Spinal Curves and IVF (Exam 1)

Describe spinal curves.

- Normal anterior to posterior bending

- Adds 10x resistance to axial compressive loads

What are excessive curves called?

Kyphosis/hyperkyphotic - hunchback

- Aging, weightlifting

Lordosis/hyperlordotic - swayback

- Pregnancy, obesity

Scoliosis - lateral bend

Describe anterior spinal curves.

- AKA Lordotic or secondary curves

- Cervical and lumber

Describe posterior spinal curves.

- AKA Kyphotic or primary curves

- Thoracic, sacrum, and coccyx

Describe the embryonic period of spinal curvature.

- Primary curves present

- Cervical begins to appear toward the end due to muscle development

Describe the neonatal period of spinal curvature.

- 3-4 days infant begins head lift

- 3-4 months cervical lordosis can be observed

Describe the infant period of spinal curvature.

- 6-9 months infant crawls and sits up

- 9-18 months infant walks

- causes lumber to curve, and increase in size and density

What is the range and degree of curve of normal cervical spine?

- Tip of odontoid process of C2 to T2

- 35-45 degrees

What is the range and degree of curve of normal thoracic spine?

- Between T2 and T12

- 20-40 degrees

What is the range and degree of curve of normal lumbar spine?

- Between T12 - lumbosacral angle

- 50-60 degrees

What is the range normal sacrococcygeal spine?

- Lumbosacral angle to tip of coccyx

What is anklyosing spondylitis?

-Complete auto fusion of the spine due to inflammation

What are the two types of bone tissue?

- Cortical bone: dense outer shell

- Cancellous bone: inner spongy

What is bone density?

Measurement of minerals in bones (more minerals=more strength)

What three cells manage bones?

- Osteocytes: maintain bone and diffuse nutrients

- Osteoblasts: secrete bone matrix

- Osteoclasts: breaks down bone matrix

When do bones grow the most?

During puberty

What happens during the ages of 25 - 50 years?

Equal amounts of bone deposition and break down

When does bone break down exceed bone deposition?

Over the age of 50 or during menopause

What bone trends are seen in women?

- Low bone density than men

- Estrogen levels are linked to osteoblast activity

What is osteoporosis?

- Bones become brittle and fragile from loss of tissue

- Linked with hormones and lack of use

Prior to the age of 40, what type of bone supports most of the compressive load?

Cancellous/spongy bone (55%)

After the age of 40, what type of bone supports most of the compressive load?

Compact bone (65%)

What is Wolffs law?

bones grow or remodel in response to demands placed on them

How does spinal flexion affect the IVF?

Opens the IVF

Collateral flexion only one opens

Decreases lordosis, increases kyphosis

How does spinal extension and rotation affect the IVF?

Closes IVF

Ipsilateral flexion closes only one

Increases lordosis, decreases kyphosis

What forms a the roof of the IVF?

Inferior pedicle notch of superior vertebrae

What forms the floor of the IVF?

Superior pedicle notch of inferior vertebrae

What forms the posterior wall of IVF?

Articular processes

What forms the anterior wall of the IVF?

Cervical and Lumbar:

- Posterior of vertebral body above and below and the disk

Thoracic:

- Posterior of vertebral body above only and the disk

What trends are seen in the IVF as you go superior to posterior?

- IVF notch height increases

- Spinal nerve diameter is constant

- Spinal nerve is always in upper 1/3

What is located in the IVF?

- Spinal nerve root

- Segmental spinal artery/veins

- Dorsal root ganglion

- Recurrent meningeal nerve

- Transforaminal ligaments

- Ligamentum flavum

- Lymphatics

- Fat

Describe the transforaminal ligaments.

- Protects nerves and vessels

- Normal structures

- Mainly in lumber

- Not present in every individual

What is the intervertebral motor unit?

2 adjacent vertebrae and their continuous structures

- Includes muscles, ligaments, and nerves