Anatomy Abdomen Flashcards
What are the skeletal components of the abdominal wall?
- Five Lumbar vertebrae
- Superior expanded parts of pelvic bones
- costal margin rib XII, end of rib XI, xiphoid process
What is the main muscle in the anterior abdominal wall?
Rectus Abdominis
+ Rectus sheath
What is the rectus sheath?
A sheath which surrounds rectus abdominis
–> built by “Sehnenplatten” (
–< muss ergänzt werden!
Intraperitoneal
structures that are suspended from abdominal wall by mesenteries
Retroperitoneal
Structures not suspended in the abdominal wall but lie between the parietal peritoneum and abdominal wall
(e.g. kidney and ureters)
Explain the nine-region pattern of the abdominal wall (Borders, planes)
Horizontal lines:
- Subcostal plane –> inferior to costal margins (rib X, LIII)
- Intertubercular plane —> Connects tubercles at iliac crest (5cm posterior of iliac spine)
Vertical lines:
- Midclavicular lines (from mid-clavicle to somewhere between anterior superior iliac spine and pubic symphysis)
Name the nine regions of the abdomen
What is the superficial fascia?
A layer of fatty, subcutaneous connective tissue of the abdominal wall
Linea Alba:
What is the function of the anterolateral muscles in the abdominal wall?
Maintainance of normal physiological functions
–> firm but flexible wall to keep abdominal viscera in the cavity
Can support quiet and forced expiration, coughing and vomiting
Involved in everything which requires increasing intrabdominal pressure
Which one is the most superficial anterolateral abdominal muscle?
Where is it atached to?
Attached to lower 8 ribs
Free ends –> turns into aponeurosis (linea alba and inguinal ligament)
In which direction does the external oblique abdominal muscles pass?
Inferomedial direction
Aponeurotic component covers the anterior part of the abdominal wall forming linea alba
In which direction do muscle fibers of the internal oblique muscles pass?
Superior medial direction
Aponeurosis also blends into linea alba
How it the deepest layer of abdominal muscles called?
In which direction does it pass?
Transversus abdominus
Across abdomen, blending into linea alba
What is the transversalis fascia?
Fascia deep to transversus abdominis
–> basically forms fascia which is thicker and thinner at some point but connects through whole abdominal cavity and back
Widens and thins from as ascending from pubic synthesis to costal margin
Paired muscle, separated by linea alba
How are the abdominal muscels innervated?
Anterior rami of lower six thoracic spinal nerves (T7-T12)
L1 for Internal oblique and Transversus abdominis)
What is the rectus sheath and how does it change over the different spinal levels?
What is it?
- Aponeurotic tendinous sheath surrounding rectus abdominis
- Formed by aponeurotic parts of internal, external oblique and transversus abdominis
Change
- A: encloses upper three-quarters of rectus abdominis
—> Anterior: External oblique, half internal oblique
—> Posterior: Half internal oblique, half transversus abdominis
- B: lower quarter: no posterior covering of rectus abdominis –> direct contact with transversalis fascia
—> Apneurotic tendons from all three muscles form anterior part
(Transition marked by arcuate line)
What is the extraperitoneal fascia?
What does it separate?
It is a Layer of connective tissue which is thick in the posterior part of the abdominal wall
It separates the transversalis fascia from the peritoneum
What is the peritoneum?
How can you classify the peritoneum?
It is a thin serous membrane lining the wall of the abdominal cavity and reflects onto abdominal viscera
Classification:
- Lining the walls: Parietal peritoneum
- Lining the viscera: visceral peritoneum
Explain the route of cutaneous nerve innervation of the abdomen
Intercostal nerves (T7-T11) + T12+ L1
Intercostal nerves run deep in their costal cartilages, continue between transversus abdominis and internal oblique
Enter the rectus sheath and pass posterior to the lateral aspect of rectus abdominis
Pass through rectus abdominis to supply the skin
By which nerve is the region around the umbillicus supplied?
T10
By which nerve is the inguinal ligament supplied?
