10/23: Small Intestine and Colon

Question 1

What makes up the small intestine?

Answer 1

Duodenum, jejunum, and ileum

Question 2

What makes up the colon?

Answer 2

Cecum
Appendix
Ascending colon
Transverse Colon
Descending colon
Sigmoid colon

Question 3

What in the small intestine is mesenteric?

Answer 3

Jejunum and ileum

Question 4

Describe the mesenteries of the duodenum

Answer 4

1st segment mesenteric
2-4th are secondarily retroperitoneal

Question 5

How long is the duodenum?

Answer 5

About a foot long

Question 6

What makes up the mucosal lining of the duodenum?

Answer 6

Many plicae circularies

Question 7

How large is the jejunum?

Answer 7

2/5 of intestine beyond the duodenum

Question 8

Where does the jejunum start and fill up?

Answer 8

Starts at duodenojejunal junction and fills up most of left side

Question 9

What is the mucosal lining of the jejunum?

Answer 9

Small amount of spread out plicae circularies

Question 10

How large is the ileum?

Answer 10

Remaining 3/5 beyond the duodenum

Question 11

What does the ileum plug ito?

Answer 11

Cecum at ileocecal junction

Question 12

Where is the cecum located?

Answer 12

At lower right quadrant, first part of the large intestine

Question 13

What is the mucosal lining of the ileum?

Answer 13

Absence of plicae circularies
Smooth wall which contains lymphoid tissue

Question 14

What does the colon (large intestine) consist of?

Answer 14

Cecum, appendix, ascending colon, transverse colon, and sigmoid colon

Question 15

What does the colon contain?

Answer 15

Haustrae
Appendices Epiploicae
Taenia coli

Question 16

What are haustrae?

Answer 16

Marginal rims that gives colon scalloped appearance

Question 17

What is the appendices epiploicae?

Answer 17

Functionless accumulated fat on outside of haustrae (enlarge as you travel towards sigmoid colon)

Question 18

What is the taenia coli?

Answer 18

Longitudinal smooth muscle streaks found on outer surface of colon

Question 19

Be able to name the colon

Answer 19

Question 20

What does the cecum meet with?

Answer 20

Ileum at the first part of the large intestine

Question 21

What is the appendix?

Answer 21

Outgrowth of cecum, found inferior to dudenojejunal junction

Question 22

How long is the ascending colon and where does it run?

Answer 22

8-10 inches
Vertically from lower right to upper right quadrant
Runs into liver and bends

Question 23

What is the ascending colon bend called?

Answer 23

Hepatic flexure (right colic flexure)

Question 24

Where does the. transverse colon run from?

Answer 24

Right to left side turns downwards when it gets to spleen

Question 25

What is the bend in the transverse colon called?

Answer 25

Splenic flexure (left colic flexure)

Question 26

Where does the descending colon run?

Answer 26

From upper left to lower left quadrant

Question 27

Where does the sigmoid colon run from?

Answer 27

Lower left to the midline

Question 28

What is the rectum?

Answer 28

End of sigmoid colon, experiences contact with outside world

Question 29

What is the mid gut blood supply from?

Answer 29

Superior mesenteric artery

Question 30

What is the jejunum supplied by?

Answer 30

Jejunal arteries forming anastomosing loops with vasa recta branches reaching the gut itself

Question 31

What is the ileum supplied by?

Answer 31

Ileal arteries forming anastomosing loops with vasa recta branches reacting the gut itself

Question 32

What is the lower ileum supplied by?

Answer 32

Ileocolic artery

Question 33

What is the cecum supplied by?

Answer 33

Ileocolic artery

Question 34

What is the ascending colon supplied by?

Answer 34

Right colic artery which runs perpendicular and has many branches that diverge to supply ascending colon and right colin flexure

Question 35

What is the transverse colon supplied by?

Answer 35

Middle colic artery (last 1/3 after transition supplied by ascending left colic artery where it forms last)

Question 36

Where does the superior mesentery artery run in?

Answer 36

Root of the mesentery toward the lower right quadrant

Question 37

Where does the middle colic artery run?

Answer 37

In transverse mesocolon

Question 38

What does the middle colic artery supply?

Answer 38

Transverse colon first 2/3

Question 39

Where does the right colic artery run?

Answer 39

Retroperitoneally

Question 40

What does the right colic artery supply?

Answer 40

Ascending colon

Question 41

Where does the intestinal branches (jejunal and ileal arteries) run?

Answer 41

Mesentary proper

Question 42

What does the ileocolic artery supply?

