Editing Neck (section)

=== '''Submandibular     gland''' ===

** Paired salivary glands      located behind and below the ramus of the mandible
** Embryology - ectodermal      origin
** '''Two lobes'''
*** Large superficial lobe -       between mandible, mylohyoid and the surrounding fascia
*** Smaller deep lobe - between       mylohyoid and hyoglossus
** '''Relations'''
*** Lies in '''submandibular       triangle''' -       between anterior and posterior bellies of the digastric, and the       inferior border of the mandible. Floor hyoglossus/mylohyoid. Roof       platysma.
*** '''Lateral       surface'''
**** Mandible
**** Deeply grooved by the        facial artery which hooks under the mandible to reach the face, running        between mandible and gland
*** '''Superficial/inferior       surface'''
**** Skin, platysma, investing        fascia
**** Crossed by the facial vein        and cervical branch of facial nerve
**** Can also be crossed by        marginal mandibular branch, if that is running very low
*** '''Medial       surface'''
**** Lies against mylohyoid
**** Towards the back it        overlaps the hyoglossus, lingual nerve, submandibular ganglion,        hypoglossal nerve and deep lingual vein
** Has a secretomotor ganglion      nearby - submandibular ganglion. Hangs from lingual nerve above deep part      of submandibular gland.
** '''Submandibular      duct''' runs      forwards between mylohyoid and hyoglossus muscles, and then between the      sublingual gland and the genioglossus muscle before opening at the      sublingual papilla, close to midline in anterior floor of mouth
*** Lingual nerve (branch of CN       V3) passes around the duct, also running between hyoglossus and       mylohyoid, can be injured during duct ligation
** Hypoglossal nerve is below      the gland, but usually quite separate, seen lying on hyoglossus
** Blood supply - branches of      facial and lingual arteries, drainage to facial vein
** There are often      submandibular lymph nodes nearby too, which drain to jugulodigastric      lymph nodes
** Innervation
*** Superior salivary nucleus
*** Facial nerve
*** Chorda tympani
*** Lingual nerve
*** Submandibular ganglion       (hangs from lingual nerve above the deep part of the gland)