Cervical Nerves and Cervical Plexus 2024 (9).pptx PDF

CERVICAL NERVES & CERVICAL PLEXUS School of Laboratory Medicine and Medical Sciences ANATOMY UKZN INSPIRING GREATNESS  CERVICAL PLEXUS Network of nerve fibres that supplies the head, neck & trunk Formed by anterior (ventral) rami...

CERVICAL NERVES & CERVICAL PLEXUS School of Laboratory Medicine and Medical Sciences ANATOMY UKZN INSPIRING GREATNESS  CERVICAL PLEXUS Network of nerve fibres that supplies the head, neck & trunk Formed by anterior (ventral) rami of spinal nerves C1-C4 C1-C4 are the roots of the cervical plexus Situated opposite upper 4 cervical vertebrae  CERVICAL PLEXUS Located in posterior triangle of the neck, at mid-sternocleidomastoid muscle level Lies on scalenus medius, plastered down by prevertebral layer of cervical fascia & covered by sternocleidomastoid muscle  FORMATION OF CERVICAL PLEXUS Each of the cervical nerves forming the plexus communicates with one another in a superior-inferior fashion close to their origins  C2 accepts communicating fibres from C1, C3 from C2, etc. These communicating fibres are contributions from the superior cervical ganglion [sympathetic trunk]  “gray rami” communicantes  FORMATION OF CERVICAL PLEXUS Each cervical nerve, except the 1st, divides into upper & lower branches They subsequently unite with U L branches of adjacent cervical U nerves to form loops L Loops & branches from the U cervical nerves contribute to L the formation of the cervical plexus  CERVICAL PLEXUS Cervical plexus supplies skin & muscles of the neck and thoracoabdominal diaphragm Its branches are ordered into deep (muscular) & superficial (cutaneous) groups  MUSCULAR BRANCHES Segmental branches to prevertebral muscles:  Rectus capitis anterior & lateralis  Longus capitis  Longus colli  Scalenes  MUSCULAR BRANCHES C1 loop (to hypoglossal): Superior root of Ansa Cervicalis:  Infrahyoid muscles Thyrohyoid & geniohyoid muscles  MUSCULAR BRANCHES Branches from C2 & 3:  SCM Branches C3 & 4:  Trapezius  MUSCULAR BRANCHES C2 & 3: Inferior Root of Ansa cervicalis  Spirals around lateral side of internal jugular vein  MUSCULAR BRANCHES Phrenic nerve C3, 4, 5 keeps the diaphragm alive Accessory Phrenic nerve  CUTANEOUS BRANCHES Lesser Occipital Nerve C2 Curves around & ascends along posterior border of SCM Supplies skin of the back of the upper neck and of the scalp posterior to the ear Gives off an auricular branch, supplies skin of over upper SCM & auricle  CUTANEOUS BRANCHES Great Auricular Nerve Largest C2 & C3 Winds around posterior border of SCM Ascends beneath platysma to parotid gland, where it divides into anterior & posterior branches:  Anterior branch: skin of face over parotid gland & communicates with facial nerve  Posterior branch: skin over mastoid process. Communicates with smaller occipital, auricular branch of vagus & posterior auricular branch of facial nerves  CUTANEOUS BRANCHES Transverse Cervical C2 & C3 Divides beneath platysma into ascending & descending branches  Ascending branches: skin upper & front part of neck  Descending branches: skin side & front of neck, as low as sternum  CUTANEOUS BRANCHES Supraclavicular Nerves C3 & C4 Emerge beneath posterior border of SCM Descend posterior triangle of neck beneath platysma & deep cervical fascia. Supplies skin to:  Medial branches: sternal angle & sternoclavicular joint,  Intermediate branches: skin anterior to clavicle to anterior axial line  Lateral branches: over acromion & upper half deltoid & posterior shoulder joint to scapula spine (posterior axial line)  CERVICAL NERVES Upper 3 cervical nerves: meningeal branches – posterior cranial fossa C1 ascends with hypoglossal nerve & C2 with vagus nerve C1 does not supply any skin  CERVICAL NERVES Anterior divisions of cervical nerves (exception 1st) lies on grooved upper surfaces of transverse processes of vertebrae Anterior division of C1 (suboccipital nerve) passes from vertebral canal above posterior arch of atlas & runs forward around lateral aspect of its superior articular process medial to vertebral artery  CERVICAL NERVES The anterior divisions of the upper 4 cervical nerves unite to form the cervical plexus Each receives a gray ramus communicans from superior cervical ganglion of sympathetic trunk The lower 4 cervical nerves, together with the greater part of the first thoracic, form the brachial plexus CERVICAL PLEXUS: SUMMARY CERVICAL PLEXUS: SUMMARY For any queries or questions, please feel free to contact me: Miss V. Bisetty - [email protected]