Gastro-intestinal tract
Stomach and intestine
THE STOMACH
The main function of the stomach is nto process and transport of the food.
Anatomically the J-shaped stomach can be divided into some major nregions: cardia with cardiac ostium, fundus or nfornix, corpus and pylorus. Last contains antrum, npyloric canal and pyloric ostium. nExternally stomach has anterior and posterior facies, nwhich meet each other in greater and lesser curvaturae. nLesser curvature orients to the right and upward and carries angular incisura.
Topography nof the Stomach
· nHolotopy: nStomach is disposed in left hypochondriac and proper epigastric nareas;
· nSkeletotopy: nStomach is related to the bodies of Th11 to L1 vertebrae. Cardiac ostium is disposed on level of the Th11 on the left from nbackbone, and pyloric ostium – on level of the nTh12-L1 to the right side; stomach fundus reaches the 5th intercostal space oleft medioclavicular line;
· nSyntopy: nthe diaphragm, left liver lobe and anterior abdominal wall adjoin to anterior nstomach wall. Posterior stomach surface adjoins to spleen, pancreas, and left kidney nwith left adrenal gland and transversal colon.
· n Stomach is covered by peritoneum from nall sides (intraperitoneally).
The nstomach wall, like the wall of most other parts of the digestive canal, nconsists of three layers: the mucosa (the innermost), the muscularis nand the serosal n– visceral sheet of peritoneum (the outermost). The mucosal nlayer itself can be divided into three layers: the mucosa (the epithelial nlining of the gastric cavity), the muscularis mucosae (low density smooth muscle cells) and the submucosal layer (consisting of connective tissue ninterlaced with plexi of the enteric nervous system). nMucous membrane contains the gastric fields, which carry the gastric npits, where the ducts of gastric glands open. Lesser curvaturae ncarries group of longitudinal folds. Mucous membrane forms in area of pyloric ostium pyloric valve, which regulates transition of bolus nof food into duodenum.
The second gastric layer, nthe muscularis, can also be divided into nthree layers: the longitudinal (the most superficial), the circular and the noblique. The thickness of the circular layer increases in the antrum and especially in the pyloric sphincter, which controls the rate of discharge of stomach ncontents into the duodenum. The nlongitudinal layer of the muscularis can be separated ninto two different categories: a longitudinal layer that is common with the noesophagus and ends in the corpus, and a longitudinal layer that originates ithe corpus and spreads into the duodenum. The oblique layer of the muscularis is clearly seen in the fundus and near the nlesser curvature of the corpus, but the oblique fibbers disappear distally n(towards the antrum). The outermost main layer is the nserosa. Double layer of peritoneum forms hepatogastric, ngastrophrenic, gastrocolic and ngastrolienal ligaments.
The OESOPHAGUS is about 25-
Oesophageal wall consists of mucous membrane, submucous stratum, muscular membrane and external nconnective tissue adventitia. Submucous nstratum is well developed, that why mucous membrane forms the longitudinal nfolds. Submucous stratum contains the numerous of noesophageal glands. Muscular membrane consists of internal circular layer nand external longitudinal layer. In superior third a muscular membrane nis formed by striped muscles, in middle part gradually replaces by smooth nmuscles, and inferiorly has only the smooth muscles. Abdominal part of noesophagus is covered by peritoneum.
Oesophagus has 3 anatomic constrictions.
• pharyngeоesophageal nconstriction is in place of transition from pharynx into oesophagus, olevel of the C7 – 7th cervical vertebra;
• constriction of thoracic part is a place, nwhere left principal bronchi, presses an oesophagus is on level of the 5th nthoracic vertebrae;
• phrenic nconstriction is a place, where an oesophagus passes through the lumbar part of nthe diaphragm on level of the 9th –10th thoracic vertebrae.
Physiological constrictions (2):
• aortic constriction is a place, where naorta bends and adjoins to oesophagus on level of the Th4 of thoracic vertebra;
• abdominal (cardiac) constriction is iplace of entry into cardiac portion of stomach – on level of the Th11 thoracic nvertebra.
BOWEL can be subdivided into nsmall intestine and large intestine. Small intestine consists of duodenum n(portion without mesentery), jejunum and ileum (mesenteric portion). Large intestine nincludes cecum and colon (ascending colon, transverse colon, descending colon, nsigmoid colon) and rectum with anal channel.
