Regions of abdominal

For the purpose of description clinicians use planes to refer nine regions of the abdominal cavity to describing the location of the organs

They use four planes two horizontal and two vertical

The nine regiona are:

Regions and their contentsRight Hypochondriac

Epigastric Left Hypochondriac

Digestive:     Liver     Gall Bladder     Small Intestine     Ascending Colon     Transverse Colon

Endocrine:     Right Kidney

Excretory:     Right Kidney

Lymphatic:     NONEReproductive:    

Digestive:     Esophagus     Stomach     Liver     Pancreas     Small Intestine     Transverse ColonEndocrine:     Right & Left Adrenal Glands     Pancreas     Right & Left KidneysExcretory:     Right & Left Kidneys     Right & Left UretersLymphatic:     SpleenReproductive:     NONE

Digestive:     Stomach     Liver (tip)     Pancreas (tail of)     Small Intestine     Transverse Colon     Descending ColonEndocrine:     Pancreas     Left Kidney

Excretory:     Left Kidney

Lymphatic:     SpleenReproductive:     NONE

Right lumber umbilicus Left lumber

Digestive:     Liver (tip)     Gall Bladder     Small Intestine     Ascending ColonEndocrine:     Right Kidney

Excretory:     Right Kidney

Lymphatic:     NONEReproductive:     NONE

Digestive:     Stomach     Pancreas     Small Intestine     Transverse Colon

Endocrine:     Pancreas     Right & Left KidneysExcretory:     Right & Left Kidneys     Right & Left UretersLymphatic:     Cisterna chyliReproductive:     NONE

Digestive:     Small Intestine     Descending Colon

Endocrine:     Left Kidney (tip)

Excretory:     Left Kidney (tip)

Lymphatic:     NONEReproductive:     NONE

Right iliac hypo gastric Left iliac

Digestive:     Small Intestine     Appendix     Cecum & Ascending ColonEndocrine:     Right Ovary (Females)Excretory:     NONE

Lymphatic:     NONEReproductive:     Female -           Right Ovary          Right Fallopian Tube     Male -          NONE

Digestive:     Small Intestine     Sigmoid Colon     RectumEndocrine:          Right & Left Ovaries (Fem.)Excretory:     Right & Left Ureters     Urinary BladderLymphatic:     NONEReproductive:     Female -           Uterus *          Right & Left Ovaries          Right & Left Fallopian Tubes     Male -          Vas Deferens          Seminal Vessicle          Prostate

Digestive:     Small Intestine     Descending Colon     Sigmoid ColonEndocrine:     Right Ovary (Females)Excretory:     NONE

Lymphatic:     NONEReproductive:     Female -           Left Ovary          Left Fallopian Tube     Male -          NONE

Abdominal Wall & Cavity

The abdomen is the part of the trunk inferior to the thorax.

Its musculomembranous walls surround a large cavity (the abdominal cavity)

is bounded superiorly by the diaphragm and inferiorly by the pelvic inlet.

The abdominal cavity may extend superiorly as high as the fourth intercostal space, and is continuous inferiorly with the pelvic cavity.

It contains the peritoneal cavity and the abdominal viscera.

LAYERS OF THE ABDOMINAL WALL

 (external to internal):1. Skin2. Superficial fascia (or subcutaneous tissue)3. Muscles and associated fascia4. Parietal peritoneum

The Superficial Fascia Above the umbilicus: A single sheet of connective tissue. This continuous

with the superficial fascia in other regions of the body. Below the umbilicus: It is divided into two layers; the fatty superficial layer

(Camper’s fascia) and the membranous deep layer (Scarpa’s fascia). Superficial vessels and nerves run between these two layers of fascia.

Muscles of the Abdominal Wall There are five muscles in the abdominal wall. They can be divided into two

groups: Vertical muscles – There are two vertical muscles, situated near the mid-line of

the body. the Rectus Abdominis and Pyramidalis. Flat muscles – There are three flat muscles, situated laterally. the external oblique, internal oblique and transversus abdominis.

ABDOMINAL VISCERA AND PERITONEAL CAVITY

Visceral peritoneum is a thin membrane (the peritoneum) lines the walls of the abdominal cavity and covers much of the viscera.

The parietal peritoneum lines the walls of the cavity and the visceral peritoneum covers the viscera.

Between the parietal and visceral layers of peritoneum is a potential space (the peritoneal cavity).

