To their margins are attached the capsules of the atlanto-occipital joints, and on the medial side of each is a rough impression or tubercle for the alar ligament.
When observed from below (worms-eye view), the alar base configures an isosceles triangle, with its apex at the infra-tip lobule, immediately beneath the tip of the nose.
The netrins act as chemoattractants to decussation of pain and temperature sensory neurons in the alar plate across the anterior white commissure, where they then ascend towards the thalamus.
Where the lateral cartilage meets the greater alar cartilage, the lateral cartilage often curls up, to join with an inward curl of the greater alar cartilage.
Apart from the transmission of the medulla oblongata and its membranes, the foramen magnum transmits the vertebral arteries, the anterior and posterior spinal arteries, the membrana tectoria and alar ligaments.
To their margins are attached the capsules of the atlantoccipital articulations, and on the medial side of each is a rough impression or tubercle for the alar ligament.
The ventral part of the neural tube is called the basal plate; the dorsal part is called the alar plate.
Alar ligaments: stress or trauma can stretch the weaker alar ligaments, causing an increase in range of motion of approximately 30%.
