Abdomen Flashcards
what makes up the abdominal wall?
- skin
- subcutaneous fat
- three flat muscles
- transversalis fascia
- parietal peritoneum
- viscera of abdominal cavity
what is the rectus sheath?
- encloses the:
- rectus abdominis muscle
- pyramidalis muscles
- superior and inferior epigastric vessels
- thoraco-abdominal and subcostal nerves
external oblique and internal oblique
innervation
action
- thoraco-abdominal nerves
- anterior rami of T7-T11, aka intercostal nerves
- subcostal nerve
- Compresses and supports abdominal viscera; flex and rotate trunk
Internal oblique is innervated by one more nerve than the external oblique. What is it?
- first lumbar nerve
Transversus abdominis
innervation and action
- Thoraco-abdominal nerves
- anterior rami of T7-T11, aka intercostal nerves
- subcostal nerve
- first lumbar nerve
- Compresses and supports abdominal viscera
Rectus abdominis
innervation and action
- Thoraco-abdominal and subcostal nerves
- anterior rami of T7-T12 sinal nerves; aka intercostal nerves
- Flexes trunk
- compresses abdominal viscera
- stabilizes and controls tilt of pelvis
Psoas major/minor
innervation and action
- lumbar plexus (L2-L4)
- flexes thigh, flexes vertebral column
- **Pelvic plexis goes between psoas major and minor
Iliacus
innervation and action
- Femoral nerve (L2-L4)
- flexes thigh and stabilizes hip joint
Quadratus lumborum
- Anterior branches of T12 and L1-L4
- Extends and laterally flexes vertebral column
- fixes 12th rib with inspiration
What innervates the abdominal wall?
- lateral and anterior cutaneous branches of thoraco-abdominal nerves. (Anterior rami T7-T11, aka intercostal nerves)
- subcostal (anterior rami T12)
- iliohypogastric nerve (anterior rami of L1)
- ilio-inguinal nerve (anterior rami of L1)
Vessels of the abdominal wall
- Superior epigastric artery
- inferior epigastric artery
- deep circumflex iliac artery
- thoraco-epigastric vein
What is the affect of a vessel being broken below the arcuate line vs above?
If a vessel is broken below the arcuate line the area is better able to expand and fill with blood
Peritoneal cavity
- parietal peritoneum
- lines internal surface of the abdominopelvic wall
- visceral peritoneum
- invests viscera
what are the intraperitoneal organs?
- Stomach and spleen
- almost completely covered with visceral peritoneum
What supplies blood to the parietal peritoneum?
What is it sensitive to?
- same blood supply and somatic nerves as the region of the abdominopelvic wall it lines
- Sensitive to heat, pressure, pain, cold
- well localized
What supplies blood to the visceral peritoneum
What is it sensitve to?
- Same blood supply as the visceral nerve supply as organ it covers
- insensitive to touch, heat, cold, and laceration
- sensitive to stretching and chemical irritation
Pharynx, esophagus, and stumach pain is referred to where?
epigastric region
What pain is referred to the umbilical region?
- small intestine
- cecum
- appendix
- ascending colon
What pain is referred to the pubic region?
descending and sigmoid colon
what is the main function of the mesentery?
provides means for neurovascular communication between the organ and the body wall
Where do the sympathetic fibers that innervate the abdomen come from?
intermediolateral cell column of the gray matterof the spinal cord T5-L2
What dermatomes does stomach pain refer to?
T8-T12
small intestine to transverse colon refers to _____
T8-T12
descending colon referrs to _____
T12-L2
Whats unique about the visceral pain fibers from the sigmoid to rectum?
they run with the parasympathetic fibers to the S2-S4 sensory ganglia and spinal cord
the liver and gallbladder afferent fibers run via the _____
phrenic and intercostal nerves
pain is referred to shoulder region
Where do the Left and Right crus insert?
- Left crus L2
- Right crus L3
Esophagus
What is the inferior sphinctor?
what separates it from the gastric mucosa?
location?
innervation
- Right crus is the inferior sphinctor
- separated by gastric mucosa by Z-line
- retroperitoneal organ
- innervated by:
- vagus- parasympathetic
- greater splanchnic- sympathetic
what causes a hiatal hernia?
the stomach getting pushed up through a weakened diaphragm
stomach innervation
- Vagus- parasympathetic
- T6-T9- sympathetic
- pass to the celiac artery plexus via the greater splenchnic nerves
what patients need Rapid sequence intubation?
(this is probably not a complete list)
- hiatal hernia
- caput medusae
What are the measurements for the different parts of the small intestine?
- Duodenum - 10 inches (25 cm)
- Jejunum - 8 feet
- ileum - 11.5 feet
Small Intestine Innervation
parasympathetic
sympathetic
- Parasympathetic- vagus
- sympathetic- Greater and lesser splanchnic nerves
- by way of the celiac and superior mesenteric artery plexuses
What are the different parts of the large intestine?
