Small Intestine and Large Intestine Flashcards
1
Q
What regulates and coordinates numerous GI tract activities?
A
enteric nervous system
2
Q
What are the activities that the enteric nervous system regulates and controls?
A
- gastric secretory activity
- GI blood flow
- peristalsis
3
Q
Where is the ENS located?
A
between the walls of the GI tract
4
Q
What is generally independent of CNS and receives input from sympathetic and parasympathetic innervation?
A
ENS
5
Q
What is the sympathetic abdominal innervation and associated levels?
A
- greater splanchnic (T5-T9)
- lesser splanchnic (T10-T11)
- least splanchnic (T12)
- lumbar splanchnic (L1-L2/L3)
6
Q
The greater splanchnic nerves run to the (1) ganglion which distribute to the (2)
A
- celiac
- foregut
7
Q
The lesser and least splanchnic nerves run to the (1) and (2) which distribute to the (3)
A
- superior mesenteric ganglion
- aorticorenal ganglia
- midgut
8
Q
The lumbar thoracic splanchnic nerves run to the (1) which distribute to the (2)
A
- inferior mesenteric ganglion
- hindgut
9
Q
The celiac, superior mesenteric, aorticorenal, and inferior mesenteric plexus communicate via what?
A
intermesenteric plexus
10
Q
What is the parasympathetic abdominal innervation and associated postganglionic distribution?
A
- vagus n. (CN X) - foregut and midgut
- pelvic splanchnic (S2-S4) - hindgut
11
Q
Descending sympathetic innervation to the pelvic organs is via what plexuses?
A
superior hypogastric plexuses
12
Q
What receives pelvic splanchnic nn. (parasympathetics)?
A
hypogastric nn (inferior hypogastric plexus)
13
Q
What are the sympathetic activities of the abdominal organs and what do they go to?
A
- vasoconstriction
- decreased peristalsis
- decreased hormonal secretion
- goes to smooth muscle and glands
14
Q
What are the parasympathetic activities of the abdominal organs and what do they go to?
A
- vasodilation
- increased peristalsis
- increased hormonal secretion
- goes to smooth muscle and glands
15
Q
Pre-synaptic sympathetic fibers synapse directly into what?
A
suprarenal gland
16
Q
What travels with sympathetic fibers (GSA)
A
pain (GVA)
17
Q
What is the function of the small intestine?
A
absorption of nutrients
18
Q
What are the parts of the small intestine?
A
- duodenum
- jejunum
- ileum
19
Q
What does the small intestine extend from?
A
from pylorus to ileocecal junction
20
Q
What do the jejunum and ileum contain that increase surface area for absorption?
A
elaborate folds of mucosa
21
Q
What part of the small intestine doesn’t absorb any nutrients?
A
duodenum
22
Q
What vertebral levels does the duodenum travel from?
A
L1 to L3
23
Q
How many parts of the duodenum are there and what are their associated vertebral levels?
A
- 1st: superior part (L1)
- 2nd: descending part (L2-L3)
- 3rd: horizontal part (L3)
- 4th: ascending part (L3)
24
Q
What is the most movable part of the duodenum?
A
superior part (first)
25
What is the very first part of the duodenum called?
duodenal cap (ampulla)
26
What attaches the superior part (1st part) of the duodenum to the porta hepatis of the liver and what is contained in it?
hepatoduodenal ligament:
- portal triad
**common bile duct
**hepatic artery
**portal vein
27
What parts of the duodenum are retroperitoneal?
the 2nd and 3rd part
28
What part of the duodenum attaches to the pancreas?
2nd part
29
What is located in the 2nd part of the duodenum and is where the bile duct + main pancreatic duct connect to the duodenum and drain into?
hepatopancreatic ampulla
30
What is the landmark located halfway along the second part of the duodenum that marks the transition from foregut to midgut?
hepatopancreatic ampulla (ampulla of Vater)
31
The hepatopancreatic ampulla connects to the duodenum via what?
major duodenal papilla
32
What is the opening of the accessory pancreatic duct into the 2nd part of the duodenum?
minor duodenal papilla
33
What part of the duodenum is important for the hepatobiliary tract?
2nd part of the duodenum
34
What does the 3rd part of the duodenum run in front of?
