Lower GI Tract Flashcards
1
Q
What are the 3 regions of the small intestine?
A
Duodenum
Jejunum
Ileum
2
Q
What are the proximal and distal boundaries of the small intestine?
A
Pyloric sphincter
Ileocecal valve
3
Q
What structure covers the small intestine anteriorly?
A
Greater omentum
4
Q
What are the proximal and distal borders of the duodenum?
A
Distal to pylorus
Duodenojejunal junction
5
Q
Which of the 3 regions is the shortest in the small intestine?
A
Duodenum
6
Q
What embryonic structure does the duodenum derive from?
A
Foregut
7
Q
Trace the path of the gastroduodenal artery
A
Celiac trunk –> common hepatic artery –> gastroduodenal artery
8
Q
Trace the path of the superior pancreaticoduodenal artery
A
Celiac trunk –> common hepatic artery –> gastroduodenal artery –> superior pancreaticoduodenal artery
9
Q
What 2 arteries supply the duodenum?
A
Gastroduodenal
Pancreaticoduodenal
10
Q
How many parts of the duodenum are there?
A
4
11
Q
Which part(s) of the duodenum is/are intraperitoneal?
A
ONLY the 1st part
12
Q
Which part(s) of the duodenum is/are retroperitoneal?
A
2nd
3rd
4th
13
Q
I am part of the duodenum covered by mesentery. Which part am I?
A
1st part (It's the only intraperitoneal one)
14
Q
I am the site of the major duodenal papilla. What am I?
A
2nd part of duodenum
15
Q
Testing my contents reveals bile and pancreatic enzymes. What am I?
A
2nd part of duodenum
16
Q
I am a part of the duodenum that travels posteriorly to the SMA. What am I?
A
3rd part
Horizontal
17
Q
What is the relationship between the duodenum and the SMA?
A
3rd part travels posteriorly to SMA
18
Q
What is the Ligament of Treitz?
A
Marks the duodenojejunal junction
19
Q
How would I distinguish between structures deriving from the foregut and midgut?
A
Foregut- everything up to duodenojejunal junction
Midgut- everything after the duodenojejunal junction (and before hindgut)
20
Q
What embryonic structure does the jejunum derive from?
A
Midgut
21
Q
Trace the path of the SMA
A
Abdominal aorta –> SMA
22
Q
Trace the path of the inferior pancreaticoduodenal artery
A
Abdominal aorta –> SMA –> inferior pancreaticoduodenal artery
23
Q
What 2 arteries supply the jejunum?
A
SMA
Inferior pancreaticoduodenal artery
24
Q
Where are all the vessels and nerves to the jejunum and ileum?
A
Within a mesentery
25
What is a mesentery?
2 layers of visceral peritoneum
26
What are the 2 major borders of the mesentery of the jejunum and ileum?
Duodenojejunal junction
| Ileocecal valve
27
I am a region with few vascular arcades. I am?
Jejunum
28
I am a region with very long vasa recta. I am?
Jejunum
29
I am a region with very prominent and numerous plicae circularis. I am?
Jejunum
30
Where does most of the absorption take place?
Jejunum
31
True or False. There is a clear distinction between the jejunum and ileum.
False. They are difficult to distinguish.
32
Which regions of the small intestine contain a mesentery with vessels and nerves?
Jejunum
| Ileum
33
I am a region with numerous vascular arcades. I am?
Ileum
34
I am a region with very short vasa recta. I am?
Ileum
35
True or False. As you move proximally to distally along the ileum, there are more plicae circularis.
False. There are LESS plicae circularis moving distally along ileum.
36
Trace the path of the ileocolic artery.
Abdominal aorta --> SMA --> ileocolic
37
What artery supplies the ileum?
Ileocolic artery
38
Which of the 4 gutters surrounding the ascending and descending colons do NOT drain into the pelvic cavity?
One medial to ascending colon
| It's blocked by small bowel mesentery
39
Rupture of the descending colon leaks blood into the retroperitoneal cavity. Would you expect to find blood in the pelvic cavity?
Yes! There are 2 gutters medial and lateral to descending colon that drain into the pelvic cavity.
40
Efferent nerve supply to the small intestine comes from?
Autonomic nerves
41
Which sympathetic nerves provide efferent innervation to the small intestines?
Thoracic splanchnics
42
What 3 nerves comprise the thoracic splanchnics?
Greater
Lesser
Least
43
Where do the sympathetic efferent nerves to the small intestine synapse?
Preaortic ganglia
44
Where would you expect to find the preaortic ganglia?
