Midgut & Hindgut Structures

Front 1

What structures are located in the mid gut?

Back 1

1. Distal half of duodenum
2. Jejunum & ileum
3. Cecum & vermiform appendix
4. Ascending & transverse colon

Front 2

What structures are located in the hind gut?

Back 2

1. descending colon
2. sigmoid colon
3. rectum

Front 3

What vertebral level does the jejunum begin at?

Back 3

L2

Front 4

Where does the ileum end?

Back 4

Ends at the ileocecal junction/ right sacroiliac joint

Front 5

What is the difference b/e the jejunum & ileum?

Back 5

Jejunum Ileum
1. fewer arcades 1. more arcades
2. larger diameter 2. fat near bowel
3. fat near the root 3. smaller diameter
4. Thicker wall 4. thinner wall
5. more plica circularis 5.less plica circularis

Front 6

What holds the jejunum/ileum to the posterior abdominal wall?

Back 6

The mesentary

Front 7

What provides the pathway for vessels and nerves that serve the jejunum and ileum?

Back 7

The mesentary proper

Front 8

Where is the root of the mesentary proper located?

Back 8

Extends from left of L2 diagonally to the right sacroiliac joint

Front 9

What does the mesentary proper cross over?

Back 9

1. The duodenum
2. Aorta & IVC
3. Right psoas major, ureter, gonadal vessels

Front 10

What does the mesentary proper contain?

Back 10

Superior mesentaric artery/branches and vein/tributaries.

Superior mesentaric nerve

Front 11

Back 11

Front 12

Where is the right colic flexure/hepatic flexure?

Back 12

The flexure b/e ascending and transverse colon.

Front 13

What is the left colic flexure?

Back 13

The "splenic flexure" b/e the transverse and descending colon.

Front 14

What part of the large intestine is intraperitoneal?

Back 14

1. Cecum
2. Vermiform appendix
3. Transverse colon
4. sigmoid colon

Front 15

What part of the large intestine is retroperitoneal?

Back 15

1. ascending colon
2. descending colon

Front 16

What fossa contains the appendix?

Back 16

The right iliac fossa

Front 17

Where is the opening for the appendix?

Back 17

~3cm below the ileocecal orifice

Front 18

What artery runs through the superior ileocecal fold/recess?

Back 18

A branch of the ileocolic artery

Front 19

Where is the origin of the taenia coli?

Back 19

At the base of the appendix.

Front 20

Where is pain referred to from the appendix?

Back 20

Afferent (pain) fibers refer pain to the T10 dermatome.

Front 21

What Sy is caused by retrocecal appendicitis?

Back 21

Psoas sign:
passive: pain on passive extension of right thigh
active: flexion of the right hip against resistance

Front 22

what is the Sy that is caused by a pelvic appendix?

Back 22

Obturator sign (pain upon internal rotation of leg w/ hip and knee flexed)

*caused by pressure of the inflamed appendix lying on the obturator muscle

Front 23

What is Rovsing's pain?

Back 23

Pressure of lower left quadrant elicits pain in the right lower quadrant

Front 24

Where is a meckel's diverticulum located?

Back 24

Located 2 feet proximal to the ileocecal valve in the mesentaric border of ileum.

Front 25

What artery supplies the transverse mesocolon?

Back 25

middle colic artery

Front 26

What do the branches of the superior mesentaric artery supply?

Back 26

distal duodenum, jejunum/ileum, large intestine to left colic flexure.

Front 27

Who are we?

Back 27

1: Aorta
2: Appendicular
3: catheter in SMA
4: ileal brs of SMA
5: ileocolic artery
6: common iliac artery
7: inferior pancreaticoduodenal
8: jejunal brs of SMA
9: lumbar artery
10: middle colic artery
11: SMA

Front 28

What do the branches of the inferior mesentaric artery supply?

Back 28

From left colic flexure to the upper half of anal canal.

Front 29

Who are 3, 5, 8 and 10?

Back 29

Branches of IMA:
3: inferior mesentaric artery
5: left colic artery
8: sigmoidal br.
10: superior rectal artery

Front 30

What is the anastomosis b/e the celiac trunk and SMA?

Back 30

Via pancreaticoduodenal artery

Front 31

What is the anastomosis b/e the superior and inferior mesentaric arteries?

Back 31

1. middle and left colic arteries
2. Riolan and marginal anastomosis

Front 32

What is the anastomosis b/e the IMA and internal iliac artery?

Back 32

Superior rectal artery and middle or inferior rectal artery

Front 33

What vertebral level does the rectum begin at?

Back 33

S3

Front 34

What does the ileocolic artery supply?

Back 34

Cecum, appendix, proximal part of ascending colon and distal ileum

Front 35

What does the middle colic artery supply?

Back 35

The proximal half of the transverse colon.

Front 36

What does the left colic artery supply?

Back 36

Distal half of the transverse colon and descending colon.

Front 37

What do the sigmoid arteries supply?

Back 37

Sigmoid colon

Front 38

What does the superior rectal artery supply?

Back 38

The rectum and proximal half of the anal canal.

Front 39

What is the marginal artery of Drummond?

Back 39

A composite artery that courses along the inner border of the colon from the ileocecal to the rectosigmoid junction.

Front 40

What is the clinical importance of the marginal artery of Drummond?

Back 40

Provides collateral circulation b/e the left branch of the middle colic artery and the branches of the inferior mesentaric artery to the left side of the colon.

Front 41

Where does the IMA run?

Back 41

Descends retroperitoneally along the left side of the abdominal aorta

Front 42

What does SMA cross anterior to along its course?

Back 42

The left renal vein and the horizontal part of the duodenum

Front 43

What is the lymphatic drainage above the upper half of rectum?

Back 43

(celiac, superior mesentaric and inferior mesentaric nodes) => intestinal lymphatic trunk => cisterna chyle => thoracic duct

Front 44

What vertebral level does the anal canal begin at?

Back 44

Tip of the coccyx

Front 45

What muscle forms a sling to form the anorectal angle?

Back 45

The puborectalis muscle

Front 46

What are Houston's valves?

Back 46

Two left transverse folds and one right transverse fold help prevent leaks.

Front 47

What is the epithelium above and below the pectinate line?

Back 47

Hindgut (above): stratified columnar
Proctodeum (below): stratified squamous

Front 48

What is the arterial supply above and below the pectinate line?

Back 48

Hindgut (above): Superior rectal from IMA
Proctodeum (below): middle rectal (form internal iliac) and inferior rectal (from internal pudendal br of internal iliac)

Front 49

What is the venous drainage above and below the pectinate line?

Back 49

Hindgut (above): Superior rectal to (IMV) to hepatic protal vein (liver)
Proctodeum (below): middle rectal (to internal iliac v) and inferior rectal veins to internal pudendal vein (IVC)

Front 50

What is the lymphatic drainage of above and below the pectinate line?

Back 50

hindgut (above): internal iliac nodes
proctodeum (below): superficial inguinal nodes

Front 51

What is the innervation above and below the pectinate line?

Back 51

Hindgut (above): autonomics (S2-4) pelvic splanchnic
Proctodeum (below): somatic via pudendal n.

Front 52

What is the afferent (sensation) above and below the pectinate line?

Back 52

Hindgut (above): only to pressure and distention
Proctodeum (below): exquisite sensitive to touch and pain.