Abdominal viscera either are suspended in the peritoneal cavity by folds of peritoneum (mesenteries) or are outside the peritoneal cavity.

Organs suspended in the cavity are referred to as intraperitoneal; organs outside the peritoneal cavity, with only one surface or part of one surface covered by peritoneum, are retroperitoneal.

The peritoneal cavity is subdivided into the greater sac and the omental bursa (lesser sac) :

I. The greater sac accounts for most of the space in the peritoneal cavity, beginning superiorly at the diaphragm and continuing inferiorly into the pelvic cavity.

II. The omental bursa is a smaller subdivision of the peritoneal cavity posterior to the stomach and liver and is continuous with the greater sac through an opening, the omental (epiploic) foramen.

EsophagusThe esophagus is a tubular structure that

joins the pharynx to the stomach. The esophagus pierces the diaphragm slightly to the left of the midline and after a short course of about 0.5 inch. (1.25 cm) enters the stomach on its right side. It is deeply placed, lying behind the left lobe of the liver

It is a straight muscular tube connecting the oral cavity to the stomach It is about 25cm long and 2cm wide

The esophagus is a muscular canal, about 23 to 25 cm. long, extending from the pharynx to the stomach. It begins in the neck at the lower border of the cricoid cartilage, opposite the sixth cervical vertebra, descends along the front of the vertebral column, through the superior and posterior mediastinum, passes through the diaphragm, and, entering the abdomen, ends at the cardiac orifice of the stomach, opposite the eleventh thoracic vertebra.

Esophageal constrictions

Normally, the esophagus has three anatomic constrictions at the following levels.

1-At the esophageal inlet, where the pharynx joins the esophagus, behind the cricoid cartilage (14-16 cm from the incisor teeth).

2-Where its anterior surface is crossed by the aortic arch and the left bronchus (25-27 cm from the incisor teeth).

3-Where it pierces the diaphragm (36-38 cm from the incisor teeth).

The distances from the incisor teeth are important as is useful for diagnostic endoscopic procedures.

Gastro esophageal junction

The junction between the esophagus and the stomach (the gastro

esophageal junction or GE junction) is not actually considered a

valve, although it is sometimes called the cardiac sphincter,

cardia or cardias, it actually better resembles a structure.

In much of the gastrointestinal tract, smooth muscles contract in

sequence to produce a peristaltic wave which forces a ball of food

(called a bolus) while in the esophagus. In humans, peristalsis is

found in the contraction of smooth muscles to propel contents

through the digestive tract.

Stomach

The stomach is a dilated part of the alimentary canal between the esophagus and the small intestine. It occupies the left upper quadrant, epigastric, and umbilical regions, and much of it lies under cover of the ribs. Its long axis passes downward and forward to the right and then backward and slightly upward.

The stomach lies between the oesophagus and the

duodenum (the first part of the small intestine). It is on

the left upper part of the abdominal cavity. The top of

the stomach lies against the diaphragm. Lying behind

the stomach is the pancreas. The greater omentum

hangs down from the greater curvature.

Two sphincters keep the contents of the stomach

contained. They are the esophageal sphincter (found

in the cardiac region, not an anatomical sphincter)

dividing the tract above, and the Pyloric sphincter

dividing the stomach from the small intestine.

The stomach is surrounded by parasympathetic (stimulant)

and orthosympathetic (inhibitor) plexuses (networks of

blood vessels and nerves in the anterior gastric, posterior,

superior and inferior, celiac and myenteric), which regulate

both the secretions activity and the motor (motion) activity

of its muscles.

In adult humans, the stomach has a relaxed, near empty

volume of about 45 ml. Because it is a distensible organ, it

normally expands to hold about 1 litre of food, but can hold

as much as 2-3 liters. The stomach of a newborn human

baby will only be able to retain about 30ml.

Sections of Stomach

The stomach is divided into 4 sections, each of which has different cells and functions. The sections are:

CardiaWhere the contents of the esophagus empty into the

stomach.FundusFormed by the upper curvature of the organ.Body or CorpusThe main, central region.PylorusThe lower section of the organ that facilitates emptying

the contents into the small intestine.

http://en.wikipedia.org/wiki/File:Regions_of_stomach.svg

Anatomy of Small Intestine

Small intestine

The small intestine is the longest part of the gastrointestinal tract and extends from the pyloric orifice of the stomach to the ileocecal fold. This hollow tube, which is approximately 6-7 m long with a narrowing diameter from beginning to end, consists of the duodenum, the jejunum, and the ileum.

