycogen, production of bile, detoxification of substances, and metabolism of nutrients and drugs.

53
Q

How is glycogen storage demonstrated in hepatocytes?

A

Glycogen storage in hepatocytes can be demonstrated using special stains. The cytoplasm of hepatocytes appears bright pink as it contains glycogen. This staining technique helps visualize the presence and distribution of glycogen in liver tissue.

54
Q

What are Kupffer cells in the liver?

A

Kupffer cells are specialized macrophages located within the sinusoids of the liver. They play a role in the immune response and are involved in the phagocytosis of foreign substances, microorganisms, and damaged cells. Kupffer cells have elongated or triangular nuclei and their cytoplasm is difficult to see.

55
Q

What is the function of the central vein in the liver?

A

The central vein receives blood from the sinusoids of the liver lobules. It serves as a drainage vessel for the blood that has passed through the liver tissue. The central veins eventually join together to form hepatic veins, which carry deoxygenated blood out of the liver.

56
Q

How is bile formed and transported in the liver?

A

Bile is formed by hepatocytes in the liver. It is secreted into bile canaliculi, which are small channels formed by adjacent hepatocyte cell membranes. The bile canaliculi collect and transport bile towards the portal tract, where they join and become progressively larger. Eventually, the bile canaliculi empty into the bile duct via the Canal of Hering.

57
Q

How are bile canaliculi visualized in liver histology?

A

Bile canaliculi are not typically visible on routine hematoxylin and eosin (H&E) staining in normal liver histology. However, they can be highlighted using immunohistochemical staining techniques. These techniques utilize specific antibodies to target and stain proteins or structures associated with bile canaliculi, allowing their visualization in brown stain between hepatocytes.

58
Q

What is the liver capsule composed of?

A

The liver capsule is a thin collagenous capsule that surrounds the liver. It is mostly covered with visceral peritoneum. The liver capsule provides structural support and protection to the liver. Collagen fibers, which appear as a red stain in histological slides, make up the composition of the liver capsule.

59
Q

What are the components of a portal tract (triad) in the liver?

A

The components of a portal tract, also known as a triad, in the liver include a branch of the portal vein (PV), a branch of the hepatic artery (HA), and a bile duct (BD). These structures play important roles in supplying blood and nutrients to the liver and transporting bile.

60
Q

What are the key features of portal tracts in liver histology?

A

Portal tracts have a distinct appearance in liver histology. They are characterized by the presence of connective tissue and stroma, a crisp interface with surrounding hepatocytes, and the varying size and shape of the structures within them. The largest structure in a portal tract is the portal vein, followed by the smaller hepatic artery and bile duct. The bile ducts have a tubular structure lined with cuboidal to columnar epithelium.

61
Q

How can immunohistochemistry be helpful in identifying bile ducts?

A

Immunohistochemistry techniques can be used to specifically target and stain proteins or markers associated with bile ducts. This can help in visualizing and identifying the bile ducts in liver histology slides. Immunohistochemistry can be particularly useful in cases of cholangitis or cholangiopathy, which affect the bile ducts.

62
Q

What is the main function of hepatocytes in the liver?

A

Hepatocytes are the main constituent of the liver and perform multiple functions. They form the hepatic cords or plates within the liver and are responsible for various metabolic activities, including protein synthesis, detoxification, storage of nutrients, and bile production.

63
Q

What is an alternative name for Kupffer cells?

A

Kupffer cells, which are macrophages found in the liver, are also known as sinusoidal macrophages or stellate sinusoidal macrophages. They are located within the sinusoids and play a role in phagocytosis of particulate matter, antigens, microorganisms, and aged red blood cells.

64
Q

Where are stellate cells located in the liver and what are their functions?

A

Stellate cells, also known as Ito cells, fat-storing cells, or hepatic lipocytes, are located in the Space of Disse, which is the space between hepatocytes and sinusoidal endothelial cells. They are responsible for storing vitamin A and have a role in the production of extracellular matrix, including collagen deposition in conditions such as cirrhosis.

65
Q

What are the components of a portal tract (triad) in the liver?

A

A portal tract, also known as a triad, is a collagenous tract within the liver that contains three structures: branches of the hepatic artery, portal vein, and bile duct (interlobular). These structures play important roles in supplying blood, nutrients, and bile to the liver.

66
Q

What is the function of the Canals of Hering in the liver?

A

The Canals of Hering are structures within the liver that transmit bile from the canalicular system, located between the hepatocytes, to the biliary system (bile ducts) within the portal tract. These canals are formed from both hepatocytes and cholangiocytes and also contain hepatic stem cells.

67
Q

What is the role of the central vein in a liver lobule?

A

The central vein is a thin-walled vein that is seen centrally within a liver lobule. It receives blood from the sinusoids and ultimately forms the hepatic vein, which carries deoxygenated blood out of the liver. The central vein plays a crucial role in the drainage of blood from the liver lobule.

68
Q

What is the limiting plate in the liver?

A

The limiting plate refers to the hepatocytes that are directly adjacent to the portal tract, forming a ring around it. It serves as a boundary between the portal tract and the hepatic cords, and its presence can be appreciated on histological sections of the liver.

69
Q

What are the components of the exocrine pancreas?

A

The exocrine pancreas consists of acini (clusters of cells) and ducts. These structures are responsible for producing and secreting digestive enzymes such as amylase, lipase, and proteases.

70
Q

What are the components of the endocrine pancreas?

A

The endocrine pancreas consists of specialized clusters of cells called Islets of Langerhans. These islets contain different types of cells that secrete hormones, including insulin, glucagon, and somatostatin.

71
Q

What are the components of the pancreas?

A

The pancreas has a lobular architecture and is composed of lobules that contain acini (clusters of acinar cells) and ducts. It is surrounded by fine connective tissue septae and contains fat, blood vessels, and nerves.

72
Q

What are the main features of pancreatic acini?

A

Pancreatic acini are triangular-shaped structures composed of 5-10 acinar cells. The nuclei of these cells are basally oriented, and they contain zymogen granules in the cytoplasm, which are apically oriented. Centroacinar ducts, the beginnings of the pancreatic duct system, are also present in the middle of the acinus.

73
Q

What is the function of pancreatic ducts?

A

Pancreatic ducts, which are part of the exocrine pancreas, carry secreted enzymes from the acini. They are formed from cuboidal to columnar epithelial cells and vary in caliber, branching out like a tree.

74
Q

What are the main features of the Islets of Langerhans in the pancreas?

A

The Islets of Langerhans in the pancreas contain neuroendocrine cells with round, pale cytoplasm and a central round nucleus with stippled chromatin. These cells are associated with capillaries to directly secrete hormones into the bloodstream. On H&E staining, it is not possible to differentiate between α, β, and δ cells. The Islets of Langerhans are sharply demarcated from the acinar cells.

NME (49 decks)

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