abdominal wall and intestines

Question 1

describe the 9 regions of the abdomen

Answer 1

R. hypochondriac - epigastric - L hypochondriac
R. Lumbar - Umbilical - L. lumbar
R. iliac - hypogastric - L. Iliac

Question 2

roles of abdominal wall

Answer 2

• Forms a firm, yet flexible boundary which keeps the abdominal viscera in the abdominal cavity and assists the viscera in maintaining their anatomical position against gravity.
• Protects the abdominal viscera from injury.
• Assists in forceful expiration by pushing the abdominal viscera upwards.
• Is involved in any action (coughing, vomiting, defecation) that increases intra-abdominal pressure.

Question 3

describe the external oblique, its attachments, functions and innervation

Answer 3

The external oblique is the largest and most superficial flat muscle in the abdominal wall. Its fibres run inferomedially.

Attachments: Originates from ribs 5-12, and inserts into the iliac crest and pubic tubercle.
Functions: Contralateral rotation of the torso.
Innervation: Thoracoabdominal nerves (T7-T11) and subcostal nerve (T12).

Question 4

describe the internal oblique, its attachments, functions and innervation

Answer 4

The internal oblique lies deep to the external oblique. It is smaller and thinner in structure, with its fibres running superomedially (perpendicular to the fibres of the external oblique).

Attachments: Originates from the inguinal ligament, iliac crest and lumbodorsal fascia, and inserts into ribs 10-12.
Functions: Bilateral contraction compresses the abdomen, while unilateral contraction ipsilaterally rotates the torso.
Innervation: Thoracoabdominal nerves (T7-T11), subcostal nerve (T12) and branches of the lumbar plexus.

Question 5

describe the transversus oblique, its attachments, functions and innervation

Answer 5

The transversus abdominis is the deepest of the flat muscles, with transversely running fibres. Deep to this muscle is a well-formed layer of fascia, known as the transversalis fascia.

Attachments: Originates from the inguinal ligament, costal cartilages 7-12, the iliac crest and thoracolumbar fascia. Inserts into the conjoint tendon, xiphoid process, linea alba and the pubic crest.
Functions: Compression of abdominal contents.
Innervation: Thoracoabdominal nerves (T7-T11), subcostal nerve (T12) and branches of the lumbar plexus.

Question 6

describe the rectus abdominis its attachments, functions and innervation

Answer 6

The rectus abdominis is long, paired muscle, found either side of the midline in the abdominal wall. It is split into two by the linea alba. The lateral borders of the muscles create a surface marking known as the linea semilunaris.

At several places, the muscle is intersected by fibrous strips, known as tendinous intersections. The tendinous intersections and the linea alba give rise to the ‘six pack’ seen in individuals with a well-developed rectus abdominis.

Attachments: Originates from the crest of the pubis, before inserting into the xiphoid process of the sternum and the costal cartilage of ribs 5-7.
Functions: As well as assisting the flat muscles in compressing the abdominal viscera, the rectus abdominis also stabilises the pelvis during walking, and depresses the ribs.
Innervation: Thoracoabdominal nerves (T7-T11).

Question 7

what is the rectus sheath

Answer 7

rectus sheath is formed by the aponeuroses of the three flat muscles and encloses the rectus abdominis

Question 8

what is the oesophagus, length, origin, destination

Answer 8

The oesophagus is a fibromuscular tube, approximately 25cm in length, that transports food from the pharynx to the stomach.

It originates at the inferior border of the cricoid cartilage (C6) and extends to the cardiac orifice of the stomach (T11).

Question 9

what is the stomach

Answer 9

an intraperitoneal digestive organ located between the oesophagus and the duodenum.

Question 10

what is the pyloric sphincter

Answer 10

The pyloric sphincter lies between the pylorus and the first part of the duodenum. It controls of the exit of chyme (food and gastric acid mixture) from the stomach.

Question 11

where is the small intestines and what makes it up

Answer 11

from the pylorus of the stomach to the ileocaecal junction, where it meets the large intestine at the ileocaecal valve. Anatomically, the small bowel can be divided into three parts; the duodenum, jejunum and ileum.

Question 12

what i the duodenum and where is it

Answer 12

from the pylorus of the stomach to the duodenojejunal junction.

The duodenum can be divided into four parts; superior, descending, inferior and ascending. Together these parts form a ‘C’ shape, that is around 25cm long, and which wraps around the head of the pancreas.

Question 13

what are the jejunum and ilium and where are they located. What is the blood supply from

Answer 13

are intraperitoneal.

superior mesenteric artery

They are attached to the posterior abdominal wall by mesentery (a double layer of peritoneum).

The jejunum begins at the duodenojejunal flexure. There is no clear external demarcation between the jejunum and ileum – although the two parts are macroscopically different. The ileum ends at the ileocaecal junction.

Question 14

what is the cecum, blood supply, location,previous and current role

Answer 14

located between the ileum (distal small bowel) and the ascending colon.

intraperitoneal
superior mesenteric vessels.

Having served as a site for cellulose digestion in our ancestors, the cecum now simply acts as a reservoir for chyme which it receives from the ileum.

Question 15

where is the right and left colic flexure

Answer 15

When it meets the right lobe of the liver, it turns 90 degrees to move horizontally. This turn is known as the right colic flexure (or hepatic flexure), and marks the start of the transverse colon.

left colic is at the spleen

Question 16

role of Large intestine, the 4 parts and which are retro and intra peritoneal

Answer 16

role - it absorbs water and electrolytes to form faeces
150cm in length, and can be divided into four parts (proximal to distal): ascending (retroperitoneal), transverse (intraperitoneal), descending (retroperitoneal) and sigmoid.

Question 17

location of the transverse colon

Answer 17

transverse colon extends from the right colic flexure to the spleen and is intraperitoneal

Question 18

draw out he inferior and superior mesenteric arteries and its branches

Answer 18

branches - superior- Right colic artery , Middle colic artery
inferior- Left colic artery

Question 19

what is the omental appendices

Answer 19

Attached to the surface of the large intestine are omental appendices – small pouches of peritoneum, filled with fat.

Question 20

what are the teniae coli

Answer 20

Running longitudinally along the surface of the large bowel are three strips of muscle, known as the teniae coli

Question 21

what are the haustra

Answer 21

The teniae coli contract to shorten the wall of the bowel, producing sacculations known as hausfrau. give the colon its segmented appearance

Question 22

the different barium contrast tests and what can be seen in each one

Answer 22

barium swallow= oesophagus
barium meal - oesophagus, stomach, 1st part of duodenum
barium follow through - small bowel
barium enema - large intestine -sigmoid, rectal, descending, transverse, ascending

Question 23

which abdominal viscera are retroperitoneal

Answer 23

S = Suprarenal (adrenal) Glands
A = Aorta/IVC
D =Duodenum (except the proximal 2cm, the duodenal cap)
P = Pancreas (except the tail)
U = Ureters
C = Colon (ascending and descending parts)
K = Kidneys
E = (O)esophagus
R = Rectum

Question 24

difference between primary and secondary peritoneum

Answer 24

Primarily retroperitoneal organs developed and remain outside of the parietal peritoneum. The oesophagus, rectum and kidneys are all primarily retroperitoneal.

Secondarily retroperitoneal organs were initially intraperitoneal, suspended by mesentery. Through the course of embryogenesis, they became retroperitoneal as their mesentery fused with the posterior abdominal wall.
include the ascending and descending colon.