Cervical Plexus Flashcards

Explore the cervical plexus, including its spinal roots, cutaneous branches, muscular innervation, phrenic nerve, and clinical anatomy.

Card 1 of 30Question

What is the cervical plexus?

A network of nerves formed by the anterior rami of the first four cervical spinal nerves.

In This Section

1. What is the cervical plexus?

A network of nerves formed by the anterior rami of the first four cervical spinal nerves.

2. Which spinal nerve roots form the cervical plexus?

The anterior rami of C1, C2, C3, and C4.

3. Where is the cervical plexus located?

Deep to the sternocleidomastoid muscle, anterior to the levator scapulae and middle scalene muscles.

4. What are the two principal functional groups of cervical plexus branches?

Superficial cutaneous branches and deep muscular branches.

5. Where do the superficial cutaneous branches of the cervical plexus emerge?

Near the midpoint of the posterior border of the sternocleidomastoid muscle.

6. What is the nerve point of the neck?

The region near the midpoint of the posterior sternocleidomastoid border where the cutaneous cervical plexus branches emerge.

7. What are the four main superficial cutaneous branches of the cervical plexus?

The lesser occipital, great auricular, transverse cervical, and supraclavicular nerves.

8. Which cervical spinal nerves contribute to the lesser occipital nerve?

Primarily C2, sometimes with a contribution from C3.

9. What region receives cutaneous sensation from the lesser occipital nerve?

The lateral occipital scalp and skin posterior to the auricle.

10. Which spinal nerve roots form the great auricular nerve?

C2 and C3.

11. What areas are supplied by the great auricular nerve?

Skin over the parotid region, angle of the mandible, mastoid region, and lower auricle.

12. Which cutaneous cervical plexus nerve crosses the sternocleidomastoid horizontally toward the anterior neck?

The transverse cervical nerve.

13. What is the sensory distribution of the transverse cervical nerve?

The skin of the anterior and anterolateral neck.

14. Which cervical spinal nerves form the supraclavicular nerves?

C3 and C4.

15. What are the three groups of supraclavicular nerves?

Medial, intermediate, and lateral supraclavicular nerves.

16. Which regions receive cutaneous sensation from the supraclavicular nerves?

The skin over the clavicle, upper chest, and superior shoulder.

17. What is the ansa cervicalis?

A motor nerve loop associated with the cervical plexus that supplies most infrahyoid muscles.

18. Which spinal nerve fibers form the superior root of the ansa cervicalis?

C1 fibers that temporarily travel with the hypoglossal nerve.

19. Which spinal nerve roots form the inferior root of the ansa cervicalis?

Primarily C2 and C3.

20. Which muscles are supplied by the ansa cervicalis?

The sternohyoid, sternothyroid, and omohyoid muscles.

21. Which infrahyoid muscle receives C1 fibers traveling with the hypoglossal nerve rather than through the ansa cervicalis loop?

The thyrohyoid muscle.

22. Which suprahyoid muscle receives C1 motor fibers carried by the hypoglossal nerve?

The geniohyoid muscle.

23. Which cervical spinal nerves contribute to the phrenic nerve?

C3, C4, and C5, with C4 usually providing the largest contribution.

24. What is the primary motor function of the phrenic nerve?

Innervation of the diaphragm, the principal muscle of inspiration.

25. Along which neck muscle does the phrenic nerve descend?

The anterior surface of the anterior scalene muscle, deep to the prevertebral fascia.

26. Which cervical plexus branches provide proprioceptive fibers associated with the sternocleidomastoid and trapezius?

Branches from C2 and C3 to sternocleidomastoid and from C3 and C4 to trapezius.

27. Which cervical plexus branches directly supply the prevertebral muscles?

Deep muscular branches from the anterior rami of the upper cervical spinal nerves.

28. What clinical finding can result from unilateral phrenic nerve injury?

Ipsilateral hemidiaphragm paralysis, often producing elevation of the affected hemidiaphragm.

29. What is the anatomical basis of referred shoulder pain from diaphragmatic irritation?

Sensory fibers from the central diaphragm travel through the phrenic nerve to C3 to C5 spinal segments, overlapping shoulder sensory pathways.

30. Where is local anesthetic commonly administered for a superficial cervical plexus block?

Near the midpoint of the posterior border of the sternocleidomastoid muscle to block the emerging cutaneous branches.