Anatomical regions of the Greater and Lesser Omentum o Anatomy of Abdominopelvic Cavity ppt (slides 17-18).; Gilroy 144-

149,159; Moore 219o Greater Omentum Four layered “apron” of peritoneum that attaches to the greater

curvature of the stomach. It its normal position, it covers most of the abdominal viscera, anteriorly. Includes three continuous ligaments/parts:

****not covered in lecture and not on exam **** Gastrophrenic

o Connects inferior surface of the diaphragm to the stomach Gastrosplenic

o Connects spleen to stomach Gastrocolic

o “Apron” portion, connects from the greater curvature of the stomach, descends, turns under, and ascends to the transverse colon.

o Lesser Omentum Double layered peritoneum that connects lesser curvature of the

stomach/proximal duodenum to the liver. Space posterior to lesser omentum=omental bursa(lesser sac) The omental foramen travels from right to left, posterior to the

hepatoduodenal ligament, connecting the greater sac to the lesser. ****not covered in lecture and not on exam ****

Includes continuous two parts/ligaments: Hepatogastric

o Connects lesser curvature of stomach to the liver Hepatoduodenal

o Connects lesser curvature of stomach to duodenumo Contains the portal triad

Portal vein, hepatic artery, and bile ducto Oral quiz questions What organ is the greater and lesser Omentum attached to and be specific

about its location. A: Greater Omentum is attached to the greater curvature of the

Stomach. The Lesser Omentum is attached to the lesser curvature of the Stomach.

What can be found within the lesser Omentum that comes off the gall bladder?

A: Common bile Duct, Right/Left branch of the hepatic artery, and the hepatic artery itself.

What ligaments are found within the lesser Omentum? A: The Hepato-duodenal ligament and the Hepato-gastric ligament

Branches of the Splenic artery o Gilroy 210-211; Moore 264-265o Largest branch of the celiac trunk, travels along the superior border of

the pancreas posterior to omental bursa but anterior to left kidney.o Branching: Celiac trunk

Splenic a.o Left Gastroomental a. (Gastroepiploic)

Main branch of splenic a. Travels along greater curvature of the stomach

o Prancreatic Branches Multiple branches

****the below branches are not covered in lecture and not on exam ****

o Short Gastric a. Superior greater curvature of the stomach

o Posterior Gastric

Branches of the Common Hepatic artery (2 Questions) o Moore 324,326; Gilroy 210-211o Branching: Celiac Trunk

Common Hepatic a.o Proper Hepatic a.

Left common hepatic a. Right common hepatic a.

Cystic a.o Right Gastric a.

Lesser curvature of stomacho Gastroduodenal a.

****the below branches are not covered in lecture and not on exam ****

Right Gastroomental a. (Gastroepiploic) Right part of the greater curvature of the

stomach Anterior Superior Pancreaticoduodenal a. Posterior Superior Pancreaticoduodenal a.

Arterial blood flow to the Adrenal glands (p296 Moore)This material will not be covered in lecture at this level of detail. Just suprarenal arteries as paired branches from the abdominal aorta is enough. Likewise major suprarenal veins. This is extra more detailed info.

o Renal Arteries and Veins. The renal arteries arise at the level of the IV disc between the L1 and L2

vertebrae. The longer right renal artery passes posterior to the IVC. Typically, each artery divides close to the hilum into five segmental arteries that are end arteries (i.e., they do not anastomose significantly with other segmental arteries, so that the area supplied by each segmental artery is an independent, surgically resectable unit or renal segment). Segmental arteries are distributed to the renal segments as follows

The superior (apical) segment is supplied by the superior segmental artery; the antero-superior and antero-inferior segments are supplied by the antero-superior segmental and antero-inferior segmental arteries; and the inferior segment is supplied by the inferior segmental artery. These arteries originate from the anterior branch of the renal artery.

The posterior segmental artery, which originates from a continuation of the posterior branch of the renal artery, supplies the posterior segment of the kidney.

