Brainscape's Knowledge GenomeTM

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


See full index

Step 1 > Gastrointestinal > Flashcards

Gastrointestinal Flashcards

1
Q

What do the foregut, midgut, and hindgut develop into, respectively?

A

Foregut - esophagus to upper duodenum
Midgut - lower duodenum to proximal 2/3 of transverse colon
Hindgut - distal 1/3 of transverse colon to anal canal above pectinate line

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

What are the two key steps in midgut development and when do they occur?

A

6th week - physiologic midgut herniates through the umbilical ring
10th week - returns to abdominal cavity + rotates around superior mesenteric artery (SMA) - 270 degrees counterclockwise

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

The pancreas is derived from the ___. The spleen is derived from the ___, but has ___ supply.

A

Foregut; mesentery of the stomach (mesodermal); foregut (celiac trunk -> splenic artery)

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

Ventral and dorsal pancreatic buds contribute to which parts of the pancreas, respectively?

A

Ventral -> uncinate process and main pancreatic duct
Dorsal -> body, tail, isthmus, and accessory pancreatic duct
Both -> pancreatic head

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

What are the retroperitoneal structures?

A 
Suprarenal (adrenal) glands
Aorta and IVC
Duodenum (2nd through 4th parts)
Pancreas (except tail)
Ureters
Colon (descending and ascending)
Kidneys
Esophagus (thoracic portion)
Rectum (partially)

SAD PUCKER

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

List the 6 important GI ligaments.

A
  1. Falciform
  2. Hepatoduodenal
  3. Gastrohepatic
  4. Gastrocolic
  5. Gastrospenic
  6. Splenorenal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the falciform ligament connect and what structures does it contain?

A

The falciform ligament connects the liver to the anterior abdominal wall. It contains the ligamentum teres hepatis (derivative of fetal umbilical vein).

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

What does the hepatoduodenal ligament connect and what structures does it contain?

A

The hepatoduodenal ligament connects the liver to the duodenum. It contains the portal triad (proper hepatic artery, portal vein, common bile duct)

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

What does the gastrohepatic ligament connect and what structures does it contain?

A

The gastrohepatic ligament connects the liver to the lesser curvature of the stomach. It contains the gastric arteries.

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

What does the gastrocolic ligament connect and what structures does it contain?

A

The gastrocolic ligament connects the greater curvature of the stomach to the transverse colon. It contains the gastroepiploic arteries.

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

What does the gastrosplenic ligament connect and what structures does it contain?

A

The gastrosplenic ligament connects the greater curvature of the stomach to the spleen. It contains the short gastrics and left gastroepiploic vessels.

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

What does the splenorenal ligament connect and what structures does it contain?

A

The splenorenal ligament connects the spleen to the posterior abdominal wall. It contains the splenic artery and vein and the tail of the pancreas.

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

What are the components of the greater omentum?

A
  1. Gastrocolic ligament

2. Gastrosplenic ligament (separates greater and lesser sacs on the left)

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

What are the components of the lesser omentum?

A
  1. Gastrohepatic ligament (separates greater and lesser sacs on the right)
  2. Hepatoduodenal ligament (borders the omental foramen which connects the greater and lesser sacs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which ligament is compressed in the Pringle maneuver to control bleeding?

A

Hepatoduodenal

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

What are the layers of the gut wall from inside to outside?

A
  1. Mucosa (epithelium, lamina propria, muscularis mucosa)
  2. Submucosa (submuocsal glands that secrete fluid and Meissner plexus)
  3. Muscularis externa (inner circular layer, Auerbach, aka myenteric, plexus, outer longitudinal layer)
  4. Serosa (when intraperitoneal) or adventitia (when retroperitoneal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the difference between an erosion and an ulcer in the gut?

A

Ulcers can extend into the submucosa, inner, or outer muscular layer

Erosions are in the mucosa only

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

Unique histology of the esophagus?

A

Nonkeratinized stratified squamous epithelium

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

Unique histology of the stomach?

A

Gastric glands

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

Unique histology of the duodenum?

A 
Villi and microvilli (increase absorptive surface)
Brunner glands (secrete bicarbonate), crypts of Lieberkuhn (stem cells that replace enterocytes/goblet cells, Paneth cells that secerete defensins, lysozyme, and TNF)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Unique histology of the jejunum?

A

Plicae circulares (also in the distal duodenum) and crypts of Lieberkuhn

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

Unique histology of the ileum?

A 
Peyer patches (lymphoid aggregates in the lamina propria, submucosa), plicae circularies (proximal ileum), crypts of Lieberkuhn
Largest number of goblet cells in the SI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Unique histology of the colon?

