S4Anatomy Flashcards
Which vertebral level is the suprasternal notch located?
T2/T3
Which vertebral level is the thyroid notch located?
C4
Which vertebral level is the lower border of cricoid cartilage located?
C6
Which vertebral level is the hyoid bone located?
C3
Describe the location of the lateral lobe of the thyroid?
The apex extends up to the oblique line of the thyroid cartilage and the base to the level of the fourth or fifth tracheal ring.
Describe the location of the Isthmus of the thyroid?
Crosses anterior to the 2nd, 3rd and 4th tracheal ring.
Describe the location of the Pyramidal lobe of the thyroid?
Projects upwards from the isthmus to the left of the midline.
What encloses the thyroid gland?
A thin connective tissue capsule, from which, septa project into the gland. A loose connective tissue sheath surrounds the gland and the capsule.
From which layer of cervical fascia is this sheath derived?
Pretracheal fascia
Where does the superior thyroid artery arise from?
External Carotid artery
Which nerve runs alongside the superior thyroid artery?
Superior laryngeal nerve
The inferior thyroid artery arises from the thyrocervical trunk. Which vessel does the thyrocervical trunk arise from?
Subclavian artery
Which nerve crosses the inferior thyroid artery?
recurrent laryngeal nerve
What supplies arterial blood to the thymus gland?
the superior and inferior thyroid arteries; the superior thyroid artery supplies the upper pole of each lobe whilst the inferior thyroid artery supplies the posteroinferior aspect
In 10% of the population, a third artery contributes to blood supply of the thyroid. What is it and where does it arise from?
Thyroid ima artery
It may arise from the brachiocephalic trunk or arch of aorta, less commonly from the right common carotid, subclavian or internal thoracic arteries.
Describe the venous drainage of the thyroid.
Three pairs of veins, the superior, middle and inferior thyroid veins drain the superior, middle and inferior parts of the thyroid gland respectively. These vessels form a plexus of nerves on the anterior aspect of the gland.
Into which vein do the superior and middle thyroid veins empty?
Internal jugular vein
Into which vein does the inferior thyroid vein empty?
Brachiocephalic vein
Where does the lymph vessels of the thyroid drain into?
These vessels drain into the prelaryngeal, pretracheal and paratracheal nodes. Efferent vessels from these nodes go to the deep cervical nodes.
What type of innervation does the thyroid receive?
Sympathetic innervation
Where do post ganglionic fibres of the thyroid arise and where do the pass through?
Post ganglionic sympathetic fibres arise in the superior, middle and inferior cervical ganglia and pass through the cardiac, superior and inferior thyroid plexuses to reach the gland.
What type of information is transmitted in Post ganglionic sympathetic fibres of the thyroid?
Vasomotor
What is a thyroid goitre?
An enlargement of the thyroid gland which may occur due to over activity or underactivity of the gland
Which directions does the thyroid gland spread when it is enlarged?
Anterior
Inferior
Lateral
Posterior
What prevents the thyroid from enlarging the superior direction?
The superior attachments of sternothyroid and sternhyoid muscles
What structures may be compressed by a goitre?
Oesophagus
Trachea
Recurrent Laryngeal Nerves
How does the thyroid develop?
It develops from a thickening on the floor of the embryonic pharynx in the developing tongue.
A diverticulum develops from this thickening forming the thyroglossal duct.
The thyroglossal duct elongates and its distal end becomes bi-lobed and proliferates into the thyroid gland.
The thyroid gland descends through the neck anterior to the hyoid bone.
At seven weeks the gland reaches its adult position.
The thyroglossal duct subsequently degenerates but a pit remains on the dorsum of the tongue marking its site of origin.
What is the name of the pit, on the dorsum of the tongue, which marks the site of origin of the thyroglossal duct?
Foramen caecum
When do Thyroglossal duct cysts occur? What are the symptoms and where are the cysts located?
When the duct fails to degenerate leaving a persistent connection between the back of the tongue and the thyroid gland.
