Block III Week II
The inferior mesenteric artery supplies what organs/structures?
Supplies the distal 1/3 of the transverse colon, descending colon, sigmoid colon, rectum and anal canal.
The common hepatic artery supplies what organs/structures?
Supplies the liver, gall bladder and biliary ways, stomach, duodenum, and pancreas
The multiple branches of the superior mesenteric artery supplying the jejunum and ileum running through the mesentery of the small intestine repeatedly divide and anastomose with each other forming a series of loops called what?
The intestinal arcades (1°, 2°, and 3°)
The jejunum and ileum can be differentiated by the number of arcades and the length of the vasa recta. Describe the difference.
The jejunum has fewer arcades (2-3) and longer vasa recta, while the ileum has more arcades (4-5) and shorter vasa recta
What does it mean to say the lips are competent or incompetent?
The lips are said to be competent when they are lightly closed at rest. The term incompetent lip describes a lip posture that, at rest with facial muscles relaxed, does not produce anterior seal.
What is cleft lip?
A congenital anomaly caused by failure of fusion of the facial premordia during facial development, frequently associated with cleft palate (unilateral, bilateral or median)
The junction between the cheeks and the lips is externally marked by what, that extends between the nose and the angle of the mouth?
Nasolabial groove (sulcus)
What is the origin and insertion of the palatopharyngeus?
O: Hard palate and palatine aponeurosis I: Lateral wall of the pharynx
What is the origin and insertion of the palatoglossus?
O: Palatine aponeurosis I: Side of the tongue
What is the origin and insertion of the levetor veli palatini?
O: cartilage of auditory tube, and temporal bone I: Palatine aponeurosis
What is the origin and insertion of the muscle of uvulae?
O: posterior nasal spine and palatine aponeurosis I: mucosa of the uvula
What is the origin and insertion of the tensor veli palatini?
O: scaphoid fossa of the lateral pterygoid plate, spine of sphenoid bone, cartilage of auditory tube I: Palatine aponeurosis
The soft palate is laterally continuous with two folds termed what?
Palatoglossal and palatopharyngeal arches
What are the arteries, veins, and nerves of the lip?
Arteries and veins - inferior and superior labial Innervation- sensory from the V2 (upper) and V3 (lower) and motor supply by the facial nerve (CN7).
Structural and functional abnormalities of ENS (congenital or acquired) cause digestive tract diseases like what?
- Achalasia - difficulty of food and liquid to pass into the stomach - Small intestinal motility disorders - Gastric outlet obstructions - Aganglionic megacolon (Hirschsprug's disease)
What is portosystemic anastomosis?
- Anastomosis b/n tributaries of portal vein and veins that drain into the systemic veins. - No valves in the portal system, therefore blood can flow in any direction - Serves as an alternate route for venous return through which portal blood is directed into the systemic veins during portal hypertension
Describe the lympatic drainage of the abdomen.
- Each organ in the abdomen has small group of lymph nodes arranged along its blood vessels - Lymph from each of these lymph nodes is drained into four major groups of lymph nodes (celiac, superior mesenteric, inferior mesenteric and para-aortic). - The lymph from the major lymph nodes is drained via 3 trunks (intestinal and right and left lumbar) into the cisterna chyli. - Troiser's (Virchow's) sign, Sister Mary Joseph nodule or sign
Veins from what four abdominal organs drains into the portal vein?
1. Abdominal part of the GI tract (except inferior rectum and anal canal) 2. Spleen 3. Pancreas 4. Gall bladder
What are the two sources of input for the enteric nervous system?
1. From GI mucosa via sensory nerve endings in the epithelium for local reflexes 2. From the CNS via the sympathetic nerves (splanchnic nerves) and parasympathetic nerves (vagus from all parts up to the right 2/3 of the transverse colon and pelvic splanchnic nerves from the left 1/3 of the transverse colon down) for activation or inhibition of certain functions
What are the two branches of the common hepatic artery?
1. Gastroduodenal 2. Proper hepatic artery
What are the four sites of portosystemic anastomosis? What are their clinical manifestations?
1. Gastroesophageal: left gastric vein to esophageal veins to azygos vein to SVC (eosphageal varices) 2. . Anorectal: superior rectal vein to middle and inferior rectal to internal iliac to IVC (anorectal varices) 3. Paraumbilical - epigastric and thoracoepigastric vein to SVC and IVC (Caput Medusae) 4. Retroperitoneal to IVC (no associated pathology)
What are the nerves of the palate?
1. Greater and lesser palatine nerves from the pterygopalatine ganglion 2. Nasopalatine nerves from the maxillary nerve.
What is the blood supply to the palate? Where do these arteries come from?
1. Greater palatine arteries 2. Lesser palatine arteries **Both from maxillary artery
What are the five branches of the superior mesenteric artery and what do they supply?
