GI anatomy II

Question 1

where do the jejunum and ileum mostly lie?

Answer 1

-jejunum = left upper quadrant (middle 2/5 of small intestine)
-ileum = lower right quadrant (remaining 3/5 of small intestine)

Question 2

what are plicae circulares?

Answer 2

ridges in the mucosa that causes chyme to spiral and increases absorption

Question 3

what is peristalsis?

Answer 3

coordinated contraction of circular and longitudinal muscle layers

Question 4

what does the large intestine consist of?

Answer 4

-cecum
-appendix
-colon
-rectum
-anus

Question 5

what is the cecum?

Answer 5

ileum terminates into cecum via ileocecal orifice and valve
-pouch for collection of food
-NO MESENTERY (can be displaced from iliac fossa; aka hernia)

Question 6

hypothesis of appendix

Answer 6

part of GI system
- “safe house” for good bacteria to repopulate colon with good bacteria after illness
??this is a hypothesis only!!

Question 7

what follows after the cecum?

Answer 7

ascending colon–> right colic hepatic flexure–> transverse colon–> left colic splenic flexure–> descending colon–> sigmoid colon–> rectum –> anus

Question 8

how does chyme move through the large intestine?

Answer 8

dehyrated, mixed with bacteria and mucus to form feces

Question 9

what is haustral churning?

Answer 9

haustra remain relaxed and distend (filling up_
-walls contract at a point and move/squeeze contents to next haustra

Question 10

what is the spleen and where?

Answer 10

largest of the lymphatic organs
-upper left quadrant
-protected by ribs 9-11

Question 11

functions of the spleen?

Answer 11

-blood monitered by T-cells for pathogens
-macrophages swallow/digest debris (worn out RBC, platelets)

Question 12

where is the liver? its functions?

Answer 12

-immediatley inferior to the diaphragm
-secretes bile, stores glycogen, produces lymph

Question 13

what is in the livers visceral surface?

Answer 13

!posteroinferior! (diaphragmatic surface is anterosuperior)
-gastric/pyloric areas
-duodenal areas
-colic areas
-renal/suprarenal areas
-gallbladder

Question 14

how are the L/R loves of the liver divided

Answer 14

by falciform ligament

Question 15

how is the livers caudate lobe seperated?from what?

Answer 15

seperated from left lobe via ligamentum venosum (vena ceva on other side)

Question 16

how is the quadrate lobe seperated? from what?

Answer 16

seperated from left lobe via round ligament (teres ligamentum)
-partially covered by gallbladder

Question 17

what are the primary arteries for liver supply?

Answer 17

-superior/inferior mesenteric artery
-hepatic artery proper

Question 18

what are the primary veins for liver supply?

Answer 18

-superior/inferior mesenteric vein
-splenic vein
-heaptic portal vein
!aka hepatic portal system

Question 19

blood flow in liver?

Answer 19

-anything below the liver is unfiltered and oxygenated
-anything over the liver is filtered and deoxygenated

Question 20

what is the portal triad made up of?

Answer 20

-bile duct
-branch of hepatic arteries
-branch of hepatic veins

Question 21

how does blood get from the liver to the heart?

Answer 21

hepatic portal vein/artery merge into sinusoid –>turns into the central vein —> drains into hepatic vein—> IVC —> right atrium

Question 22

what are hepatic sinusoids?

Answer 22

-portal vein enters and breaks up into the livers capillary network known as hepatic sinusoids
-leaky due to being fenestrated