Duodenum

The first part of the small intestine is the duodenum. This C-shaped structure, adjacent to the head of the pancreas, is 20-25 cm long and is above the level of the umbilicus; its lumen is the widest of the small intestine . It is retroperitoneal except for its beginning, which is connected to the liver by the hepatoduodenal ligament, a part of the lesser omentum.

Conti…………

The duodenum is divided into four sections1.superior part2.descending part3. inferior part4. ascending part

The superior part (first part) extends from the pyloric orifice of the stomach to the neck of the gallbladder

The descending part (second part) of the duodenum is just to the right of midline and extends from the neck of the gallbladder to the lower border of vertebra LII. This part of the duodenum contains the major duodenal papilla, which is the

common entrance for the bile and pancreatic ducts,and the minor duodenal papilla,

The inferior part (third part) of the duodenum is the longest section, crossing the inferior vena cava the aorta, and the vertebral column .

The ascending part (fourth part) of the duodenum passes upward on, or to the left of, the aorta to approximately the upper border of vertebra LII and terminates at the duodenojejunalflexure.

Jejunum

The jejunum represents the proximal two-fifths. It is mostly in the left upper quadrant of the abdomen and is larger in diameter and has a thicker wall than the ileum. Additionally, the inner mucosal lining of the jejunum is characterized by numerous prominent folds that circle the lumen

Ileum

Ileum makes up the distal three-fifths of the small intestine and is mostly in the right lower quadrant.

The ileum opens into the large intestine where the cecum and ascending colon join together.

Large intestine

The large intestine extends from the distal end of the ileum to the anus, a distance of approximately 1.5 m in adults. It absorbs fluids and salts from the gut contents, thus forming feces, and consists of the cecum, appendix, colon, rectum.

Cecum and appendix

The cecum is the first part of the large intestine It is inferior to the ileocecal opening and in the right iliac fossaThe cecum is continuous with the ascending colon at the entrance of the ileum and is usually in contact with the anterior abdominal wall.

The appendix is a narrow, hollow, blind-ended tube connected to the cecum. It has large aggregations of lymphoid tissue in its walls and is suspended from the terminal ileum by the mesoappendix , which contains the appendicular vessels.

colonThe colon extends superiorly from the cecum and

consists of the ascending, transverse,descending, and sigmoid colon . Its ascending and descending segments are retroperitoneal and its transverse and sigmoid segments are intraperitoneal. The final segment of the colon (the sigmoid colon) begins above the pelvic inlet and extends to the level of vertebra SIII, where it is continuous with the rectum . This S-shaped structure is quite mobile except at its beginning, where it continues from the descending colon.

Rectum and anal

Extending from the sigmoid colon is the rectum . The rectosigmoid junction is usually described as being at the level of vertebra SIII or at the end of the sigmoid mesocolon because the rectum is a retroperitoneal structure. The anal canal is the continuation of the large intestine inferior to the rectum.

Anatomy of Liver

The liver is a reddish brown organ with four lobes of unequal size and shape. A human liver normally weighs 1.4–1.6 kg (3.1–3.5 lb), and is a soft, pinkish-brown, triangular organ. It is both the largest internal organ (the skin being the largest organ overall) and the largest gland in the human body.

It is located in the right upper quadrant of the abdominal cavity, resting just below the diaphragm. The liver lies to the right of the stomach and overlies the gallbladder

The biliary tree&Biliary Flow

The term biliary tree is derived from the arboreal branches of the bile ducts. The bile produced in the liver is collected in bile canaliculi, which merge to form bile ducts. Within the liver, these ducts are called intrahepatic (within the liver) bile ducts, and once they exit the liver they are considered extrahepatic (outside the liver). The intrahepatic ducts eventually drain into the right and left hepatic ducts, which merge to form the common hepatic duct. The cystic duct from the gallbladder joins with the common hepatic duct to form the common bile duct.

Bile can either drain directly into the duodenum via the common bile duct, or be temporarily stored in the gallbladder via the cystic duct. The common bile duct and the pancreatic duct enter the second part of the duodenum together at the ampulla of Vater.

Lobes of The Liver

the liver is Divided into four lobes based on surface features. The falciform ligament is visible on the front (anterior side) of the liver. This divides the liver into a left anatomical lobe, and a right anatomical lobe.