They can be asymptomatic but fluid may accumulate in small pockets and infection may occur.
The cysts are often located close to the hyoid bone.
Their position in the neck will rise if the patient sticks their tongue out.
When does accessory thyroid tissue occur and where can it be found?
Accessory thyroid tissue may present anywhere along the route of descent of the thyroglossal duct.
It occurs when isolated pockets of glandular tissue of the thyroglossal duct fails to degenerate.
How do pyramidal lobes of the thymus develop? Where are they, and how many people have them?
They develop from the remnants of the epithelium and connective tissue of the thyroglossal duct.
They are present in approximately 50% of the population. These lobes extend upwards from the isthmus usually to the left of the median plane
How does Ectopic thyroid glands occur?
Ectopic thyroid glands occur when the gland fails to descend. In incomplete descent the gland will be located high in the neck. Rarely, the gland may fail to leave the tongue and a lingual thyroid develops.
Describe the histology of the thyroid gland
The thyroid gland consists of numerous rounded follicles containing colloid. The walls of each follicle consist of a single layer of cuboidal epithelial cells which secrete the colloid into the central colloid lake. The colloid is iodinated whilst it is within the colloid lake forming triiodothyronine (T3) and thyroxine (T4).
A second cell type are also present in the thyroid gland. They are called parafollicular or C cells and they contribute to 2% of the cells within the gland.
What do parafollicular cells secrete?
Calcitonin
What are the differences between active and inactive follicular cells?
In the inactive state the follicular cells are cuboidal in shape and have round nuclei. The cells appear taller and more columnar in shape when they are active and their nuclei appear paler.
T/F
The parathyroid glands are embedded into the posterior aspect of the thyroid gland, they lie deep to the fascial sheath.
True
T/F
The position of the superior parathyroid glands is more variable that that of the inferior ones
True
T/F
The superior parathyroid glands usually lie below the point where the superior thyroid vessels enter the thyroid gland.
True
T/F
The inferior parathyroid glands may be located in the superior mediastinum
True
T/F
The parathyroid glands are most commonly supplied by the inferior thyroid artery.
True
T/F
The parathyroid glands are innervated by postganglionic sympathetic fibres from the superior or middle cervical ganglia
True
T/F
The sympathetic nervous system provides secretomotor fibres to the parathyroid gland
False
The fascial sheath that surrounds the parotid gland is derived from where?
investing layer of fascia
Parasympathetic innervation to parotid gland is provided by which nerve?
glossopharyngeal nerve
The nerve cell bodies of postganglionic fibres that supply the sublingual gland are located where?
Pterygopalatine ganglion
What runs through the parotid gland?
External carotid artery
facial nerve
superficial temporal artery
superficial temporal artery
What runs through the parotid gland?
External carotid artery
facial nerve
superficial temporal artery
superficial temporal artery
List components of pancreatic juice
Chymotripsinogen Trypsinogen Amylase Ribonuclease Lipase Elatase
List secretions of the islets of Langerhans
Vasoactive intestinal polypeptide
Glucagon
Somatostatin
Insulin
Where does the pancreas lie?
Retroperitoneally in both the right and left upper quadrants of the abdomen
Which anatomical plane does the pancreas lie across?
Transoyloric
Describe the location of the head of the pancreas.
Expanded part of the gland which lies in the concavity of the duodenum
Describe the location of the ucinate process of the pancreas.
The part of the head which extends behind the superior mesenteric vessels
Describe the location of the neck of the pancreas.
The hepatic portal vein is formed posterior to this constricted part of the gland
Describe the location of the body of the pancreas.
Runs upwards to the left, crossing the midline
Describe the location of the tail of the pancreas.