Multiple renal arteries are common and usually enter the hilum of the kidney. Extra hilar renal arteries from the renal artery or aorta may enter the external surface of the kidney, commonly at their poles. Several renal veins drain each kidney and unite in a variable fashion to form the right and left renal veins. The right and left renal veins lie anterior to the right and left renal arteries. The

longer left renal vein receives the left suprarenal vein, the left gonadal (testicular or ovarian) vein, and a communication with the ascending lumbar vein, then traverses the acute angle between the SMA anteriorly and the aorta posteriorly. Each renal vein drains into the IVC

o Suprarenal Arteries and Veins. The endocrine function of the suprarenal glands makes their abundant blood

sup-ply necessary. The suprarenal arteries branch freely before entering each gland so that 50–60 branches penetrate the capsule covering the entire surface of the glands. Suprarenal arteries arise from three sources:

Superior suprarenal arteries (6–8) from the inferior phrenic arteries. Middle suprarenal arteries (≤1) from the abdominal aorta near the level

of origin of the SMA. Inferior suprarenal arteries (≤1) from the renal arteries.

o Venous Drainage The venous drainage of the suprarenal glands occurs via large suprarenal veins.

The short right suprarenal vein drains into the IVC, whereas the longer left suprarenal vein, often joined by the inferior phrenic vein, empties into the left renal vein.

External and Internal anatomy of the Stomach (p231 Moore)o ***This material will not be covered in lecture at this level of detail***.o The size, shape, and position of the stomach can vary markedly in persons

of different body types (bodily habitus)and may change even in the same individual as a result of diaphragmatic movements during respiration, the stomach’s contents (empty vs. after a heavy meal), and the position of the person. In the supine position, the stomach commonly lies in the right and left upper quadrants, or epigastric, umbilical, and left

hypochondrium and flank regions (Fig. 2.36A). In the erect position, the stomach moves inferiorly. In asthenic (thin, weak) individuals, the body of the stomach may extend into the pelvis (Fig. 2.36B).The stomach has four parts (Figs. 2.36A and 2.37A–C):

o Cardia: The part surrounding the cardial orifice, the superior opening or inlet of

the stomach. In the supine position, the cardial orifice usually lies posterior to the 6th left costal cartilage, 2–4 cm from the median plane at the level of the T11 vertebra.

o Fundus: The dilated superior part that is related to the left dome of the diaphragm

and is limited inferiorly by the horizontal plane of the cardial orifice. The cardial notch is between the esophagus and the fundus. The fundus maybe dilated by gas, fluid, food, or any combination of these. In the supine position, the fundus usually lies posterior to the left 6th rib in the plane of the MCL (Fig. 2.36A).

o Body: the major part of the stomach between the fundus and pyloric antrum.o Pyloric part: the funnel-shaped out flow region of the stomach; its wider part, the

pyloric antrum, leads into the pyloric canal, its narrower part (Fig. 2.37A–E). The pylorus (G., gatekeeper) is the distal, sphincteric regionof the pyloric part. It is a marked thickening of the circular layer of smooth muscle that controls discharge of the stomach contents through the pyloric orifice (inferior opening or outlet of the stomach) into the duodenum(Fig. 2.37D). Intermittent emptying of the stomach occurswhen intragastric pressure overcomes the resistance of thepylorus. The pylorus is normally tonically contracted sothat the pyloric orifice is reduced, except when emitting chyme (semifluid mass). At irregular intervals, gastricperistalsis pushes the chyme through the pyloric canal and orifice into the small intestine for further mixing, digestion, and absorption.

In the supine position, the pyloric part of the stomach lies at the level of the transpyloric plane, midway between the jugular notch superiorly and the pubic crest inferiorly (Fig. 2.36A).

*** This material will not be covered in lecture and not on exam.*** The plane transects the 8th costal cartilages and the L1 verte-bra. When

erect its location varies from the L2 through L4 ver-tebra. The pyloric orifice is approximately 1.25 cm right of the midline. The stomach also features two curvatures (Fig. 2.37A–C):

o Lesser curvature:

forms the shorter concave right bor-der of the stomach. The angular incisure (notch), the most inferior part of the curvature, indicates

the junction of the body and pyloric part of the stomach (Fig. 2.37A &B). The angular incisure lies just to the left of the midline.

o Greater curvature: forms the longer convex left border of the stomach.*** This material will not

be covered in lecture.*** It passes inferiorly to the left from the junction of the 5th intercostal space and MCL, then curves to the right, passing deep to the 9th or 10th left car-tilage as it continues medially to reach the pyloric antrum****. Because of the unequal lengths of the lesser curvature on the right and the greater curvature on the left, in most people the shape of the stomach resembles the letter J.

