Abdomen Flashcards

1
Q

Name the layers of the anterior abdominal wall.

A
Skin
Superficial fascia (Camper's & Scarpa's)
External oblique
Internal oblique
Transversus abdominus
Transversalis fascia
Extraperitoneal fat
Peritoneum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name the attachments of the external oblique muscle.

A

Origin: ribs 5-12
Insertion: linea alba, iliac crest & pubic tubercle

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

Name the attachments of the inguinal ligament.

A

Origin: ASIS
Insertion: pubic tubercle

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

What is the lacunar ligament?

A

A fibrous extension from the medial part of the inguinal ligament toward the pectineal line.

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

Name the attachments of the internal oblique muscle.

A

Origin: iliac crest & ASIS / inguinal ligament (lowermost fibres)
Insertion: ribs 10-12 / conjoint tendon

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

Name the attachments of transversus abdominus.

A

Origin: costal cartilages 7-12 & iliac crest / inguinal ligament (lowermost fibres)
Insertion: linea alba & pubic crest / conjoint tendon

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

What is the arcuate line?

A

The arcuate line demarcates the lower limit of the posterior layer of the rectus sheath.

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

Name the attachments of rectus abdominis.

A

Origin: pubic crest & pubic symphysis
Insertion: xiphoid process & costal cartilage of ribs 5-7

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

What is the rectus sheath?

A

The rectus sheath is the aponeurosis of the three flat-layer muscles that encloses rectus abdominus; it is deficient in the lower 1/4 of the abdomen.

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

Which artery supplies the anterior abdominal wall, superiorly and laterally?

A

The musculophrenic artery.

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

What does the musculophrenic artery supply?

A

The anterior abdominal wall, superiorly and laterally.

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

Which artery provides blood supply to rectus abdominis?

A

The superior epigastric artery.

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

Which arteries run within the rectus sheath posteriorly?

A

The superior & inferior epigastric arteries.

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

Which muscle does the superior epigastric artery supply?

A

Rectus abdominis.

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

Which artery provides blood supply to the inferior aspect of the anterior abdominal wall muscles laterally?

A

The deep circumflex iliac artery.

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

Which artery provides blood supply to the inferior aspect of the abdominal wall (superficial fascia, not muscular)?

A

The superficial epigastric artery.

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

Which spinal segments innervate the anterior abdominal wall?

A

T6-L1

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

What is the inguinal canal?

A

The inguinal canal is a passage through the anterior abdominal wall formed by the descent of the testes from the posterior abdominal wall to the scrotum.

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

What is the deep inguinal ring?

A

A hole in the transversalis fascia.

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

What is the superficial inguinal ring?

A

A fibrous split in the aponeurosis of the external oblique muscle.

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

Describe the path that the testes take through the inguinal canal.

A

The testes originally develop within the extraperitoneal fat. They create a hole in the transversalis fascia, go underneath the arch of the fibres of transversus abdominus & internal oblique and find a fibrous split within the aponeurosis of external oblique.

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

Name the boundaries of the inguinal canal.

A

RAFP / MALT

Roof: Muscles (IO & TA)
Anterior: Aponeurosis (EO & IO)
Floor: Ligaments (inguinal & lacunar)
Posterior: Tendon (conjoint tendon & transversalis fascia)

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

What is an inguinal hernia?

A

A protrusion/passage of abdominal contents into the inguinal canal.

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

What is the difference between an indirect & a direct inguinal hernia?

A

An INDIRECT inguinal hernia is a protrusion through the deep ring into the inguinal canal. Contents may traverse through the entire length and pass into the scrotum. They arise from incomplete closure of the processus vaginalis.

A DIRECT inguinal hernia is a protrusion into the inguinal canal through an area of weakness in its posterior wall. The contents do not traverse the length of the canal and rarely enter the scrotum. They often result from a weakened muscular wall of the abdomen.

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

What is the processus vaginalis?

A

When the testes descend into the scrotum, they drag a layer of peritoneal membrane with them, creating the processus vaginalis, a tube that connects the intra-abdominal cavity and the scrotum.

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

Name the attachments of psoas major.

A

Origin: transverse processes of T12-L4
Insertion: lesser trochanter of the femur

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

Name the attachments of quadratus lumborum.

A

Origin: iliac crest
Insertion: 12th rib & L1-L5

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

Name the attachments of iliacus.

A

Origin: iliac crest
Insertion: lesser trochanter of the femur

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

Name the compartments of the thoracolumbar fascia and their contents.

