What happens at L1?

[han14tra]

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I've searched Moore's and my lecture notes for a list, but I can't seem to find one. And, the profs said it's fair game for the test. So, what happens at the L1 level?

Something with pancreas.....something with SMA or renal vein? Duodenum turns here?

 

[Dwindlin]

Conus medullaris is around L1/2 region.

 

[Cp22kjer]

Hmm. I think the lumbosacral enlargement starts at L1 and ends around S3. L1 to L2 is also considered the end of the spinal cord/beginning of cauda equina depending on the text you look at. And probably 20 other things!

Hey atkinsje....I'm from Dayton.....crazy. I'm guessing you go to Wright State Med?

 

[greatnt249]

I've searched Moore's and my lecture notes for a list, but I can't seem to find one. And, the profs said it's fair game for the test. So, what happens at the L1 level?

Something with pancreas.....something with SMA or renal vein? Duodenum turns here?

It would help if you would elaborate a little more on what that "something" is. The spinal cord ends around L1/L2, the transpyloric plane is at this level, etc.

 

[Dwindlin]

Hmm. I think the lumbosacral enlargement starts at L1 and ends around S3. L1 to L2 is also considered the end of the spinal cord/beginning of cauda equina depending on the text you look at. And probably 20 other things!

Hey atkinsje....I'm from Dayton.....crazy. I'm guessing you go to Wright State Med?

You guess correct.

 

[han14tra]

It would help if you would elaborate a little more on what that "something" is. The spinal cord ends around L1/L2, the transpyloric plane is at this level, etc.

I finally found the answer..or at least part of it.

SMA arises at vertebra L1, passing under the neck of the pancreas and splenic vein. Just under the SMA, you have the left renal vein crossing, the 3rd part of the duodenum, and the uncinate process of the pancreas. L1 is also the level of the transpyloric plane.

Clinical: Left renal vein can be compressed by the SMA leading to nutcracker syndrome (left testicular pain or varicocele, hematuria, or flank pain). Similarly, duodenum can be compressed by SMA leading to SMA syndrome (vomiting with bile in it and malnutrition).

 

[bleeker10]

You have the transpyloric plane there, so you would also have the hila of the kidneys, spleen, duodenojejunal junction, transverse mesocolon, left and right colic flexures, fundus of the gallbladder, and upper part of conus medullaris

 

[Igor4sugry]

L1 can be used as a landmark for Celiac trunk and the SMA.

Celiac Trunk comes off at the top of L1
SMA comes off at the bottom of L1

I think IMA comes off at L3

 

[ensuii]

vertebral levels make awful landmarks imo

 

[greatnt249]

vertebral levels make awful landmarks imo

Doesn't stop profs from asking questions on them, though.🙁

 

[Music MD]

Just made this up last night. Keep in mind there is probably some variation from text to text, so don't let this list potentially stump you if your professors are using something different. But we're not learning this for the test right?

Superior Cervical Ganglion C2
Hyoid bone C3
Bifurcation of common carotid Between C3-C4
Laryngeal prominence C4
Cricoid cartilage C6
Middle cervical ganglion C6
First easily palpable spinous process C7
Inferior cervical ganglion C7
Medial edge of scapular spine Spinous T3, body T4
Sternal Angle Disc T4-T5
Trachea bifurcation
Upper border pericardium
Separation Sup and Inf mediastinum
Inferior angle of scapula Spinous T7, body T8
Caval hiatus T8
Esophageal hiatus T10
Aortic hiatus T12
End of spinal cord L1
Transpyloric line L1
Celiac Trunk
Superior mesenteric artery
Neck of pancreas
Pylorus of stomach
1st part of duodenum
Fundus of Gallbladder
Spinal taps L2-S1
Subcostal line L3
Inferior Mesenteric Artery
Paired Gonadal Arteries
Head of Pancreas
Third part of Duodenum
Interiliac line (iliac crests) L4
Bifurcation of the aorta
Common illiac veins join to form IVC
End of dura mater S1-S2

 

[themule]

Doesn't stop profs from asking questions on them, though.🙁

Some profs take great pride in proving that they know more minutiae about anatomy than you do.

 

[da8s0859q]

L1 can be used as a landmark for Celiac trunk and the SMA.

Celiac Trunk comes off at the top of L1
SMA comes off at the bottom of L1

I think IMA comes off at L3

Other than us going with "T12" for the trunk, yep. OP: my two were going to be SMA origin and the conus. Don't know about any others at this stage of the game (other than L1's spinal segments innervating the abdominal muscles in part, but I digress).