1. Inferior pancreaticoduodenal - divides into the anterior and posterior inferior pancreaticoduodenal arteries to the distal duodenum and head of the pancreas 2. Middle colic artery - to the proximal 2/3 of the transverse colon 3. Right colic artery - to the ascending colon 4. Ileocolic artery - Colic branch - to the ascending colon - Ileal branch - to the terminal ileum (ileal branch), to the cecum and ileocecal junction (anterior and posterior cecal) and to the appendix (appendicularartery arises from the ileal branch of right colic artery) 5. Jejunal and ileal (intestinal) branches to the jejunum and ileum
What are the three branches of the inferior mesenteric artery and what do they supply?
1. Left colic artery (ascending and descending branches) - to the distal 1/3 of the transverse colon and descending colon. **Anastomoses with the middle colic artery and connects the superior and inferior mesenteric arteries 2. Sigmoid arteries to the sigmoid colon 3. Superior rectal artery to rectum. **Connects the inferior mesenteric artery with internal iliac artery through its anatomoses with middle and inferior rectal arteries from internal iliac
What are the three branches of the celiac trunk?
1. Left gastric 2. Common hepatic 3. Splenic
In some segments of the colon the marginal artery could be poorly developed or even absent (watershed areas) with inadequate formation of vasa recta. Such segments of the colon that are vulnerable to ischemia/infarction include what?
1. Middle portion of the ascending colon 2. Transitional area between the midgut and hind gut (Griffiths' point). 3. Rectosigmoid junction (Sudek's point)
What are the five muscles of the soft palate?
1. Palatoglossus 2. Palatopharyngeus 3. Musculus uvulae 4. Tensor veli palatini 5. Levator veli palatini
The hepatic portal vein receives from what four veins?
1. Right and left gastric veins along the lesser curvature of the stomach and lower esophagus 2. Cystic vein from the gallbladder 3. Paraumbilical 4. Prepyloric - runs anterior to gastroduodenal junction and drains into the right gastric
What are the three branches of the proper hepatic artery and what do they supply?
1. Right gastric artery to the right side of the lesser curvature 2. Left hepatic artery to the left lobe of the liver 3. Right hepatic artery to the right lobe of the liver - Cystic artery to the gall bladder - Right gastric artery (occasionally)
What are the five functions of the tongue?
1. Sensation of taste 2. Mastication 3. Swallowing 4. Articulation of speech 5. Oral cleansing
What are the five branches of the splenic artery, and what do they supply?
1. Short gastric arteries - multiple branches to the fundus of the stomach 2. Left gastroepiploic (gastroomental) artery - to the left part of the greater curvature of the stomach 3. Dorsal pancreatic artery to the body of the pancreas **Inferior (transverse) pancreatic artery - to the body and tail 4. Great pancreatic artery - to the tail of the pancreas 5. Splenic branches to spleen
The splenic vein drains the spleen and runs with the splenic artery. It receives from what four tributaries?
1. Short gastric veins from the fundus of the stomach 2. Left gastroepiploic or gastroomental vein from the left part of the greater curvature of the stomach 3. Pancreatic veins from the body and tail of the pancreas 4. Inferior mesenteric vein from the hindgut
What are the three branches of the gastroduodenal artery, and what do they supply?
1. Supraduodenal arteries to the superior duodenum 2. Right gastroepiploic (gastro-omental) artery to the right part of the greater curvature 3. Superior pancreaticoduodenal - divides into anterior and posterior superior pancreaticoduodenal arteries to the duodenum and the head of the pancreas
Where does output from the ENS go?
1. To areas in the spinal cord via spinal nerves that have their cell bodies in the dorsal root ganglia. 2. To areas in the brain stem via vagus nerve (constitute about 8% of vagal fibers)
What are the two parts of the oral cavity?
1. Vestibule 2. Oral (mouth) cavity proper
What is cancrun oris?
A non-contagious multimicrobial gangrenous destruction of the face (lips, cheeks, nose, chin) seen in poor communities living in unhygienic conditions
What is the difference between anorectal varices and hemorrhoids?
Anorectal varices are usually due to portal hypertension, while hemorrhoids are usually due to straining with defacation, pregnancy, or chronic cough.
The paraumbilical veins connect the portal vein to what?
Anterior abdominal wall veins
What are the four boundaries of the oral cavity proper?
Anteriorly and on the sides - alveolar processes, the teeth, and the gums. Posteriorly - oropharyngeal (faucial) isthmus between the palatoglossal arches, the soft palate, and the tongue. Roof - formed by the hard and soft palate, Floor - the tongue and other soft tissue structures including the geniohyoid, mylohyoid and hyoglossus muscles
Another possible communication between the SMA and the IMA is an inconstant _______ ______ ___________ connecting the SMA or any of its primary branches with the IMA or any of its primary branches.