SMALL nINTESTINE. Topography: holotopy – small intestine lies in abdominal cavity and noccupies epigastrium, mesogastrium and partly nhypogastrium (pubic region). Skeletotopy – small nintestine extends from the level of Th12 vertebral body till area of right niliac fossa. Syntopy – large intestine, duodenum, npancreas, liver, ductus choledochus, nright kidney lie around coils of small intestine.
Horseshoe-shaped Duodenum projected in umbilical area. nThe duodenum was given its name because it is usually 12 fingerbreadths long n(about 25cm –
Duodenum nadjoins above to quadrate lobe of liver and gallbladder, iinferiorly – to right kidney with adrenal gland and by internal nsurface girds head of pancreas. Duodenum is covered by peritoneum from none side (retroperineal position). Hepatoduodenal ligament passes from liver to intestine.
Structure of duodenal wall:
• nexternal membrane (fibrous and in front – anterior serous n/peritoneum/);
• nmiddle membrane – muscular, which consists of external longitudinal and ninternal circular fibres;
• ninternal membrane – mucous membrane with well developed submucous stratum. nThere are circular folds in all duodenal portiotns, nmedial wall of descending part contains longitudinal fold of duodenum, nwhich carries major papilla (ampoule of ductus ncholedochus and pancreatic duct opens here) and minor npapilla of duodenum, where accessories duct of pancreas opens.
The Jejunum occupies ninitial 2/5 part of mesenteric small intestine and has a structure typical for ngastric-intestinal tract. The wall consists of: Serous membrane, muscular nmembrane, formed by longitudinal layer (stratum longitudinale) nand circular layer (stratum circulare), and mucous nmembrane (tunica mucosa). Last forms the numerous of circular folds. Mucous nmembrane carries a numerous of specific finger-like processes that project from nthe surface of the mucosa into the lumen. They are fingerlike nprojections consisting of a core of reticular tissue covered by a surface nepithelium. The connective tissue core contains numerous blood capillaries nforming a plexus. The endothelium lining the blood capillaries is fenestrated nthus allowing rapid absorption of nutrients into the blood. They are nresponsible for absorption of amino acids and carbohydrates, present idigested food. Some villi contain a central lymphatic vessel and called a nlacteal (for absorption of fat). Solitary lymphatic follicles represent nlymphoid apparatus of mucous membrane of the jejunum.
The Ileum occupies n3/5 terminal portion of small intestine and has a structure, analogic to njejunum. Lymphoid apparatus of mucous membrane of the ileum is represented by aggregated nlymphatic follicles (Payer’s patches). An ileal diverticulum (Meckel’s diverticulum) nis one of the most common malformations of the digestive tract. It occurs in 1 nto 2% of people. This blind sac or fingerlike pouch nis the remnant of the proximal part of the embryonic yolk stalk, jt is of clinical significance because it sometimes becomes ninflamed and may cause symptoms that appendicitis.
Serous nmembrane /Peritoneum/ cover Jejunum and Ileum completely, and forms for them mesentery nwhich contains blood and lymphatic vessels, nodes, nerves that supply the bowel nalso adipose tissue.
LARGE nINTESTINE extends from the end of the nileum to the anus. It is about
The Cecum is situated in right iliac fossa, projected on right ninguinal region. Cecum covered by peritoneum fully (intraperitoneal nposition) and does not have own mesentery. In place of gathering of three teniae ostium of worm-shaped 8-cm nin length blind tube vermiform appendix disposes, which has own mesentery. nTransition of ileum into cecum is ileocolic njunction. Superior labium and inferior labium of this orifice ncommunicate by frenulum, they form ileocolic nvalve, which serves for closing of ileocolic ostium and prevents return the chyme ninto ileum.
The nAscending colon is situated in right lateral abdominal area, covered by nperitoneum from three sides (mesoperitoneal nposition), does not have an own mesentery. Transition into transverse cologenerates a right flexure of colon, which adjoins to right lobe of the nliver that is why called as hepatic flexure of colon.
The nTransverse colon passes in abdominal cavity from the right to the left, nso mobile portion of bowel because has mesentery (intraperitoneal nposition). Transition into descending colon forms left colic flexura, which adjoins to spleen (splenic flexura).
The nDescending colon positioned in left lateral abdominal region, covered by nperitoneum from three sides (mesoperitoneal nposition), without mesentery.
S-shaped nSigmoid colon contained in left iliac fossa; covered by peritoneum from nall sides (intraperitoneally) and has a mesentery.
