Ingegneria delle tecnologie per la salute
Fondamenti di anatomia e istologia
aa. 2019-20
Lesson 7. Digestive system and peritoneum
Peritoneum, abdominal vessel
and spleen
= a thin serous membrane that line walls of abdominal and pelvic cavities and cover organs within these cavities •Parietal peritoneum -lines walls of abdominal and pelvic cavities •Visceral peritoneum -covers organs •Peritoneal cavity - potential space between parietal and visceral layer of peritoneum, in male, is a closed sac, but in female, there is a communication with exterior through uterine tubes, uterus, and vagina
PERITONEUM: General features
Function
• Secretes a lubricating serous fluid that continuously moistens associated organs
• Absorb • Support viscera
Peritoneum Histology
The peritoneum is a serosal membrane that consists of a single layer of mesothelial cells and is supported by a basement membrane.
The layer is attached to the body wall and viscera by a glycosaminoglycan matrix that contains collagen fibers, vessels, nerves, macrophages, and fat cells.
relationship between viscera and peritoneum
• Intraperitoneal viscera -viscera completely surrounded by peritoneum, example, stomach, superior part of duodenum, jejunum, ileum, cecum, vermiform appendix, transverse and sigmoid colons, spleen and ovary
• Interperitoneal viscera -most part of viscera surrounded by peritoneum, example, liver, gallbladder, ascending and descending colon, upper part of rectum, urinary bladder and uterus
• Retroperitoneal viscera -some organs lie on the posterior abdominal wall and are covered by peritoneum on their anterior surfaces only, example, kidney, suprarenal gland, pancreas, descending and horizontal parts of duodenum, middle and lower parts of rectum, and ureter
Intraperitoneal viscera
Interperitoneal viscera
Retroperitoneal viscera
Interperitoneal viscera
Structures which are formed by peritoneum
Omentum = 2-layered fold of peritoneum that extends from stomach to adjacent organs
Structures which are formed by peritoneum
Lessor omentum
2-layered fold of peritoneum which extends from porta hepatis to lesser curvature of stomach and superior part of duodenum
• Hepatogastric ligament -extends from porta hepatis to lesser curvature of stomach
• Hepatoduodenal ligament Extends from porta hepatis to superior part of duodenum
– Contains common bile duct, proper hepatic a. and hepatic portal v.
• Behind the right border of hepatoduodenal ligament
• Superior-caudate lobe of liver
• Inferior-superior part of duodenum
• Anterior-hepatodudenal ligament
• Posterior-peritoneum covering the inferior vena cava
Omental foramen
Greater omentum -four-layered fold of
peritoneum, the anterior two layers descend from the greater curvature of stomach and superior part of duodenum and hangs down like an apron in front of coils of small intestine, and then turns upward and attaches to the transverse colon. If an infection occurs in the intestine, plasma cells formed in the lymph nodes combat the infection and help prevent it from spreading to the peritoneum.
Structures which are formed by peritoneum
Lessor omentum
Greater omentum
Structures which are formed by peritoneum
Omental bursa Position-situated behind the lesser omentum
and stomach Walls • Superior-peritoneum which covers the
caudate lobe of liver and diaphragm • Anterior-formed by lesser omentum,
peritoneum of posterior wall of stomach, and anterior two layers of greater omentum
• Inferior-conjunctive area of anterior and posterior two layers of greater omentum
• Posterior-formed by posterior two layers of greater omentum, transverse colon and transverse mesocolon, peritoneum covering pancreas, left kidney and suprarenal gland
Structures which are formed by peritoneum
• Left-formed by the spleen, gastrosplenic ligament and splenorenal ligament
• Right-formed by omental foramen
The Omental bursa (lesser sac) communicates with the greater sac through the omental foramen.
