The<unk>  (or cervicothoracic<unk>  is a sympathetic<unk>  formed by the fusion of the inferior cervical<unk>  and the first thoracic (superior thoracic sympathetic)<unk> , which exists in 80% of people. Sometimes, the second and the third thoracic ganglia are included in this fusion. The<unk>  is relatively big (10–12 x 8–20 mm) compared to much smaller thoracic, lumbar and sacral ganglia, and is polygonal in shape ().<unk>  is located at the level of C7, anterior to the transverse process of C7 and the neck of the first rib, superior to the cervical pleura and just below the subclavian artery. It is superiorly covered by the prevertebral lamina of the cervical fascia and anteriorly in relation with common carotid artery, subclavian artery and the beginning of vertebral artery which sometimes leaves a groove at the apex of this<unk>  (this groove can sometimes even separate the<unk>  into so called vertebral<unk> . Relations of the apex of the<unk> : * covered by the endothoracic fascia and parietal pleura * right<unk>  is in relation with right brachiocephalic vein anteriorly * right<unk>  is in relation with sternal part of subclavian artery anteriorly * laterally: first intercostal artery * medially: longus colli muscle
Stellate ganglion
Ciliary ganglion
Olfactory trigone
Middle cervical ganglion
Medulla 
Medulla
Subfornical organ
Cortical minicolumn