The Rectum is continuous above with the sigmoid colon, while nbelow it ends in the anal canal. It forms two flexurae nin sagittal plane: superior sacral flexura, responses concave anterior surface of sacrum and ninferior anоrectal flexura nor perineal flexura, that nis situated on transition of rectum into anal canal in pelvic perineal diaphragm. Also rectum has lateral flexurae in frontal plane. Upper broadened part of rectum ncalled as the rectal ampulla. External layer of rectum wall is nconnective tissue – adventitia and serous peritoneum; middle layer is muscularis, which has the longitudinal and circular fibres; nmucous membrane forms the transverse folds of rectum (plicae transversae recti – superior, middle and inferior).
The Anal Canal is terminal portion of the large intestine, begins nat the level of the apex of the prostate, is directed downward and backward, nand ends at the anus. External sphincter muscle of anus (musculus sphincter ani externus) lies under skin. It formed by striated (voluntary ncontrolled) muscles of perineum. Internal sphincter of anus (m. nsphincter ani internus) npositioned deeper. It is formed by continuation of the circular musclular layer of the intestine and built by smooth nmuscular fibres (involuntary). Above the external and the internal sphincter nmuscles lies the puborectal muscle n(part of levalor ani nmuscle) is important muscle of the sphincter. Part of the pubococcygeal muscle also takes part in anal nclosure. The muscles are under permanent tension except during the act of ndefecation.
Mucous membrane of the anal canal forms 8-10 permanent longitudinal nfolds columne anales, nbetween which are anal sinuses, which end below in small valve-like nfolds, termed anal valves. They join together the lower ends of the nrectal columns. Submucous stratum in this area ncontains developed venous plexus hemorrhoidal nplexus.
The rectum is covered by peritoneum above on its anterior surface and nsides; below, on its anterior aspect only; the anal canal is entirely devoid of nany serous covering.
The liver, the largest gland in the body, also nperforms important exocrine and metabolic functions:
· nThe secretion of bile.
· nThe protective role by detoxifying nsubstances.
· nThe storehouse for various nsubstances.
· nMetabolising the products of ndigestion.
· nThe synthesis of proteins.
· nThe metabolism of carbohydrates and nthe regulation of blood glucose.
· nThe metabolism of fats and the nregulation of blood lipids.
· nThe conjugation of substances.
· nThe transformation of substances.
· nThe production of carbohydrates from nproteins.
· nThe haemopoietic nfunction – especially during foetal life the liver is a centre for haemopoiesis and new-born.
· nThe production of thrombolitic nagents.
· nThe synthesis of procoagulants.
Topography nof the liver. Holotopy: Liver occupies right nhypochondriac region, proper epigastric region and nsmall part of left hypochondriac region. Skeletotopy: nThe upper edge of the liver projects in right 10th intercostal space (middle naxillar line). Than it lifts to level of 4th rib (middle clavicular nline) and passes across the sternum a bit upper from xiphoid process, nterminates in left 5th intercostal space (between middle clavicular nline and parasternal lines). The lower edge of the liver passes along the ncostal arch from right 10th intercostal space (middle axillar line). Than it ncrosses cartilage of right 9th rib and runs in epigastrium 1,5 cm lower from xiphoid nprocess to cartilage of left 8th rib and meets the upper margin.
We distinguish the convex diaphragmatic surface of the liver and nlower visceral surface. Visceral surface adjoins to the organs, which nform on surface of the liver suitable ‘tracks’: renal, adrenal, gastric, nduodenal, oesophageal and colic impressions. Diaphragmatic surface ncarries cardiac impression.
Liver nis almost entirely covered with peritoneum except posteriorly positioned ‘area nnuda’. The superior surface is attached to the ndiaphragm and anterior abdominal wall by a fold of peritoneum, the falciform ligament, in the free margin of nwhich is a rounded cord, the ligamentum teres (obliterated umbilical vein). The liver is nconnected to the lower surface of the diaphragm by the coronal ligament nand the right and left triangular ligaments. The falciform nligament conventionally separates greater right lobe of liver and nlesser left lobe of liver.