Structures which are formed by peritoneum
Mesenteries or mesocolons-two-layered fold of peritoneum that attach part of the intestines to the posterior abdominal wall
Structures which are formed by peritoneum
Mesentery -suspends small intestine
from posterior abdominal wall
• Broad and a fan-shaped
• Consists of two peritoneal layers
• Intestinal border-folded, 7 m long
• Radix of mesentery – 15 cm long
– Directed obliquely from left side of L2 to in front of right sacroiliac joint
Structures which are formed by peritoneum
Structures which are formed by peritoneum
Mesoappendix • Triangular mesentery-extends from terminal part of ileum to appendix
• Appendicular artery runs in free margin of the mesoappendix
Structures which are formed by peritoneum
Transverse mesocolon -a double fold of peritoneum which connects the transverse colon to the posterior abdominal wall
Sigmoid mesocolon -inverted V-shaped, with apex located in front of left ureter and division of common iliac artery
Structures which are formed by peritoneum
Ligaments -two-layered folds of
peritoneum that attached the lesser mobile solid viscera to the abdominal wall
Ligaments of liver
• Falciform ligament of liver – Consists of double peritoneal
layer – Extends from anterior
abdominal wall (umbilicus) to live
– Free border of ligament site of ligamentum teres
Structures which are formed by peritoneum
• Coronary ligament -the area between upper and lower parts of the coronary ligament is the bare area of live, this area is devoid of peritoneum and lies in contract with the diaphragm
• Left and right triangular ligaments
-formed by right extremity of coronary ligament and left leaf of falciform ligament, respectively
Structures which are formed by peritoneum
• Hepatogastric ligament
• Hepatoduodenal ligament
• Ligamentum teres hepatis
Structures which are formed by peritoneum
Ligaments of spleen • Gastrosplenic ligament -
a double layer of peritoneum that connects the fundus of stomach to hilum of spleen. In this double layer of peritoneum are the short gastric and left gastroepiploic vessels
• Splenorenal ligament -extends between the hilum of spleen and anterior aspect of left kidney. The splenic vessels lies within this ligament, as well as the tail of pancreas
• Phrenicosplenic ligament • Splenocolic ligament
Structures which are formed by peritoneum
Ligaments of stomach
• Hepatogastric ligament • Gastrosplenic ligament • Gastrophrenic ligament • Gastrocolic ligament • Gastropancrestic ligament
Structures which are formed by peritoneum
Folds and recesses of posterior abdominal wall
• Superior duodenal fold and recess
• Inferior duodenal fold and recess
• Intersigmoid recess -formed by the inverted V attachment of sigmoid mesocolon
Structures which are formed by peritoneum
• Retrocecal recess - in which the appendix frequenty lies
• Hepatorenal recess - lies between the right lobe of liver, right kidney, and right colic flexure, and is the lowest parts of the peritoneal cavity when the subject is supine
Structures which are formed by peritoneum
Folds and fossas of anterior abdominal wall • Median umbilical fold -
contain the remnant of urachus (median umbilical ligaments)
• Medial umbilical fold -contains remnants of the umbilical arteries (medial umbilical ligaments)
• Lateral umbilical fold -contains the inferior epigastric vessels
• Supravesical fossa • Medial inguinal fossa • Lateral inguinal fossa
Structures which are formed by peritoneum
Pouches
• In male-rectovesical pouch
• In female – Rectouterine pouch -between rectum and uterus
– Vesicouterine pouch -between bladder and uterus
Structures which are formed by peritoneum
Peritoneal subdivisions The transverse colon and
transverse mesocolon divides the greater sac into supracolic and infracolic compartments.
Supracolic compartments
(subphrenic space)-lies between diaphragm and transverse colon and transverse mesocolon
Suprahepatic recess lies between the diaphragm and live-the falciform ligament divides it into right and left suprahepatic recesses
Structures which are formed by peritoneum
• Left suprahepatic recesses – left anterior suprahepatic
spaces
– left posterior suprahepatic spaces
• Right suprahepatic recesses – right anterior suprahepatic
spaces
– right posterior suprahepatic spaces
– bare area of live (extraperitoneal space)
Structures which are formed by peritoneum
Infrahepatic recess
lies between the liver and transverse colon and transverse mesocolon-the ligamentum teres hepatic divides it into right and left infrahepatic recesses
• Right infrahepatic recesses (hepatorenal recess)
• Left infrahepatic recesses
– left anterior infrahepatic space
– left posterior infrahepatic space
Structures which are formed by peritoneum
Infracolic compartments -lies below the transverse colon and transverse mesocolon
• Right paracolic sulcus (gutter) • -lies lateral to the ascending colon.
It communicates with the hepatorenal recess and the pelvic cavity. It provides a route for the spread of infection between the pelvic and the upper abdominal region.
• Left paracolic sulcus (gutter) • -lies lateral to the descending colon.
It is separated from the area around the spleen by the phrenicocolic ligament, a fold of peritoneum that passes from the colic flexure to the diaphragm.