o Interior Stomach: The smooth surface of the gastric mucosa is reddish brown during life,

except in the pyloric part, where it is pink. In life, it is covered by a continuous mucous layer that protects its surface from the gastric acid the stomach’s glands secrete. When contracted, the gastric mucosa is thrown into longitudinal ridges or wrinkles called gastric folds(gastric rugae)(Fig. 2.38A & B);

***This material will not be covered in lecture.*** they are most marked toward the pyloric part and along the greater curvature. During swallowing, a temporary groove or furrow-like gastric canal forms between the longitudinal gastric folds along the lesser curvature. It can be observed radiographically and endoscopically. The gastriccanal forms because of the firm attachment of the gastricmucosa to the muscular layer, which does not have an obliquelayer at this site. Saliva and small quantities of masticated food and other fluids drain along the gastric canal to the pyloric canal when the stomach is mostly empty. The gastric folds diminish and obliterate as the stomach is distended (fills)****.

oLayering of stomach musculature more important than most of this detail.

Similarities and Anatomical Differences between jejunum and ileum (pg.244 Moore)

Characteristics of jejunum and ileum – please refer to pic’s in Moore p. 244

Characteristic Jejunum IleumColor Deeper Red Paler pinkCaliber 2-4 cm 2-3 cmWall Thick and heavy Thin and lightVascularity Greater LessVasa Recta Long ShortArcades A few large loops Many short loopsFat in mesentery Less MoreCircular folds Large, tall and closely

packedLow and sparse, absent in distal parts

Lymphoid nodules Few Many

Hepatic Portal system o The hepatic portal system shunts oxygenated blood from the abdominal

aorta to the liver, and it shunts deoxygenated blood from the small intestine (via the superior mesenteric vein) and large intestine (via inferior mesenteric vein) to the hepatic portal vein which sends collected nutrients to the liver for processing.

Branches of the Abdominal Aorta (2 Questions) o Inferior phrenico Celiac Trunk

Left gastric Splenic

Short gastric (don’t worry to much about these branches. Refer to textbook and notes)

Splenic Left gastroepiploic

Hepatic Right hepatic

o Cystic Left hepatic

Right gastric Gastroduodenal

o Right gastroepiploico Renal aa

Inferior suprarenal arteryo Superior Mesenteric

Inferior pancreaticoduodenal Middle colic Right colic Intestinal a ileocolic

o Inferior Mesenteric Left colic Sigmoidal Superior rectal

o Lumbar aa (4 pairs)

***This material will not be covered in lecture and not on exam***.

Branches of the Internal Iliac aa. o Iliolumbaro Superior Gluteal ao Lateral sacralo Umbilical

Superior vesical Artery to ductus deferens (males)

o Obturatoro Inferior vesicalo Middle rectalo Internal pudendal

Inferior rectalo Inferior glutealo (Uterine a. and Vaginal a. in females)***

Blood flow to the Intestines (Moore pg 250.)

Origin Artery Distribution

Abdominal Aorta Superior Mesenteric Part of GI tract from midgutSuperior Mesenteric Intesinal (jejunal/ileal)

Middle colicRight colicIleocolic

Jejunum/IleumTransverse colonAscending colonIleum, cecum, ascending colon

Ileococlic artery Appendicular AppendixAbdominal Aorta Inferior mesenteric Supplies part of digestive

tract derived from hindgutInferior Mesenteric Left colic

SigmoidSuperior rectal

Descending colonDescending and sigmoid colonProximal part of rectum

Internal Iliac Middle rectal Midpart of rectumInternal pudendal Inferior rectal Distal part of rectum and

anal canal

Ligaments of the Liver ****This is in more detail than you will be expected to know**** The falciform ligament is a broad and thin antero-posterior peritoneal fold,

falciform in shape, its base being directed downward and backward, its apex upward and backward. It is situated in an antero-posterior plane, but lies obliquely so that one surface faces forward and is in contact with the peritoneum behind the right Rectus and the diaphragm, while the other is directed backward and is in contact with the left lobe of the liver. It is attached by its left margin to the under surface of the diaphragm, and the posterior surface of the sheath of the right Rectus as low down as the umbilicus; by its right margin it extends from the notch on the anterior margin of the liver, as far back as the posterior surface. It is composed of two layers of peritoneum closely united together. Its base or free edge contains between its layers the round ligament and the parumbilical veins.

The coronary ligament consists of an upper and a lower layer. The upper layer is formed by the reflection of the peritoneum from the upper margin of the bare area of the liver to the under surface of the diaphragm, and is continuous with the right layer of the falciform ligament. The lower layer is reflected from the lower margin of the bare area on to the right kidney and suprarenal gland, and is termed the hepatorenal ligament.