The nporta hepatis, nthe entrance into the liver forms a cross-connection between the sagittal ngrooves which together are shaped like an H. Visceral nsurface carries furrows: right sagittal sulcus and left sagittal nsulcus, which communicate by transversal sulcus (is called ‘porta hepatis’). nLeft sagittal sulcus anteriorly contain fissure of teres nligament, where umbilical vein in foetus passes. It obliterates in adult nand forms teres liver ligament. nPosterior portion of left sagittal sulcus is formed by fissura nof venous ligament (obliterated venous duct of Arantii). nRight sagittal sulcus anteriorly contains fossa of ngall bladder, and behind – sulcus of inferior vena cava. Vena portae, proper hepatic artery and nerves enter through the porta hepatis into nliver, common hepatic duct and lymphatic vessels leave the parenchyma in this nplace. Sagittal and transversal sulcuses limit the quadrate nlobe, positioned ventrally and caudate lobe, disposed dorsally. nCaudate lobe carries papillary and caudate processes.
The nliver is held together by a tense connective tissue capsule Glisson n’s capsule. At the porta it separates the lobules nof liver. The lobules form the chief mass of the hepatic substance. Branches of nportal vein, hepatic artery and biliary duct form a hepatic triad are nsituated in stratums between liver lobules.
Unlike nall other organs a liver obtains arterial blood from proper hepatic artery nand venous – from portal vein. Entering into liver porta, a portal vein and hepatic artery disintegrate into nright and left lobar, segmental and lobular veins and arteries, nwhich pass along interlobular bile duct. Capillaries from these vessels njoining together form sinusoid capillaries that receive mixed nblood and empty into a central vein, which occupies the centre of the nlobule. Central vein drains into hepatic veins, which leave the liver to nend in the inferior vena cava. This system is called as wonderful venous nliver net.
Hepatic ncells ‘hepatocytes’ excrete the bile, which get into bile canaliculi. Last pass to periphery emtpy ninto interlobular ductuli that form right nhepatic duct and left hepatic duct (from right and left hepatic nlobes). Common hepatic duct, which originated in porta, npasses in hepatoduodenal ligament, meets the cystic nduct and forms ductus choledochus. It flows together with pancreatic duct nand forms common hepalopancreatic ampulla, nwhich opens on major duodenal papilla. The ampulla may itself be closed nby its own sphincter muscle, the sphincter ampullae n(Oddi).
The nGallbladder is na pear-shaped, thin-walled bag, which collects up to 30–50 nml bile. We distinguish fundus, body and neck of gallbladder, nwhich continues into cystic duct. The gallbladder lies in a fossa in the nliver to which it is attached by connective tissue and covered by peritoneum nfrom below (mesoperitoneal position). The lumen of nthe neck of the gallbladder and of its connections with the cystic duct is nincompletely subdivided by spiral fold of mucosa, known as the spiral fold n(Heisler’s valve).
The npancreas nis the most important intestinal gland. The pancreas is shaped like a nhorizontal wedge with its thin end on the left. The head is the thickest npart, fills into the duodenal loop to the right of the spine. The horizontal body ncontinues into tail. The pancreatic duct runs right through the nlength of the gland. It receives short, vertical tributaries from the lobules nand has owns sphincter muscle of pancreatic duct. The pancreatic nduct ends together with the common bile duct on the major duodenal npapilla. If present, the accessory pancreatic duct ends above the nbile duct on the minor duodenal papilla.
Topography nof the pancreas. Pancreas lies in upper abdominal region behind the peritoneum n(retroperitoneal position) at the level of the from 1st to 3d nlumbar vertebrae. Along the upper margin of the pancreas runs the splenic nartery. The right kidney and adrenal gland adjoin to body of pancreas. Anterior nsurface of gland touches the stomach, posterior surface – inferior vena cava nand aorta. Tail adjoins to splenic hilus.
Endocrine part of pancreas is represented by nislets of Langerhans. They produce insulin and glucagon that nregulate metabolism of carbohydrates, regulative a sugar contents in organism. nAttached to insufficient production of these hormonal disease sugar diabetes narises.
The SPLEEN lies iepigastrium and belongs to secondary lymphatic organs and is a big lymphatic nnode. Spleen is disposed in left hypochondriac region on the level of 9 th -11th ribs. Spleen has inferior nmargin and superior margin, anterior extremity and nposterior extremity. It has a diaphragmatic surface (superior) and visceral nsurface (inferior). To the last adjoin stomach (facies ngastrica), left kidney with suprarenal gland (facies renalis), left colic nflexure (facies colica) nand tail of pancreas (facies pancreatica). nPlace on visceral surface, where vessels and nerves enter and leave, is called nas splenic hilus. Spleen is covered by nperitoneum from all sides (lies intraperitoneally).
