GI Anatomy Flashcards
What cranial nerve innervates the tongue muscles?
CNXII - The hypoglossal
What cranial nerve innervates the palatoglossus?
CNX - Vagus
What are the constrictor muscles of the pharynx?
The external layer of pharyngeal muscles
What cranial nerve innervates the constrictor muscles of the pharynx?
CNX - Vagus
What cranial nerve innervates the inner longitudinal muscles of the pharynx?
CNIX - Glossopharyngeal nerve & CNX - Vagus
What cranial nerve innervates the stylopharyngeus muscle?
CNIX - Glossopharyngeal nerve
What cranial nerve is involved in the sensory limb of the gag reflex?
CNIX - Glossopharyngeal nerve
What cranial nerve is involved in the motor limb of the gag reflex?
CNIX - Glossopharyngeal nerve & CNX - Vagus
What cranial nerve innervates the general sensory anterior 2/3rds of the tongue?
CNV3 - The mandibular division of the trigeminal nerve
What cranial nerve innervates the special sensory anterior 2/3rds of the tongue?
CNVII - The facial nerve
What cranial nerve innervates the posterior 1/3rd of the tongue?
CNIX - Glossopharyngeal nerve
What cranial nerve innervates the muscles of the jaw opening and closing?
CNV3 - The mandibular division of the trigeminal nerve
What muscle(s) are involved in the closing of the jaw?
Masseter, temporalis, medial pterygoid
What muscle(s) are involved in the opening of the jaw?
Lateral pterygoid
What are the pterygoid plates a part of?
The sphenoid bone
How would a patient with appendicitis describe the pain?
It starts as a dull ache around the umbilicus, then moves to become a localised sharp pain in the right iliac fossa due to irritation of the parietal peritoneum
What part of the gastrointestinal tract does the Vagus nerve innervate?
Up to the distal end of the transverse colon
What part of the gastrointestinal tract do the pelvic splanchnic nerves (S2,S3,S4) innervate?
From the descending colon to the anal canal
What type of organ is the liver?
Intraperitoneal
Where do the sympathetic nerve synapse?
Directly onto the cells of the adrenal gland
What are the visceral afferent nerve fibres of the foregut?
T6 to T9
What are the visceral afferent nerve fibres of the midgut?
T8 to T12
What are the visceral afferent nerve fibres of the hindgut?
T10 to L2
What is the function of the gallbladder?
To store and concentrate bile
What is the function of the coeliac trunk?
Supplies the organs of the foregut
Where is the coeliac trunk found?
At T12 level
What is the origin of the coeliac trunk?
It is a branch of the abdominal aorta
What is the function of the spleen?
Breaks down red blood cells to produce bilirubin
What protects the spleen?
Ribs 9-11
What artery supplies the foregut?
The celiac trunk
What artery supplies the midgut?
Superior mesenteric artery
What artery supplies the hindgut?
Inferior mesenteric artery
What vein drains the foregut?
The splenic vein
What vein drains the midgut?
The portal venous system
What vein drains the hindgut?
The inferior mesenteric vein
What supplies the stomach with blood?
The right and left gastric arteries & the right and left gastro-omental arteries
What is the origin of the left gastric artery?
The hepatic artery
What is the origin of the left gastric artery?
The coeliac trunk
What is the origin of the right gastro-omental artery?
The gastro-duodenal branch of hepatic artery
What is the origin of the left gastro-omental artery?
The splenic artery
What are the folds of the stomach called?
Rugae
Where is the liver found?
Lies deep to ribs 7-11
What are the different liver lobes?
Right, left, caudate, quadrate
How is the right liver lobe described?
It’s the largest lobe
How is the left liver lobe described?
The flattened smaller one
What separates the left and right liver lobes?
The fossae for the gallbladder and the inferior vena cava
Where is the caudate liver lobe located?
Between the fissure for the ligamentum venosum and the inferior vena cava
Where is the quadrate liver lobe located?
Between the gallbladder and the fissure for the ligamentum teres hepatis
What artery supplies the gallbladder?
The cystic artery
What is the hepatorenal recess?
The hepatorenal recess is a space located on the inferior right aspect of the liver, between this organ and the right kidney and suprarenal gland
What is the subphrenic recess?
The subphrenic recess is a space between the diaphragmatic surface of the liver from the inferior surface of the diaphragm; it is split by the falciform ligament of the liver into right and left areas
Where are the hepatorenal and subphrenic recesses located?
The greater sac
What does the portal triad consist of?
Hepatic portal vein, hepatic artery and common bile duct
How is the ampulla of vater formed?
The bile duct joins with the pancreatic duct
What is calots triangle?
A small anatomical space in the abdomen
What is the medial border of calots triangle?
Common hepatic duct
What is the inferior border of calots triangle?
Cystic duct
What is the superior border of calots traingle?