A

Crypts of Lieberkuhn, but no villi; abundant goblet cells

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

Where is the plicae circulares found?

A

Distal duodenum to the proximal ileum

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

Where are the crypts of Lieberkuhn found?

A

Small and large intestines

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

Arteries supply Gi structures branch ___. Arteries supplying non-GI structures branch ___.

A

Anteriorly; laterally and posteriorly

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

Branches of the aorta at T12?

A

Inferior phrenic
Superior suprarenal
Middle suprarenal
Celiac

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

Branches of the aorta at L1/L2?

A

SMA
Renal -> inferior suprarenal
Gonadal

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

Branches of the aorta at L3?

A

IMA

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

Location of aortic artery bifurcation into the iliac arteries?

A

L4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

For each embryonic gut region (foregut, midgut, and hindgut), state the correlating arterial and nervous supply, and the vertebral level.

A

Foregut - celiac, vagus, T12/L1

Midgut - SMA, vagus, L1

Hindgut - IMA, pelvic, L3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does the celiac artery supply?

A

Lower esophagus to proximal duodenum

Liver, gallbladder, pancreas, spleen (mesoderm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does the SMA supply?

A

Distal duodenum to proximal 2/3 of transverse colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does the IMA supply?

A

Distal 1/3 of transverse colon to upper portion of rectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the branches of the celiac trunk?

A

Common hepatic
Splenic
Left gastric

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the major anastomoses of the celiac trunk?

A

L and R gastroepiploics

L and R gastrics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

List the major sites of portosystemic anastomoses.

A
  1. Esophagus
  2. Umbilicus
  3. Rectum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

List the anastomosing veins at the major sites of portosystemic anastomoses.

A
  1. Left gastric <> azygos
  2. Paraumbilical <> small epigastric veins of the anterior abdominal wall
  3. Superior rectal <> middle and inferior rectal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the pectinate (dentate) line?

A

Where the endoderm (hindgut) meets the ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What pathologies are found above the pectinate line?

A

Internal hemorrhoids, adenocarcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What pathologies are found below the pectinate line?

A

External hemorrhoids, anal fissures, squamous cell carcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Compare the arterial supply above and below the pectinate line.

A

Above: superior rectal artery (branch of IMA)
Below: inferior rectal artery (branch of internal pudendal artery)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Compare the venous supply above and below the pectinate line.

A

Above: superior rectal vein -> inferior mesenteric vein -> splenic vein -> portal vein
Below: inferior rectal vein -> internal pudendal vein -> internal iliac vein -> common iliac vein -> IVC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Compare the lymphatic drainage above and below the pectinate line.

A

Above: internal iliac lymph nodes
Below: superficial inguinal lymph nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

The apical surface of hepatocytes faces ___. The basolateral surface faces ___.

A

Bile canaliculi; sinusoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What forms the lining of the sinusoids in the liver?

A

Kupffer cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What cells are found in the space of Disse in the liver?

A

Hepatic stellate (Ito) cells - store vitamin A (when quiescent) and produce extracellular matrix (when activated)

48
Q

What affects zone 1 first (periportal zone)?

A

Viral hepatitis

49
Q

What affects zone 2 (intermediate zone)?

A

Yellow fever

50
Q

What affects zone 3 first (pericentral/centrilobular zone)?

A

Ischemia (also the site of alcoholic hepatitis)

51
Q

Compare the effects of ingested toxins (eg, cocaine) and metabolic toxins on the zones of the liver.

A

Ingested toxins affect zone 1; metabolic toxins affect zone 3

52
Q

Where is the cytochrome P450 system found in the liver?

A

Zone 3

53
Q

What is contained in the femoral triangle?

A

Femoral nerve, artery, and vein

54
Q

What is contained in the femoral sheath and where is it located?

A

3-4 cm below inguinal ligament

Contains femoral vein, artery, and canal (deep inguinal lymph nodes), but NOT the femoral nerve

55
Q

Where is a femoral nerve block given?

A

Inguinal crease at the lateral border of the femoral artery

56
Q

What are the locations of the internal (deep) and external (superficial) inguinal rings?

A

Internal - lies in transversalis fascia, just lateral to the inferior epigastric vessels

External - triangular opening in the external oblique aponeurosis that lies just lateral to the pubic tubercle

57
Q

What are the anterior boundaries of the inguinal canal?

A

Anterior - aponeuroses of external oblique and internal oblique muscles

58
Q

What are the posterior boundaries of the inguinal canal?

A

Posterior - aponeurosis of transversus abdominis muscle and transversalis fascia

59
Q

What are the inferior boundaries of the inguinal canal?