Around celiac trunk and SMA
45
Which parasympathetic efferents innervate the small intestine?
Vagus nerve
46
Which 2 embryonic structures does the large intestine derive from?
Midgut
| Hindgut
47
What are the divisions of the colon?
```
Cecum/appendix
Ascending
Transverse
Descending
Sigmoid
Rectum
Anus
```
48
I am a region with 3 longitudinal bands of smooth muscle. What am I? What are the muscles called?
Colon, taeniae coli
49
What forms haustra in colon?
Outpouchings of colon between taenae coli
50
I am a region with fatty blobs covering my outsides. I am?
Colon with appendices epiploicae
51
The 2 flexures of the colon are?
Hepatic flexure- between ascending and transverse
| Splenic flexure- between transverse and descending
52
True or False. The cecum has a mesentery and is intraperitoneal.
Both! The cecum does NOT have a mesentery but it IS intraperitoneal.
53
The ileocecal valve?
Marks junction between ileum and cecum
54
Which artery supplies the cecum?
Ileocolic
55
Which vein drains the cecum?
Superior mesenteric vein
56
Which regions of the colon are intraperitoneal?
Cecum
Transverse
Sigmoid
57
Which regions of the colon are retroperitoneal?
Ascending
| Descending
58
Which regions of the colon are subperitoneal?
Rectum
| Anus
59
The vermiform appendix lies in what orientation to the cecum?
Inferior and medial
60
The 3 taeniae coli merge in which structure?
Vermiform appendix
61
What artery supplies the vermiform appendix?
Ileocolic
62
What vein drains the vermiform appendix?
Superior mesenteric vein
63
Trace the path of the right colic artery
Abdominal aorta --> SMA --> right colic artery
64
What artery supplies the ascending colon?
Right colic
65
What vein drains the ascending colon?
Superior mesenteric vein
66
Where does the transition from the midgut to hindgut occur?
Distal transverse colon but proximal to splenic flexure
67
What are the bounds of the foregut?
All GI tract up to the duodenojejunal junction
68
What are the bounds of the midgut
From the duodenojejunal junction to the distal transverse colon before the splenic flexure
69
What forms the bounds of the hindgut?
Distal transverse colon before splenic flexure to anus
70
The distal transverse colon marks the switch from midgut to hindgut. What else does it mark the transition from (2 things)?
Blood supply from SMA to IMA
| Parasympathetic nerve supply from vagus nerve to pelvic splanchnics
71
Trace the path of the middle colic
Abdominal aorta --> SMA --> middle colic
72
The transverse colon is supplied by which general 2 arteries?
SMA
| IMA
73
The proximal 2/3 of the transverse colon is supplied by which artery?
Middle colic
74
The proximal 2/3 of transverse colon is drained by which vein?
Superior mesenteric vein
75
The distal 1/3 of transverse colon is supplied by which artery?
Left colic artery
76
Trace the path of the left colic artery
Abdominal aorta --> IMA --> left colic
77
The distal 1/3 transverse colon is drained by which vein?
Inferior mesenteric vein
78
Which parasympathetic nerves innervate the transverse colon?
BOTH the vagus nerve AND pelvic splanchnics
79
What artery supplies the descending colon?
Left colic artery
80
What vein drains the descending colon?
Inferior mesenteric vein
81
Trace the path of the sigmoid artery
Abdominal aorta --> IMA --> sigmoid artery
82
What artery supplies the sigmoid colon?
Sigmoid artery
83
What vein drains the sigmoid colon?
Inferior mesenteric vein
84
True or False. The rectum do not have taeniae coli.
True! They have a complete circumferential layer of longitudinal smooth muscle.
85
Name the 7 parts of the foregut
```
Esophagus
Stomach
Part 1 duodenum
Part 2 duodenum
Liver
Gallbladder
Pancreas
```
86
Name the 8 parts of the midgut
```
Part 3 duodenum
Part 4 duodenum
Jejunum
Ileum
Cecum
Appendix
Ascending colon
Proximal 2/3 transverse colon
```
87
Name the 7 parts of the hindgut
```
Distal 1/3 transverse colon
Descending colon
Sigmoid colon
Rectum
Superior anus
Bladder
Urethra
```
88
What supplies the blood to the foregut?
Celiac trunk
89
What supplies the blood to the midgut?
SMA
90
What structures does the ileocolic artery supply?
Cecum
Appendix
Ileum
91
What structures does the right colic artery supply?
Ascending colon
92
What structures does the middle colic artery supply?
Proximal 2/3 transverse colon
93
What is SMA syndrome?
