Lecture 4 - Lumbar Spine

Question 1

Vertebral column

Answer 1

5 cervical vertebrae 
12 thoracic vertebrae 
5 lumbar vertebrae 
5 sacral vertebrae
4 coccygeal vertebrae

Question 2

Single separate vertebrae capable of individual movement

Answer 2

C1-C7
T1-T12
L1-L5

Question 3

Thoracic vertebrae

Answer 3

Less mobile as joined by by the ribs to the sternum

Question 4

Fused vertebrae

Answer 4

Sacrum

Coccyx

Question 5

Kyphotic curvature

Answer 5

Thoracic and sacral
Anteriorly concave
Develop during foetal period

Question 6

Lordotic curvature

Answer 6

Cervical and lumbar
Anteriorly concave
Develop during childhood - lifting the head and sitting

Question 7

Why do vertebral bodies increase in size inferiority

Answer 7

Compression forces increase

Question 8

Sacral vertebrae

Answer 8

Fused
Widened
Anteriorly concave
Transmits the weight of the body through the pelvis to the legs

Question 9

Functions of the vertebral column

Answer 9

1. Supports the weight of the skull, pelvis, upper limbs and thoracic cage
2. Protects the spinal cord and the cauda equina
3. Posture
4. Locomotion
5. Haematopoiesis - bone marrow

Question 10

Components of a vertebrae

Answer 10

1 spinal process
2 transverse processes 
2 superior articular processes (facets)
2 inferior articular processes (facets)
1 vertebral body 
1 Vertebral foramen
2 Lamina
1 vertebral notch 
1 vertebral arch
2 pedicels

Question 11

Vertebral foramen

Answer 11

Contains
Conus medullaris
Cauda equina
Meninges

Question 12

Vertebral body

Answer 12

10% cortical bone

90% cancellous bone - reduces weight
Permits haematopoiesis

Major load bearing structure of the spinal column

Question 13

Vertebral end plates

Answer 13

Superior and inferior articular surfaces

Covered in hyaline cartilage

Question 14

Intervertebral discs

Answer 14

Link adjacent vertebral bodies

Question 15

Posterior elements

Answer 15

All structures posterior to vertebral body

1/3 of the upright posture load is carried

Question 16

Vertebral arch

Answer 16

Protective gunnel in which the spinal cord runs

Made up of 2 pedicles and 2 laminae

Question 17

Lamina

Answer 17

Connect the transverse processes to the spinous processes

Question 18

Pedicles

Answer 18

Connect the transverse processes to the ventral body

Question 19

Which structures provide attachment points for muscles and ligaments

Answer 19

Spinous

Transverse

Question 20

Inferior articular facets

Answer 20

Project caudally (down)

Question 21

Superior articular facets

Answer 21

Project cephalically (up)

Question 22

Inferior and superior articular facets

Answer 22

Articulate with adjacent vertebrae - provides a mobile facet joint (synovial) - zygapophyseal joint

Concave - produce vertebral notch

Vertebral notch can form intervertebral foramen

Question 23

Intervertebral foramen

Answer 23

Allows passage of of the spinal nerves from the spinal canal to the periphery

Question 24

Flexion and rotation in cervical vertebra

Answer 24

45 degrees to the axial in the coronal plane

Flexion - nodding
Extension
Lateral flexion
Rotation

Question 25

Thoracic vertebrae flexion and rotation

Answer 25

60 degrees to axial plane | 20 degrees to coronal plane

Question 26

Lumbar flexion and rotation

Answer 26

90 degrees to axial | 45 degrees to coronal

Question 27

Intervertebral discs

Answer 27

25% of the length of the vertebral column 70% water 20% collagen 10% proteoglycans Strong in axial compression Less strong under tangential loading Therefore important to keep spine straight while lifting heavy loads

Question 28

2 regions of the intervertebral discs

Answer 28

Nucleus pulposus (central) Annulus fibrosus (peripheral) The nucleus pulposus is surrounded entirely by the annulus fibrosus

Question 29

Annulus fibrosus

Answer 29

Shock absorber of the spine - resilient to axial compression (top to bottom) Stronger than vertebral body Avascular Anueral Comprises: - lamellae of annular bands of collagen in varying orientations - outer lamellae - type 1 collagen (fibrous) - inner lamellae- fibrocartilaginous

Question 30

Nucleus pulposus

Answer 30

Remnants of the embryonic notochord Gelatinous Type 2 collagen High oncotic pressure Decreases in height: - during the day as water is squeezed out due to mechanical pressure - with age Becomes more posteriorly located in adults

Question 31

How much weight is transmitted through the vertebral body and facet joints when young?

Answer 31

80% of the body weight - vertebral body | 20% - facet joints

Question 32

What proportion of a persons body weight is transmitted through the vertebral body and facet joints as we age?

Answer 32

Vertebral bodies - 65% Facet joints - 35% Increased load on facet joints causes osteoarthritis changes