vertrebal column Flashcards
(14 cards)
the vertebral column
The spinal vertebrae, also known as the vertebral column or spine, is a long, flexible structure that extends from the skull, which it supports, down to the pelvis, where it helps transfer the body’s weight to the lower limbs.
It is made up of 26 irregular bones called vertebrae, which are reinforced by ligaments to allow flexibility and maintain its curved shape, rather than being stiff or rigid.
The spinal cord, a delicate and vital part of the nervous system, runs through a central cavity in the vertebrae, and the vertebral column surrounds and protects it.
used to be 33 vertabrae
Before we were born, we had 33 vertebrae.
Later, 9 of those bones fuse together to form two parts of the lower spine:
The sacrum (made of 5 fused vertebrae)
The coccyx (made of 4 fused vertebrae)
That leaves 24 individual vertebrae, which are:
7 cervical vertebrae (in the neck)
12 thoracic vertebrae (in the upper and middle back)
5 lumbar vertebrae (in the lower back)
invertable discs
Basically, each vertebra is separated by an intervertebral disc, which is made of fibrocartilage. These discs:
Protect the vertebrae
Absorb shock
Cushion the spine
In young people, the intervertebral discs contain about 90% water, making them soft, spongy, and flexible.
As we age, the water content decreases, and the discs become harder and less flexible, which can lead to stiffness or discomfort.
herinated discs
Older people are more likely to get herniated discs because their intervertebral discs dry out and the spinal ligaments weaken with age.
However, younger people can also get herniated discs if they do excessive twisting or put too much pressure on their spine.
A herniated disc happens when the soft part of the disc bulges out and presses on nearby spinal nerves or the spinal cord.
This can cause:
Tingling
Numbness
Excruciating pain
primary and secondary curves
Basically, the primary curves of the spine are the thoracic and sacral curves because they are present from birth.
When a baby lifts their head, the cervical curve develops.
When the baby starts walking, the lumbar curve forms.
These secondary curves help the body balance its weight over the legs.
sciolosis khyoiosis and lordosis
Were you ever given a “spine check” in middle school? There are several types of abnormal spinal curvatures that can be identified by simple observation. Three of these are scoliosis (sko″le-o′sis), kyphosis (ki-fo′sis), and lordosis (lor-do′sis). These spinal abnormalities may be congenital (present at birth) or may result from disease, poor posture, unequal muscle pull on the spine, or injury. Generally, unless there is a congenital problem, young healthy people have no skeletal problems, assuming that their diet is nutritious and they stay reasonably active. As you look at these photos, try to pinpoint how each of these conditions differs from a normal healthy spine. The usual treatments for these abnormal curvatures are braces, casts, or surgery.
features of the vertabrae
Body (Centrum):
The thick, disc-shaped part of the vertebra that bears weight and faces anteriorly (toward the front).
Vertebral Arch:
Formed by the joining of the laminae and pedicles (posterior extensions) coming off the vertebral body, creating an arch.
Vertebral Foramen:
The canal or hole through which the spinal cord passes.
Transverse Processes:
Two lateral (side) projections that extend from the vertebral arch.
Spinous Process:
A single posterior (back) projection from the vertebral arch formed by fused laminae.
Superior and Inferior Articular Processes:
Paired projections on either side of the vertebral foramen that form joints with adjacent vertebrae.
atlas c1
Atlas (C1) has no body. Its transverse processes have depressions that hold the occipital condyles, allowing us to nod “yes.”
axis c2
The axis (C2) acts as a pivot for the atlas (C1) and the skull. The dens, a process on the axis (C2), serves as the pivot point. The joint between the atlas (C1) and the axis (C2) allows us to rotate our head from side to side to say “no.”
cevical c3 to c7
Basically, the cervical vertebrae C3 to C7 are the smallest and lightest vertebrae. They usually have a split (bifid) spinous process with two branches. Each has a foramen (a hole) in the transverse process that allows arteries to pass through on their way to the brain. Whenever you see these foramina, you know it’s a cervical vertebra.
spinal vertabrae
There are 12 thoracic vertebrae, all considered typical.
They are larger than the cervical vertebrae.
Unique because they are the only vertebrae that connect (articulate) with ribs.
Their body is somewhat heart-shaped.
Each side of the body has two costal facets (joint surfaces) that connect with the heads of the ribs.
The transverse processes articulate with the tubercles (small knobs) of the ribs.
The spinous process is long and points sharply downward, giving the vertebra a shape like a giraffe’s head when viewed from the side.
lumbar
Basically, the lumbar vertebrae go from L1 to L5. They have block-like bodies shaped somewhat like kidney beans and are located at the lower part of the spine. Because they support most of the body’s weight, they are the sturdiest vertebrae.
sacrum
The sacrum (sa′krum) is formed by the fusion of five vertebrae (Figure 5.19). Superiorly it articulates with L5, and inferiorly it connects with the coccyx. Each winglike ala articulates laterally (at the auricular surface) with the hip bone, forming a sacroiliac joint. The sacrum forms the posterior wall of the pelvis. Its posterior midline surface is roughened by the median sacral crest, the fused spinous processes of the sacral vertebrae. This is flanked laterally by the posterior sacral foramina. The vertebral canal continues inside the sacrum as the sacral canal and terminates in a large inferior opening called the sacral hiatus.
cocyx
Formed by the fusion of 3 to 5 tiny, irregular vertebrae.
Known as the human “tailbone.”
It is a vestigial structure, meaning it’s a leftover from evolution—a remnant of the tail found in other vertebrate animals.
