Sacrum & Coccyx

Question 1

What part of the sacral ala is derived from the costal element?

Answer 1

anterior 2/3

Question 2

What part of the sacral ala is derived from the true transverse process?

Answer 2

posterior 1/3

Question 3

How many fibrous (amphiarthorsis) symphysis joint surfaces are present on the S1 vertebral body?

Answer 3

four

Question 4

How many joint surfaces are present on the vertebral body of the first sacral segment?

Answer 4

five

Question 5

How many cartilagenous (amphiarthrosis) syndesmosis joint surfaces are present on the S1 vertebral body?

Answer 5

one

Question 6

What muscle(s) may attach to the first sacral vertebral body?

Answer 6

psoas major

Question 7

What is the position of the sacral zygapophysis in adults?

Answer 7

lies in coronal plane for L5/S1

Question 8

What is the orientation of the first sacral superior articular facet?

Answer 8

backward, upward, medial (BUM);

typically concave

Question 9

What is the name given to the projection on the first sacral superior articular facet?

Answer 9

mammillary process

Question 10

What muscles will attach to the sacral mammillary processes?

Answer 10

multifidis

Question 11

What is the usual condition for the first sacral spinous process?

Answer 11

non-bifid and short

Question 12

An imaginary line drawn along the dorsal midline of the sacrum is identified as the ______

Answer 12

medial sacral crest

Question 13

What is the name given to the congenital condition in which the fifth lumbar spinous process is elongated, the sacrum exhibits spina bifida, and dorsiflexsion produces pain?

Answer 13

Knife’s Clasp syndrome

Question 14

An imaginary line drawn from the superior articular process of S1 to the sacral cornu will form what feature?

Answer 14

intermediate sacral crest

Question 15

What features may be identified along the intermediate sacral crest?

Answer 15

mammillary process of S1 and the sacral cornu of S5

Question 16

What does the sacral cornu represent?

Answer 16

inferior articular process and facet of S5

Question 17

What is the name of the inferior opening of the sacral spinal canal?

Answer 17

sacral hiatus

Question 18

An imaginary line is drawn from the transverse process of S1 to the inferior lateral sacral angle will form what feature?

Answer 18

lateral sacral crest

Question 19

What is the sacral tuberositiy?

Answer 19

enlarged transverse tubercle of S2

Question 20

What is the name of the joint formed by the sacral tuberosity?

Answer 20

accessory sacro-iliac joint

Question 21

What feature is identified on the lateral surface of S1-S3?

Answer 21

auricular surface

Question 22

What feature does the anterior surface of the superior epiphyseal rim of S2 form?

Answer 22

sacral promontory

Question 23

The continuation of the posterior longitudinal ligament below S3 form what ligament?

Answer 23

deep posterior sacrococcygeal ligament

Question 24

What forms the posterior boundary for the fifth sacral spinal nerve intervertebral foramen?

Answer 24

sacral cornu, coccygeal cornu, superficial posterior sacrococcygeal ligament, intercornual ligament

Question 25

What forms the anterior boundary for the fifth sacral spinal nerve intervertebral foramen?

Answer 25

vertebral body S5, vertebral body Co1, deep posterior sacrococcygeal ligament, intervertebral disc

Question 26

What forms the inferior boundary for the spinal canal?

Answer 26

the union of the superficial posterior and deep posterior sacrococcygeal

Question 27

What ligament divides the sciatic foramen into the greater and lesser sciatic foramina?

Answer 27

sacrospinous ligament

Question 28

Which ligament has a broad attachment along the lateral margin of the sacrum and coccyx and then attaches to the ischial tuberosity?

Answer 28

sacrotuberous ligament

Question 29

Which ligament is the strongest of the sacro-iliac ligaments and is penetrated by dorsal rami of the sacral spinal nerves?

Answer 29

interosseous sacro-iliac ligament

Question 30

What is the homolog for the inferior articular process and facet at S5?

Answer 30

sacral cornu

Question 31

What is the homolog for the superior articular process and facet at Co1?

Answer 31

coccygeal cornu

Question 32

What is the number of the coccygeal somites?

Answer 32

ten

Question 33

What is the typical number of segments that unite to form the adult coccyx?

Answer 33

4 segments

Question 34

When is ossification of coccyx completed?

Answer 34

about age 30

Question 35

What is the direction of fusion of coccygeal segments?

Answer 35

from caudal to cranial, the last segments to fuse together are Co1 and Co2

Question 36

What is the direction of the coccygeal curve?

Answer 36

posterior (kyphotic)

Question 37

What is the major motion and range of motion for the coccyx?

Answer 37

flexion-extension: 5-20 degrees

Question 38

How many coccygeal nerves are present in the fetus?

Answer 38

typically 5 pairs of coccygeal nerves are present

Question 39

What forms the coccygeal nerve plexus?

Answer 39

S4, S5, and Co1 nerves

Question 40

What is the ganglion impar?

Answer 40

a midline sympathetic ganglion

Question 41

What is the coccygeal glomus or coccygeal body?

Answer 41

an enlarged encapsulated arteriovenous anastamosis location near the last segment of coccyx