Left renal vein and 3rd part of duodenum lie anterior to abdominal aorta and posterior to SMA and they become squished in really thin females
94
What vein drains the midgut?
Superior mesenteric vein
95
Where does the superior mesenteric vein drain?
Portal vein
96
What artery supplies the hindgut?
IMA
97
What structures does the left colic artery supply?
Distal 1/3 transverse colon
| Descending colon
98
What structures does the sigmoid artery supply?
Sigmoid colon
99
What are the branches of the SMA that supply the midgut?
Ileocolic
Right colic
Middle colic
100
What are the branches of the IMA that supply the hindgut?
Left colic
| Sigmoid
101
What vein drains the hindgut?
Inferior mesenteric vein
102
Trace the path of the inferior mesenteric vein
Inferior mesenteric vein -->splenic vein --> portal vein
103
What forms the anastomosis between the SMA and IMA?
Marginal artery
104
What branches of the SMA and IMA does the marginal artery connect?
Middle colic of SMA to left colic of IMA
105
What structures does the splenic vein drain?
Spleen
| Tail of pancreas
106
What are the sympathetic nerves that supply the foregut, midgut, hindgut? Where do they originate? Where do they synapse?
Foregut- greater splanchnic (T5-T9) to celiac ganglion
Midgut- Lesser and least splanchnics (T10-T12) to superior mesenteric ganglion
Hindgut- lumbar splanchnics (L1-L2) to inferior mesenteric ganglion
107
Where do the greater splanchnics originate and synpase? Which structures do they innervate?
T5-T9
Celiac ganglion
Foregut
108
Where do the lesser and least splanchnics originate? Where do they synapse? What do they innervate?
T10-T12
Superior mesenteric ganglion
Midgut
109
Where do the lumbar splanchnics originate? Synapse? What do they innervate?
L1-L2
Inferior mesenteric ganglion
Hindgut
110
What is the parasympathetic nerve supply to the foregut, midgut and hindgut?
Foregut- vagus nerve
Midgut- vagus nerve
Hindgut- pelvic splanchnics (S2-S4)
111
Visceral afferent information in the foregut, midgut and hindgut travel via which nerves?
Sympathetic nerves! Along with sympathetic efferents!
Foregut and midgut- thoracic splanchnics
Hindgut- lumbar splanchnics
112
Trace the path of lymphatics in the lower GI system
Superior and inferior mesenteric lymph nodes near aorta --> cisterna chyli --> thoracic duct
113
What 2 embryonic structures does the small intestine derive from?
Foregut
| Midgut
114
The greater thoracic splanchnic nerve originates where?
T5-T9
115
The lesser thoracic splanchnic nerve originates where?
T10-T11
116
The least thoracic splanchnic nerve originates where?
T12
117
Where do the lumbar splanchnic nerves originate?
L1-L4
118
What 3 sympathetic nerves provide sensory innervation to the abdominal wall and parietal peritoneum?
Intercostals
Subcostal
Iliohypogastric
119
What 3 sympathetic nerves provide motor innervation to the muscles of the anterior abdominal wall?
Intercostals
Subcostal
Iliohypogastric
120
The ilihypogastric nerve provides sensory and motor innervation to what structures?
Sensory- skin of anterior ab wall, parietal peritoneum
| Motor- muscles of anterior ab wall
121
The ilioinguinal nerve travels through what structure?
Inguinal canal
122
How does the ilioinguinal nerve enter and exit the inguinal canal?
Enters by piercing through posterior wall
| Exits through superficial ring
123
What sympathetic nerve provides sensory information from the medial skin of the thigh?
Ilioinguinal
124
What sympathetic nerve provides sensory information from the anterior/superior scrotum and labia majora?
Ilioinguinal
125
What 4 sympathetic nerves provides motor information to the muscles of the anterior abdominal wall?
Intercostals
Subcostal
Iliohypogastric
Ilioinguinal
126
What sensory and motor innervation does the ilioinguinal nerve carry?
Sensory- skin of medial thigh, anterior/superior scrotum/labia
Motor- muscles of anterior ab wall
127
The genitofemoral nerve travels in what structure?
Inguinal canal
128
How does the genitofemoral nerve enter the inguinal canal?
Through the deep inguinal ring
129
What nerve provides sensory information from the anterior scrotum/labia?
Genitofemoral
130
What nerve provides motor information to the cremaster muscle?
Genitofemoral
131
What are the sensory and motor actions of the genitofemoral nerve?
Sensory- anterior scrotum/labia
| Motor- cremaster muscle
132
How do the posterior body wall muscles become innervated?
Unnamed muscular branches of the lumbar plexus
