Week 3/ Lab 3 Flashcards
Sympathetic innervation
Preganglionic fibers originate in LOWER THORACIC and UPPER LUMBAR spinal cord segments
- T5-L2
-postganglionic fibers originate from prevertebral ganglion and form plexuses around corresponding arteries and their branches to reach target organs.
Sympathetic general pathway
- leave spinal cord from spinal nerves
- white rami communicantes
- through sympathetic trunk NO SYNAPSE
- through splanchnic nerves(greater, lesser, least, lumbar)
- terminate in prevertebral ganglion and SYNAPSE with postganglionic neurons
Celiac ganglion
- prevertebral ganglion
- supplies postganglionic SYMPATHETIC fibers to…
1. stomach
2. Duodenum
3. Pancreas
4. Liver
5. Spleen
6. Gallbladder
Superior mesenteric ganglion
-sympathetic fibers to organs associated with superior mesentery artery branches
Inferior mesenteric ganglion
- supplies postganglionic sympathetic fibers to organs associated with inferior mesentery artery branches
Parasympathetic innervation
- Vagas nerve (CN X) and pelvic splanchnic nerves carry preganglionic parasympathetic fibers
- synapse in walls of target organs
Vagas nerve innervation
- Vagas nerve enters abdomen as anterior(left) and posterior(right) Vagal trunks
- Vagal trunks join celiac plexus and superior mesenteric plexus
- synapse with postganglionic neurons in walls of target organs
- distributed along branches of abdominal aorta
Pelvic splanchnic nerve innervation
- carry preganglionic parasympathetic fibers from spinal cord segments S2-S4
- fibers enter inferior hypogastric plexus and inferior mesenteric plexus
- go to target organs associated with inferior mesenteric ganglion
- synapse with postganglionic neurons in walls of target organs
Name layers of abdomen superficially to deep
- skin
- camper fascia
- Scapa fascia
- External oblique
- Internal oblique
- Transversus abdominis
- transverslis fascia
- extraperitoneal fat
- parietal peritoneum
Retroperitoneal space
- between posterior abdominal wall and parietal peritoneum
- from 12th rib to sacrum and iliac crest
Posterior wall of retroperitoneal space
- spine
- medial-lateral: psoas muscle, quadratus lumborum, and transversus abdominis
- all muscle layers covered by fascia
In front of the posterior wall of the retroperitoneal space
- fatty connective tissue
- forms a protective bed for retroperitoneal organs
three spaces of retroperitoneal space
- separated by perirenal fascia
1. Anterior para-renal space: in front and next to
2. Peri-renal space: all around
3. Posterior para-renal space: behind and next to
Inferior vena cava and aorta location
- lie directly anterior to the vertebral column and beside each other
- Aorta on left and IVC on right
- Aorta path is shorter than IVC because it doesnt hit hatus until T12
Duodenum shape/ retroperitoneal
- C-shaped around the head of the pancreas
- only 2-4 part are in retroperitoneal due to it curving back
- head of pancreas is the only part in the retroperitoneal because it is looped in the duodenum
Ureters
-from each kidney and run straight down on top of the psoas muscle to the bladder
Colon position
- transverse colon bends anteriorly so it is not in retroperitoneal space
- splenic and hepatic structures bend transverse horizontally and anteriorly
Kidney position
- high up on posterior abdominal wall on each side of the vertebral column
- Left kidney is higher than the right because the left lobe of the liver is smaller than the right
- adjacent to the diaphragm and move up and down with breathing
Diaphragm position
- posterior reflection forms the most superior part of the posterior abdominal wall
- does not hit vertebrae at 90 degrees, it bends to also create the ceiling of the retroperitoneal space
Diaphragm blood supply
1, branches of internal thoracic arteries (pericardiophrenic and musculophrenic)
- superior phrenic arteries (arise from thoracic aorta)
- lower internal intercostal arteries
Diaphragm nerve supply
- phrenic nerve
- originates C3-C4
- passes motor information to diaphragm and gets sensory information from it
Diaphragm interfaces
- Caval opening: IVC
- Esophageal Hiatus: Esophagus
- Aortic Hiatus: Descending Aorta
- Gaps for Psoas Major: insertion for psoas muscle (two holes)