The triangular ligaments (lateral ligaments) are two in number, right and left. The right triangular ligament is situated at the right extremity of the bare area, and is a small fold, which passes to the diaphragm, being formed by the apposition of the upper and lower layers of the coronary ligament. The left triangular ligament is a fold of some considerable size, which connects the posterior part of the upper surface of the left lobe to the diaphragm; its anterior layer is continuous with the left layer of the falciform ligament.

The round ligament (ligamentum teres hepatis) is a fibrous cord resulting from the obliteration of the umbilical vein. It ascends from the umbilicus, in the free margin of the falciform ligament, to the umbilical notch of the liver, from which it may be traced in its proper fossa on the inferior surface of the liver to the porta, where it becomes continuous with the ligamentum venosum.

Structures of the porta hepatis (p. 270—Moore)The porta hepatis is a transverse fissure where all the following that supply/drain the liver enter and leave:

Vessels—hepatic portal vein (entering), hepatic artery (entering) and lymphatics

Hepatic nerve plexus common hepatic bile ducts (leaving)

Synthesis and Flow of Bile ****This is in more detail than you will be expected to know****

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.

*This is extra info that will most likely not be tested on*

Blood Flow through the Kidney (Gilroy Pg 176-179, 208-209/ Moore Pg 290-300)

Abdominal Aorta Renal Artery Segmental Artery Lobar Artery Interlobar Artery Arcuate Artery Interlobular Artery Afferent Arteriole Glomerulus Efferent Arteriole Peritubular Capillaries Interlobular Vein Arcuate Vein Interlobar Vein Renal Vein Inferior Vena Cava

Internal macroscopic anatomy of the kidney There are 3 layers of the kidney

1. Renal capsule2. Renal cortex3. Renal medulla

If the front half of the kidney is removed you can see it divided into three regions. The most external region is the renal cortex numerous tubes and blood vessels located in the cortex. Deep to the cortex is the renal medulla. This area is filled with renal pyramids. The expanded base of a pyramid lies adjacent to the cortex and the papilla is oriented toward the medial side of the kidney. Numerous tubules and ducts make up the pyramids. Next to the medulla is the renal sinus. This medial pocket contains the large blood vessels that pass in and out of the kidney and the tubes that conduct urine to the ureters and bladder.

Describe the dual autonomic innervation of the kidneys, the ureters, bladder and the adrenal glands. (Refer to Gilroy pgs. 245 – 247.)

*** Review from f rom previous exam ***

PARASYMPATHETIC INNERVATION TO KIDNEYS, URETERS, ADRENAL GLANDS

Preganglionic fibers from S2, 3, 4 unite to form Pelvic splanchnic nerves. Synapse with postganglionic neurons in the hypogastric plexus. Postganglionic fibers Ureters and Internal urethral sphincter = Initiate

micturition reflex.

Preganglionic fibers from the dorsal motor nucleus of CNX the vagus nerve. Synapse with postganglionic neurons in renal plexus. Vasodialtion of renal aa. Increased GFRIncreased urine output.

SYMPATHETIC INNERVATION TO ADRENAL GLANDS

Preganglionic neurons in lateral horn of gray matter at spinal cord levels T5 – T9. Preganglionic fibers travel as Greater thoracic splanchnic nerves THROUGH Celiac

ganglion. Synapse with postganglionic neurons = CHROMAFFIN CELLS in adrenal medulla. Chromaffin cells release epinephrine and norepinephrine into blood stream.

SYMPATHETIC INNERVATION TO KIDNEYS AND URETERS

Preganglionic neurons in lateral horn of gray matter at spinal cord level T12. Preganglionic fibers travel as Least splanchnic nerve to aorticorenal ganglion. Postgangionic fibers move through renal plexus to renal aa. Vasoconstriction of renal aa. Decreased GFRDecreased urine output.

SYMPATHETIC INNERVATION TO BLADDER/INTRENAL URETHRAL SPHINCTER

Preganglionic neurons in lateral horn of gray matter at spinal cord levels L1-L2. Preganglionic fibers travel as Lumbar splanchnic nerves to Hypogastric plexus. Synapse with postganglionic neuronsInduce contraction of Internal urethral

sphincter.

