Innervation Post Tri

Question 1

CN XI: Spinal Accessory innervates? lesion affects? pathway?

Answer 1

• Only innervated SCM and trapezius
• Comes up through foramen magnum and loops over to exit through jugular foramen
• Lesion = mostly trapezius

Question 2

anterior scalene helps identify what?

Answer 2

different parts (proximal and distal) of subclavian and brachial plexus
*brachial plexus is sandwiched between the anterior and middle scalene

Question 3

Phrenic nerve is found on top of what muscle? innervates what?

Answer 3

anterior scalene

*innervates the diaphragm (C3, C4, C5 keeps you alive)

Question 4

______ vein and _______ vein come together to form brachiocephalic vein

Answer 4

Subclavian and internal jugular vein come together to form brachiocephalic vein

Question 5

cervical plexus is made up of?

Answer 5

ventral rami of C1-C5

*emerges at the intervertebral rami

Question 6

plexuses are ALWAYS?

Answer 6

ventral rami

*Ventral rami = mixed spinal nerves (both sensory and motor)

Question 7

Each emerging spinal nerve of cervical plexus splits into? This allows?

Answer 7

two parts (ascending bundle of fibers and descending bundle of fibers)
*allows communication with both above and below spinal nerves (C2 can communicate with both C1 and C3)

Question 8

posterior or anterior triangles have all of the sensory or motor branches of plexus?

Answer 8

• -Posterior triangle = sensory branches= carry sensation from all of neck up along side of scalp and ear
• -Anterior triangle = motor branches = innervate muscles of the neck

Question 9

Back of the neck cutaneous innervation is through?

Answer 9

dorsal rami aka posterior rami

Question 10

sides and front of neck and edges of ear cutaneous innervation is through?

Answer 10

ventral rami aka anterior rami

Question 11

face cutaneous innervation is through?

Answer 11

trigeminal nerve

Question 12

Erb’s point

Answer 12

nerve point of the neck - this is where all of the sensory branches emerge

Question 13

Cervical plexus block

Answer 13

inject anesthesia Erbs point because it numbs all of these branches

Question 14

External jugular vein is located?

Answer 14

on top of the first layer of deep cervical fascia (superficial layer of deep cervical fascia aka investing layer)

Question 15

External jugular peirces through? Meets up with?

Answer 15

the investing layer to meet up with transverse cervical vein and then together dump into subclavian

Question 16

to expose everything in posterior triangle, what layer of fascia must you remove?

Answer 16

Prevertebral layer of deep cervical fascia removed

Question 17

Investing layer is a sheet of fascia that splits into two layers and surrounds what muscles?

Answer 17

envelopes SCM and trapezius

*then it comes back together as one sheet so on the back side of the muscle you would still see investing fascia

Question 18

Posterior triangle lacks what fascia layer?

Answer 18

middle layer of deep cervical fascia aka pretracheal