Abdominal Viscera Flashcards
Explain the path of food from entrance to exit of the body
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
Where are most of the feces made?
descending and sigmoid colon
What does the celiac trunk supply?
the foregut (most of the superior structures in abdominal cavity)
What does the Superior Mesenteric artery supply?
the Midgut (all small intestine, large intestine to the beginning of descending colon, i.e. left colic flexure)
What does the Inferior Mesenteric artery supply?
the Hindgut (rest of larger intestine, i.e. from left colic flexure down)
What does the Inferior Mesenteric vein drain?
the Hindgut
What does the Superior Mesenteric vein drain?
the Midgut
What does the splenic vein drain?
only the spleen
What veins make up the Portal venous system?
Superior/Inferior mesenteric vein
Splenic vein
Pathway for sympathetic nerve supply to visceral organs in the abdominal cavity
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
What does the sympathetic nervous system do to abdominal viscera?
create vasoconstriction, decreasing peristalsis and digestion
Pathway for parasympathetic nerve supply to visceral organs in the abdominal cavity
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
What are some of the mechanisms that prevent the reflux of gastric contents into the esophagus?
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
What are the 4 parts of the stomach?
Cardia
Fundus
Body
Pyloric part
Describe the 4 parts of the stomach?
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
Special features of the duodenum
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
Sympathetic effects on the small intestines
Drives blood away from organs to muscles
Decreases peristalsis activity
vasoconstriction
Parasympathetic effects on the small intestines
Increases peristalsis
restores digestive activity
Function of the appendix
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
Explain the neurovascular supply to the colon proximal to the left colic flexure
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
Explain the neurovascular supply to the colon distal to the left colic flexure
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)
How does the Duodenum receive bile from the gallbladder and the pancreas
Pancreas: Main pancreatic duct -> Common Bile duct -> Duodenum
Gallbladder: Cystic duct -> Common Bile duct -> Duodenum
Drainage of bile from the liver to the gallbladder to the Duodenum
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
Function of the spleen
to house white blood cells (lymphocytes)
monitor & respond to immune system
remove dead/damaged RBC’s & platelets
Function of the Pancreas
Exocrine secretion to duodenum (digestive fluids)
Endocrine secretion (Glucagon & Insulin)
What structures make up the Portal Triad?
Portal vein
Hepatic artery
Bile passages
Function of the liver
Metabolize nutrients from the GI tract (besides fat)
stores glycogen
secretes bile constantly (stored in gallbladder)
What are some special features of Renal arteries?
Right artery is longer (goes under IVC)
Both branch into 5 branches each
At the level of L1/L2
Branch off of the aorta
At what vertebral level do the kidneys sit at?
T12 - L3
What are some special features of Renal Veins?
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)
Explain Parietal Peritoneum Pain
Severe and localized
Rebound tenderness positive because this is sensitive to stretch
Explain how abdominal viscera can refer pain to other areas of the body
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
Why is pancreatic cancer so deadly?
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
How does Cirrhosis of the liver lead to Hepatomegaly (enlarged liver) and Portal Hypertension?
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
What are Gallstones?
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
What are Kidney stones?
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
What is an Ileostomy?
ileum is connected to the stoma
What is a colostomy?
end of the colon is attached to the stoma