Inferior surface of the liver
What is jaundiced caused by?
Increased levels of blood bilirubin
What supplies the pancreas with blood?
Mainly from pancreatic branches of splenic artery and superior & inferior pancreaticoduodenal arteries
What is the origin of the superior pancreaticoduodenal artery?
From the gastroduodenal branch of the hepatic artery
What is the origin of the inferior pancreaticoduodenal artery?
From the superior mesenteric artery
What part(s) of the duodenum are intraperitoneal?
The 1st part
What part(s) of the duodenum are retroperitoneal?
The 2nd, 3rd & 4th parts
What is meant by the term visceral peritoneum?
Peritoneum that lines organs
What is meant by the term parietal peritoneum?
Peritoneum that lines under skin
What is the purpose of the omentum?
It separates the peritoneal cavity into the lesser and greater sacs
At what level does the abdominal aorta bifurcate into the common iliacs?
At L4 level
What is the the main arterial anastamosis in the large intestine called?
The marginal artery of Drummond
What is the hindgut part of the blood supply to the rectum and anal canal?
Superior rectal artery from the internal mesenteric artery
What is the somatic part (below the pectinate line) of the blood supply to the rectum and anal canal?
Middle and inferior rectal arteries from the internal iliac artery
What are the 3 important sites of portal systemic anastomoses?
- Distal end of oesophagus
- Skin around the umbilicus
- Rectum/anal canal
What muscle for the majority of the pelvic floor?
Levator ani muscle
When does the sigmoid colon become the rectum?
At the rectosigmoid junction, anterior to S3
When does the rectum become the anal canal?
Anterior to the tip of the coccyx
What are the 3 muscles associated with the levator ani muscle?
iliococcygeus, pubococcygeus, puborectalis
What nerves supply the levator ani muscle?
- Nerve to levator ani (a branch of the sacral plexus, S3, S4)
- Pudenal nerve (S2,S3,S4)
What is the function of the pudenal nerve?
Stimulates the contraction of the external anal sphincter, keeping the pelvis off the floor
Where does the pudenal nerve enter?
Via the greater sciatic foramen
Where does the pudenal nerve exit?
Through the lesser sciatic foramen
What is the function of the common hepatic duct?
Where bile travels through from the liver
What is the function of the bile duct?
Where bile travels through from the gallbladder
Where do inguinal ligaments attach?
Between the anterior superior iliac spine and the pubic tubercle
Where is the deep ring located?
The midpoint of the inguinal ligament
What is meant by the term direct inguinal hernia?
A bit of peritoneum is forced through the posterior wall of the inguinal canal, and directly out of the superficial ring
What is meant by the term indirect inguinal hernia?
A bit of peritoneum is forced through the deep ring, into the inguinal canal, then out of the superficial ring
How do you differentiate between a direct and indirect inguinal hernia?
Reduce the hernia, occlude the deep ring with finger-tip, and ask patient to cough. If it is a direct hernia, the lump will reappear as it does not need to pass through the deep ring to get out into the scrotum
What is the thyroid cartilage?
It is the largest of the nine laryngeal cartilages
Where is thyroid cartilage located?
The thyroid cartilage is situated between the cricoid cartilage and the hyoid bone
What is the thyroid cartilage composed of?
Two identical hyaline cartilage laminae that meet at the midline and form the laryngeal prominence (i.e. the Adam’s apple) and a third, superior, unfused lamina that creates the laryngeal notch
What is the cricoid cartilage?
It is a complete circle of cartilage
Where is the cricoid cartilage located?
It is attached superiorly via the median cricothyroid ligament to the inferior aspect of the thyroid cartilage
What is the purpose of the cricotracheal ligament?
It holds the upper and lower respiratory tracts together
What is the epiglottic cartilage/epiglottis?
It is an elastic cartilage which looks like a leaf
What is the function of the epiglottic cartilage/epiglottis?
When oral contents are swallowed, it functions by closing over the laryngeal inlet (rima glottidis)
Where is the epiglottic cartilage/epiglottis located?
It is situated between the hyoid bone and the dorsal part of the tongue anteriorly and the laryngeal inlet posteriorly
Where is the superior tip of the epiglottic cartilage/epiglottis located?
It is left standing free
Where is the base of the epiglottic cartilage/epiglottis located?
It is fastened to the thyroid laminae in the midline via the thyroepiglottic ligament
What are the arytenoid cartilages?
They are a pyramidal cartilage with three faces
Where is the arytenoid cartilage located?
It articulates with the lateral superoposterior aspects of the lamina of cricoid cartilage
What are the three processes of an arytenoid cartilage?
The apex, vocal and muscular processes
What is the hyoid bone?
A horseshoe-shaped bone in the neck
Where is the hyoid bone located?
In the anterior midline of the neck between the chin and the thyroid cartilage
