Abdominal Viscera

Question 1

Explain the path of food from entrance to exit of the body

Answer 1

Mouth -> teeth/ tongue/ salivary glands form bolus -> oropharynx -> esophagus -> stomach -> bolus turns to chyme -> small intestines (duodenum - jejunum - ileum) -> large intestines (cecum - ascending - transverse - descending - sigmoid colon) -> rectum -> anal canal

Question 2

Where are most of the feces made?

Answer 2

descending and sigmoid colon

Question 3

What does the celiac trunk supply?

Answer 3

the foregut (most of the superior structures in abdominal cavity)

Question 4

What does the Superior Mesenteric artery supply?

Answer 4

the Midgut (all small intestine, large intestine to the beginning of descending colon, i.e. left colic flexure)

Question 5

What does the Inferior Mesenteric artery supply?

Answer 5

the Hindgut (rest of larger intestine, i.e. from left colic flexure down)

Question 6

What does the Inferior Mesenteric vein drain?

Answer 6

the Hindgut

Question 7

What does the Superior Mesenteric vein drain?

Answer 7

the Midgut

Question 8

What does the splenic vein drain?

Answer 8

only the spleen

Question 9

What veins make up the Portal venous system?

Answer 9

Superior/Inferior mesenteric vein
Splenic vein

Question 10

Pathway for sympathetic nerve supply to visceral organs in the abdominal cavity

Answer 10

IML’s T5-L2/3 -> anterior roots -> anterior rami -> white rami communicantes -> sympathetic ganglia -> abdominopelvic splanchnic -> prevertebral ganglia (celiac, Superior/Inferior mesenterics, aorticorenal) -> peri-arterial plexuses -> organ

Question 11

What does the sympathetic nervous system do to abdominal viscera?

Answer 11

create vasoconstriction, decreasing peristalsis and digestion

Question 12

Pathway for parasympathetic nerve supply to visceral organs in the abdominal cavity

Answer 12

2 Paths
1) Vagal Trunks (from vagus nerve) -> split into anterior and posterior trunks after esophageal plexus -> presynaptic fibers to aortic plexuses and peri-arterial plexuses (stops at left colic flexure)

2) Pelvic splanchnics (S2-4) -> presynaptic fibers to inferior hypogastric trunks -> supplies left colic flexure inferiorly through pelvic viscera -> postsynaptic fibers on or within viscera

Question 13

What are some of the mechanisms that prevent the reflux of gastric contents into the esophagus?

Answer 13

Sphincter mechanism at the esophagogastric junction (z-line at right crus)
when not eating, lumen is collapsed to prevent food/stomach juices from being regurgitated

Question 14

What are the 4 parts of the stomach?

Answer 14

Cardia
Fundus
Body
Pyloric part

Question 15

Describe the 4 parts of the stomach?

Answer 15

Cardia -> cardial orifice (has the cardiac sphincter)
Fundus -> Cardial Notch and part that is associated with left dome of the diaphragm
Body -> major part of the stomach
Pyloric part -> pyloric antrum, pyloric canal, pyloric orifice, and the pyloric sphincter

Question 16

Special features of the duodenum

Answer 16

short but widest and most fixed part of the small intestines
“C” shape
has for parts (Superior, descending, inferior, ascending)
Proximal end: foregut
Distal end: Midgut

Question 17

Sympathetic effects on the small intestines

Answer 17

Drives blood away from organs to muscles
Decreases peristalsis activity
vasoconstriction

Question 18

Parasympathetic effects on the small intestines

Answer 18

Increases peristalsis
restores digestive activity

Question 19

Function of the appendix

Answer 19

Mass of lymphoid tissue that assists with maturation of B lymphocytes in early development and helps with production of immunoglobulin a-antibodies

Helps direct movements of lymphocytes throughout the body

Question 20

Explain the neurovascular supply to the colon proximal to the left colic flexure

Answer 20

Arterial supply: Superior mesenteric artery
Venous drainage: Superior mesenteric vein to portal system
Nerve supply:
sympathetic = lower thoracic trunks -> through splanchnic -> superior mesenteric plexus
parasympathetic= vagal trunks