Passes between the layers of the splenorenal ligament and contacts the hilum of the spleen
Describe the main pancreatic duct
Extends from the tail to the head of the pancreas
Receives many tributaries and increases in diameter
Unites with the bile duct to form the hepatopancreatic ampulla
Enters the duodenum at the major duodenal papilla
Describe the accessory pancreatic duct
Drains the upper part of the head of pancreas
May communicate with the main duct
Opens into duodenum at the minor duodenal papilla
Occasionally absent
How is the flow of bile and pancreatic juice into the duodenum controlled?
The hepatopancreatic sphincter, this sphincter also prevents reflux of duodenal content back into the pancreatic and bile ducts.
From which vessel does the gastroduodenal artery arise?
-
From which vessel does the inferior pancreaticoduodenal artery arise?
Superior mesenteric artery
From which vessel does the splenic artery arise?
-
What supplies the head of the pancreas?
The superior and inferior pancreaticoduodenal arteries
What supplies the rest of the pancreas?
Splenic artery
What drains the head of the pancreas?
Superior and inferior pancreaticoduodenal veins
What drains the rest of the pancreas?
Splenic vein
Which vein does the inferior pancreaticoduodenal vein drain into?
Superior mesenteric vein
Which vein is formed by the union of the superior mesenteric and splenic veins?
Hepatic portal vein
Which vein does the superior pancreaticoduodenal vein drain into?
-
How much does the liver weigh approximately?
1.5kg
Which abdominal regions is a healthy liver located?
R. Hypochondriac
Epigastrium
L/ Hypochondriac
What is the difference between diaphragmatic and visceral surfaces on the liver?
The diaphragmatic surface is smooth as it is moulded by the under surface of the diaphragm. In contrast the visceral surface is irregular as it is in contact with the irregular shaped viscera.
What is the falciform ligament?
A double fold of peritoneum that connects anterior & superior surfaces of the liver to the anterior abdominal wall.
What is the Ligamentum teres (round ligament)?
Remnant of the umbilical vein, it runs in the free edge of the falciform ligament.
What is the Ligamentum venosum?
Remnant of the ductus venosus, it is attached to the portal vein and the IVC.
What is the Coronary ligament?
A reflection of visceral peritoneum that extends from the posterior surface of the liver onto the diaphragm.
What is the right and left triangular ligament?
The left and right extremity of the coronary ligament
What is the hepatogastric ligament?
The part of the lesser omentum which extends from liver to lesser curvature of stomach.
What is the hepatoduodenal ligament?
The free border of the lesser omentum, it contains the bile duct, portal vein and hepatic artery.
Posteriorly, the liver looks like it has a letter H on it. What forms the H?
Two sagittal fissures joined together in the middle by the porta hepatis.
Which structure lies in the fossa that forms the anterior part of the right sagittal fissure?
-
Which structure lies in the groove that forms the posterior part of the right sagittal fissure?
-
Which structure lies in the groove that forms the posterior part of the left sagittal fissure?
-
Which structure lies in the groove that forms the anterior part of the left sagittal fissure?
-
What is the porta hepatis?
The site where structures enter or leave the liver
What can be found in the porta hepatis?
Hepatic arteries Hepatic ducts Portal veins Lymphatics Autonomic fibres
What is the bare area of the liver?
a small area posteriorly where it comes into direct contact with the diaphragm.
What is the basic structural unit of the liver?
Liver lobule
Describe the histology of the liver?
Each lobule is hexagonal in shape and consists of plates of hepatocytes radiating towards a central vein. Vascular channels, the liver sinusoids, are placed between the plates of hepatocytes. They convey blood from the periphery of the lobule to the central vein. A portal triad is located at each angle of the hexagonal lobule.
What is in the portal triad?
Each lobule is hexagonal in shape and consists of plates of hepatocytes radiating towards a central vein. Vascular channels, the liver sinusoids, are placed between the plates of hepatocytes. They convey blood from the periphery of the lobule to the central vein. A portal triad is located at each angle of the hexagonal lobule.
What percentage of blood to the liver is delivered by the hepatic artery proper?
20-25%
From which vessel does the hepatic artery proper (hepatic artery) arise?