- Cecum
- ascending colon (reabsorption of water)
- transverse colon
- descending colon (retroperitoneal
- Sigmoid colon
- rectum
- anal canal
Large intestine innervation
parasympathetic
sympathetic
- parasympathetic
- Vagus- up to left colonic flexure
- Sacral- after left colonic flexure
- Sympathetic
- lumbar splanchnic nerves
- via inferior mesenteric ganglion
- lumbar splanchnic nerves
what part of peritoneaum is the spleen in?
intraperitoneal- entirely surrounded by peritoneum except hilum area
spleen innervation
parasympathetic
sympathetic
- parasympathetic- vagus
- sympathetic- celiac artery plexus vasomotor function
- ***spleen is mostly SNS
What is the flow of exocrine secretions from the pancrease?
- flows through main pancreatic tail to join with bile duct.
- hepatopancreatic sphincter (sphincter of oddi) opens
- bile and exocrine secretions go through hepatopancreatic ampulla (ampulla of Vater)
pancrease innervation
parasympathetic
sympathetic
- parasympathetic- vagus
- sympathetic- abdominal splanchnic nerves
what is the flow of bile?
- bile flows from gallbladder through Cystic duct to join the common hepatic duct
- Common hepatic duct unites with the main pancreatic duct
- hepatopancreatic sphincter (oddi) opens to allow the bile and exocrine secretions through the hepatopancreatic ampulla (ampulla of Vater)
what are the lobes of the liver?
- Right
- left
- cuadate
- quadrate
what was the function of the ligamentum venosum?
- it is the fibrous remnant of the fetal ductus venosus
- shunted blood from umbilical vein to IVC, bypassing liver
What is in the portal triad?
- Porta hepatis
- portal vein
- hepatic artery
- bile duct
portal vein blood flow vs o2
75% of blood flow
50% of O2
hepatic artery blood flow vs O2
25% blood flow
50% O2
Liver innervation
parasympathetic
sympathetic
- Parasympathetic- vagus
- sympathetic- celiac artery plexus
Explain the flow of blood from mother to fetus
- Blood goes through placenta and through umbilical cord
- blood enters fetus through umbilical vein
- Ductus venosus allows the blood to skip the liver and go directly to the inferior vena cava and RA
- Most of the blood crosses from RA into LA via the Foramen Ovale
- Most of the blood goes from LA into LV and systemic
- Most of the blood that went into the RV will cross from the pulmonary artery into the Aorta via the ductus arteriosus
what kind of anastomoses causes esophageal varices?
Esophageal and azygos vein with the left gastric vein
What is a portosystemic anastomoses?
- When the portal venous system communicates with the systemic venous system where it shouldnt
Hemorrhoids are caused by what anastomoses?
Inferior and middle rectal veins (systemic system)
with the superior rectal vein (inferior mesenteric vein) (portal system)
Caput medusae is caused by what anastemoses?
superficial epigastric veins (system system) with the para-umbilical veins (portal system)
what is a TIPS procedure?
- transjugular intrahepatic portosystemic shunt
- decreases portal hypertension if blood flow through the portal vein becomes impaired
How are the kidneys located?
- retroperitoneal
- posterior abdominal wall
- level T12-L3
- left higher than right
what is in the renal hilum?
- renal artery
- renal vein
- renal pelvis
Kidney innervation
parasympathetic
sympathetic
- parasympathetic- vagus
- sympathetic- abdominal pelvic splanchnic nerves (greater, lesser, and least) via celiac and superior mesenteric ganglion
Ureter innervation
P
S
- PNS- vagus and sacral division
- SNS- splanchnic nerves via inferior mesenteric ganglion
Suprerenal glands
function and blood supply
- secrete corticosteroids, androgens, epi, NE
- receives blood from branches of the aorta, inferior phrenic artery and renal arteries
suprarenal gland innervation
sympathetic
- Abdominopelvic (greater lesser and least) splanchnic nerves via celiac artery plexus
- myelinated presynaptic sympathetic fibers from the intermediolateral horn of the spinal cord
- Do not synapse at paravertebral ganglia
- synapse directly with adrenal gland
Where does the abdominal aorta begin and where does it bifurcate?
- begins at T12
- bifurcates at L4
what organs do the branches of celiac trunk deliver blood to?
liver
stomach
duodenum
spleen
what organs do the branches of the superior mesenteric artery supply blood to?
pancrease, duodenum, jejunum, ileum
*middle and right colonic arteries supply blood up to left colonic flexure
What organ does the inferior mesenteric artery supply blood to?
left colonic arteries from left colonic flexure to rectum