Blood supply of Posterior abdomen
Aorta: from aortic hiatus and divides to R and L common iliac arteries -T12-L4 -Bifucation Aorta-->common iliac Common iliac-->External and internal
Branches of the aorta
- 3 anterior visceral branches
- 3 lateral visceral branches
- 5 lateral abdominal wall branches
- 3 terminal branches
Anterior visceral branches
- supply organs with blood
- celiac artery
- SMA
- IMA
Lateral visceral brancher
- supplies organs with blood
- Suprarenal arteries
- renal artery
- testicular/ovarian artery
Lateral abdominal wall branches
- do not supply organs, just structures
- inferior phrenic artert
- 4 lumbar arteries
terminal branches
- two common iliac arteries
- median sacral artery
Inferior vena cava tributaries
- 2 anterior visceral tributaries
- 3 lateral visceral tributaries
- 5 lateral abdominal wall tributaries
- 3 veins of origin
Anterior visceral tributaries
-2 hepatic veins
Lateral visceral tributaries
- right suprarenal vein
- renal veins
- right testicular/ovarian vein
Lateral abdominal wall tributaries
- inferior phrenic vein
- 4 lumbar veins
Veins of origin
- two common iliac veins
- median sacral vein
Lymphatics of deep abdomen
Above the diaphragm
-drain in thoracic duct
Below the diaphragm
-thoracic duct morphology changes into collection of fused nodes (Cysterna Chyli)
-below cysterna chyli, nodes run and envelop the abdominal aorta (hug)
Lumbar plexus
- main nerve supply for lower limbs
- formed in psoas muscle
- formed by anterior rami of upper 4 lumbar spinal nerve
List Lumbar plexus components superior to inferior
- iliohypogastric nerve
- ilioinguinal nerve
- lateral cutaneous nerve of the thigh
- femoral nerve
Lumbar plexus composition
- anterior rami receive GRAY rami communicantes from sympathetic trunk
- upper two give off white rami communicantes to the sympathetic trunk
- branches of the plexus emerge from the lateral and medial borders of the psoas muscle and its anterior surface
Iliohypogastric and ilioinguinal nerves
- L1
- enter lateral and anterior abdominal walls
- iliohypogastric: nerves supply to skin and lower anterior abdominal wall
- ilioinguinal: nerve supply to skin of the groin and scrotum/labium majus
Lateral cutaneous nerve of the thigh
- crosses iliac fossa in front of the iliacus muscle and enters thigh behind lateral end of inguinal ligament
- supplies nerves to skin over lateral surface of the thigh
Femoral nerve
- L2,L3,L4
- largest branch of lumbar plexus
- down and laterally between psoas muscle and iliacus muscle
- enters thigh behind the inguinal ligament and lateral to the femoral vessels/sheath
- supplies nerves to iliacus muscle
Lesser branches of lumbar plexus
- Obturator nerve: innervates inner thigh muscles
- Genitofemoral nerve: genital branch innervates the cremaster muscle of spermatic cord. femoral branch innervates small area of the inner thigh
Sympathetic trunk
- right sympathetic trunk lies behind the right border of the IVC
- left lies close to the left border of the aorta
White rami communicantes
- join first two ganglia to the first two lumbar spinal nerves
- contains PREGANGLIONIC fibers and afferent sensory fibers that run to organs
- has not synaped
Grat rami communicantes
- join each ganglion to lumbar spinal nerve
- contains POSTGANGLIONIC nerve fibers
- fibers are distributed through branches of the spinal nerve to blood vessels, glands, muscles of the skin
- has synapsed
Sympathetic Branches of the abdomen
- fibers pass MEDIALLY to the sympathetic plexuses on the abdominal aorta and its branches
- receive fibers from splanchnic nerves and the vagas
- fibers pass DOWNWARD AND MEDIALLY in front of the common iliac vessels into the pelvis
Superior hypogastric plexus
-large bundle of fibers from sympathetic nerves in front of the aorta and the nerves from in front of the common iliac plexus
Aortic Plexus
-preganglionic and postganglionic sympathetic fibers
-preganglionic parasympathetic fibers
-visceral afferent fibers
formed around abdominal part of the aorta
Aortic plexuses in order from superior to inferior along abdominal aorta
- celiac plexus
- renal plexus
- superior mesenteric plexus
- inferior mesenteric plexus