Structures which are formed by peritoneum
• Right mesenteric sinus -triangular space, lies between root of mesentery, ascending colon, right 2/3 of transverse colon and transverse mesocolon
• Left mesenteric sinus -lies between root of mesentery, descending colon, right 1/3 of transverse colon and transverse mesocolon, its widens below where it is continuous with the cavity of the pelvis
Structures which are formed by peritoneum
Supracolic region
Structures which are formed by peritoneum
abdominal part of esophagus
stomach
duodenum
liver
extrahepatic biliary apparatus
spleen
pancreas
ABDOMINAL VESSELS
Abdominal aorta • Continuation of
thoracic aorta at aortic hiatus of diaphragm in front of T12
ABDOMINAL VESSELS
• Terminates at lower border of L4 vertebra by dividing into right and left common iliac arteries
Parietal branches • Inferior phrenic a.
(one pair)
• Lumbar a. (four
pairs of arteries that
supply the posterior
abdominal wall)
• Median sacral a.
ABDOMINAL VESSELS
Visceral branches
• Paired branches – Middle suprarenal
artery
– Renal artery
– Testicular (ovarian) artery
ABDOMINAL VESSELS
• Unpaired branches – Celiac trunk
– -a short thick vessel that arises from the front of aorta, at the level of T12
– Superior mesenteric a. -arises from the front of aorta, at the level of L2
– Inferior mesenteric a. -arises from the front of aorta, at level of L3
ABDOMINAL VESSELS
Left gastric a.
Common
hepatic a. Splenic a.
Gastroduodenal a.
Proper hepatic a.
Right gastric a.
Left branch
Right branch
Cystic a.
Short gastric a.
Left gastrioeploic a.
Right gastroepiploic a.
Superior pancreaticoduodenal a.
Splemic branches
Celiac trunk
ABDOMINAL VESSELS
Celiac trunk
ABDOMINAL VESSELS
Superior
mesenteric a.
Inf. pancresticodudenal a.
Jejunal and ileal a. Ileocolic a.
Appendicular a.
Right colic a.
Middle colic a. Superior
Mesenteric v.
ABDOMINAL VESSELS
Inferior mesenteric a.
Left colic a.
Sigmoid a.
Superior rectal a.
Inferior mesenteric v. ABDOMINAL VESSELS
Colic marginal artery
ABDOMINAL VESSELS
Relations of abdominal aorta
• Anteriorly (from above
downward)
– Pancreas
– Ascending part of duodenum
– Radix of mesentery
• Posteriorly
– Upper four lumber vertebrae
• On its right
– Inferior vena cava
• On its left
– Left sympathetic trunk
ABDOMINAL VESSELS
Veins of abdomen and pelvis
Internal iliac vein • Parietal tributaries: accompany with arteries
• Visceral tributaries
→superior rectal vein→inferior mesenteric v.
①Rectal venous plexus →inferior rectal vein→internal iliac v.
→anal vein→internal pudendal v.
②Vesical venous plexus →vesical v.
③Uterine venous plexus →uterine v.
ABDOMINAL VESSELS
• External iliac vein– accompany the artery
• Common iliac vein– formed by union of internal and external iliac veins in front of sacroiliac joint, end upon L4~L5 by uniting each other to form inferior vena cava
ABDOMINAL VESSELS
Inferior vena cava • Formed by union of two
common iliac veins anterior to and just to the right of L4~L5
• Ascends on the right side of aorta, pierces vena cava foramen of diaphragm opposite the T8 and drains into the right atrium
• Conveys blood from the whole body below the diaphragm to the right atrium
ABDOMINAL VESSELS
Chief tributaries • Parietal
– Paired inferior phrenic v.
– paired lumbar v. (four)
• Visceral
– Right and left renal veins
– Right suprarenal vein (left drain into left renal vein)
– Right testicular or ovarian v. (left drain into left renal vein)
– Hepatic veins : right, left and intermediate
ABDOMINAL VESSELS
Relations of inferior vena cava • Anteriorly (cranially to caudally)
– Liver
– Head of pancreas
– Horizontal part of duodenum
– Right testicular (or ovarian) a.
– Radix of mesentery
• Posteriorly – Right crus of diaphragm
– Upper four lumber vertebrae
– Left sympathetic trunk
– Parietal branches of abdominal aorta
• On its right – Psoas major
– Right kidney
– Right suprarenal gland
• On its left – Abdominal aorta
ABDOMINAL VESSELS
Hepatic portal vein
General features
• Formed behind the neck of pancreas by the union of superior mesenteric vein and splenic vein
• Ascends upwards and to the right, posterior to the first part of duodenum and then enters the lesser omentum to the porta hepatis, where it divides into right and left branches
• There are no functioning valves in hepatic portal system
• Drains blood from gastrointestinal tract from the lower end of oesophagus to the upper end of anal canal, pancreas, gall bladder, bile ducts and spleen
ABDOMINAL VESSELS
Variation and anomalies
of hepatic portal vein
ABDOMINAL VESSELS
Tributaries of
hepatic portal
vein
1. Superior mesenteric
v.