L1
Summarise the blood supply of the superficial anterolateral abdominal wall
Superior part:
- Musculophrenic artery (terminal branch of internal thoracic artery)
Inferior part
- Medial: Superficial epigastric artery
- Lateral: Superficial circumflex iliac artery
–> Both branches from femoral artery
Summarise the deeper blood supply of the anterior abdominal wall
Superior Part
- Superior epigastric artery (terminal branch of the thoracic artery)
Lateral part:
- 10+11 intercostal artery + subcostal artery
Inferior part:
- inferior epigastric artery and deep circumflex iliac artery (both from femoral artery)
What is the faith of the superior and inferior epigastric arteries?
Both enter recuts sheath (always posterior to rectus abdominis) and anastomose with each other
In which two segments can the superficial fascia be devided?
Campers fascia: Superficial fatty fascia (varies in thickness)
Scarpas fascia: Deeper, thin and membranous
Summarise the layers (from superficial to deep) you cut when making an incision into the abdominal wall.
- Skin
- Superficial fascia: Campers fascia, Scarpans fascia
- Muscles/Aponeuroses
- Transversalis fascia
- Extraperitoneal fascia
- Peritoneum
What passes through the inguinal canal?
Genital branch of the genitofemoral nerve
Men: Spermatic cord
Women: round ligament of uterus
ilio-inguinal nerve thorough part of the canal (exit with other contents)
What it the deep inguinal ring?
Where is it located?
Beginning of the inguinal canal
–> Begining of tubular evagination of the transversalis fascia (form internal spermatic fascia/ round ligament of uterus)
It is located midway between anterior superior ilia spine and the pubic symphysis (just above inguinal ligament, lateral to inferior epigastric vessels
What is the superficial or external inguinal ring?
What is itformed by?
It is the end of the inguinal canal –> marks beginning of external spermatic fascia
Triangular opening in the aponeurosis of the external oblique
—> other sides Attached to the pubic symphysis and pubic tubercle
Where are the superior and inferior crus of the superficial inguinal ring attached to?
Inferior= attached to the pubic tubercle
Superior= attached to pubic symphysis
What forms the,, bottom”, floor of the inguinal canal?
What is the most inferior border of the inguinal canal?
The inguinal ligament
What forms the anterior side of the inguinal canal?
The aponeurosis part of the external oblique muscle
+ reinforced laterally by fibres of the internal oblique
By which structure its the roof (superior wall) of the inguinal canal formed?
Arching fibers of the transversus abdominis and internal oblique muscle
Come together to form conjoint tendon attached to the pubic symphisis
What forms the posterior wall of the inguinal canal?
Transverse fascia
Medial third: reinforced by conjoint tendon
What is the inguinal ligament?
Extension of the aponeurosis part of the external oblique muscles attached to the superior anterior pubic spine and pubic tubercle
What is a hernia?
Is is the formation of a sack by the parietal peritoneum (with or without content)
often occurring at weakened parts of the abdominal wall
What is the difference between a direct and an indirect hernia?
An indirect hernia passes through the inguinal canal while the direct hernia passes through a weakening of the abdominal wall
Direct: Direktes Durchtreten des Bruchsacks durch die Bauchwand ohne Beziehung zum Funiculus spermaticus
How long is the inguinal canal in adult males?
About 4 cm
Which type of hernia is more common in males than in females?
Indirect inguinal hernia
In females: most of the time a femoral hernia
In which area do most direct inguinal hernias occur?
In the Hesselbachs triangle
Boundaries:
Lateral: inferior epigastric artery
Medially: rectus abdominis
Interior: Inguinal ligament
How do you clinically distinguish between a femoral and an inguinal hernia?
Inguinal:
- Reducible
- above inguinal ligament
- (Male)
Femoral:
- Irreducible
- below inguinal ligament
- more common in females
What is the peritoneum?
Thin membrane (simple squamous) that lines walls of the abdominal cavity and many viscera
What are mesenteries
Folds of the peritoneum which contain abdominal organs
–> Components of the GI tract are suspended in peritoneal reflections
What is the peritoneal cavity?
The space enclosed by the two layers of the peritoneum
How can the peritoneal cavity be subdivided?
