Week 12 finished

Question 1

List the functions of the abdomen?

Answer 1

• Encloses “housing” and protects abdominal organs and contents.
• Allows flexibility between the more rigid thorax and pelvis required by respiration, posture and locomotion.
• Raise in intra-abdominal pressure through voluntary and reflexive muscular contraction aids with respiration (contracting during respiration and reducing the thoracic cavity) coughing and sneezing.
• Changes in intra-abdominal pressure also assists in (Voiding urine, flatus, feces or fetuses from the abdominopelvic cavity).

Question 2

What are the two common way in which to define the abdominal regions?

Answer 2

• Can be divided into quadrant: Midline and transumbilical line. 4: Right upper, Left, upper, right lower and left lower.
• Can be divided into 9 segments: Two mid-clavicular lines, Subcostal line and intertubecular line. 9: Right hypochondrium, Epigastric region, Left hypochondrium, Right flank/lumbar, umbilical region, Left flank/lumbar, Right groin/iliac, Pubic region, and Left groin/iliac.

Question 3

What are the omenta?

Answer 3

-Double-layered extension or fold of peritoneum that passes from the stomach and proximal part of the duodenum to adjacent organs in the abdominal cavity.

-Two layers of the omentum:
1 -Greater omentum
2 -Lesser omentum

-The greater and lesser omenta suspend the stomach in the peritoneal cavity.

Question 4

What are the attachments of the greater omentum?

Answer 4

• The greater omentum is a prominent, four-layered peritoneal fold that hangs down like an apron from the greater curvature of the stomach and the proximal part of the duodenum.
• After descending it folds back and attaches to the anterior surface of the transverse colon and its mesentery.

Question 5

What are the attachments of the lesser omentum?

Answer 5

• The lesser omentum is a much smaller, double-layered peritoneal fold that connects the lesser curvature of the stomach and the proximal part of the duodenum to the liver.
• It also connects the stomach to the triad structures that run between the duodenum and liver in the free edge of the lesser omentum.

Question 6

What is the peritoneum?

Answer 6

-A continuous, glistening and slippery transparent serous membrane. It lines the abdominopelvic cavity and invests the viscera.

-The peritoneum consists of two continuous layers:
Parietal peritoneum, which lines the internal surface of the abdominopelvic wall.

-The Visceral peritoneum, invests viscera such as stomachs and intestines.

Question 7

What is the nerve supply to the peritoneum ?

Answer 7

N/S: T6-T12, takes supply from adjacent structures

Question 8

To what regions does the parietal peritoneum refer pain?

Answer 8

-The nerve supply of the parietal peritoneum is similar to that of the abominal wall over which it passes. The parietal peritoneum anterior and posterior is generally well localised, except for that on the inferior surface of the central part of the diaphragm.

The parietal pleura that lines the diaphragm is supplied by the phrenic nerve. Referring pain to C3-5, over the neck and shoulder

Question 9

What is the visceral peritoneum nerve supply and referral?

Answer 9

• The visceral peritoneum is supplied by the same nerves as the organ it covers. It is insensitive to heat, cold, touch and laceration: Stimulated by stretching and chemical irritation.
• Pain is poorly localised and referred to the associated dermatomes, particularly in the midline anteriorly.

Question 10

Referral of gut??

Answer 10

• Foregut pain is usually experienced in the epigastric region.
• Midgut pain is usually in the umbilical region.
• Hindgut pain is felt in the pubic region.

Question 11

What is the retroperitoneum ?

Answer 11

The retroperitoneum is the anatomical space behind the abdominal cavity. Organs are retroperitoneal if
they only have peritoneum on their anterior side.

Question 12

List the viscera that are retroperitoneal ?

Answer 12

Retroperitoneal Viscera: SADPUCKER
o Suprarenal Glands
o Aorta and Inferior Vena Cava
o Duodenum (2nd, 3rd, 4th)
o Pancreas (head and neck)
o Ureter
o Colon (ascending and descending)
o Kidneys
o Eosphagus
o Rectum

Question 13

What is the mesentery? What is its function?

Answer 13

• A double layer of peritoneum that occurs as a result of the invagination of the peritoneum by an organ and constitutes a continuity of the visceral and parietal peritoneum.
• Provides means for neurovascular communication between the organ and the abdominal wall.

Question 14

Where is the mesentery of the small intestine attached?

Answer 14

The mesentery is a double layered fold of peritoneum
which suspends the jejunum and ileum from the posterior
abdominal wall.