A

Anterior muscle compartment (formed by anterior & medial layers of thoracolumbar fascia): quadratus lumborum

Posterior muscle compartment (formed by medial & posterior layers of thoracolumbar fascia): erector spinae muscles

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

Where are the kidneys located in relation to the peritoneum?

A

Retroperitoneal - they sit against the posterior abdominal wall in a fixed position (T12-L3) outside the peritoneal cavity.

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

What covers the anterior & posterior surfaces of the kidneys?

A

Anterior: peritoneum
Posterior: quadratus lumborum

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

Name the structures at the renal hilum.

A

RAP (from front to back)

Renal vein
Renal artery
Renal pelvis

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

The right renal vein goes directly to the IVC. Why doesn’t the left renal vein? Describe its pathway.

A

The left renal vein’s path is obstructed by the aorta, so it passes in front of it (but behind the superior mesenteric artery).

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

Where is the lymph drained from the kidneys collected?

A

The paravertebral nodes.

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

What is the accessory renal artery, and how does it develop?

A

The accessory renal artery supplies additional arterial blood to the kidneys. Initially, the kidneys develop lower down in the pelvis, but they appear to move upwards as the abdominal wall grows due to their different growth rates. While in the pelvis, they receive blood supply at this level, but when they move up, they receive a new blood supply from the renal arteries. In some people, this original artery (the accessory renal artery) remains.

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

Describe the path of a ureter once it leaves the kidney, naming the structures it passes over.

A

The ureter runs in front of psoas major and over the tips of the transverse processes of the lumbar vertebrae.

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

Name the location of the three narrowing points of the ureters.

A
  1. Ureteropelvic junction (just below renal pelvis)
  2. Pelvic brim
  3. Terminal portion (at the bladder)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the clinical significance of narrowings in the ureter?

A

Kidney stones can get lodged there.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Describe the arterial supply of the ureters.

A

Abdominal: renal artery, gonadal artery, branches of abdominal aorta
Pelvic: branches of common iliac artery (superior & inferior vesical arteries)

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

Where are the ureters located in relation to the peritoneum?

A

Retroperitoneal.

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

What happens to the mucosa at the esophagogastric junction? Is it gradual or sudden?

A

There is a sudden change from oesophageal mucosa to gastric mucosa.

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

What is a hiatal hernia?

A

A hiatal hernia is when part of the stomach is pulled through the oesophageal hiatus.

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

What is the difference between a paraesophageal and sliding hiatal hernia?

A

A paraesophageal hernia is when the oesophagus pulls part of the top of the stomach into the thorax ALONGSIDE it.

A sliding hiatal hernia is when the oesophagus pulls the proximal part of the stomach directly into the thorax.

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

What is the cardiac notch?

A

The angle between the distal part of the oesophagus and the fundus of the stomach.

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

What is the difference between a functional and anatomical sphincter?

A

Functional sphincters achieve their action through muscle contraction around or within the structure.

Anatomical sphincters have a localised muscle thickening to facilitate their action as a sphincter.

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

What is the function of the pyloric sphincter?

A

It stops the contents of the stomach being dumped into the duodenum by slowing the process down.

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

What is the angular notch?

A

The angular notch is an anatomical landmark that represents where the body of the stomach ends and the pyloric part begins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Where is the stomach located relative to the peritoneum?

A

Intraperitoneal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are the name of the mesenteries attached to the stomach, and what are their other attachments?

A

Lesser omentum: connects the lesser curvature (including the beginning of the abdominal oesophagus) to the visceral part of the liver

Greater omentum: connects greater curvature to the posterior abdominal wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the mucosa of the stomach called?

A

Rugae.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Name the vessels that run along the lesser curvature.

A

The left & right gastric arteries.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Name the vessels that run along the greater curvature.

A

The left & right gastro-omental arteries.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Where is the duodenum located related to the peritoneum?

A

Retroperitoneal (except for the very beginning, which is intraperitoneal and has a mesentery). It sits against the posterior abdominal wall.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Describe the first part of the duodenum.

A

The first part of the duodenum, the ampulla, sits against the IVC and is very short.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Describe the second part of the duodenum.

A

The major duodenal papilla are located within the second part of the duodenum. These represent the common opening point for the main pancreatic duct and the common bile duct, and are thus where the majority of enzymes and bile are secreted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Where are the majority of enzymes & bile secreted in the digestive tract?

A

At the major duodenal papilla in the second part of the duodenum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Where are the major duodenal papilla located?

A

On the posterior and medial wall of the second part of the duodenum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Describe the third part of the duodenum.

A

This is the longest part of the duodenum. It is located at L3 and crosses from the right to the left, in front of the IVC and abdominal aorta but behind the superior mesenteric artery and vein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Which section of the duodenum is the longest?