Spleen is covered by fibrous capsule, from which numerous small nfibrous bands, trabeculae are given off in all ndirections into parenchyma, these uniting, and constitute the framework of the nspleen. Parenchyma consists of splenic pulp, which has a white pulp and nred pulp and its structure described in detail in histology course.
The PERITONEUM is nserous membrane that covers the walls of abdominal cavity and viscera iabdomen and pelvis. It may be subdivided into parietal peritoneum and visceral nperitoneum. Transition of parietal peritoneum into visceral peritoneum realizes nby derivatives: ligament, mesentery and omentum. nIf organ covered by peritoneum from all sides, such position is called intraperitoneal; if from three sides – mesoperitoneal nposition; if only one side – extraperitoneal or retroperitoneal.
Abdominal ncavity is limited:
· nabove – by diaphragm
· nanteriorly and laterally – by nmuscles, fasciae, skin
· nbehind – by lumbar and sacral nportions of backbone and lumbar muscles
· nfrom below – by bones, ligaments and nmuscles of pelvis.
Abdominal ncavity contains the organs of digestive and urogenital systems and spleen.
Peritoneal ncavity is complex of fissure betweeabdominal organs and walls lined by parietal and visceral sheets that contaiserous liquid. It can be subdivided into superior storey and inferior storey, nalso cavity of lesser pelvis.
Superior nstorey of peritoneal cavity positioned between diaphragm and nlevel of mesocolon of transverse colon. It contains:
• hepatic nbursa surrounds right hepatic lobe and gallbladder;
• pregastric bursa accommodates left hepatic nlobe and anterior wall of stomach;
• omental bursa is situated behind lesser omentum and it is in touch with posterior stomach surface.
Lesser nomentum is formed by double nperitoneal sheet that forms of hepatogastric nligament and hepatoduodenal ligament. nLesser omentum carries common bile duct, nportal vein and proper hepatic artery (DVA).
Hepatic nbursa communicates with omental bursa by the medium nof epiploic foramen (of Winslow). Last nlimited from above by caudate lobe of the liver, from below – by superior part nof duodenum, anteriorly – hepatoduodenal ligament, nbehind – by parietal sheet of peritoneum.
Greater nomentum develops nfrom 4 peritoneal sheets, which continue from gastrocolic nligament and, freely hanging down, covers the abdominal organs in front. nThe gastrocolic ligament connects the ntransverse colon with the greater curvature of the stomach.
Inferior nfloor of peritoneal cavity extends from mesocolon nof transverse colon to entrance into lesser pelvis.
Root nof small intestine mesentery divides the inferior storey into right and nleft mesenteric sinuses. They naccommodate the loops of small intestine. Right mesenteric sinus is bordered by nmesenteric root and ascending colon. In place, where ileum continues into cecum nsuperior and inferior ileocecal recesses nare situated. One can see retrocecal recess nbehind cecum. Right paracolic sulcus nruns between ascending colon and parietal peritoneum of lateral abdominal wall. nMesenteric root, descending colon and sigmoid colon border left mesenteric nsinus. Superior and inferior duodenal recesses are positioned nin area of duodenojejunal junction. Mesocolon of sigmoid forms intersigmoidal nrecess. Left paracolic sulcus nruns between descending colon and parietal peritoneum of left abdominal wall.
Parietal nsheet of peritoneum covering back surface of anterior abdominal form plicae (folds) and fossae. The median umbilical fold contains the remnant of the embryonic urachus; the medial umbilical folds carry nobliterated umbililal arteries; lateral umbilical nfolds contain inferior epigastric arteries. Supravesical fossae positioned between mediaand medial umbilical folds. Medial umbilical fossae located betweemedial and lateral umbilical folds. Lateral umbilical fossae nlocated laterally from lateral umbilical folds. Medial and lateral umbilical nfossae can be projected into superficial inguinal ring and deep inguinal nring.
Cavity nof lesser pelvis
Peritoneal ncavity in the male pelvis contains rectovesical excavation n(pouch). Peritoneum in the female between uterus and urinary bladder form vesicouterinae excavation. Behind the uterus nperitoneum descends into the rectouterine npouch (pouch of Douglas), which is the lowest point of the peritoneal ncavity. That is why some liquid from all peritoneal cavity can collect here nduring some pathology. The entrance into the rectouterine npouch is narrowed by the rectouterine folds, nin which the rectouterine muscles run.