Gilroy Pg 176-179, 208-209

Moore Pg 290-300

. Name the organs that comprise the hindgut.- Distal ½ of the transverse colon, descending colon, sigmoid colon, and rectum

 2. Identify the vessels that supply blood to the rectum and the arteries from which they originate.

- Superior rectal artery - from the Inferior mesenteric artery- Middle rectal artery - from the internal iliac artery- Inferior rectal artery - from the internal pudendal artery, which is a branch of the internal iliac artery

 3. Locate the following on the model of the torso:

- Splenic flexure- Haustra- Taenia libra- Epiploic appendages

 4. The sigmoid colon is located on the posterior wall of the lower abdominal wall, and

upper region of the pelvic cavity. So why is it considered a portion of the hind gut, and not retroperitoneal?

- The sigmoid colon is completely covered by the peritoneum, and thus is part of the hind gut  5. The hind gut is innervated by two sets of nerves. What are they, and what type of innervation do they supply?

- The lumbar splanchnic nerves provide sympathetic innervation- The pelvic splanchnic nerves provide parasympathetic innervation

35. What structures, primarily composed of adipose, are associated with the greater and lesser curvatures of the stomach? Describe their function.

- Greater curvature: greater omentum- Lesser curvature: lesser omentum- The greater and lesser omenta function structurally as "shock absorbers" that surround and

protect the abdominal viscera from physical injury. The omenta also function as insulators, protecting the organs from temperature change.

36. Describe the flow of bile (beginning with its production in the liver and ending in the duodenum).

- Liver(production of Bile) Right and Left Hepatic Duct Common Hepatic Duct Cystic Duct Gallbladder (storage until needed) Cystic Duct Common Bile Duct (joining with the main pancreatic duct) Sphincter of Oddi Duodenum

***The following material will not be covered in lecture and not on your test. This is extra information for future medical anatomy courses***

Nerves of the Anterolateral Abdominal Wall – Iliohypogastric and Ilioinguinal nn. (Gilroy pp. 424-427, Moore pp. 193-194)

o The map of dermatomes of the anterolateral abdominal wall is almost identical to the map of peripheral nerve distribution. This is because the anterior rami of spinal nerves, T7-T12, which supply most of the abdominal wall, do not participate in plexus formation. The exception occurs at the L1 level, where the L1 anterior ramus bifurcates into two named peripheral nerves.

o The skin and muscles of the anterolateral abdominal wall are innervated by the following nerves:

Thoracoabdominal nerves: anterior rami of T7-T11 Lateral (thoracic) cutaneous branches: T7-T9 or T10 Subcostal nerves: large anterior ramus of spinal nerve T12 Iliohypogastric and Ilioinguinal nerves: terminal brances of the

anterior ramus of spinal nerve L1 During their couse though the anterolateral abdominal wall, the

thoracoabdominal, subcostal, and iliohypogastric nerves communicate with each other.

Nerves Origin Course DistributionThoracoabdominal Continuation of

lower (7th -11th ) intercostal nerves distal to costal margin

Run between 2nd and 3rd layers of abdominal muscles; branches enter subcutaneous tissue as lateral cutaneous branches of T10-T11 (in anterior axillary line) and anterior cutaneous branches of T7-T11 (parasternal line)

Muscles of anterolateral abdominal wall and overlying skin

Lateral (thoracic) cutaneous branches

7th- 9th intercostal nerves (ant rami of T7-T9)

Anterior division continue across costal margin in subcutaneous tissue

Skin of right and left hypochondriac regions

Subcostal Spinal nerve T12 Runs along inferior border of 12th rib; then passes onto subumbilical wall between second and third layers of abdominal muscles

Muscles of anterolateral abdominal wall (including most inf slip of external oblique) and overlying skin, superior to iliac crest and inferior to umbilicus

Iliohypogastric A superior terminal branch of anterior ramus of L1

Pierces trans. Abd. Muscle to course between 2nd and 3rd layers of abdominal muscles; branches pierce external oblique and aponeuroses of most inferior abdominal walls

Skin overlying iliac crest, upper inguinal, and hypogastric regions; internal oblique and transversus abdominal muscles

Ilioinguinal A inferior terminal branch

Passes between second and third layers of abdominal mauscles; then traverses inguinal canal

Skin of lower inguinal regions, mons pubis, anterior scrotum or labium majora, and

of anterior ramus of L1

adjacent medial thigh; inferiormost internal oblique and transversus abdominus