Interval 6: Back and Gluteal Region Flashcards
What nerves innervate the upper limbs? How about the lower limbs?
- Upper: C5-T1
- Lower: L2-S2
What are the 4 curvatures of the adult back?
- Cervical: secondary curvature directed anteriorly
- Thoracic: primary curvature directed posteriorly
- Lumbar: secondary curvature directed anteriorly
- Sacral: primary curvature directed posteriorly
Movements between vertebrae occur at their ___________
- Zygapophyseal joints.
- Also by compression and traction of the discs
Zygapophyseal (facet) joints are formed between the _____________ at the junction of each ________ and __________.
- Superior and inferior articular processes
- each pedicle and lamina
What muscles act on facet joints?
-Deep or intrinsic back muscles
Describe the structure of intervertebral discs
-consists of fibrocartilaginous annulus fibrosus that surrounds a nucleus pulposus
What is the nucleus pulposus a remnant of?
-Fetal notochord
The anterior longitudinal ligament functions to limit ___________ and the posterior longitudinal ligament functions to limit ________.
- Extension of vertebra
- Flexion of vertebra
Individual vertebrae are separated by ___________.
-Intervertebral foramina
What are the anterior and posterior borders of intervertebral foramina?
- Anterior: bodies and intervertebral joints
- Posterior: facet joints
Elastic ligamentum flavum
- extends between the laminae of adjacent vertebrae
- limits vertebral flexion and helps maintain normal vertebral curvature
Which ligament of the vertebral column is yellow?
-Ligamentum flavum: yellow due to high content of elastic fibers
What ligaments of the vertebral bodies and what are ligaments of the vertebral arches?
- Bodies: anterior and posterior longitudinal ligaments
- Arches: ligamentum flava
Cervical vertebrae morphology
- small bodies
- short spinous processes with bifid tips
- transverse processes that transmit the vertebral arteries
Facet joints of cervical vertebrae
- C3-C7
- oriented at 45-degree angle relative to the transverse plane
- allows flexion, extension, lateral bending, and rotation
Uncinate processes of bodies of cervical vertebrae
- C3-C7 bodies
- form uncovertebral synovial joints with the vertebral bodies superior to them
- osteoarthritis in these joints make result in compression of the roots of C3-C7 spinal nerves
Atlas
- C1 vertebrae
- posterior arch and anterior arch
- no body or spinous process
- Yes joints found here
yes joints
- found between superior articular processes of atlas as they articulate with the occipital condyles of the skull
- permit flexion and extension
Axis
-C2 vertebra
Dens of axis
- stolen body of C1
- articulates with anterior arch of atlas and forms “no” joint
“no” joint
- where dens of axis articulates with anterior arch of the atlas
- permits rotation of the atlas and skull
What holds the dens in place and what happens if this ruptures?
- transverse ligament of the atlas
- rupture of this ligament causes dislocation of the atlantoaxial joint and displacement of dens posteriorly into cervical spinal cord which may lead to quadriplegia
What ligament keeps the dens from excessively rotating?
-Attached to the margins of the foramen magnum by alar ligaments
What is unique about C7?
- vertrebra prominens
- has long spinous process and small transverse foramina that do not transmit the vertebral arteries
Thoracic vertebrae morphology
- heart-shaped bodies
- long,obliquely oriented, spinous processes
- costal facets on the bodies and on the transverse processes for articulation with ribs
Facet joints of thoracic vertebrae
-60-degree angle relative to transverse plane
-permits lateral bending and rotation
(flexion and extension limited by ribs)
Lumbar vertebrae morphology
- large, kidney-shaped bodies
- short, horizontally oriented spinous processes
- long transverse processes
facet joints of lumbar vertebrae
- oriented perpendicular to the transverse plane
- permits flexion and extension and lateral bending
- limited rotation
The sacrum contains the sacral canal, which ends at the sacral hiatus in the dorsal midline; the canal contauns the ___________ and the sacral hiatus transmits_________.
- Canal: roots of the S1-coccygeal spinal nerves
- Hiatus: S5 and coccyeal spinal nerves
The coccyx is formed by 3-5 fused coccygeal vertebrae. It is an attachment site for what?
- gluteus maximus
- anococcygeal ligament (attachment site for muscles of pelvic diaphragm)
Foramen magnum
- boundary between brain and spinal cord
- where skull articulates with atlas
Meninge layers
Dura mater: exterior, tough, fibrous
Arachnoid mater: delicate, avascular, not adherent to dura
Pia mater: innermost layer; covers SC and roots of nerves; contains blood vessels and is indissectible from the spinal cord
Subarachnoid space
- space between pia and arachnoid membranes
- contains CSF
CSF
- derived from blood
- devoids of cells and proteins, and less glucose
- salt composition different from serum indicating it is secreted and not filtered
- secreted into ventricles of the brain, circulated in subarachnoid space, and is returned via venous system
The spinal cord ends at what vertebral level and what is the tapered structure called?
- L2
- Conus medularis
Denticulate ligament
-small, saw-tooth shaped extension of pia mater run to dura mater and serve to support cord within its sheath of dura
3 exits for spinal nerves
- intervertebral foramina
- sacral foramina
- sacral hiatus
1st 7 cranial nerves exit _____ to cervical vertebrae for which they are named.
- Superior
- Ex. C4 exits between C3 and C4
Beginning with T1, all other spinal nerves exit ______ to the vertebrae for which they are named.
- Inferior
- Ex: L4 exits between L4 and L5
C8 spinal nerve exits….
-through intervertebral foramina between C7 and T1 because there are 8 cervical nerves but only 7 cervical vertebrae
Cauda equina
-formed by dorsal and ventral roots of lumbar ans sacral spinal nerves that extend inferior to end of SC at L2
With a lumbar disk herniation, what muscles contribute to reducing the curvature of the spine?
- Psoas major
- Rectus abdominus
Muscles of rotator cuff
SITS Supraspinatus Infraspinatus Teres minor Subscapularis