2. Inferior mesenteric v.
3. Splenic v.
4. Left gastric v.
5. Right gastric v.
6. Cystic v.
7. Paraumbilical v.
ABDOMINAL VESSELS
Portal-systemic anastomoses
1. At the lower end of the oesophagus Hepatic portal vein → left gastric vein → esophageal
venous plexus → esophageal vein → azygos vein
→ superiorvena cava
2. At rectal venous plexus Hepatic portal vein → splenic vein → inferior mesenteric
vein → superior rectal vein → rectal venous plexus →
inferior rectal and anal veins → internal iliac vein →
inferior vena cava
3. At periumbilical venous plexus Hepatic portal vein→paraumbilical vein→periumbilical
venous plexus→
– thoracoepigastric and superior epigastric vein → superiorvena cava
– superficial epigastric and inferior epigastric veins → inferior vena cava
ABDOMINAL VESSELS
4. Portal-retroperitoneal anastomosis
Between the retroperitoneal branches of the colic veins and the lumbar veins, pancreaticoduodenal veins with the renal veins and the subcapsular veins of the liver with the phrenic veins twigs of colic veins (portal) anastomosing with systemic retroperitoneal veins
ABDOMINAL VESSELS
Lymphatic drainage of
abdominal wall
• To axillary lymph node from
region above umbilicus
• To superficial inguinal lymph
node from region below
umbilicus
• To lumbar lymph node from
post wall of abdomen
Lymphatic drainage of abdomen
Lymphatic drainage of abdominal viscera
• Lumbar lymph nodes
– Lie on posterior abdominal wall, along the abdominal aorta and inferior vena cava
– Receive lymph from kidneys, suprarenal glands, testes, ovaris, fundus of uterus, ovary, and common iliac nodes
– Right and left lumbar trunks formed by efferent vessel
– Paired viscera-drain to the lumbar lymph nodes
Lymphatic drainage of abdomen
• Celiac lymph nodes -situated around the celiac trunk
• Superior mesenteric lymph node -situated around superior mesenteric a.
• Inferior mesenteric lymph node -situated around inferior mesenteric a.
• Intestinal trunk -formed by efferent vessel of celiac, superior and inferior lymph nodes
Lymphatic drainage of abdomen
Thoracic duct • Begins in front of L1 as a dilated sac, the cisterna
chyli, which formed by joining of left and right lumbar trunks and intestinal trunk
• Enter thoracic cavity by passing through aortic hiatus of the diaphragm and ascends along on the front of the vertebral column, between thoracic aorta and azygos vein
• Travels upward, veering to left at the level of T5
• At the roof of the neck, it turns laterally and arches forwards and descends to enter the left venous angle
• Just before termination, it receives the left jugular, subclavian and bronchomediastinal trunks
• Drains lymph from lower limbs, pelvic cavity, abdominal cavity, left side of thorax, and left side of the head, neck and left upper limb
Lymphatic drainage of abdomen
Location: lies in the left
hypochondriac region
(between stomach
and diaphragm) deep
to the 9th to 11th rib,
its long axis
corresponds roughly
to the 10th rib
Shape-reddish in
colour
Spleen
Two surfaces
• Diaphragmatic: smooth, convex
• Visceral: concave, hilum of spleen
Two extremities
• Anterior-wider
• Posterior-rounder
Two border
• Superior-has 2-3 splenic notch, which serve as a landmark on palpation when it is enlarge; normally it is not palpable
• Inferior-rounder
Functions: considered to be important in:
• Formation of lymphocytes and monocyte
• Phagocytosis of bacteria, inert particles and white blood cells and platelets
• Destroying effete or abnormal red blood cells
• Making antibodies
Spleen
Erythrocyte storage
Phagocytosis Cytopoiesis Immune
responses
Spleen function
Relationships of spleen
Diaphragmatic surface
-diaphragm
Visceral surface
• Anteriorly-fundus of
stomach
• Posteriorly-left
suprarenal gland and
kidney
• Inferiorly-tail of
pancreas and left colic
flexure
Spleen
Spleen: Histology
Spleen: Histology
Spleen: Histology