A

The third section.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Describe the blood supply of the duodenum.

A

The first half of the duodenum is supplied by the gastroduodenal artery (a branch of the celiac trunk). The rest is supplied by the inferior pancreaticoduodenal arteries (branches of the superior mesenteric artery). These arteries meet & anastomose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the DJ flexure?

A

The point where the small intestine transitions from the retroperitoneal duodenum to the intraperitoneal jejunum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Where is the jejunum located in relation to the peritoneum?

A

Intraperitoneal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is the name of the landmark where the duodenum transitions into the jejunum?

A

The DJ flexure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Name the main differences between the jejunum and the ileum.

A
Jejunum:
larger in diameter (to accomodate larger volume of gastric content)
more mucosal folds
thicker wall
less fat in mesentery
65
Q

Describe the blood supply of the jejunum & ileum.

A

The jejunum and ileum are supplied by the arterial rectae, which are branches of the superior mesenteric artery.

66
Q

Name the features that are unique to the large intestine (as compared to the small intestine).

A
Tenia coli (muscular bands)
Haustra (baggy appearance of intestine)
Omental appendices (fatty tags on tenia coli)
67
Q

Where is the caecum positioned in relation to the peritoneum?

A

Intraperitoneal.

68
Q

Where is the appendix positioned in relation to the peritoneum?

A

Intraperitoneal.

69
Q

Where is the appendix located?

A

The base of the appendix attaches to the inferomedial aspect of the caecum where the three tenia coli bands meet, but its position can be variable.

70
Q

Where is the colon located in relation to the peritoneum?

A

Ascending colon: retroperitoneal
Transverse colon: intraperitoneal
Descending colon: retroperitoneal
Sigmoid colon: intraperitoneal

71
Q

What happens to the tenia coli at the rectum?

A

They merge to form a complete muscle layer to support the rectum.

72
Q

What is the function of the falciform ligament?

A

The falciform ligament connects the liver to the anterior abdominal wall.

73
Q

What is the falciform ligament made of?

A

Folded over peritoneum.

74
Q

Name the contents of the portal triad.

A

Portal vein
Hepatic artery
Bile duct

75
Q

Which lobe of the liver does the gall bladder sit on?

A

The quadrate lobe.

76
Q

Which lobe of the liver does the IVC run over?

A

The caudate lobe.

77
Q

Where is the liver located in relation to the peritoneum?

A

Intraperitoneal.

78
Q

What is the function of the ductus venosus?

A

The umbilical vein passes the visceral surface of the liver, and there is a potential that blood may be passed into the portal vein. The liver is not fully functional in the foetus, so the ductus venosus is a bypass that allows blood from the umbilical cord to be shunted through to the IVC.

79
Q

Describe the pathway of foetal circulation.

A

The placenta sends oxygen-rich blood into the umbilical vein, which goes through the ductus venosus to the IVC and the right atrium. From here, blood is shunted through the foramen ovalis into the left atrium, the left ventricles and into the foetal body through the aorta.

80
Q

What happens to the umbilical vein upon birth?

A

It becomes ligamentous and turns into the round ligament.

81
Q

Where would you clamp to stop blood flow to the liver, allowing you to operate on it?

A

The free right edge of the lesser omentum, as the hepatic artery and portal vein run along here.

82
Q

What structure can be obstructed if the head of the pancreas is swollen?

A

The common bile duct.

83
Q

Where does the common bile duct sit?

A

Behind the first part of the duodenum and in front of the head of the pancreas.

84
Q

What is a common symptom of common bile duct obstruction?

A

Jaundice.

85
Q

Describe the process that allows bile to be secreted into the small intestine.

A

Before they enter the major duodenal papilla, the common bile duct & the main pancreatic duct meet and form the sphincter of Oddi. Usually, this sphincter is closed, allowing bile to be stored and concentrated in the gall bladder, but certain hormones are secreted in response to a fatty meal that cause relaxation of this sphincter, allowing bile to be secreted.

86
Q

Where is the pancreas located in relation to the peritoneum?

A

Retroperitoneal.

87
Q

Where is the pancreas located?

A

Behind the body of the stomach and above the DJ flexure.

88
Q

What is the function of the uncinated process of the pancreas?

A

This is where a small proportion of pancreatic enzymes are secreted into the accessory pancreatic duct.

89
Q

Where does the accessory pancreatic duct enter the small intestine?

A

The minor duodenal papilla.

90
Q

Where is the spleen located in relation to the peritoneum?