A

Inguinal and lacunar ligament

60
Q

What are the contents of the spermatic cord?

A
  1. Fascia
  2. Arteries
  3. Nerves
  4. Other
61
Q

What are the fascial components of the spermatic cord?

A
  1. Internal spermatic fascia (frome transversalis fascia)
  2. Cremasteric fascia and muscle (from internal oblique fascia)
  3. External spermatic fascia (from external oblique fascia)

(ICE tie)

62
Q

What are the components of the inguinal (hesselbach) triangle?

A

Inferior epigastric vessels
Lateral border of rectus abdominis
Inguinal ligament

63
Q

What is the source and action of gastrin?

A

G cells (antrum of stomach, duodenum)

Increase gastric acid secretion, growth of gastric mucosa, and gastric motility

64
Q

What is the source and action of somatostatin?

A 
D cells (pancreatic islets and GI mucosa)
Decrease gastric acid and pepsinogen scretion, pancreatic and SI fluid secretion, gallbladder contraction, insulin and glucagon release
65
Q

What is the source and action of cholecystokinin?

A 
I cells (duodenum and jejunum)
Increase pancreatic secretion, gallbladder contraction, decrease gastric emptying, increase relaxation of the sphincter of Oddi
66
Q

What is the source and action of secretin?

A

S cells (duodenum)

Increase pancreatic bicarbonate secretion, decrease gastric acid secretion, increase bile secretion

67
Q

What is the source and action of glucose-dependent insulinotropic peptides?

A 
K cells (duodenum and jejunum)
Exocrine - decrease gastric acid secretion
Endocrine - increase insulin release
68
Q

What is the source and action of motilin?

A

Small intestine

Produces migrating motor complexes (MMCs)

69
Q

What is the source and action of vasoactive intestinal polypeptide (VIP)?

A

Parasympathetic ganglia in sphincters, gallbladder, SI

Increase intestinal water and electrolyte secretion, increase relaxation of intestinal smooth muscle and sphincters

70
Q

What is the action of NO?

A

Increase smooth muscle relaxation (including the LES)

71
Q

What is the source and action of ghrelin?

A

Stomach

Increase appetite

72
Q

What is the source and action of IF?

A

Parietal cells (stomach)

Vitamin B12 binding protein (required for uptake in terminal ileum)

73
Q

What is the source and action of gastric acid?

A 
Parietal cells (stomach)
Decrease stomach pH
74
Q

What is the source and action of pepsin?

A 
Chief cells (stomach)
Protein digestion
75
Q

What is the source and action of bicarbonate?

A

Mucosa cells (stomach, duodenum, salivary glands, pancreas) and Brunner glands (duodenum)

Neutralizes acid

76
Q

How is gastrin regulated?

A

Increased by stomach distention/alkalinization, amino acids, peptides, vagal stimulation via gastrin-releasing peptide

Decreased by pH < 1.5

77
Q

How is somatostatin regulated?

A

Increased by acid

Decreased by vagal stimulation

78
Q

How is CCK regulated?

A

Increased by fatty acids and amino acids

79
Q

How is secretin regulated?

A

Increased by acid, fatty acids in lumen of duodenum

80
Q

How are glucose-dependent insulinotropic peptides regulated?

A

Increased by fatty acids, amino acids, oral glucose

81
Q

How is motilin regulated?

A

Increased in fasting state

82
Q

How is VIP regulated?

A

Increased by distention and vagal stimulation, decreased by adrenergic input

83
Q

How is ghrelin regulated?

A

Increased in fasting state, decreased by food

84
Q

How is gastric acid regulated?

A

Increased by histamine, ACh, gastrin

Decreased by somatostatin, GIP, prostaglandin, secretin

85
Q

How is pepsin regulated?

A

Increased by vagal stimulation, local acid

86
Q

How is bicarbonate regulated?

A

Increased by pancreatic and biliary secretion with secretin

87
Q

What cell types are found in the body of the stomach?

A

Parietal and chief cells

88
Q

What cell types are found in the antrum of the stomach?

A

D cells, G cells, mucus cells

89
Q

What cell types are found in the duodenum?

A

I, K, and S cells

90
Q

Why is secretin-mediated bicarbonate release important for pancreatic enzyme function?

A

The increased bicarbonate neutralizes gastric acid in the duodenum, allowing pancreatic enzymes to function

91
Q

What is the primary mechanism by which gastrin increases acid secretion?

A

Effects on enterochromaffin-like (ECL) cells, leading to histamine release; NOT through direct effect on parietal cells

92
Q

What ion is high in pancreatic secretions with low flow? With high flow?