Question 21

Explain the neurovascular supply to the colon distal to the left colic flexure

Answer 21

Arterial supply: Inferior mesenteric artery
Venous drainage: Inferior mesenteric vein to portal system
Nerve supply:
Sympathetic = Lumbar trunks -> through splanchnics -> superior mesenteric plexus + peri-arterial plexuses -> following inferior mesenteric artery + branches
Parasympathetic = Pelvic splanchnic nerves (S2-4)

Question 22

How does the Duodenum receive bile from the gallbladder and the pancreas

Answer 22

Pancreas: Main pancreatic duct -> Common Bile duct -> Duodenum

Gallbladder: Cystic duct -> Common Bile duct -> Duodenum

Question 23

Drainage of bile from the liver to the gallbladder to the Duodenum

Answer 23

Hepatocytes -> Bile canaliculi -> Interlobular Biliary ducts -> Intrahepatic portal triad -> Right & Left hepatic ducts -> Common Hepatic Duct (joined by cystic Duct from Gallbladder) -> Common bile duct -> Duodenum

Question 24

Function of the spleen

Answer 24

to house white blood cells (lymphocytes)
monitor & respond to immune system
remove dead/damaged RBC’s & platelets

Question 25

Function of the Pancreas

Answer 25

Exocrine secretion to duodenum (digestive fluids)
Endocrine secretion (Glucagon & Insulin)

Question 26

What structures make up the Portal Triad?

Answer 26

Portal vein
Hepatic artery
Bile passages

Question 27

Function of the liver

Answer 27

Metabolize nutrients from the GI tract (besides fat)
stores glycogen
secretes bile constantly (stored in gallbladder)

Question 28

What are some special features of Renal arteries?

Answer 28

Right artery is longer (goes under IVC)
Both branch into 5 branches each
At the level of L1/L2
Branch off of the aorta

Question 29

At what vertebral level do the kidneys sit at?

Answer 29

T12 - L3

Question 30

What are some special features of Renal Veins?

Answer 30

Drain into the IVC
Left is longer to reach IVC (goes OVER aorta)
Left collects from 3 other veins (Left suprarenal vein, gonadal vein, and ascending lumbar vein)

Question 31

Explain Parietal Peritoneum Pain

Answer 31

Severe and localized
Rebound tenderness positive because this is sensitive to stretch

Question 32

Explain how abdominal viscera can refer pain to other areas of the body

Answer 32

The brain interprets pain is coming from skin since the dermatomes are also supplied there
Usually this pain is associated with dermatomes because the spinal nerves are mixed

Question 33

Why is pancreatic cancer so deadly?

Answer 33

It is hard to detect early
metastasizes in the liver early through the Hepatic portal veins

Since the main detox center for the GI tract is the liver it is very susceptible to metastasis of other cancers

Question 34

How does Cirrhosis of the liver lead to Hepatomegaly (enlarged liver) and Portal Hypertension?

Answer 34

Hepatocytes are destroyed and replaced by fat/fibrous tissue which leads to enlargement

The fibrous tissue impedes the Hepatic circulation which leads to portal hypertension and varicose veins in lower esophagus and abdominal wall begin to appear

Question 35

What are Gallstones?

Answer 35

Cholesterol crystals
located in the Gallbladder, cystic duct, bile duct
Could cause spasmodic pain and pain is usually referred to the epigastric region and right hypochondriac regions
Could also cause jaundice

Question 36

What are Kidney stones?

Answer 36

Accumulations of salts
located in kidneys, ureters, and urinary bladder
Could block kidneys dependent upon the size
Pain is usually referred to lumbar, inguinal, or external genitalia regions

Question 37

What is an Ileostomy?

Answer 37

ileum is connected to the stoma

Question 38

What is a colostomy?

Answer 38

end of the colon is attached to the stoma