Sacrum and Coccyx

Question 1

body (first sacral body)

Answer 1

lumbosacral articulation(the bodies of the 2nd–5th sacral vertebrae are typically referred to as such only when they are unfused)

Question 2

ala(e)

Answer 2

each comprised of a transverse process (posterior) and costal process or element (anterior); “ala” usually refers to one of those of the first sacral vertebra, but it can also refer to those of the 2nd–5th if they are unfused

Question 3

base

Answer 3

entire superior extent, including first sacral body and the left and right alae

Question 4

superior articular processes and facets

Answer 4

superior; of the first sacral vertebrae

Question 5

Lamina(e)

Answer 5

posterior; similar to those of true vertebrae

Question 6

median sacral crest/spine

Answer 6

posteromedial; analogous to the spinous processes of true vertebrae

Question 7

sacral canal

Answer 7

analogous to the spinal canal circumscribed by the arches of true vertebrae

Question 8

posterior surface(dorsal wall)

Answer 8

convex, rough, and ridged; comprised of the fused laminae and articular processes of the sacral vertebrae

Question 9

posterior sacral foramina

Answer 9

typically four on each side

Question 10

intermediate sacral crest

Answer 10

medial to the posterior sacral foramina

Question 11

lateral sacral crest

Answer 11

Lateral to the posterior sacral foramina

Question 12

sacral hiatus

Answer 12

caudal opening of the sacral canal, caudal to the median sacral crest/spine

Question 13

sacral cornu(a)

Answer 13

caudally/inferiorly projecting caudal termination of intermediate sacral crests; help to define the sacral hiatus

Question 14

anterior (or pelvic) surface

Answer 14

concave and relatively smooth

Question 15

transverse ridges/lines

Answer 15

fusion lines between sacral vertebral bodies (typically four)on the anterior/pelvic surface

Question 16

anterior or pelvic sacral foramina

Answer 16

typically four on each side

Question 17

intervertebral foramina (left and right)

Answer 17

open between the sacral canal and the canal formed by each set of anterior and posterior sacral foramina; typically four on each side

Question 18

apex

Answer 18

tapered caudal end(articulates with the coccyx)

Question 19

promontory

Answer 19

anterosuperior lip of first sacral body

Question 20

auricular surface

Answer 20

ear-shaped sacroiliac joint comprising the superior lateral sides of the sacrum

Question 21

sacral tuberosity

Answer 21

roughened area between the auricular surface and the lateral sacral crest

Question 22

Coccyx, Coccyges (pl.), Coccygeal (adj.):

body

coccygeal cornu(a)

transverse process

Answer 22

vestigial in form

cranially/superiorlyprojectingprocesses (tubercles)onthe posterior aspect of the first coccygeal vertebral body

lateral processes (most obvious on the first coccygeal vertebra)