A

Intraperitoneal.

91
Q

Which vessels are present at the hilum of the spleen?

A

The splenic artery & vein.

92
Q

Where is the spleen located?

A

Behind ribs 9, 10 & 11 on the left.

93
Q

Where does the visceral peritoneum receive its innervation from?

A

The autonomic nervous system.

94
Q

Where does the parietal peritoneum receive its innervation from?

A

The somatic nervous system.

95
Q

Explain how appendicitis demonstrates the types of pain felt in the visceral and parietal peritoneum.

A

Initial pain (in the viscus & the visceral peritoneum) is dull and poorly localised. Once it spreads to the parietal peritoneum, it becomes severe and extremely localised.

96
Q

How many mesenteries does the primitive gut initially have?

A

Two: the ventral & dorsal mesenteries.

97
Q

What does the ventral mesentery become?

A

The falciform ligament.

98
Q

Which viscera are derivatives of the primitive gut?

A

The retroperitoneal unpaired viscera.

99
Q

What is the name of the part of the lesser omentum connecting the lesser curvature of the stomach to the liver?

A

The hepatogastric ligament.

100
Q

What is the name of the thick part of the lesser omentum on the right side?

A

The hepatoduodenal ligament.

101
Q

Name the three ligaments that make up the greater omentum and what they connect.

A

The gastrophrenic ligament connects the fundus of the stomach and the interior surface of the diaphragm.

The gastrosplenic ligament connects the proximal part of the greater curvature of the stomach to the spleen. It splits and surrounds the spleen.

The gastrocolic ligament is a double-folded structure connecting the rest of the greater curvature to the posterior abdominal wall.

102
Q

What is the space between the two layers of the gastrocolic ligament called?

A

The omental bursa.

103
Q

What is the mesentery of the jejunum & ileum called?

A

The mesentery.

104
Q

Name the attachments of the mesentery.

A

It starts from the DJ flexure and ends at the ileocaecal junction.

105
Q

What are the boundaries of the lesser sac/omental bursa?

A
Superior: liver
Inferior: greater omentum
Posterior: posterior abdominal wall
Anterior: stomach
Left side: spleen
Right side: open
106
Q

What does the transverse mesocolon connect?

A

The two colic flexures.

107
Q

Through which structure can the lesser and greater sacs communicate?

A

The free right edge of the lesser omentum.

108
Q

At what level does the abdominal aorta begin?

A

T12

109
Q

At what level does the abdominal aorta bifurcate into the common iliac arteries?

A

L3

110
Q

Name the three unpaired branches that arise from the front of the abdominal aorta.

A

Celiac trunk
Superior mesenteric artery
Inferior mesenteric artery

111
Q

Name the three paired branches that arise from the side of the abdominal aorta.

A

Renal arteries
Suprarenal arteries
Gonadal arteries

112
Q

Which paired arteries arise from the back of the abdominal aorta?

A

The parietal branches.

113
Q

Name the blood supply for each part of the primitive gut.

A

Foregut: celiac trunk
Midgut: superior mesenteric artery
Hindgut: inferior mesenteric artery

114
Q

Name the contents of the foregut.

A

PEG’S on LSD

Pancreas
(O)esophagus
Gall bladder
Spleen

Liver
Stomach
Duodenum (1 & 2)

115
Q

Name the contents of the midgut.

A

JAILED CAT

Jejunum
Appendex
ILEum
Duodenum (2, 3, 4)

Caecum
Ascending colon
Transverse colon (proximal 2/3)

116
Q

Name the contents of the hindgut.

A

Descending RATS

Descending colon

Rectum
Anus
Transverse colon (distal 1/3)
Sigmoid colon

117
Q

Which structures does the left gastric artery supply?

A

The proximal part of the stomach (and the abdominal oesophagus via the oesophageal branch).

118
Q

Which artery supplies the proximal part of the stomach?

A

The left gastric artery.

119
Q

Which artery supplies the abdominal oesophagus?

A

The oesophageal branch of the left gastric artery.

120
Q

Which structures does the splenic artery supply?

A

The spleen and the body & tail of the pancreas.

121
Q

Which artery supplies the spleen?

A

The splenic artery.

122
Q

Which arteries supply the pancreas?

A

The splenic artery (body & tail) and the common hepatic artery & superior and inferior pancreaticoduodenal arteries (neck & head).

123
Q

Which structures does the short gastric artery supply?

A

The fundus of the stomach.

124
Q

Which artery supplies the fundus of the stomach?

A

The short gastric artery.

125
Q

Which structures does the left gastro-omental artery supply?

