Back (VC and SC) Flashcards
How long is the adult vertebral column?
72-75 inches
What does the back consist of?
Posterior Trunk, SC, VC
True/False: The back is the region to which the neck, head, and limbs are attached.
True
What six things does the back include?
- skin and subcutaneous tissue 2. Muscles 3. VC (w/ associated structures) 4. Ribs 5. SC and meninges 6. Segmental nerves and vessels
What protects the SC and nerves?
Vertebral Column
What are the other three major functions of the VC?
Support weight, provide axis, and posture & locomotion
How many vertebrae are there in total?
33
How many cervical vertebrae are there?
7
How many thoracic vertebrae are there?
12
How many lumbar vertebrae are there?
5
How many sacral vertebrae are there?
5
How many coccygeal vertebrae are there?
4
What are the sacral vertebrae fused to form?
Sacrum
What are the coccygeal vertebrae fused to form?
Coccyx
At what age does fusing of the coccygeal vertebrae occur?
approx after age 30
What is it called when L5 abnormally fuses to the sacrum?
Sacralization
What is it called when S1 is not fused to the sacrum, but instead the Lumbar vertebrae?
Lumbarization
What type of joints primarily make up the VC?
Synovial Zygapophysial (facet) joints
What do the zygapophysial joints function to do?
Facilitate and control flexibility
What three components make up a typical vertebra?
Body, Arch, and 7 processes
Name three characteristics of the vertebral body.
More massive, cylindrical anterior part. Size increases as VC decends, and it is primarily made of spongy bone enclosed by a thing external layer of compact bone
What is most the vertebral body covered in?
Discs of Hyaline cartilage
What are the two parts of the vertebral arch?
Two pedicles and laminae
What is formed between the arch and the body?
Vertical Foramen
What structure is indicated by an indentation in lateral views above and below the pedicles?
Vertical Notch
What are the three types of processes found on a vertebrae?
Spinous, Tranverse, and Articular
How many spinous processes are on a given vertebrae?
one
How many transverse processes are on a given vertebrae?
Two, one on each side from junction pedicle and laminae
How many articular processes are on a given vertebrae?
four, two superior and two inferior
What structure does each articular process bear on?
Articular surface (facet)
What structure provides the attachment for epaxial muscles and serves as levers?
The Vertebral Arch
What type of vertebrae is formed of the skeleton of the neck?
Cervical
What structure is present in cervical vertebrae in the transverse processes?
Foramen Transversarium
What is the name of the C1 vertebrae?
Atlas
What is the name of the C2 vertebrae?
Axis
Vertebral arteries pass through all cervical vertebrae except for which one?
c7, only small accessory veins
Where on the cervical vertebrae do the anterior ramus of nerves course?
Grooves on the transverse processes between the tubercles
What paired structure is specific to the atlas to which the transverse processes arise from?
Lateral masses
What special structure does the axis have that allows promotes better articulation?
Dens of axis
T/F: The dens of axis is a tubercle.
False. it is a protuberance (projection)
What type of vertebrae provide the attachment for the ribs?
Thoracic
What special type of facets do thoracic vertebrae have?
Costal facets
What is unique about the shape of the spinous processes on thoracic vertebrae?
Extra long and thick spiky
What type(s) of movements do the thoracic vertebrae allow?
Rotation and some Lateral Flexion
What type of movement do the cervical vertebrae allow?
Flexion, Extension, LFlexion, Rotation
True/False: T7-12 are missing the costal facets restricting movement to only flexion and extension.
True
Describe the rule of “threes” for spinous processes of thoracic vertebrae.
T1-T3 are at the same level. T4-6 are half a level below. T7-10 are one whole level below. T11 is a half level below. T12 is at the same level.
Which vertebrae have massive bodies for weight bearing?
Lumbar vertebrae
What type of process is special to lumbar vertebrae?
Mamillary processes
What do the the transverse processes allow attachment of?