Common hepatic
What percentage of blood is delivered to the liver from the portal vein?
75-80%
Which two veins unit to form the portal vein?
Splenic and superior mesenteric
Describe the blood flow through the liver
Branches of hepatic artery and portal vein enter the portal triad
Blood is conveyed through the liver sinusoid and drains into the central vein.
Blood drains into the right and left hepatic veins
These vessels drain into the inferior vena cava
Why are anastomoses between the hepatic portal system and systemic circulation important?
If portal circulation through the liver is obstructed blood can return to the heart via the systemic circulation. As the portal vein and its tributaries have no valves the blood can flow in a retrograde direction to the IVC.
Describe the inferior oesophagus anastomose site
Lower third drains via left gastric vein into portal vein - middle third drains into azygos vein.
Describe the Anal canal anastomose site
Superior rectal veins drain into portal system - middle and inferior rectal veins drain into internal iliac and internal pudendal veins.
Describe the Secondary retroperitoneal structures anastomose site
Superior mesenteric, inferior mesenteric and splenic vessels drain into portal system - renal, lumbar and phrenic veins drain into IVC.
Describe the Anterior abdominal wall anastomose site
Paraumbilical veins drain into portal system – superficial veins of abdomen drain into axillary or femoral veins
How much of total lymph production is from the liver?
up to half
Which group of lymph nodes recieves lymph from the hepatic nodes?
celiac lymph nodes
Which lymphatic trunk drains lymph from the coeliac nodes?
Intestinal lymphatic trunk
Which structure does the intestinal trunk drain into?
Cisterna chyli
Which splanchnic nerve provides sympathetic innervation to the liver and gall bladder?
Greater Splanchnic
In which ganglion do postganglionic sympathetic fibres for the liver and gall bladder arise?
Coeliac
Which nerve transmits parasympathetic fibres to the liver and gallbladder ?
Vagus
What type of control do nerves to the liver provide?
Vasomotor
What is the gall bladder?
a pear-shaped sac whose function is to store and concentrate bile. It lies in the fossa of the gall bladder.
What is the fundus of the gall bladder?
Rounded portion of the gall bladder that projects from the lower border of the liver. Located at the tip of the 9th costal cartilage in the midclavicular line.
What is the body of the gall bladder?
Main part of gall bladder that is located posterior to the liver, superior part of duodenum and the transverse colon
What is the neck of the gall bladder?
The part of the gall bladder which is continuous with the cystic duct, it lies superior to the duodenum.
From which vessel does the cystic artery usually arise?
Right hepatic
Where is the cystic artery usually located?
in the cystohepatic triangle between the inferior border of the liver, cystic duct and common hepatic duct.
What drains the neck and cystic of the gall bladder duct?
Cystic veins which drain into liver directly or via portal vein
How does the fundus and body of the gallbladder drain venous blood?
Directly through visceral surface of liver into hepatic sinusoids
Describe the lymph drainage from gall bladder to bloodstream
Cystic nodes Hepatic nodes Coeliac nodes Intestinal trunk Cisterna Chyli Thoracic duct Left subclavian vein
Describe the path of bile.
Bile is continuosly secreted by the liver. It passes down the right and left hepatic ducts into the common hepatic duct and then through the bile duct to the duodenum. If fat is present in the duodenum the sphincter of Oddi (hepatopancreatic sphincter) will be open and bile will be able to enter. In the absence of fat, the sphincter will be closed and the bile will track back up the bile duct, into the cystic duct and into the gall bladder.
What is the name given to the hormone that is released by the enteroendocrine cells when fat is present in the duodenum?
CCK
Describe the histology of the salivary glands
The secretory units of the salivary glands consist of a branched tubulo-acinar structure. The acinar cells produce either serous, mucous or a mixed saliva. In some cases the serous cells form caps around the mucous secreting acini. These caps are referred to as serous demilunes. Cells which produce serous saliva stain much darker with H&E stain compared to mucous secreting cells.
