Lecture 7: Functional Anatomy - Trunk

Question 1

Vertebral column

Answer 1

• Rigid support and flexibility
• 33 vertebrae, 24 contribute to trunk movement
• Protects spinal cord

Question 2

Spinal cord

Answer 2

Starts at medulla oblongata, ends at L1/L2
Cervical enlargement: brachial plexus
Lumbar enlargement: Cauda equina -> lumbosacral plexes

Question 3

Lordosis

Answer 3

Curving inward of lower back

Sticking out butt

Question 4

Kyphosis

Answer 4

Forward rounding of back

Bad posture

Question 5

Scoliosis

Answer 5

Sideways curvature/longitudinal twisting of spine

Question 6

Posture while standing

Answer 6

S-shaped spine acts as elastic rod support

Erector spinae = keep spine erect

Question 7

Posture while sitting

Answer 7

• Unsupported sitting is more strenuous on spine
• upper body center of gravity shifts forward
• lumbar load is reduced in supported sitting

Question 8

Cervical region

Answer 8

• C1-C7

- very mobile, relatively long spinous processes and short transverse processes

Question 9

Atlas

Answer 9

C1

• only cervical vertebrae with no body
• connects to occipital bone
• 50% of head forward and backward range of motion

Question 10

Axis

Answer 10

C2

- odontoid process, large bony protrusion, fits into axis

Question 11

Vertebra prominens

Answer 11

C7

Question 12

Thoracic region

Answer 12

T1-T12

• connects to ribs, orientation to facets, long spinous processes
• flexion, extension, rotation, lateral flexion

Question 13

T9-T12 injuries

Answer 13

Paraplegia; lack of function in legs
Lack of bowel/bladder control
Reduced ability to control trunk of body and abdominal muscles

Question 14

Lumbar region

Answer 14

L1-L5

• most highly loaded structure in skeletal system
• large range of motion in flexion and extension

Question 15

Lumbar spinal cord injuries

Answer 15

Paraplegia: lack of function in legs

• lack of bowel/bladder control
• may have some ambulatory capabilities

Question 16

Cervical injuries

Answer 16

Death, respiratory failure, or quadriplegia (lack of function in arms, legs, bladder/bowel, etc)

Question 17

Disc degeneration

Answer 17

• Back pain common from 25-60 years of age. Highest incidence at age 40
• 85% of general population
• recurs 30-70% of time after initial incidence

Question 18

Vertebral joint strength

Answer 18

Strongest: trunk extension

• flexion
• lateral flexion
• rotation

Question 19

Effects of aging on trunk

Answer 19

• flexibility decrease as little as 10%
• trunk muscles lose 1% of strength every year
• between ages 30-80, loss of 30% cartilage, 20% bone, 18% ligaments
• shape and length also change with age
• smaller fluid region in aging discs