Lecture 7: Functional Anatomy - Trunk Flashcards
Vertebral column
- Rigid support and flexibility
- 33 vertebrae, 24 contribute to trunk movement
- Protects spinal cord
Spinal cord
Starts at medulla oblongata, ends at L1/L2
Cervical enlargement: brachial plexus
Lumbar enlargement: Cauda equina -> lumbosacral plexes
Lordosis
Curving inward of lower back
Sticking out butt
Kyphosis
Forward rounding of back
Bad posture
Scoliosis
Sideways curvature/longitudinal twisting of spine
Posture while standing
S-shaped spine acts as elastic rod support
Erector spinae = keep spine erect
Posture while sitting
- Unsupported sitting is more strenuous on spine
- upper body center of gravity shifts forward
- lumbar load is reduced in supported sitting
Cervical region
- C1-C7
- very mobile, relatively long spinous processes and short transverse processes
Atlas
C1
- only cervical vertebrae with no body
- connects to occipital bone
- 50% of head forward and backward range of motion
Axis
C2
- odontoid process, large bony protrusion, fits into axis
Vertebra prominens
C7
Thoracic region
T1-T12
- connects to ribs, orientation to facets, long spinous processes
- flexion, extension, rotation, lateral flexion
T9-T12 injuries
Paraplegia; lack of function in legs
Lack of bowel/bladder control
Reduced ability to control trunk of body and abdominal muscles
Lumbar region
L1-L5
- most highly loaded structure in skeletal system
- large range of motion in flexion and extension
Lumbar spinal cord injuries
Paraplegia: lack of function in legs
- lack of bowel/bladder control
- may have some ambulatory capabilities
Cervical injuries
Death, respiratory failure, or quadriplegia (lack of function in arms, legs, bladder/bowel, etc)
Disc degeneration
- 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
Vertebral joint strength
Strongest: trunk extension
- flexion
- lateral flexion
- rotation
Effects of aging on trunk
- 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