Answer 42

Cecum and lower ileum

Question 43

Where does the ileocolic artery run?

Answer 43

Retroperitoneally toward ileocecal junction

Question 44

What do jejunal and ileal arteries supply?

Answer 44

Jejunum and ileum

Question 45

What is the hind gut supply from?

Answer 45

Inferior mesenteric artery

Question 46

What does the hind gut blood supply come from?

Answer 46

Inferior mesenteric artery

Question 47

What is the descending colon supplied by?

Answer 47

Left colic artery

Question 48

What does the left colic artery (LCA) branch into?

Answer 48

Descending and ascending branches

Question 49

What is the sigmoid colon supplied by?

Answer 49

Sigmoid artery loops

Question 50

What is the rectum supplied by?

Answer 50

Superior rectal artery

Question 51

What runs between the jejunum and ileuM/

Answer 51

Mesentary proper

Question 52

What runs in the mesentary proper?

Answer 52

Intestinal branches (jejunal and ileal arteries)

Question 53

Where does the mesentary proper stop at?

Answer 53

Ileocecal junction because gut has now become secondarily retroperitoneal

Question 54

What happens when gut loses its mesentary?

Answer 54

It will take its blood supply with it i.e., retroperitoneal parts of the GI tract are supplied by retroperitoneal A and V

Question 55

What mesentary contains middle colic artery?

Answer 55

Transverse colon

Question 56

What does the middle colic artery supply?

Answer 56

Transverse colon

Question 57

What is a triangular shaped mesentary attached to the appendix?

Answer 57

Mesoappendix

Question 58

What does the mesoappendix contain?

Answer 58

Appendicular artery (branch of ileocolic)

Question 59

What does the ileal branch turn into and supply?

Answer 59

Turns into mesentery proper; supplies the distal ileum

Question 60

What is the appendicular artery?

Answer 60

A mesenteric branch to the appendix (in the mesoappendix)

Question 61

What are the two branches of the superior mesenteric artery (SMA)?

Answer 61

Jejunum and ileum

Question 62

What does the jejunal artery loop into?

Answer 62

Smaller lops called arcades

Question 63

Describe the jejunal artery

Answer 63

- 2 arcade rows - long vasa recti directly to organ wall - little fat in this area "light signs through mesentery"

Question 64

What does the ileal artery loop into?

Answer 64

Many smaller loops called arcades

Question 65

Describe the ileal artery

Answer 65

Describe the ileal artery - 4 arcaede rows - short vasa recti directly to organ wall - lots of fat

Question 66

What does the inferior mesenteric artery (IMA) originate from?

Answer 66

The aorta at about L3 and is mostly retroperitoneal

Question 67

What artery is the mostly retroperitoneal?

Answer 67

Left colic artery

Question 68

What does the left colic artery become when it enters the transverse mesocolon?

Answer 68

Mesenteric to anastomose with middle colic (from SMA)

Question 69

What does the left colic artery supply?

Answer 69

Last 1/3 of transverse colon

Question 70

What does the majority of the left colic artery supply?

Answer 70

Descending colon

Question 71

What is secondary retriperitoneal?

Answer 71

Descending colon

Question 72

Where do the sigmoid arteries lie?

Answer 72

Within sigmoid mesocolon

Question 73

What arteries are mesenteric?

Answer 73

Sigmoid arteries

Question 74

What arteries are secondary retroperitoneal with the rectum?

Answer 74

Superior rectal artery

Question 75

What do superior rectal arteries supply?

Answer 75

Rectum

Question 76

What are inferior and superior mesenteric arteries anastomoses important for?

Answer 76

If arteriole blockage occurs, all areas can still be supplied

Question 77

What does the middle colic a. (SMA) anastomose with?

Answer 77

Left colic arteries (IMA) at the left colic flexure

Question 78

What does the ileocolic artery (SMA) anastomose with?

Answer 78

Right colic artery (SMA) near the ileocecal junction

Question 79

What does the sigmoid artery (IMA) anastomose with?

Answer 79

The superior rectal artery (IMA) at the transition from the sigmoid colon to the rectum

Question 80

Where are paramesenterics?

Answer 80

Posterior and superior to the mesentery proper

Question 81

Where are paracolic gutters?

Answer 81

On outside of large intestine curves

Question 82

What do paramesenteric and paracolic gutters provide?

Answer 82

Channels for infections within the abdominal cavity

Question 83

What is an example of a channel that a paramesenteric and paracolic gutter provide?

Answer 83

Pus from a burst appendix (lower right quadrant) can flow up with right paracolic gutter to form an abscess in the right hepatorenal recess