IVC and aorta
35
What runs in front of the 3rd part of the duodenum?
superior mesenteric vessels
36
What is the duodenojejunal junction?
where the 4th part of the duodenum meets and continues as the jejunum
37
What is a thin band of tissue that connects the duodenojejunal junction to the right crus of the diaphragm?
ligament of Treitz
38
What is the ligament of Treitz critical in ruling out?
malrotation of the gut in children
39
A GI bleed above the ligament of Treitz will lead to (1)
vomiting up blood
40
A GI bleed below the ligament of Treitz will lead to (1)
dark, tarry, maybe purplish stool
41
What two arteries supplies the duodenum and what does this mark the transition of?
- celiac trunk via gastroduodenal a
- superior mesenteric artery via inferior pancreaticoduodenal a
**marks transition between foregut and midgut**
42
What branches off the gastroduodenal artery to supply the upper portion of duodenum and head of pancreas?
ant. and post. superior pancreaticoduodenal a
43
What branches off the superior mesenteric artery and supplies the lower portion of the duodenum?
ant. and post. inferior pancreaticoduodenal a
44
What is the direct venous drainage of the duodenum?
hepatic vein
45
What is the indirect venous drainage of the duodenum?
- superior mesenteric vein
- splenic vein
46
The anterior lymphatic vessels of the duodenum drain into the (1) located alone the superior and inferior pancreaticoduodenal arteries and into the (2) which lie along the gastroduodenal artery, and then drains into (3)
1. pancreaticoduodenal lymph nodes
2. pyloric lymph nodes
3. celiac lymph nodes
47
The posterior lymphatic vessels of the duodenum pass posterior to the head of the pancreas and drain into the (1); efferent lymphatic vessels from the duodenal lymph nodes drain into the (2)
1. superior mesenteric lymph nodes
2. celiac lymph nodes
48
What is the parasympathetic innervation of the duodenum?
vagus n
49
What is the sympathetic innervation pathway of the duodenum?
- spinal cord T5-T11
- greater and lesser splanchnic
- celiac and superior mesenteric plexuses
- peri-arterial plexuses extending to pancreaticoduodenal aa
- duodenum
50
What does the jejunum begin at and what part of the small intestine is considered the jejunum?
- begins at duodenojejunal flexure
- proximal 2/5 of intestine
51
Where does the ileum end at and what part of the small intestine is considered the ileum?
- ends at ileocecal junction
- distal 3/5 of intestine
52
What keeps the jejunum and ileum attached to the posterior abdominal wall?
mesentery
53
What is the function of the jejunum?
lipid and protein digestion
54
What are in the jejunum but not in the ileum?
plicae circulares
55
How does the jejunum differ from the ileum?
- thicker walls
- larger diameter
- arteries
56
What is the function of the ileum?
absorption of most digested nutrients
57
What has peyer's patches?
ileum
58
How does the ileum differ from the jejunum?
- thinner walls
- smaller diameter
- arteries
59
What is the caliber of the jejunum in relation to the ileum?
jejunum : greater
ileum : lesser
60
What is the plicae of the jejunum in relation to the ileum?
jejunum : many
ileum : few
61
What is the mesentery length of the jejunum in relation to the ileum?
jejunum : shorter
ileum : longer
62
What is the peyer's patches of the jejunum in relation to the ileum?
jejunum : few
ileum : present
63
What is the vascularity of the jejunum in relation to the ileum?
jejunum : greater
ileum : less
64
What is the length of vasa recta in the jejunum in relation to the ileum?
jejunum : longer
ileum : shorter
65
How many arcades are there in the jejunum in relation to the ileum?
jejunum : few
ileum : many
66
what extends from the duodenojejunal flexure obliquely downwards and to the right to the ileocecal junction?
root of the mesentery
67
What is the arterial supply of the jejunum and ileum?
superior mesenteric artery
- jejunal aa
- ileal aa
68
What are the characteristics of the jejunal aa?
- less arcades
- longer vasa recta
69
What are the characteristics of the ileal aa?
- more arcades
- shorter vasa recta
70
The jejunal and ileal aa unite to form loops or arches, called (1), which give rise to straight arteries, called (2)
1. arterial arcades
2. vasa recta
71
Why are arterial arcades important?
may help maintain arterial perfusion of the gut if the mesentery is twisted or stretched
72
What are the 6 branches of the SMA and mnemonic?
