Vertebral Levels

C4	Hyoid bone; Bifurcation of common carotid artery.
C5	Thyroid cartilage
C6	Cricoid cartilage Trachea begins Oesophagus begins Pharynx and larynx ends
C7	Thoracic duct reaches its greatest height; Isthmus of thyroid gland
T1	Sternoclavicular joint; Highest point of apex of lung.
T2	Sternal notch Jugular notch
T4	Sternal angle (of Louis) Junction of superior and inferior mediastinum Ascending aorta ends Arch of aorta begins and ends. Bifurcation of trachea
T8	IVC hiatus
T9	Xiphisternal joint
T10	Oesophageal hiatus
T12	Aortic hiatus Thoracic duct through diaphragm Azygos vein through diaphragm
L1	End of spinal cord in adults Transpyloric plane Pylorus of stomach Superior mesenteric artery origin Hilum of kidneys (renal artery–left is above and right is below) Celiac artery originates just above and renal arteries originate just below this line.
L2	Thoracic duct begins; Azygos and hemiazygos begin
L3	Umbilicus End of spinal cord in newborns Inferior mesenteric artery
L4	Iliac crest Aorta bifurcates into common iliac arteries. Inferior vena cava formed from common iliac veins.
S1	Sacral promontory
S2	Posterior superior iliac spine End of dural sac (Dura, arachnoid, subarachnoid space, CSF) Middle of sacroiliac joint
S3	Posterior inferior iliac spine End of sigmoid colon Rectum begins (important landmark in surgery of recto sigmoid carcinoma).