Arc of Riolan
What is the innervation and action of the muscle of the uvulae?
Innervation: vagus (pharyngeal plexus) Action: pulls the uvula cranially (shortens it) and unilateral contraction deviates the uvula to the same side
What is the function of the soft palate?
It closes the nasopharynx during swallowing and speech.
The lips and cheeks meet at the angles of the mouth, also called what?
Labial commissures
What veins does the inferior mesenteric vein receive? What does it drain?
Drains the hindgut and receives left colic, sigmoid and superior rectal veins and joins the splenic vein posterior to the body of the pancreas (occasionally joins the superior mesenteric or the junctional area between splenic and superior mesenteric veins).
What is the innervation and action of the palatoglossus?
Innervation: Vagus (pharyngeal plexus) Action: Elevate root of the tongue, draws the soft palate on to the tongue, bilateral contraction closes off the oral cavity from the oropharynx
What is the innervation and action of the palatopharyngeus?
Innervation: Vagus (pharyngeal plexus) Action: Tenses the soft palate, pulls the pharynx cranially, anteriorly and medially to help close the nasopharynx during swallowing
What is the innervation and action of the levator veli palatini?
Innervation: Vagus (pharyngeal plexus) Action: elevates the soft palate and draws it posteriorly during swallowing, sucking, phonation and yawning
Describe the orientation of the hepatic portal vein.
Formed at the level of L2 posterior to the neck of the pancreas by the union of the splenic and superior mesenteric veins. Runs through the hepatoduodenal lig. to the porta hepatis where it divides into right and left branches that enter the corresponding lobes of the liver
The bony plate of the hard palate is formed by what bones?
Formed by the palatine process of maxilla and the horizontal plate of palatine bone.
The tongue is attached to the floor of the mouth by a median fold of mucous membrane termed as the what?
Frenulum of the tongue (frenulum linguae)
The inferior surface of the tongue is connected to the floor of the mouth by a median fold of mucous membrane called what?
Frenulum of the tongue (frenulum linguae).
What are the symptoms of portal hypertension?
GI bleeding, ascites, splenomegaly, and encephalopathy
What is the innervation and action of the tensor veli palatini?
Innervation: trigeminal (mandibular branch) Action: Bilaterally: tenses the soft palate and flattens its arch, separates the nasopharynx from the oropharynx during swallowing, opens the pharyngeotympanic tube during swallowing and yawning. Unilaterally: deviates the soft palate to the same side.
The hepatic portal vein with all its tributaries is called what?
Hepatic portal system or portal venous system
What is portal hypertension?
Increased pressure in the portal vein and any of its tributaries (normal portal pressure 1 - 5mmHg) causing retrograde flow of portal blood through its tributaries that form anastomosis with systemic veins that return blood to the heart (portosystemic anastomosis)
The arteries that supply the colon: ileocolic, right colic and middle colic arteries from the SMA and left colic and sigmoid arteries from the IMA, divide and form a continuous anastomotic arcade on the mesocolic border of the colon extending from the cecum to the rectum called what?
Marginal artery (of Drummond): This anastomotic artery gives radial branches (vasa recta) that enter the wall of the colon. The marginal artery forms anastomotic connection between the branches of SM and IM arteries and provides a route for the collateral flow of blood if any of their branches is occluded.
What is the venous pathway from the portal vein for developing esophageal varices?
Portal vein → left gastric vein → esophageal venous plexus → esophageal veins → azygos and hemiazygos → SVC
What are the causes of portal hypertension?
Posthepathic or suprahepatic (e.g. heart failure), hepatic or intrahepatic (e.g. liver cirrhosis), prehepatic or infrahepatic (e.g. portal vein thrombosis, compression)
Where do the pre and post ganglionic fibers for sympathetic effects on the GI end, and what is their effect?
Preganglionic fibers from T5 -L2(3) end on the celiac, superior mesenteric, inferior mesenteric and hypogastric ganglia. The post ganglionic fibers from these ganglia end on the enteric ganglia. Their effect is inhibition of secretion, peristalsis, sphincter contraction and vasoconstriction.
Where do the parasympathetic fibers end on the GI, and what is their effect?
Preganglionic fibers of vagus from the brain stem and pelvic splanchnic nerves from spinal cord segments S2 -S4, end on enteric ganglion cells. Their effect is activation of secretion, peristalsis, sphincter relaxation, vasodilatation.
What vein is used by surgeons as a guide to find gastroduodenal junction?
Prepyloric vein
The skin of the face superior and posterior to the groove is slightly raised forming the nasolabial fold. This becomes prominent in what actions?
Prominent during smiling and grimacing (flattens during facial nerve (CN 7) paralysis)
What veins does the superior mesenteric vein receive?