"In my room, I'm in jail"
I: inferior pancreaticoduodenal
M: middle colic
R: right colic
I: ileocolic
I: ileal
J: jejunal
73
What does the inferior pancreaticoduodenal aa supply?
duodenum
74
What does the middle colic a supply?
transverse colon
75
What does the right colic a supply?
ascending colon
76
What does the ileocolic a supply?
- ascending colon
- small portion of ileum
- cecum
77
What do the ileum aa supply?
ileum
78
What do the jejunal aa supply?
jejunum
79
What is the position of the SMV in relation to the SMA?
lies anterior and to the right of the SMA
80
Where does the SMV end?
posterior to the neck of the pancreas
81
What unites to form the hepatic portal vein?
SMV & splenic vein
82
Where are lacteals found?
in intestinal villi (only in the jejunum and ileum)
83
What is the function of lacteals?
absorb fat and drain into lymphatic plexuses in walls
84
What do lacteals drain into?
cisterna chyli
85
What are the 3 groups of lymph nodes in the lymphatic drainage of the jejunum and ileum and what do they drain into?
- juxta-intestinal
- mesenteric
- central superior
**drain into superior mesenteric nodes**
86
Where are juxta-intestinal lymph nodes located?
close to the intestinal wall
87
Where are mesenteric lymph nodes located?
scattered in arterial arches
88
Where are central superior lymph nodes located?
along proximal SMA
89
What do lymph nodes of the terminal ileum drain into?
ileocolic lymph nodes
90
What is the pattern of sympathetic innervation of the jejunum and ileum?
- spinal cord T8-T10
- greater, lesser, least splanchnic nn
- superior mesenteric nerve plexus
- synapse on celiac and superior mesenteric ganglia
- pre-arterial nerve plexuses on SMA branches
91
What provides parasympathetic innervation to the jejunum and ileum (specific trunk)?
- vagus nerve (posterior vagal trunks)
**preganglionic synapse with postganglionic in myenteric and submucosal plexuses in intestinal wall**
92
What type of fibers does the parasympathetic innervation provide to the jejunum and ileum?
intestine sensory fibers (GVA)
93
Intestine sensory fibers (GVA) are (1) to most pain stimuli, including cutting and burning; but are (2) to sudden distention (gas) and transient ischemia from abnormally long contractions (colic, spasmodic abdominal pains)?
1. insensitive
2. sensitive
94
What is the function of the large intestine?
water absorption and create feces
- helps reabsorb electrolytes and makes vitamins
95
Without enough electrolytes, what can happen?
small bowel obstruction
96
What does the large intestine span from?
ileocecal fold to the anus
97
What are the large intestine characteristics?
- omental appendices
- teniae coli
- haustra
- great internal diameter
98
What are small, fatty, omentum-like projects in the large intestine?
omental appendices
99
What is a thickened band of smooth muscle in the large intestine that is absent in the rectum and appendix?
teniae coli
100
What are the sacculations of the wall of the colon between the teniae?
haustra
101
What are the retroperitoneal organs and mnemonic?
SAD PUCKER
S: suprarenal gland
A: aorta/IVC
D: duodenum (2nd and 3rd)
P: pancreas (except tail)
U: ureters
C: colon (ascending/descending)
K: kidneys
E: esophagis
R: rectum
102
What parts of the large intestine are retroperitoneal structures?
- ascending colon
- descending colon
- rectum
103
Most tumors of the large intestine occur in the (1) and (2) or (3)
1. sigmoid colon
2. rectum
3. ascending colon
104
Tumors in the ascending colon are more common among (1) and (2)
- women
- older patients
105
Rectosigmoidal tumors are more common among (1) and (2)
1. men
2. younger patients
106
With suspected GI bleeds, where is a person scoped first and why?
from above because an upper GI bleed is more life threatening
107
The interior of the colon can be observed and photographed in a procedure called (1) or (2)
1. colonoscopy
2. coloscopy
108
The interior of the sigmoid colon is observed with a (1), a shorter endoscope, in a procedure called (2)
1. sigmoidoscope
2. sigmoidoscopy
109
What is a blind-ended pouch in the RLQ that has no mesentery so it may be displaced?
cecum
110
What is suspended from the cecum and contains masses of lymphoid tissues?
appendix
111
What is the portion of mesentery connecting the ileum to the appendix?
meso-appendix
112
What can contain blind diverticulum?
appendix
113
What is found 2/3 of the way from umbilicus to ASIS?