Intertransversarii muscles
What do the mamillary processes allow attachment of?
Multifidus and intertransversarii muscles
What is special about the sacral vertebrae?
They are fused
What are the two “functions” of the sacrum?
Provides strength and stability to pelvis AND transmits the body weight to pelvic girdle
Where does the vertebral canal end?
Approximately L1
What is formed beyond L1 containing a bundle of spinal nerve roots?
Cauda Equina
What structure special to the posterior sacral vertebrae surfaces provide the exit of rami of spinal nerves.
Sacral Foramina
How many pairs of sacral foramina are there?
4
Where is the base and apex relative to the sacral/coccygeal vertebrae?
Base - top. Apex - bottom.
At what age does fusion of the sacrum begin?
~20
In which gender is the sacrum typically wider in/?
Females
What structure forms from the absense of laminae and process of L5?
Sacral hiatus
What structure represents the inferior articular processes of S5? (projects on each side of sacrum)
Sacral Cornea
What forms in the middle of the sacrum starting at the base?
Sacral canal
What structures does the coccyx provide attachment for?
Gluteus maximus, coccygeus muscles, anococcygeal ligament
When does ossification begin?
Embryonic period
From what does ossification begin?
Mesenchymal condensations around notochords
What forms next from the mesenchymal bone models?
Cartilaginous Vertebrae
When does ossification typically begin?
End of embryonic period (8th week)
What are the three primary ossification centers?
Endochondral Centrum and two pericondral centers
Which ossification centers constitutes the majority of the VC body?
Endochondral
Where are the perichondral centers?
One in each half of the neural arch
Typically, at birth what does the VC consist of?
3 bony parts united by hyaline cartilage
At what age does fusing of neural arches typically begin and finish?
3,6
Where are the five secondary ossification centers that develop during puberty?
- tip of spinous process 2. tip of each transverse process 3. two annular epiphyses
When does secondary ossification usually unite by?
25
What can developmental errors result in?
One less or one extra vertebrae
What is it called when vertebral foramen narrows?
Lumbar Spinal Stenosis
What abnormality can form from C7 transverse process enlarging?
Cervical Rib
What is hemisacralization?
L5 fused with sacrum
What is it called when epiphyses fail to fuse?
Spina bifida
What type of joints are at the vertebral bodies?
Symphyses
What two things connect the articulating surfaces of adjacent vertebrae?
IV discs and ligaments
How much of the length of VC do IV discs account for?
20-25%
What secondary function do IV disks provide?
Shock absorbers
Between which two vertebrae is no IV disc present?
c1 and c2
What is the gelatinous middle of an IV disk?
Nucleus pulposus
What surrounds the nucleus pulposus?
Annulus fibrosus
What develops between the unci of the bodies of C3/C4 and C6/C7?
Clefts (unconvertebral joints)
Where are these clefts located?
Lateral and posterolateral margins of IV discs
What abnormality can develop at these clefts?
Bone spurs
What ligament connects and covers the anterolateral aspects of vertebral bodies and IV discs?
Anterior Longitudinal Ligament
What motion is prevented because of this ligament?
Hyperextension
What movement is limited by all other ligaments?
Flexion
What ligament runs within the VC along the posterior vertebral bodies?
Posterior Longitudinal Ligament
What benefit does the PLL have for the nucleus pulposis?
Redirects herniation
What type of nerve endings innervate the PLL?
Nociceptive (pain)
What type of joint are at the vertebral arches between the superior and inferior processes?
Zygapophysial (facet) joints
What type of joint are these facet joints?
Plane synovial
What movement do these joints permit?
Gliding
What rami innervates the facet joints? how many nerves supply each articular branch?
Posterior, 2
What ligament joins adjacent laminae?
Ligamenta flava
What do ligamenta flava function to provide?
Resist separation of laminae, limit abrupt flexion of VC, preserve the normal curvatures and promote separating
What ligaments connect adjoining spinous processes?
Interspinous Ligaments