If the liver is flipped over, to look at it from behind (the visceral surface), there are two additional lobes between the right and left. These are the caudate lobe (the more superior) and the quadrate lobe (the more inferior).

From behind, the lobes are divided up by the ligamentum venosum and ligamentum teres (anything left of these is the left lobe), the transverse fissure (or porta hepatis) divides the caudate from the quadrate lobe, and the right sagittal fossa, which the inferior vena cava runs over, separates these two lobes from the right lobe.

Each of the lobes is made up of lobules; a vein goes from the centre, which then joins to the hepatic vein to carry blood out from the liver.

On the surface of the lobules, there are ducts, veins and arteries that carry fluids to and from them.

Anatomy of Gall Bladder

Conti……………

he gallbladder is a hollow system that sits just beneath the liver.In adults, the gallbladder measures approximately 8 cm in length and 4 cm in diameter when fully distended. It is divided into three sections: fundus, body and neck. The neck tapers and connects to the biliary tree via the cystic duct, which then joins the common hepatic duct to become the common bile duct. The angle of the gallbladder is located between the costal margin and the lateral margin of the rectus abdominis muscle.

Parts of Gall Bladder

The gall bladder is consisting of the following parts if seen from below upwards and also backwards: the fundus, body, and the neck. Each of them is given a brief description below:

Conti……..

Funds: the lower free and the expanded end of the Gall bladder is known as the fundus of the gall bladder. It is projection from below the liver and its direction is downwards, forwards, and also to the right where it comes in contact with the anterior wall of the abdomen where it makes an angle of about thirty degrees.

Conti…………..

Body: the body of the gall bladder is the portion that is lying between that of the funds and also the neck. The direction of the body is upwards, backwards, and to the left.

Conti………………..

Neck: it is the “S” shaped curve present above the body, and extends up to the cystic duct. Direction is upwards, forwards and then takes a turn and becomes downwards and backwards. Sometimes there is a presence of some diverticulum’s known as the Hartmann’s pouch and this portion is often termed as the isthmus of the gall bladder.

Anatomy of Spleen

spleen, in healthy adult humans, is approximately 11 centimeters (4.3 in) in length. It usually weighs between 150 grams (5.3 oz) and 200 grams (7.1 oz) and lies beneath the 9th to the 12th thoracic ribs.

Anatomy Of Kidney

Relationship of the Kidneys to Vertebra and Ribs57

Figure 23.1b

They are retroperitoneal and are located in the

abdominal cavity.

They are at the level of T12 to L3, so they are at the costal margin, and the ribs protect them a little.

Even though they are protected by thoracic ribs, they are NOT in the thoracic cavity because they are below the diaphragm.

Conti……………

The kidney has a bean-shaped structure, each kidney has concave and convex surfaces. The concave surface, the renal hilum, is the point at which the renal artery enters the organ, and the renal vein and ureter leave. The kidney is surrounded by tough fibrous tissue, the renal capsule, which is itself surrounded by perinephric fat , renal fascia (of Gerota) and paranephric fat.

59

Arcuate arteries

Interlobular arteries

Interlobar arteries

Renal fascia

Conti…………

The superior border of the right kidney is adjacent to the liver; and the spleen, for the left border. Therefore, both move down on inhalation.

The kidney is approximately 11–14 cm in length, 6 cm wide and 4 cm thick.

It weighs about 150 Grams.The Superior part of the kidney has a

suprarenal gland(Adrenal Gland)

Blood Supply to Kidney61

AORTA RENAL ARTERY SEGMENTAL ARTERIES INTERLOBAR ARTERIES ARCUATE ARTERIES (form arcs) INTERLOBULAR ARTERIES

INTERLOBULAR VEIN ARCUATE VEIN INTERLOBAR VEINS SEGMENTAL VEINS RENAL VEIN INF. VENA CAVA

Internal Anatomy of the Kidneys62

Figure 23.3b

Interlobar artery

Ureter

the ureters are muscular tubes that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually 25–30 cm (10–12 in) long and ~3-4 mm in diameter.

In humans, the ureters arise from the renal pelvis on the medial aspect of each kidney before descending towards the bladder on the front of the psoas major muscle. The ureters cross the pelvic brim near the bifurcation of the iliac arteries (which they run over). This is a common site for the impaction of kidney stones (the others