McBurney's point
114
Acute inflammation of the appendix, (1), is a common cause of an acute abdomen
1. appendicitis
115
Digital pressure over the (1) registers maximum abdominal tenderness in appendicitis?
McBurney point
116
What is appendicitis in young people usually caused by?
hyperplasia of lymphatic follicles in appendix that occludes the lumen
117
What is appendicitis in older people usually caused by?
an obstruction from fecalith, a cocreation formed around fecal matter
118
The pain of appendicitis usually commences as vague pain in the (1) because of afferent pain fibers entering the spinal cord at T10 level; later the sever pain transmits to (2) from irritation of parietal peritoneum lining the posterior abdominal wall
1. umbilical region
2. right lower quadrant
119
Acute infection of the appendix may result in (1) in the (2) artery
1. thrombosis
2. appendicular
120
The ascending colon is covered anteriorly and on both sides with (1)
1. peritoneum
121
What is located between the lateral aspect of the ascending colon and adjacent abdominal wall AND extends between right subphrenic space to the pelvis?
right paracolic gutter
122
What is the right colic flexure?
where the ascending colon turns into transverse colon
123
Why are the paracolic gutters clinically important?
allow for passage for infectious fluids from different compartments of abdomen
- ex: fluid from infected appendix can track up to the right paracolic gutter to hepatorenal recess
124
What is found between right and left colic flexures, and is horizontally oriented?
transverse colon
125
What is the transverse colon suspended from the posterior abdominal wall by?
transverse mesocolon
126
What is the most mobile part of the large intestine?
transverse colon
127
What is found between the left colic flexure to the left side of the groin?
descending colon
128
What covers the colon anteriorly and laterally, binding it to the posterior abdominal wall?
peritoneum
129
What is found between the lateral aspect of the descending colon and adjacent abdominal wall?
left paracolic gutter
130
What is "S" shaped, and begins at the pelvic inlet and descends to the level of S3?
sigmoid colon
131
What is the sigmoid attached to the pelvic wall by?
sigmoid mesocolon (mesentery)
132
What does the sigmoid colon have and why it is important?
- considerable freedom of movement
- important because this part of colon can get firm/hard as bowel moves through so you need the sigmoid colon to be able to move around
133
What is the most common site for diverticulitis?
sigmoid colon
134
What is a fixed, retroperitoneal organ that is continuous with the sigmoid colon at S3?
rectum
135
What is the rectum continuous with inferiorly?
anal canal
136
What branches off the aorta at L3?
inferior mesenteric artery
137
What are the 3 branches of IMA?
- left colic a
- sigmoid aa
- superior rectal artery
138
What is the main artery that gives off the marginal artery?
left colic artery
139
What gives off an appendicular artery that is important for the appendix?
ileocolic artery
140
What does the left colic artery supply?
descending colon
141
What do the sigmoidal arteries supply?
sigmoid colon
142
What does the superior rectal artery supply?
rectum
143
What provides collateral circulation to the large intestine?
marginal artery
144
What is the venous drainage of the large intestine?
**portal system of veins**
- superior mesenteric vein
- splenic vein
- inferior mesenteric vein
**portal vein**
- splenic v + SMV; R and L branches
145
What joins the splenic vein and drains blood from the hindgut?
inferior mesenteric vein
146
What is the lymphatic drainage of the cecum and appendix?
lymph nodes in meso-appendix drain to **ileocolic nodes**
147
What is the lymphatic drainage of the ascending colon?
- epicolic and paracolic nodes drain to:
- ileocolic and intermediate right colic nodes which drain to:
- **superior mesenteric nodes**
148
What is the lymphatic drainage of the transverse colon?
- middle colic nodes drain to
- **superior mesenteric nodes**
149
What is the lymphatic drainage of the descending and sigmoid colons?
- epicolic and paracolic drain to intermediate colic nodes which drain to **inferior mesenteric nodes**
- left colic flexure nodes drain to **superior mesenteric nodes**
150
What is the sympathetic innervation of the large intestine?
- superior mesenteric plexus
**cecum and appendix
**ascending colon
**transverse colon
- lumbar part, inferior mesenteric plexus, and peri-arterial plexuses following IMA:
**descending and sigmoid colon
151
What is the parasympathetic innervation of the large intestine proximal to the left colic flexure?
vagus nerve
152
What is the parasympathetic innervation of the large intestine distal to the left colic flexure?
pelvic splanchnic nerves (S2-S4)
- via inferior hypogastric plexus and nn
