GI Anatomy

Question 1

What cranial nerves innervate the tongue muscles?

Answer 1

All are innervated by CNXII (hypoglossal), except the palatoglossus which is innervated by CNX (vagus)

Question 2

Constrictor muscles of the pharynx are the external layer of the pharyngeal muscles. What CN are they innervated by?

Answer 2

CNX

Question 3

What CN are the inner longitudinal muscles of the pharynx innervated by?

Answer 3

CNIX and CNX

Question 4

What muscle is the only one innervated by CNIX?

Answer 4

Stylopharyngeus

Question 5

In relation to the gag reflex what CN are related to the sensory and motor limb?

Answer 5

Sensory limb – CNIX.
Motor limb – CNIX + CNX.

Question 6

At the anterior 2/3rd of the tongue what CN are related to general an special sensory?

Answer 6

General sensory – CNV3.
Special sensory (taste) – CNVII.

Question 7

At the posterior 1/3rd of the tongue what CN is related to general and special sensory?

Answer 7

General and special sensory – CNIX.

Question 8

What CN are the muscles of the jaw closing and opening all innervated by?

Answer 8

CNV3 – the mandibular division of the trigeminal nerve.

Question 9

What are the muscles involved in the jaw closing?

Answer 9

masseter, temporalis, medial pterygoid

Question 10

What are the muscles involved in the jaw opening?

Answer 10

lateral pterygoid

Question 11

Pterygoid plates are part of what bone?

Answer 11

Sphenoid bone

Question 12

Describe the pain associated with appendicitis

Answer 12

Starts as a dull ache around the umbilicus, the moves to become a localised sharp pain in the RIF due to irritation of the parietal peritoneum

Question 13

Is the liver an intra or reteroperitoneal organ?

Answer 13

Intraperitoneal

Question 14

What are the visceral afferent nerve fibres of the gut? (foregut,midgut,hindgut)

Answer 14

Foregut- T6 to T9
Midgut- T8 to T12
Hindgut- T10 to L2

Question 15

What does the gallbladder do?

Answer 15

Stores AND concentrates bile

Question 16

What is the first branch of the abdominal aorta?

Answer 16

Coeliac Trunk

Question 17

What level is the coeliac trunk at?

Answer 17

T12

Question 18

What organs does the coeliac trunk supply?

Answer 18

Organs of the foregut

Question 19

What does the spleen do?

Answer 19

Breaks down red blood cells to produce bilirubin

Question 20

What ribs protect the spleen?

Answer 20

Ribs 9-11

Question 21

Describe the blood supply to the stomach

Answer 21

Right (from hepatic artery) and left (from coeliac trunk) gastric arteries.
Right (from gastro-duodenal branch of hepatic artery) and left (from splenic artery) gastro-omental arteries

Question 22

What ribs does the liver lie deep to?

Answer 22

Ribs 7-11

Question 23

What are the four liver lobes?

Answer 23

right, left, caudate, quadrate

Question 24

What is the blood supply to the gallbladder via?

Answer 24

The cystic artery

Question 25

Where are the heptorenal and subphrenic recesses located?

Answer 25

Within the greater sac

Question 26

What are the components of the portal triad?

Answer 26

Hepatic portal vein, hepatic artery and common bile duct

Question 27

What does the bile duct join with the pancreatic duct to form?

Answer 27

The ampulla of vater/hepatopancreatic ampulla

Question 28

Jaundice is caused by an increase in blood levels of what?

Answer 28

Bilirubin

Question 29

Describe blood supply to the pancreas

Answer 29

Mainly from pancreatic branches of splenic artery. And superior (from gastroduodenal branch of hepatic artery) + inferior (from SMA) pancreaticoduodenal arteries.

Question 30

Is the duodenum intraperitoneal or retroperitoneal?

Answer 30

First part of the duodenum is intraperitoneal. The other 3 parts are retroperitoneal

Question 31

Where is the appendiceal orifice loacted?

Answer 31

Posteromedial wall of the caecum, 1/3rd of the way between right ASIS, and the umbilicus. This corresponds to McBurney’s point.

Question 32

At what level does the abdominal aorta bifrucate into the comon iliacs?

Answer 32

L4

Question 33

What is the main arterial anastomosis in the large intestine called?

Answer 33

The marginal artery of Drummond

Question 34

Describe the blood supply to the rectum and anal canal

Answer 34

Hindgut part – superior rectal artery from IMA. Somatic part (below the pectinate line) – middle and inferior rectal arteries from the internal iliac artery

Question 35

Name three important sites of portal systemic anastomoses

Answer 35

Distal end of oesophagus. Skin around the umbilicus. Rectum/anal canal

Question 36

What is levator ani muscle?

Answer 36

The pelvic floor

Question 37

Where does the sigmoid colon become the rectum?

Answer 37

At the rectosigmoid junction, anterior to S3

Question 38

Where does the rectum become the anal canal?

Answer 38

At the tip of the coccyx

Question 39

Name three muscles associated with levator ani

Answer 39

iliococcygeus, pubococcygeus, puborectalis

Question 40

Describe the nerve supply to levator ani

Answer 40

Nerve to levator ani (a branch of the sacral plexus, S3, S4). Pudendal nerve (S2, S3, S4).

Question 41

What lies on either side of the anal canal?

Answer 41

Ischioanal fossae

Question 42

What happens in the common hepatic duct?

Answer 42

Bile travels through from the liver