The acini cells secrete saliva into small intercalated ducts which, in turn, drain into larger striated ducts and then into even larger excretory ducts.
Describe the histology of the pancreas
The pancreas is a mixed endocrine and endocrine gland. It is surrounded by a thin connective tissue capsule. Septa extend into the gland from the capsule separating the pancreatic lobules.
Describe the histology of the exocrine pancreas
Consists of closely packed secretory acini which drain into a duct system. The smallest intercalated ducts drain into intralobular ducts which, in turn, drain into interlobular ducts. The interlobular ducts are located in the septa of the gland. The interlobular ducts drain into either the main pancreatic duct or the accessory pancreatic duct.
Describe the histology of the endocrine pancreas
Comprised of clusters of cells known as the pancreatic islets (islets of Langerhans). These are scattered throughout the gland but are most numerous in the tail. The islets vary in size and are composed of a number of different cell types, each of which is responsible for secreting one type of hormone.
Describe the histology of the liver
The liver is covered by a thin capsule, termed Glisson’s capsule. The capsule is thicker at the porta hepatis and it surrounds the vessels and ducts as they extend into the gland. The hepatocytes and the sinusoids are surrounded by a fine, supportive reticular network.
Describe the histology of the gall bladder
The wall of the gall bladder is similar to that of the gastrointestinal tract but it lacks the submucosal layer. The mucosa consists of a layer of simple columnar epithelium and a supporting lamina propria. There is no distinct submucosa and only one muscularis is evident. This is a thin layer which is composed of muscle fibres orientated in many directions. The outer layer of the gall bladder is serosa in parts and an adventia in others.
What is the name of the vertical line that extends from the midpoint of the clavicle to the midinguinal point?
Midclavicular
What is the name of the horizontal plane that passes through the inferior border of the tenth costal cartilage and lies at the level of L2?
Subcostal
What is the name of the horizontal plane that passes through the iliac tubercles and lies at the level of L5?
Transtubercular
What is the name of the horizontal plane that lies halfway between the umbilicus and the xiphisternum, or midway between the upper border of the manubrium and the symphasis pubis and lies at the level of L1?
Transpyloric
What structures can be found in the R upper quadrant?
Right lobe of liver Gallbladder Hepatic flexure Right suprarenal gland Right kidney
What structures can be found in the L upper quadrant?
Left kidney Spleen Splenic flexure Left lobe of liver Left suprarenal gland
What structures can be found in the R lower quadrant?
Right uterine tube Right ovary Right ureter Caecum Appendix
What structures can be found in the L lower quadrant?
Left uterine tube
Left ureter
Sigmoid colon
Left ovary
Inferiorly, the abdominal wall is bounded by what?
Iliac crest
Pubic crest
Pubic symphasis
Inguinal ligament
Anterolaterally, the abdominal wall is bounded by what?
Costal margin
Xiphisternum
What does the abdominal wall consist of?
skin, fascia, muscles and their aponeuroses, endoabdominal fascia, extraperitoneal fat and the parietal peritoneum
What can the superficial fascia be divided into?
the fascia of Camper and the fascia of Scarpa
Which layer of fascia forms the deep membranous layer which blends with the fascia of the inner thigh and extends into the scrotum and labia majora as Colles’ fascia?
Scarpa’s fascia
Which layer of fascia is the outer fatty layer which is continuous with the superficial fat over the rest of the body?
Camper’s fascia
Which muscle originates from the lower eight ribs?
External oblique
Which muscle originates from the lower six costal cartilages, lumbodorsal fascia, iliac crest and inguinal ligament?
Transversus abdominis
The inguinal ligament is formed by the free lower border of which muscle?
External oblique
Which muscle inserts into ribs ten to twelve, linea alba and the pectin pubis?
Internal oblique
Which muscles insert into the linea alba?
Internal oblique
Transversus abdominis
Pyramidalis
External Oblique
The conjoint tendon is formed from the tendons of which two muscles?
