The back anatomy Flashcards
What are the visible landmarks on the back?
Trapezius Latissimus dorsi Eretor spinae Vertebral prominens Posterior median furrow
How many vertebrae do must people have? Break it down into regions.
33 Cervical: C1-C7 Thoracic: T1-T12 Lumbar: L1-L5 Sacral: S1-S5 coccygeal: Co1-Co4
What type of joint is found between C1 and C7?
synovial
What is C7 AKA?
vertebral prominens
What do spinal nerves runs through?
intervertabreal foramina
Describe the spinal curvatures
Cervical: lordotic
Thoracic: kyphotic
Lumbar: lordotic
Sacral + coccyx): kyphotic
What term describes the pathologic increase in curvature?
hyperlordosis/hyperkyphosis
Describe the facets found on thoracic vertebrae
Found on transverse processes and the body
T1: one facet and one inferior dmeifacet
T2-T9: contain superior and inferior demifacets
T10: one superior demifacet
T11-T12: facets
Normal variations in vertebral number
32-34L usually thoracic and coccygeal (sometimes lumbar or sacral)
What are variations in rib number usually due to?
NOT the number of vertebrae
Normally an extra pair: C7 or L1
More frequent than vertebral variations
What is thoracic outlet syndrome?
an extra rib on C7 - disrupts subclavian vein, subclavian artery and brachial plexus
function of intervertebral discs/symphyses
cushions the spine
What are the two main parts of the intervertebral joints?
Annulus fibrosus
Nucleus palposus
Describe the annulus fibrosus
tough fibrocartilage, fibers run arouns in a circle and also longitudinally into the rim of the vertebral body
Describe the nucleus palposus
Made up of tough collagen fibers and hydrated proteoglycan gel; soft, slightly taller than the annulus palposus when it is not in the column (will level out with pressure)
Why do you become shorter in the afternoon or when dehydrated?
not enough fluid in the Nucleus palposus
What supporting ligaments are found in the intervertebral joints?
anterior longitudinal ligament
posterior longitudinal ligament
Describe zygapophyseal joints
AKA interfacet joints
Found between articulating facets
synovial joints
What supporting ligaments are found in zygapophyseal joints?
- ligamentum flavin: runs along inside of the vertebrae (near the cord)
- interspinous ligaments: between spines
- supraspinous ligament: run along the spines, extends only up to C7
What does the supraspinous ligament become?
nuchal ligament: extends from C7 to the skull to stabilize the head
- Very thick in animals that run (NOT pigs, YES cats)
Describe the atlanto axial joints
- synovial
- 3 total: 2 lateral (btwn articular facets of atlas and axis), 1 median (btwn the dens and the dens fossa)
What are the supporting ligaments of the atlanto-axial joint?
- cruciate ligament
- alar ligament
Describe the parts of the cruciate ligament
- Transverse ligament: runs to the inner portions of the atlas and supports the dens from going backward
- superior longitudinal band: runs from the transverse ligament to the front of the foramen magnum
- inferior longitudinal ligament: run from transverse ligament to the body of the axis
Describe the alar ligaments
- suspend from the top of the dens
- go to the sides of the foramen magnum
- orients the dens upward
Where does the spinal cord generally stop?
L1-L2
What is the end of the spinal cord called?
conus medularis
What is the term for the remnant of the spinal cord that extends down to the coccyx
filum terminate internum
What is the function of the gray matter of the spinal cord
Synapses occur here
- Sensory neurons synapse at the dorsal horn
- Somatic motor neurons synapse at the ventral horns
- Autonomic motor neurons synapse at the lateral horns
Where can you find lateral horns of the spinal cord?
T1-L2, S2-S4