The nglistening appearance of the deep surface of the abdominal wall and of the surfaces nof the exposed viscera is due to the fact that the former is lined, and the nlatter are more or less completely covered, by a serous membrane, the nperitoneum.
The nPeritoneum (Tunica Serosa)—The peritoneum is the largest serous membrane in the nbody, and consists, in the male, of a closed sac, a part of which is applied nagainst the abdominal parietes, while the remainder nis reflected over the contained viscera. In the female the peritoneum is not a nclosed sac, since the free ends of the uterine tubes open directly into the nperitoneal cavity. The part which lines the parietes nis named the parietal portion of the peritoneum; that which is reflected over nthe contained viscera constitutes the visceral portion of the peritoneum. The nfree surface of the membrane is smooth, covered by a layer of flattened nmesothelium, and lubricated by a small quantity of serous fluid. Hence the nviscera can glide freely against the wall of the cavity or upon one another nwith the least possible amount of friction. The attached surface is rough, nbeing connected to the viscera and inner surface of the parietes nby means of areolar tissue, termed the subserous areolar tissue. The parietal portion is loosely connected nwith the fascial lining of the abdomen and pelvis, nbut is more closely adherent to the under surface of the diaphragm, and also ithe middle line of the abdomen.
The nspace between the parietal and visceral layers of the peritoneum is named the nperitoneal cavity; but under normal conditions this cavity is merely a potential none, since the parietal and visceral layers are in contact. The peritoneal ncavity gives off a large diverticulum, the omental nbursa, which is situated behind the stomach and adjoining structures; the neck nof communication between the cavity and the bursa is termed the epiploic foramen (foramen of Winslow). Formerly the maiportion of the cavity was described as the greater, and the omental nbursa as the lesser sac.
The nperitoneum differs from the other serous membranes of the body in presenting a nmuch more complex arrangement, and one that can be clearly understood only by nfollowing the changes which take place in the digestive tube during its ndevelopment.
To ntrace the membrane from one viscus to another, and nfrom the viscera to the parietes, it is necessary to nfollow its continuity in the vertical and horizontal directions, and it will be nfound simpler to describe the main portion of the cavity and the omental bursa separately.
Vertical nDisposition of the Main Peritoneal Cavity (greater sac)—It is convenient to ntrace this from the back of the abdominal wall at the level of the umbilicus. nOn following the peritoneum upward from this level it is seen to be reflected naround a fibrous cord, the ligamentum teres (obliterated umbilical vein), which reaches from the numbilicus to the under surface of the liver. This reflection forms a somewhat ntriangular fold, the falciform ligament of the liver, nattaching the upper and anterior surfaces of the liver to the diaphragm and nabdominal wall. With the exception of the line of attachment of this ligament nthe peritoneum covers the whole of the under surface of the anterior part of nthe diaphragm, and is continued from it on to the upper surface of the right nlobe of the liver as the superior layer of the coronary ligament, and on to the nupper surface of the left lobe as the superior layer of the left triangular nligament of the liver. Covering the upper and anterior surfaces of the liver, nit is continued around its sharp margin on to the under surface, where it npresents the following relations: (a) It covers the under surface of the right nlobe and is reflected from the back part of this on to the right suprarenal ngland and upper extremity of the right kidney, forming in this situation the ninferior layer of the coronary ligament; a special fold, the hepatorenal ligament, is frequently present between the ninferior surface of the liver and the front of the kidney. From the kidney it nis carried downward to the duodenum and right colic flexure and medialward in front of the inferior vena cava, where it is ncontinuous with the posterior wall of the omental nbursa. Between the two layers of the coronary ligament there is a large ntriangular surface of the liver devoid of peritoneal covering; this is named nthe bare area of the liver, and is attached to the diaphragm by areolar tissue. nToward the right margin of the liver the two layers of the coronary ligament ngradually approach each other, and ultimately fuse to form a small triangular nfold connecting the right lobe of the liver to the diaphragm, and named the nright triangular ligament of the liver. The apex of the triangular bare area ncorresponds with the point of meeting of the two layers of the coronary nligament, its base with the fossa for the inferior vena cava. (b) It covers the nlower surface of the quadrate lobe, the under and lateral surfaces of the ngall-bladder, and the under surface and posterior border of the left lobe; it nis then reflected from the upper surface of the left lobe to the diaphragm as nthe inferior layer of the left triangular ligament, and from the porta of the liver and the fossa for the ductus venosus to the lesser ncurvature of the stomach and the first