Into
- greater sac –> most of the space from the diaphragm to pelvic cavity
- Omental bursa: subdivision posterior to stomach and liver
—> are continuous with each other
What is the function of the mesenteries?
These parietal folds attach some viscera to the posterior abdominal wall
They allow some movement and are conduits for vessels, nerves and lymphatics
What is the greater omentum?
Where does it attach and what are included structures?
It is a large peritoneal fold (green)
Attaches to: greater curvature of the stomach and first part of the duodenum
It normally contains an accumulation of fat + right and left gastro-omental vessels just inferiorly to the stomach
What is the lesser omentum?
What does it attach to?
Which structures does it contain?
A fold of the peritoneum
Extends from the lesser curvature of stomach + first part of the duodenum to the liver
It has a free edge (because of the ventral mesentery which ends at the midgut) where the hepatic artery, the bile duct and the portal vein run through
How can organs in the abdominal cavity be classified according to their relation with the peritoneum?
Inraperitoneal= in suspended from abdominal wall by mesenteries
Retroperitoneal= organs held between abdominal wall+ parietal peritoneum
In what three compartments can the GI tract be separated?
- FOREGUT– Distal 3rdof oesophagus to the 2ndpart of the duodenum at the entrance of the bile duct (Major duodenal papilla).
- MIDGUT– 2ndpart of the duodenum to two-thirds along transverse colon.
- HINDGUT– Distal third of transverse colon to the rectum
–> each part has own supply
Where does the esophagus pass the diaphragm?
Which important nerve trunks are associated with it?
Passes it at T10
–> diaphragm contributes to the lower oesophageal sphincter
Anterior+ posterior vagal trunks are associated with it
How is the muscular ring in the stomach called which prevents backflow of chyme from the duodenum?
It is called the pyloric sphincter
By which vessel is the Foregut supplied?
The foregut is supplied by the Coeliac trunk
In what sections can the duodenum be subdivided?
- Superior part
- Descending part
- Inferior part
- Ascending part
What is important about the superior part of the duodenum?
Fist two centimetres: DUodenal Cap/Apulla —> common place for ulcers to occur
It passes anteriorly to bild duct , gastroduondenal artery, portal vein and IVC
What is important about the descending part of the duodenum?
Contains major duodenal papilla –> where the pancreatic duct enters the duodenum
What is important about the inferior part of the duodenum?
Largest part, crosses IVC and Aorta (lie posteriorly)
Anteriorly Mesenteric artery and vein
What is important about the ascending part of the duodenum?
It terminates at duodenojejunal flexure and passes left of aorta
How can you distinguish between the jejunum and the ileum?
Jejenum(A): mucosal folds : pilcae circulares
also: less prominent arterial arcades and longer vasa recta than ileum (B)
In which quadrant of the abdomen can the jejenum be found
proximal two fifth
in left upper quadrant of abdomen
In which quadrant of the abdomen can the iliac be found?
Distal three-fifth of the small intestine
Found in the right lower quadrant of the abdomen
How can you differentiate between the large intesine and the small intestine?
Large intestine
- has mostly a larger diameter (though not reliable)
- accumulation of fat covering —> omental apendicies
- ribbons of longitudinal muscle —> taeniae coli
- saculation/segmentation of wall –> haustra of coli
Name the eight different parts of the colon
Which major artery supplies the midgut?
Branches of the superior mesenteric artery
Which artery supplies the hindgut?
The inferior mesenteric artery
What are the anterior branches of the abdominal aorta?
- Celiac trunk
- Superior mesentery artery
- Inferior mesenteric artery
Which arteries supply the stomach with blood?
- Left gastric artery from celiac trunk
- right gastric artery from hepatic artery proper
- right and left gastro-omental arteries (from right: gastroduodenal from common hepatic, left splenic)
- Posterior gastric artery from splenic artery (not always present)
–> All branches from the caeliac trunk!
How is the small intestine supplied with blood?
Duodenum:
- Branches of gastroduodenal artery
- Branches of superior mesenteric artery
Jejeum
- Jejunal arteries form superior mesenteric arteries
Ileum:
- Ilial arteries from superior mesenteric artery and
- ileal branch from ileocoliac artery
How are the cecum and appendix supplied with blood?
