Lecture 11 - Sacral/ Coccygeal Plexuses, Dermatome and Myotomes

Question 1

what 2 major categories foes the pudendal nerve (S2-S4) supply?

Answer 1

perineal muscles (superficial and deep)
skin of external genital organs (penis/scrotum; clitoris, labia, and vagina)

Question 2

what 2 major categories do the motor nerves of the sacral plexus suppy?

Answer 2

gluteal muscles

deep lateral rotators/ABDuctor muscle of the thigh

Question 3

what muscles are included in the gluteal muscle group?

Answer 3

max, medius, minimus, and TFL

Question 4

what muscles are included in the deep lateral rotators and ABDuctors of the thigh?

Answer 4

pirformis, obturator internus, superior gemellus, inferior gemellus, and quadratus femoris (obturator externus = obturator nerve)

Question 5

what nerve roots of the sacral plexus does the superior gluteal nerve arise from?

Answer 5

L4, L5, S1

Question 6

What muscles does the superior glutes nerve innervate?

Answer 6

gluteus minimus, medius and TFL

Question 7

what nerve roots of the sacral plexus does the inferior gluteal nerve arise from?

Answer 7

L5, S1, S2

Question 8

What muscle does the inferior glutes nerve innervate?

Answer 8

glute max

Question 9

what nerve roots of the sacral plexus does the nerve to piriformis arise from?

Answer 9

S1, S2

Question 10

what nerve roots of the sacral plexus does the nerve to quadratus femoris arise from?

Answer 10

L4, L5, S1

Question 11

What muscles does the nerve to quadratus femoris innervate?

Answer 11

quadratus femoris AND inferior gemellus

Question 12

what nerve roots of the sacral plexus does the nerve to obturator internus arise from?

Answer 12

L5-S2

Question 13

What muscles does the nerve to obturator internus innervate?

Answer 13

obturator internus AND superior gemellus (obturator externus=obturator nerve**)