Internal oblique
Transversus abdominis
What makes up the anterior wall of rectus sheath above the umbilicus?
Aponeurosis of external oblique and anterior lamina of aponeurosis of internal oblique
What makes up the anterior wall of rectus sheath below the umbilicus?
Aponeurosis of external oblique, internal oblique and transversus abdominis
What makes up the posterior wall of rectus sheath below the umbilibus?
Posterior lamina of aponeurosis of internal oblique and aponeurosis of transversus abdominis
What is the name given to the free lower border of the posterior wall of the rectus sheath?
Arcuate line
Which structure is formed by the anterior and posterior fibres of the rectus sheath as they interlace in the anterior median line?
Linea alba
Which layer of the rectus sheath is anchored to the rectus abdominis by the tendinous intersections?
Anterior
From which vessel does the superior epigastric artery arise?
Internal thoracic artery
From which vessel does the inferior epigastric artery arise?
External iliac artery
From which vessel does the musculophrenic artery arise?
Internal thoracic
From which vessel does the subcostal artery arise?
Thoracic aorta
From which vessel does the superificial epigastric artery arise?
Femoral
From which vessel does the superficial circumflex iliac artery arise?
Femoral
From which vessel does the deep circumflex iliac artery arise?
External Iliac
What level(s) provide sensory innervation for the abdominal wall above the umbilicus?
T7-T9
What level(s) provide sensory innervation for the abdominal wall below the umbilicus?
T11-L1
What level(s) provide sensory innervation for the abdominal wall around the umbilicus?
T10
T/F
The transversalis fascia and the conjoint tendon form the posterior wall of the inguinal cana
True
T/F
The external oblique aponeurosis contributes to the roof of the inguinal canal.
False
T/F
The lacunar ligament forms the most lateral part of the floor of the inguinal canal.
False
T/F
The deep inguinal ring lies medial to the inferior epigastric vessels.
False
T/F
The superficial inguinal ring lies superolateral to the pubic tubercle
True
What name is given to the endoabdominal fascia that is located in the region of the anterolateral abdominal wall?
transversalis fascia
What is the mucosa?
The innermost layer which consists of an epithelium, an underlying lamina propria and a layer of smooth muscle.
What is the submucosa?
A connective tissue layer that contains blood vessels, lymphatics and Meissner’s plexus.
What is the Muscularis externa?
A smooth muscle layer, whose inner fibres are arranged circularly and outer ones longitudinally. Contains the myenteric plexus
What is the adventitia?
The outer, connective tissue layer which contains blood vessels and lymphatics. It is referred to as a serosa if it is covered by a mesothelial layer.
Define an intraperitoneal organ.
An organ that is suspended from the body wall by a mesentery
Define a retroperitoneal organ.
An organ that is pushed up against the body wall and is only partially covered by peritoneum
What is the lesser omentum?
A double layer of peritoneum that connects the liver with the lesser curvature of the stomach
What is the greater omentum?
A double layer of peritoneum that connects the greater curvature of the stomach with the transverse colon
What is the mesentery?
A double layer of peritoneum that connects an intraperitoneal organ with the body wall (eg. The mesentery, transverse mesocolon, mesoappendix)
What is the parietal peritoneum?
The serous membrane that lines the inner surface of the body wall
What is the peritoneal cavity?
The fluid-filled potential space between the parietal and visceral peritoneums
What is the visceral peritoneum?
The serous membrane that covers the external surfaces of the abdominal organs
What is the greater sac?
The largest portion of the peritoneal cavity
What is the hepatorenal recess?
The part of the peritoneal cavity which lies inferior to the liver and anterior to the kidney and suprarenal gland
What is the infracolic compartment?
The part of the peritoneal cavity inferior to the transverse mesocolon
What is the left paracolic gutter?
The depression/recess lateral to the descending colon
What is the lesser sac?
