abdominal wall and intestines Flashcards
describe the 9 regions of the abdomen
R. hypochondriac - epigastric - L hypochondriac
R. Lumbar - Umbilical - L. lumbar
R. iliac - hypogastric - L. Iliac
roles of abdominal wall
- 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.
describe the external oblique, its attachments, functions and innervation
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).
describe the internal oblique, its attachments, functions and innervation
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.
describe the transversus oblique, its attachments, functions and innervation
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.
describe the rectus abdominis its attachments, functions and innervation
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).
what is the rectus sheath
rectus sheath is formed by the aponeuroses of the three flat muscles and encloses the rectus abdominis
what is the oesophagus, length, origin, destination
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).
what is the stomach
an intraperitoneal digestive organ located between the oesophagus and the duodenum.
what is the pyloric sphincter
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.
where is the small intestines and what makes it up
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.
what i the duodenum and where is it
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.
what are the jejunum and ilium and where are they located. What is the blood supply from
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.
what is the cecum, blood supply, location,previous and current role
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.
where is the right and left colic flexure
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
role of Large intestine, the 4 parts and which are retro and intra peritoneal
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.
location of the transverse colon
transverse colon extends from the right colic flexure to the spleen and is intraperitoneal
draw out he inferior and superior mesenteric arteries and its branches
branches - superior- Right colic artery , Middle colic artery
inferior- Left colic artery
what is the omental appendices
Attached to the surface of the large intestine are omental appendices – small pouches of peritoneum, filled with fat.
what are the teniae coli
Running longitudinally along the surface of the large bowel are three strips of muscle, known as the teniae coli
what are the haustra
The teniae coli contract to shorten the wall of the bowel, producing sacculations known as hausfrau. give the colon its segmented appearance
the different barium contrast tests and what can be seen in each one
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
which abdominal viscera are retroperitoneal
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
difference between primary and secondary peritoneum
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.