Via branches of superior mesenteric artery (branches of ileocolic artery)
Which vessel supplied the cecum and appendix with blood?
Branches from the ileocolic atery (a branch of the superior mesenteric artery)
How does the parietal peritoneum and visceral peritoneum differ in pain sensation?
Parietal: localised pain
Visceral: dull, referred pain
Which important arterys are branche of the caeliac trunk?
Left gastric artery (smallest branch)
Splenic artery (largest branch)
Common hepatic artery
What is meant by the bare area of the liver?
The are where the liver is not covered in visceral peritoneum because it fused in development
–> Has direct contact to diaphragm
In which two surfaces can the liver be subevided?
It can be subdivided in the Diaphragmatic (anterior, superior and posterior surface)
And in the visceral surface (inferior)
Which recesses are associated with the diaphragmatic surface of the liver? Where are they located?
- Subphrenic recess (superior, separates diaphragmatic surface from the diaphragm). It is divided by the falciform ligament in right and left areas
- Hepatorenal recess –> part of the peritoneal cavity (between the liver, and right kidney(suprarenal gland))
Was ist ein Recessus? (Recess)
Mit einem Recessus (lateinisch, maskulin, Plural Recessūs mit langem u, von re~ „zurück~“ und cedere „weichen“, „gehen“) wird in der Anatomie das „Zurückgehen“ einer Struktur oder ihre Einbiegung, Vertiefung, ihr Winkel, ihre Tasche oder Nische bezeichnet.
Which structures relate to the visceral surface of the liver?
It is covered in visceral peritoneum except in the fossa for the gallbladder and it is associated with
- esophagus
- right anterior oart of stomach
- superior part of duodenum
- lesser omentum
- gallbladder
- rigth colic flexure
- right transverse colon
- Right kindney + suprarenal gland
What structure in the liver serves as a point of entry into the liver for the hepatic arteries and portal veins?
The porta hepatis
Which associated ligaments surround the liver?
- The falciform ligament (separeates two lobes, attaches it to anterior abdominal wall)
- Connection to the stomacch (hepatogastric ligament)
- Connection to the duodenum (hepatoduodenal ligament)
- Connection to diaphragm (left and right triangular ligaments + anterior and posterior coronary ligaments)
*
Where are the quadrate and caudate lobe of the liver located? Where do they structurally and functionally belong to?
Structure: Both derived from right hepatic lobe
But
- The quadrate lobe is positioned anteriorly + functionally related to the left lobe of the liver
- The Caudate lobe is positioned posteriorly and functionally separate to both lobes of liver
(Picture= inferior view)
Name the different parts of the gall bladder
What is the embryological origin of the spleen? (Where does it develop)?
It develops in the dorsal mesentery as part of the vascular system
How would you describe the position of the spleen in adults?
(Position + relations)
It can be found in the are of rib IX to rib X
It is surrounded by visceral peritoneum except for the hilum of the spleen
Connected to:
- the greater curvature of the stomach (by gastrosplenic ligament, containing short gastric and gastro-omental vessels)
- Left kidney by a splenorenal ligament (contains splenic vessels)
—> Both are part of greater omentum
What is the blood supply of the spleen?
It is supplied by splenic artery, the largest branch of the celiac trunk
Which structures lie retroperitoneally in the abdomen?
Which of them had originally a mesentey?
–Kidneys & ureters
–Suprarenal glands
–Aorta/Inferior vena cava
–Nerves: lumbar plexus, sympathetic trunk
–Oesophagus
–Rectum
–Duodenum (except the first part) *
–Pancreas (tail is INTRAperitoneal) *
–Colon (ascending and descending only)*
*These organs originally had a mesentery, then became secondarily retroperitoneal when the mesentery fused with the body wall
Draw/imagine the organisation of the great abdominal vessels, pancreas, duodenum, kindeys and spleen to one another
Describe the relationships of the liver and the jejunum to the kidneys
Note the relations of both kidneys, remembering that the liver is anterior to the upper part of the R kidney and the jejunum to the lower part of the L kidney