The smallest portion of the peritoneal cavity which lies posterior to the lesser omentum and stomach
What is the right paracolic gutter?
The depression/recess lateral to the ascending colon
What is the subphrenic space?
The part of the peritoneal cavity which lies between the diaphragm and liver
What is the supracolic compartment?
The part of the peritoneal cavity which lies above the transverse mesocolon
How does the lesser sac communicate with the greater sac?
a small opening termed the epiploic foramen (omental foramen).
What are the boudaries of the epiploic foramen?
Anterior - Hepatoduodenal ligament
Superior - Liver
Inferior - Superior part of duodenum
Posterior - Inferior vena cava
What forms to heaptoduodenal ligament?
The free border of the lesser omentum
What structures run through the hepatoduodenal ligament?
Hepatic artery
Bile duct
Portal vein
What is the median umbilical ligament a remnant of?
urachus
What are the medial umbilical ligaments remnants of?
umbilical arteries
Which structure does the lateral umbilical ligaments overlie?
inferior epigastric vessels (?)
What type of innervation does the peritoneum receive?
The parietal peritoneum receives somatic innervation from the nerves that supply the abdominal wall. It is therefore sensitive to pain which can clearly be localised.
The visceral peritoneum receives autonomic innervation.
Define the foregut
Extends from the lower part of oesophagus to the second part the duodenum and also includes the liver, spleen and part of the pancreas.
Define the midgut
Extends from the second part of the duodenum to the distal third of the transverse colon, it also includes part of the pancreas.
Define the hindgut
Extends from the distal third of transverse colon to the proximal part of the anus.
What organs form the foregut?
Gall bladder Duodenum proximal to major papilla Spleen Liver Pancreas Stomach
What organs form the midgut?
Hepatic flexure Jejunum Duodenum distal to major papilla Ascending colon Proximal 2/3 of transverse colon Caecum Ileum Appendix
What organs form the Hindgut?
Proximal part of the anus Rectum Distal 1/3 of transverse colon Splenic flexure Sigmoid colon Descending colon
What is the forguts blood supply?
Coeliac trunk
What is the midguts blood supply?
Superior mesenteric artery
What is the hindguts blood supply?
Inferior mesenteric artery
Into which trunk do the efferent vessels from the coeliac, superior mesenteric and inferior mesenteric nodes drain into?
Intestinal trunk
The intestinal trunk empties into the cysterna chyli which is located at the inferior end of which structure?
Thoracic duct
Where does the thoracic duct drain into the venous system?
Left subclavian vein
Describe the autonomic innervation pathway og the GI tract.
Preganglionic sympathetic fibres arise in the lateral horn of grey matter of the thoracolumbar regions of the spinal cord. Their axons pass in the ventral root, spinal nerve, ventral ramus and white ramus communicantes to enter the sympathetic chain. They pass through the chain without synapsing and continue on to the prevertebral ganglia as splanchnic nerves. They terminate in prevertebral ganglia by synapsing with the postsynaptic fibres that pass to the effector organ
What is the autonomic innervation of the foregut?
Preganglionic fibres originate T5-T9
Coeliac ganglion
Greater splanchnic nerve
What is the autonomic innervation of the midgut?
Preganglionic fibres arise T10-T11
Superior mesenteric ganglion
Lesser splanchnic nerve
What is the autonomic innervation of the hindgut?
Preganglionic fibres arise T12-L1
Inferior mesenteric ganglion
Lumbar splanchnic nerve
Which nerve provides parasympathetic innervation to the gut?
Vagus
What is the myenteric plexus responsible for?
Gastointestinal motility
What is the submucosal plexus responsible for?
senses environmental changes in the lumen and regulates gastrointestinal blood flow and epithelial cell function
What are the functions of the stomach?
Storage of ingested food
Control of chyme entering the dudoenum
Protection against invading pathogens
What is the name given to the folds seen on the internal surface of the stomach?
