Vertebral Column 1

Question 1

what is the main function of the vertbral column (5)

Answer 1

1. internal support for body
2. protection of spinal cord
3. support and protection of local structures
4. muscle attachment (extrinsic muscles of limbs)
5. locomotion - transfer of propulsive motion from hindlimbs

Question 2

what are irrefular bones

Answer 2

located in the axial skeleton

Question 3

what are the outer and centre layer of irregular bones

Answer 3

outer: compact bone
centre: cancellous bone

Question 4

what are the structures shown

Answer 4

1. compact bone
2. cancellous bone

Question 5

what are the features of the vertebral body

Answer 5

massive region of bone

roughly cylindrical

Question 6

what is the convex cranial surface and concave caudal surface called

Answer 6

convex cranial surface = cranial endplate

concave caudal surface = caudal endplate

Question 7

what is the invertebral disc space

Answer 7

space between adjacent vertebral bodies when aligned to form vertebral column

Question 8

what is the invertebral disc space occupied by

Answer 8

soft tissue structure called invertebral disc

Question 9

where is the vertebral arch located

Answer 9

arch of bone located dorsal to the vertebral body

Question 10

what is the vertebral arch composed of

Answer 10

left and right vertical wall = pedicles

right and left laminae that come together to form the roof

Question 11

how does the vertebral foramen form

Answer 11

combination of the vertebral arch dorsally and the vertebral body ventrally –> forms vertebral foramen

Question 12

what is the function of the vertebral foramen

Answer 12

route for the spinal cord to run through the bone

Question 13

how does the vertebral canal form

Answer 13

when the vertebral align the vertebral foraminae aligns to form a hollow channel running the length of the vertebral column = vertebral canal

Question 14

what does the vertebral canal contain

Answer 14

contains the spinal cord allowing it to run the length of the body while being protected by the boney tube formed between the vertebral bodies and the vertebral arches

Question 15

what structures are shown

Answer 15

vertebral foramen

Question 16

what structure is shwon

Answer 16

vertebral canal

Question 17

what are on the lateral aspect of the vertebra

Answer 17

there is a notch present at the cranial and caudal aspects of each pedicle –> cranial and caudal notches

Question 18

how many notches are there

Answer 18

the vertebrae are the same on both left and right side –> total of 4 notches per vertebrae

Question 19

what forms the invertebral foramen

Answer 19

when the vertebrae align to form the vertebral column –> notches line up with each other to form a series of gaps or spaces = intervertebral foramen

Question 20

what is the function of intervertebral foramen

Answer 20

allows passage of spinal nerves and blood vessels from the spinal cord out of the vertebral canal to supply the body

Question 21

what is this structure

Answer 21

intervertebral foramen

Question 22

what are articular facets

Answer 22

each vertebra has articular facets that allow it to articulate with the vertebrae cranial and caudal to it

Question 23

where are the articular facets located

Answer 23

at junction between the pedicle and the lamina at the cranial and caudal aspects of the vertebra

present on left and right sides of vertebra

Question 24

how many articular facets are there per vertebra

Answer 24

located on left and right sides of vertebra so there are 4/vertebra

Question 25

where do the articular facets articulate

Answer 25

with facets on adjacent vertebrae to form synovial joints (cranial and caudal) the orientation depends on how much movement between vertebrae is permitted in each region

Question 26

what are these structures

Answer 26

articular facets

Question 27

what are the spinous processes

Answer 27

bony projections --\> increase surface area for muscle attachment length and inclination vary with region

Question 28

what is the dorsal spinous process

Answer 28

single boney projection located on the dorsal aspect of the vertebral arch at the point where the laminae meet in midline

Question 29

what is the transverse processes

Answer 29

2 boney projections located on the lateral aspect of the vertebral arising where the pedicle meets the vertebral body

Question 30

what structures are shown

Answer 30

1. dorsal spinous process 2. transverse processes

Question 31

what are the typical features of vertebra (6)

Answer 31

1. vertebral body 2. intervertebral disc spaces 3. vertebral arch --\> pedicles/laminae, vertebral foramen (vertebral canal) 4. cranial and caudal notches --\> intervertebral foramen 5. articular facets 6. spinous processes --\> dorsal and transverse

Question 32

how does the axial skeleton develop

Answer 32

paraxial mesoderm --\> somites --\> dermatone --\> skin somites --\> myotome --\> muscle **somites --\> sclerotome --\> axial skeleton**

Question 33

how does each side of vertebra develop

Answer 33

Question 34

what does the paraxial mesoderm form from

Answer 34

more than 40 pairs of somites these each split into 3 parts

Question 35

what does the sclerotome form

Answer 35

develop a diffuse cranial section and dense caudal section --\> on the left side of the neural tube combines with the diffuse cranial section of the adjacent sclerotome to form the left half of the same vertebra same process occurs on the right side of the neural tube

Question 36

how does the sclerotome split

Answer 36

into cranial and caudal sections the caudal section combines with the cranial section of the adjacent slcerotome to form a **hemivertebra**

Question 37

what occurs to the hemivertebra

Answer 37

the left and right hemivertebra come together and fuse to form complete vertebra

Question 38

what encloses the neural tube and what forms in the process

Answer 38

the neural arch which is formed from the caudal sections of the sclerotome --\> encloses neural tube and fuses dorsally --\> **forming vertebral foramen and canal**

Question 39

what occurs to the notochord q

Answer 39

when the vertebral body arises from the cranial section of the sclerotome it obliterates the notochord but does still remain in the spaces between the adjacent vertebral bodies

Question 40

in the space that the notochord occupied, what now occupies it

Answer 40

occupied by the intervertebral disc and these remnants of the notochord are incorperated into the invertebral disc as the nucleus pulposus (chusioning and shock absorption between adjacent vertebrae)

Question 41

how many centres of ossification do the body of vertebrae develop from

Answer 41

3 centres 1. body 2. cranial endplate 3. caudal endplate

Question 43

what can be seen on radiographs in young animals

Answer 43

physes or growth plates between these centres of ossification are visible on radiographs

Question 44

what is an example of abnormal development of vertebrae

Answer 44

block vertebrae --\> 2 fused together with no disc space

Question 45

what structures are shown

Answer 45

1. body 2. cranial endplate 3. caudal endplate

Question 46

what is transitional vertebrae

Answer 46

located at the boundary between different regions of the vertebral column and get confused in which region they belong to in this ex. the last lumbar vertebra that is missing a transverse process other ex. include the 1st lumbar vertebrae with a rib or the last thoracic vertebra without one

Question 47

what is hemivertebra

Answer 47

wedge/butterfly vertebrae the vertebral body fails to form properly instead of being normal cylindrical shape --\> its triangular instead can cause devation of the column