Vertebral Column and Back Musculature

Question 1

what is the skeleton?

Answer 1

structural support that provides system of levers for muscular movement as well as protects soft tissues/organs

Question 2

what makes up the axial skeleton?

Answer 2

skull/cranium,
vertebral column
ribs and sternum

Question 3

what makes up the appendicular skeleton?

Answer 3

limb bones
pelvis
scapula
clavicle –> reduced in animals to increase movement range

Question 4

what are joints?

Answer 4

articulations either firmly unite bones or allow specific movements between bones

Question 5

what is flexion?

Answer 5

movement that REDUCES the angle between bones

Question 6

what is extension?

Answer 6

movement that INCREASES the angle between bones

Question 7

describe the cervical region characteristics

Answer 7

-spinous process is small
-transverse process splits into dorsal and ventral tubercles

Question 8

describe the thoracic region characteristics

Answer 8

-articulate with the ribs
-prominent spinous process
-transverse process –> short

Question 9

describe the lumbar region characteristics

Answer 9

-transverse process cranioventrally oriented
-articular processes in sagittal plane
-blunt spinous process

Question 10

describe the sacrum characteristics

Answer 10

-3-5 fused vertebrae
-articulate with ilium at sacroiliac joint

Question 11

what are the intervertebral discs? where are they positioned?

Answer 11

-between vertebral bodies
-are compressible and absorb shock
-allow movements along multiple axes

Question 12

what do plane/synovial joints allow? what are they?

Answer 12

-allow for sliding movements between articular processes of adjacent vertebrae
-enclosed capsular joint containing a smooth, viscous lubricant

Question 13

what are anulus fibrosus?

Answer 13

-concentric rings of fibrocartilage
-usually thinner dorsal and sometimes also lateral

Question 14

what are nucleus pulposus?

Answer 14

-central core of IV disc
-semifluid at birth –> dehydrates with age

Question 15

what do ligaments do?

Answer 15

limit excessive movement across joints

Question 16

what is the vertebral canal formed by?

Answer 16

sequence of vertebral foramina

Question 17

what is the purpose of the verterbal column?

Answer 17

protects the spinal cord

Question 18

how do dorsal rami travel?

Answer 18

dorsally

Question 19

how do ventral rami travel?

Answer 19

ventrolaterally

Question 20

which is bigger: dorsal rami or ventral rami:

Answer 20

ventral rami

Question 21

what do epaxial muscles do and where are they found?

Answer 21

-support vertebral column and are a major part of locomotion
-found along a narrow region of the back and neck

Question 22

what does origin mean?

Answer 22

(usually) the proximal end of a muscle that is fixed during contraction

Question 23

what does insertion mean?

Answer 23

(usually) the distal end of a muscle that attaches to the mobile portion of bone

Question 24

what is the nuchal ligament?

Answer 24

supports much of mass of head without muscular effort
site of muscle attachment

Question 25

what does innervation mean? (N)

Answer 25

the peripheral nerve that provides motor innervation to and takes sensory innervation from a muscle

Question 26

what does action mean? (A)

Answer 26

product of the movement generated by muscle contraction

Question 27

what are hypaxial muscles?

Answer 27

function in limb movement and stability –> locomotion

positioned superficial to the epaxial muscles

Question 28

what makes up the epaxial muscles?

Answer 28

iliocostalis system (most lateral)
longissimus system
transversopinalis system (semispinalis) –> most medial

Question 29

what makes up the transversospinalis system?

Answer 29

spinalis (capitis, cervicis)
semispinalis (capitis, cervicis) –> found near head, neck and thorax
multifidus –> closer to lumbar region

Question 30

name the O of the semispinalis cervicis

Answer 30

spinous processes of the first 3 thoracic vertebrae; nuchal ligament

Question 31

name the I of the semispinalis cervicis

Answer 31

nuchal crest and mastoid process

Question 32

name the N of the semispinalis cervicis

Answer 32

dorsal rami of spinal nerves along the extent of the muscles

Question 33

name the A of the semispinalis cervicis

Answer 33

extend neck and head; assists in turning neck laterally

Question 34

what is the thoracolumbar fascia?

Answer 34

is a deep, dense fascia that gives attachment to multiple muscle groups

also provides stability and support to the caudal lumbar region

Question 35

what do dorsal rami innervate?

Answer 35

the epaxial muscles

Question 36

what do ventral rami innervate?

Answer 36

the hypaxial muscles and all other somatic muscles of the back