-Attached at the root of the mesentery
o The left side L2 to the right SIJ.

Question 15

List the three anterior branches of the abdominal aorta. Where does each arise? What part of the
gastrointestinal tract is supplied by each?

Answer 15

Celiac branch (Superior L1)= Foregut (stomach, liver, spleen, the head of the pancreas and the duodenum)

Superior Mesenteric branch (Inferior L1) = Midgut (supplies the jejunum, part of the pancreas, ileum, cecum, right colon and 2/3 of the transverse colon)

Inferior Mesenteric Branch (L3)= Hindgut- Last 1/3 of the transverse colon, sigmoid colon and rectum.

Question 16

List the three major veins draining into the portal vein?

Answer 16

• Splenic vein,
• Superior mesenteric vein
• Inferior mesenteric vein

Blood from the spleen, pancreas, gallbladder and gastointestinal tract (except inferior rectum) drains via splenic, superior mesenteric and inferior mesenteric veins into the portal vein to the liver.

Question 17

Which veins drain blood from the liver to the inferior vena cava?

Answer 17

-Left, Right and Intermediate Hepatic veins – formed by union of
collecting veins from central veins.

-Open into the IVC just inferior to the diaphragm

Question 18

How may portal hypertension manifest in the venous system?

Answer 18

In cases of portal hypertension (such as liver cirrhosis), varicosities tend to occur where there is anastamosis
between the portal and systemic venous systems.

Such as:
o Hemorrhoids at the anorectal junction (inferior rectal veins)

o Esophageal varices at the gastoroesophageal junction.

o Caput medusae at the umbilicus (Caput medusae is a network of dilated veins surrounding the umbilicus. It is caused by increased blood flow in the umbilical and periumbilical veins and is often
accompanied by an audible venous hum over the umbilical vein )

Question 19

How does Liver Cirrhosis cause Portal hypertension?

Answer 19

-Hepatomegaly resulting from fatty changes and fibrosis creates a “hobnail” appearance. Fibrous tissue surrounds the the intrahepatic blood vessels and biliary ducts, making the liver firm and impeding the circulation of blood through it.

Question 20

What nerves contribute to the abdominal prevertebral plexuses? List the three major ganglia of these plexuses.

Answer 20

The major ganglia are arranged about and named for the three anterior branches of the abdominal aorta:
o Celiac
o Superior mesenteric
o Inferior mesenteric.

• The abdominal prevertebral plexus is contributed to by thoracic and lumbar splanchnic nerves
  (sympathetic) , the vagus and pelvic splanchnic nerves (parasympathetic).

Question 21

Which components of the gastrointestinal system derive parasympathetic supply from the pelvic splanchnic
nerves?

Answer 21

Pelvic supply the hind gut: 1/3 transverse, descending and sigmoid colon.

-These are parasympathetic fibers arising from
the spinal cord at S2-4 levels.

Question 22

What is the typical nature of viscerosomatic pain?

Answer 22

• It is poorly localised and dull.

- Pain arising from viscera is usually referred to the dermatomal region.

Question 23

From what region is the sympathetic outflow to the kidney derived?

Answer 23

T10-L1 (aorticrenal ganglia?)

Nerve supply is via the renal plexus which receives fibres from the splanchnic nerve (especially least)

Question 24

How does the left renal vein differ from the right?

Answer 24

Left renal vein is longer than the right and runs posterior to SMA
- Because the inferior vena cava is not laterally symmetrical and located on the right side, the left
renal vein also recieves left inferior phrenic, suprarenal and gonadal veins
- Right veins drain directly into IVC.

Question 25

List the structures passing under the inguinal ligament?

Answer 25

• Femoral Artery and Vein
• Femoral Nerve
• Muscles – Psoas Major, Iliacus and Pectineus
• Lateral Femoral Cutaneous Nerve

Question 26

What is the inguinal canal?

Answer 26

is an oblique passage about 4cm long running inferomedially through the inferior part of the anterolateral abdominal wall. It lies parallel and superior to the medial half of the inguinal ligament.

Question 27

List the structures found in the inguinal canal in males and females?

Answer 27

Males: Spermatic Cord in men – ductus deferens, testicular artery, ductus deferens artery, cremasteric artery, venous plexus, genital branch of genitofermoral nerve

Females: round ligament of the uterus. Ilioinguinal Nerve (L1), Genital branch of genital femoral nerve, blood and lymph vessels