Rugae
A double fold of peritoneum extends from the liver to the lesser curvature of the stomach and proximal part of duodenum. What is the name given to this structure?
Lesser omentum
What is the name given to the free edge of the peritoneal fold that extends between the liver and lesser curvature of the stomach?
-
A double fold of peritoneum extends from the greater curvature of the stomach to the transverse colon. What is the name given to this structure?
Greater omentum
What branches of the coeliac trunk supply the stomach?
Common hepatic
Left gastric
Splenic
What arteries supplies blood to the different parts of the stomach?
Fundus - short gastric
Lesser curvature - L/R gastric
Greater curvature - L/R gastroepiploic
From which vessel does the short gastric arteries arise?
Splenic artery
From which vessel does the right gastric artery arise?
Common hepatic artery
The right gastroepiploic artery arises from the gastroduodenal artery. Where does the gastroduodenal artery arise?
Common hepatic artery
From which vessel does the left gastrioepiploic artery arise?
Splenic artery
Into which vessel do the right and left gastric veins drain to?
Portal vein
Where do the short gastric and left gastroepiploic veins drain to?
Splenic vein
Where does the right gastroepiploic vein drain to?
Superior mesenteric vein
Which vessel is formed by the union of the splenic and superior mesenteric veins?
Portal vein
Behind which structure is the portal vein formed?
Pancreas
Which group of lymph nodes receives lymph from the regional nodes of the stomach?
Coeliac
Which spinal cord segments do preganglionic sympathetic fibres to the stomach arise?
T6-T9 (?)
Which splanchnic nerve conveys preganglionic sympathetic fibres for the stomach?
Greater spanchnic
Which prevertebral ganglion do postganglionic sympathetic fibres for the stomach arise?
Coeliac plexus (?)
Which nerve transmits parasympathetic fibres to the stomach?
Vagus
In which abdominal region is visceral pain from the stomach perceived?
Epigastric
What are plicae circulares?
Circular folds in the mucosa that can be seen with the naked eye.
What are microvilli?
Microscopic protrusions from the luminal surface of the intestinal cells.
What are villi?
Finger-like projections of the mucosa.
How long is the root of the mesentery?
15cm
The root of the mesentery is attached to the posterior wall along a line that extends from the left side of the second lumbar vertebra to the region of which joint?
right sacroiliac
What is the duodenum?
The duodenum is the first part of the small intestine and the main site of digestion. It is a C-shaped tube that is approximately 25cm long (12 finger breadths) that extends from the pyloric sphincter to the jejunum. The duodenum is divided into four parts
What are the four parts of the duodenum, in order?
Superior
Descending
Horizontal
Ascending
Which part of the duodenum do the minor and major papillae open into?
Descending
Which part of the duodenum is the most distal part of the foregut?
Descending
Which part of the duodenum has part of the lesser omentum attached to its superior border and part of the greater omentum attached to its inferior border?
Superior
Which part of the duodenum is supported by the suspensory muscle of the duodenum (ligament of Treitz)?
Ascending
Which part of the duodenum has an intraperitoneal section?
Superior
The parts of the duodenum proximal to the major duodenal papilla are supplied by a branch of the gastroduodenal artery which arises from the coeliac trunk. What is the name of this branch?
Superior pancreaticoduodenal
The parts of the duodenum distal to the major duodenal papilla are supplied by a branch of the superior mesenteric artery. What is the name given to this branch?
Inferior pancreaticoduodenal
Most absorption occurs in the jejunum but the terminal ileum is the only site of absorption for which substance?
Vitamin B12
What is the structure of the jejunum?
Fewer larger arcades Less fat in mesentery Long vasa recta Redder in colour Thicker walled More vascular Wider in diameter Mostly located in l. upper quadrant of the infracolic compartment
What is the structure of the ileum?
Thinner walled Narrower in diameter More fat in mesentery Many short looped arcades Less vascular Paler in colour Short vasa recta Mostly located in r. lower quadrant of the infracolic compartment