A

Low flow - high Cl-

High flow - high HCO3-

93
Q

What are the major enzymes secreted from the pancreas?

A
  1. Alpha-amylase
  2. Lipase
  3. Protease
  4. Trypsinogen
94
Q

What is the role of alpha-amylase?

A

Starch digestion

95
Q

Which pancreatic enzyme is secreted in its active form?

A

Alpha-amylase

96
Q

What are the proteases secreted from the pancreas?

A

Trypsin, chymotrypsin, elastase, carboxypeptidase (secreted as proenzymes, aka zymogens)

97
Q

How are pancreatic enzymes activated?

A

Trypsinogen is converted to trypsin by enterokinase/enteropeptidase, a brush-border enzyme on the duodenal and jejunal mucosa; trypsin converts all other proenzymes

98
Q

What types of carbohydrates are absorbed by enterocytes?

A

Only monosaccharides - glucose, galactose, fructose

99
Q

How are carbohydrates absorbed?

A

SGLT1 - glucose and galactose (Na+ dependent)
GLUT5 - fructose (facilitated diffusion)
GLUT2 - all are transported to the blood via this

100
Q

What is the purpose of the D-xylose absorption test?

A

Distinguishes GI mucosal damage form other causes of malabsorption

101
Q

What are the key sites of vitamin and mineral absorption in the small intestine?

A

Duodenum - iron (absorbed as Fe2+)
Jejunum - folate
Terminal ileum - B12, bile salts

102
Q

What are the components of bile?

A

Bile salts (bile acids conjugated to glycine or taurine, making them water soluble), phospholipids, cholesterol, bilirubin, water, and ions

103
Q

What catalyzes the rate-limiting step of bile acid synthesis?

A

Cholesterol 7-alpha hydroyxlase

104
Q

What are the functions of bile?

A
  1. Digestion and absorption of lipids and fat-soluble vitamins
  2. Cholesterol excretion (primary means of doing so)
  3. Antimicrobial activity (membrane disruption)
105
Q

Explain bilirubin metabolism.

A
  1. In macrophages, RBCs are converted to heme. Heme is converted to biliverdin via heme oxygenase. Biliverdin is reduced to unconjugated bilirubin.
  2. In the blood, albumin binds unconjugated bilirubin and brings it to the liver.
  3. in the liver, unconjugated bilirubin is converted to conjugated bilirubin by UDP-glucuronosyl-transferase (conjugated with glucuronate).
  4. In the gut, conjugated bilirubin is converted to urobilinogen via gut bacteria. 80% is excreted in the feces as stercobilin (brown color of stool). Of the remaining 20%, 10% is excreted in the urine as urobilin (yellow color of urine). 90% is recycled to the liver via enterohepatic circulation.
106
Q

What is the major difference between unconjugated and conjugated bilirubin?

A

Unconjugated (indirect) bilirubin - water insoluble

Conjugated (direct) bilirubin - water soluble

107
Q

List the enzymes released in liver damage.

A
  1. Aspartate aminotransferase (AST)
  2. Alanine aminotransferase (ALT)
  3. Alkaline phosphatase
  4. Gamma-glutamyl transpeptidase
108
Q

What is indicated by changes in AST and ALT?

A

Increased in most liver disease, ALT>AST
Increased in alcoholic liver disease AST>ALT
AST>ALT in nonalcoholic liver disease suggests progression to advanced fibrosis or cirrhosis

109
Q

What is indicated by changes in alkaline phosphatase?

A

Increased in cholestasis (eg, biliary obstruction), infiltrative disorders, bone disease

110
Q

What is indicated by changes in gamma-glutamyl transpeptidase?

A

Increased in various liver and biliary diseases (just as ALP can), but not in bone disease; associated with alcohol use

111
Q

List the functional liver markers.

A
  1. Bilirubin
  2. Albumin
  3. Prothrombin time
  4. Platelets
112
Q

What is indicated by changes in bilirubin?

A

Increased in various liver disease (eg, biliary obstruction, alcoholic or viral hepatitis, cirrhosis), hemolysis

113
Q

What is indicated by changes in albumin?

A

Decreased in advanced liver disease (marker of liver’s biosynthetic function)

114
Q

What is indicated by changes in prothrombin time?

A

Increased in advanced liver disease (decreased production of clotting factors, thereby measuring the liver’s biosynthetic function)

115
Q

What is indicated by changes in platelets?

A

Decreased in advanced disease (decreased thrombopoietin, liver sequestration) and portal hypertension (splenomegaly/splenic sequestration)

Step 1 (19 decks)

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