Receives the right gastroepiploic (gastroomental) vein, and both pairs of superior and inferior pancreaticoduodenal veins
The submandibular glands open into the oral cavity proper on elevations on both sides of the frenulum called what?
Sublingual caruncle or papilla
Each of the sublingual glands produces an elevation, the _____________ ____________, in the mucous membrane on each side of the frenulum.
Sublingual fold - most of the sublingual ducts open on the sublingual fold.
What organs/structures does the left gastric artery supply?
Supplies major part of the lesser curvature of the stomach and abdominal part of the esophagus
What specific organs/structures does the celiac trunk supply?
Supplies the abdominal part of esophagus, stomach, duodenum up to the greater duodenal papilla, hepatobiliary system, pancreas, and spleen (not a derivative of the foregut)
The parotid duct opens into the vestibule of the oral cavity opposite what structure?
The 2nd upper molar tooth
All arteries of the digestive tract arise from what?
The abdominal aorta
What constitutes the body of the tongue?
The anterior 2/3 of the tongue situated in the oral cavity. Has two surfaces- superior (dorsal surface or dorsum) and inferior (ventral)
The anterior and posterior inferior pancreaticoduodenal arteries anastomose with what arteries to interconnect the celiac trunk with the superior mesenteric artery?
The anterior and posterior superior parncreaticoduodenal arteries
The parotid duct pierces what two structures to open into the vestibule of the oral cavity?
The buccal pad of fat and the buccinator muscle
What forms the core of the cheek?
The buccinator muscle -the buccal pad of fat overlies the buccinator and extends deep between the buccinator and masseter muscles
Derivatives of the foregut are supplied by which artery?
The celiac trunk or artery - artery of the foregut
What makes up the vestibule of the oral cavity?
The cleft between the lips and cheeks externally and the teeth and gums internally. Its roof and floor are formed by the reflections of the mucous membranes of the lips and cheeks to the gums.
The GI system is controlled by what, a collection of ganglion cells in the wall of the GI tract organized as myenteric (Auerbach's) and submucosal (Meissner's) plexuses that contain the ganglion cells?
The enteric nervous system
The left gastric vein connects the portal vein with what?
The esophageal plexus that drains into the azygos veins via the esophageal veins
The tongue is attached by muscle to which structures?
The hyoid bone, mandible, styloid process of the temporal bone, and the soft palate.
Derivatives of the hind gut are supplied by which artery?
The inferior mesenteric - artery of the hind gut
The right colic artery is absent in about 13% of cases, and can also arise from what two other arteries in about 50% of cases?
The middle colic or ileocolic arteries
The two mylohyoid muscles form a flat sheet of muscle between the mandible and the hyoid bone called what?
The oral diaphragm
The lips are separated by the opening of the mouth, also called what?
The oral fissure or rima oris
The core of the lip is formed by what muscle?
The orbicularis oris muscle
At the median plane, the upper lip is externally marked by a shallow groove called the what?
The philtrum
What constitutes the apex of the tongue?
The pointed most anterior end that rests against the incisor teeth
Superior rectal vein anastomoses with the middle and inferior rectal veins via the rectal venous plexus connecting what two structures?
The portal vein with internal iliac vein
When the teeth are in their occlusal position, the vestibule communicates with the oral cavity proper only by a gap between the last molar and the ramus of the mandible called what?
The retromolar space or retromolar trigone
The superior mesenteric artery supplies what organs/structures?
The small intestine distal to the greater duodenal papilla, pancreas, cecum, appendix, ascending colon, and right 2/3 of the transverse colon.
What organs does the splenic artery supply?
The stomach, pancreas, and spleen
At the median plane the upper and lower lips are attached to the corresponding gums by what structures?
The superior and inferior labial frenulums
Derivatives of the midgut are supplied by which artery?
The superior mesenteric - artery of the midgut
What innervates the muscles of the soft palate?
Vagus nerve (CN X) with the exception of the tensor veli palatine muscle innervated by the mandibular branch of trigeminal nerve (CN5).
The intestinal arcades give branch to what that enter the wall of the intestines?
Vasa recta (straight arteries )
Describe the orientation of the superior mesenteric vein. What does it drain?
With SMA on its left side, it passes through the pancreatic notch between the uncinate process and the body of the pancreas posterior to the neck. It drains the midgut.
What are the prominent features of the superior surface of the tongue?
• Marked by numerous small elevations, called the papillae • It is characterized by a V-shaped groove, the terminal sulcus, which runs laterally and forward on each side from a small pit, the foramen caecum • The terminal sulcus may be conveniently taken as the boundary between the anterior 2/3 (body) and the posterior 1/3 (root or base) of the tongue. • Presents a shallow longitudinal median groove (sulcus).
What is microstomia and macrostomia in relation to the lips?
• Microstomia - small mouth (narrow oral fissure) • Macrostomia - wide mouth (wide oral fissure)