Chapter 7: The Axial Skeleton - Vertebral Column Flashcards
Spinal column functions (3)
- encloses and protects the spinal cord
- supports the head
- serves as a point of attachment for ribs, pelvic girdle, and muscles of the back and upper limbs
How many vertebrae does an adult have?
A child?
26
33 (some fuse later)
What is the neck region of the spinal column and how many vetebrae are there?
the cervical region
7 vertebrae
What is the section of spinal column posterior to the thoracic cavity and how many vertebrae does it contain?
thoracic vertebrae
12 thoracic vertebrae
Area of spinal column posterior the abdomen and how many vertebrae?
Lumbar vetebrae
5 lumbar vetebrae
Area of spinal column below th e lumbar region that consists of how many fused vertebrae?
the sacrum
consists of 5 fused sacral vertebrae
Area of vertebral column thtat usually consists of how many fused of what kind of vertebrae
(Tailbone)
Coccyx
usually 4 fused coccygeal vertebrae
What are the slight curves in the spinal column called and how many are there?
normal curves
4
What are the two curves that buldge out the back of the body?
cervical and lumbar curve
What are the two normal curves that curve into the body?
thoracic and sacral
FUnctions of the normal curves of the spine? (4)
- increase strength of spine
- help maintain balance
- absorb shock during walking
- help protect vertebrae from fractures
Describe the curve(s) of a fetal spine
A single, anteriorly concave curve (buldging out the back) throughout the entire length of the spinal column
Why are sacral and thoracic curves called the primary curves?
They maintain the curvature present in the fetus
Why are cervical and lumbar curves known as seconday curves?
These curves form later, several months after birth
By what age are all curves fully developed?
10
Which curves can be progressively lost with old age?
seconday curves - cervical and lumbar
These are found between the bodies of adjacent vertebrae from the second cervical vertbrae to the sacrum
intervertebral discs
What are the two components of an intervertebral disc
annulus fibrosus
nucleus pulposus
The annulus fibrosis is what?
outer ring of the intervertebal disc that is made of fibrocartilage
What is the nucleus pulposus?
The inner, soft, pulpu, highly elastic substance inside the intervertebral disc
What is found on the inferior and superior surfaces of the intervertebral discs?
hyaline carticlage
What are the functions of the intervertebral discs?
- form strong joints
- permit various movements of the vertebral column
- absorb vertical shock
What happens to intervertebral disc under compression?
they flatten and broaden
The basic components typically found in a vertbrae?
- Vertebral body
- vertebral arch
- several processes
This part of a vartebrae is the thick, disc shaped anterior portion that is weight bearing.
Surfaces roughened for attachment of the intervertebral discs
contains the nutrient formina for blood vessels
veretbral body
Describe the size of the cervical vertebrae
smallest body
largest arch
contain the cervical enlargement of the vertebral column and therefore the vertebral foramina is largest here
contain one vertebral foramen and 2 transverse foramina
What do transverse foramina on the cervical vertebrae house and where on the vertebrae are they located?
One through each cervical transverse process
houses the vertebral artery and the accompanying vein and nerve fibres
How is C1 different from all other vertbrae?
Called atlas
A ring of bone with anterior and posterior arches and large lateral masses
no body or spinous process
What do the superior articular facets of the lateral masses of the atlas vertbra (C1) articulate with?
They articulate with the occipital bone to form the atlantooccipital joints
What do the inferior articular facts of the atlas (C1) articulate with?
C2 - the second cervical vertebrae called the AXIS
Describe the axis vertebra
has a vertebral body
has an odotoid process - called the dens
what is the process on the AXIS called that projects superiorly through the anterior portion of the vertebral foramen of the atlas?
The odontoid process or DENS
What makes the atlanto-axial joint
the C1 Atlas and the C2 Axis
They articulate between the anterior arch of the atlas and dens of the axis and between their articular facets
What is C7 called?
vertebra prominens
What is C7 vertebra prominens different from C3-C6
has a large, ninbifid spinous process that may be seen and felt at the base of the neck
Difference between t1-t10 and t11 and 12
The spinous process of T1-T10 are long, laterally flattened and directed inferiorly
The spinous process of T11 and T12 are shorter and broader and directed more posteriorly
What facets are unique to the thoracic vertebra (T1-T10, not 11 or 12)?
costal facets
articular surfaces for ribs
What does a demifacet articulate with?
when the head of a rib articulates with two adjacent vertebral bodies
What does a facet articulate with?
one vertebral body and one head of a rib
Joints between ribs and thoracic verttebra are called?
vertebrocostal joints
Largest and strongest unfused bones in vertebral column
lumbar spine
What is the sacrum
a triangular bone formed by union of 5 sacral vetebrae
begin to fuse between 16-18 years old and usually complete by 30
female sacrum is shorter and wide and more curved between S2 and S3 than the male sacrum
This is triangular in shape, formed by the fusion of 4 coccygeal vertebra (Co1-Co4)
usually fuses around 20 -30 years old
the coccyx
Coccygeal cornua
connected by the ligaments to the sacral cornua
What does thorax mean?
Entire chest region
The skeletal part of the thorax?
the thoracic cage
This is formed by the sternum, ribs and their costal cartilages, and the bodies of the thoracic vetebra
Thoracic cage
The flat, narrow bone that is located in the center of the anterior thoracic wall and is about 15 cm and consists of three parts
Sternum (breastbone)
The three parts of the sternum (typically fuse by age 25)
- Manubrium
- body
- xiphoid process
The middle and largest part of the sternum
The Body
The superior portion of the sternum
Manubrium
The inferior part of the sternum
the xiphoid process
Junction of the manubrium and body forms this
sternal angle
the depression on the manubriums superior surface
the suprasternal notch
Lateral notches on the superior surface on the manubrium, that articulate with the clavicles
clavicular notches
What joint is formed by the articulation of the clavicular notches of the manubrium and the clavicles
sternoclavicular joints
What does the xiphoid process consist of until about age 40
hyaline cartilage
Function of xiphoid process
attachment of some abdominal muscles
How many pairs of ribs are there
12
Rib 1-7
increase in length
Rib 7-12
decrease in length
Which ribs have a direct anterior attachment to teh sternum by a strip of hyaline cartilage called costal cartilage?
These are called true ribs
ribs 1-7
the joints between true ribs (1-7) and the sternum with hyaline cartilcage is called
sternocostal joints
What are ribs 8-12 known as since they do not directly articulate with sternum
false ribs
What are vertebrochondral ribs?
ribs 8-10 attch together with cartilage and that aartilage connects them to the 7th rib
What are the false ribs 11 and 12 called?
floating ribs
Why are 11 and 12 called floating ribs?
they do not connect to the sternum indirectly or directly at all