A

The inferior part of the stomach.

126
Q

Which artery supplies the inferior part of the stomach?

A

The left gastro-omental artery.

127
Q

Which structures does the common hepatic artery supply?

A
Distal part of the stomach
Duodenum
Liver
Gall bladder
Neck & head of pancreas
128
Q

Which artery supplies the distal part of the stomach?

A

The common hepatic artery (via the right gastric artery).

129
Q

Which artery supplies the liver?

A

The common hepatic artery (via the left & right hepatic arteries).

130
Q

Which artery supplies the gall bladder?

A

The common hepatic artery (via the cystic artery).

131
Q

Which structures do the anterior & posterior pancreaticoduodeneal arteries supply?

A

The proximal part of the duodenum (down to the major duodenal papilla).

132
Q

Which structures does the inferior pancreaticoduodenal artery supply?

A

The distal part of the duodenum (below the major duodenal papilla) and the head & neck of the pancreas.

133
Q

Which structures does the ileocolic artery supply?

A

Appendix
Caecum
Inferior part of ascending colon

134
Q

Which artery supplies the appendix?

A

The ileocolic artery.

135
Q

Which artery supplies the caecum?

A

The ileocolic artery.

136
Q

Which structures does the right colic artery supply?

A

The ascending colon (apart from the inferior part).

137
Q

Which arteries supply the ascending colon?

A

The ileocolic artery (inferior part) and the right colic artery.

138
Q

Which structures does the middle colic artery supply?

A

The proximal 2/3 of the transverse colon.

139
Q

Which artery supplies the proximal 2/3 of the transverse colon?

A

The middle colic artery.

140
Q

Which structures does the left colic artery supply?

A

Distal 2/3 of transverse colon

Descending colon

141
Q

Which artery supplies the distal 2/3 of the transverse colon?

A

The left colic artery.

142
Q

Which artery supplies the descending colon?

A

The left colic artery.

143
Q

Which artery supplies the sigmoid colon?

A

The sigmoid artery.

144
Q

Which arteries supply the rectum?

A

The superior & inferior rectal arteries.

145
Q

Describe venous drainage in the abdomen.

A

Everything below the diaphragm drains into the IVC. Paired structures drain directly into the IVC, but unpaired structures drain into the portal vein for metabolism before draining into the IVC.

146
Q

Which veins form the portal vein?

A

The splenic and superior mesenteric veins.

147
Q

Which structures drain into the portal vein?

A

Abdominal GIT
Spleen
Pancreas
Gall bladder

148
Q

What is the function of portosystemic anastomoses? Why can they be dangerous?

A

If there is a blockage in the portal system, portosystemic anastomoses mean that the blood can still reach the systemic circulation. However, bypassing the liver can be dangerous as it is the main site of detoxification.

149
Q

Where are the main portosystemic anastomoses located?

A

BLU APL (blue apple)

Bare area of liver
Liver
Umbilicus

Anal canal
Posterior abdominal wall
Lower end of oesophagus

150
Q

Describe the innervation of the abdominal viscera.

A

The abdominal viscera are innervated by the ANS. They receive sympathetic fibres from the splanchnic nerve and parasympathetic fibres from the vagus nerve. These fibres form the aortic plexus.

151
Q

Describe the sympathetic innervation of the abdominal viscera.

A

The sympathetic fibres come from T6-L2 and form the sympathetic trunk. The sympathetic trunk sends out thoracic & lumbar splanchnic and form the pre-aortic ganglia which cluster around the three unpaired branches of the aorta. These ganglia then send nerve fibres to individual abdominal viscera.

152
Q

Describe the parasympathetic innervation of the abdominal viscera.

A

The foregut & midgut are supplied by the vagus nerve; the hindgut is supplied by the pelvic splanchnic nerves from S2-S4.

153
Q

At what level does the vagus nerve pass through the diaphragm?

A

T10

154
Q

Describe the segmental innervation of the abdominal viscera.

A

Foregut: T6-T9
Midgut: T8-T12
Hindgut (down to mid sigmoid colon): T12-L2
Hindgut (beyond mid sigmoid colon): S2-S4

155
Q

Describe the segmental innervation of the foregut.

A

T6-T9

156
Q

Describe the segmental innervation of the midgut.

A

T8-T12

157
Q

Describe the segmental innervation of the hindgut.

A

Down to mid sigmoid colon: T12-L2

Beyond mid sigmoid colon: S2-S4

158
Q

Describe the lymphatic drainage of the abdominal viscera.

A

Unpaired structures drain into the pre-aortic nodes; paired structures drain into the para-aortic nodes.