Axial Skeleton: Vertebral Column and Thoracic cage
What is the sternum?
"breastbone", it's an elongated, "sword-shaped" bone that forms the anterior midline of the thoracic wall.
which transverse processes contain rib attachments?
(T1-T10)
what are the 7 processes that arise from the vertebral arch?
1 spinus process, 2 transverse, 2 superior articular processes and 2 inferior
How many pairs of ribs are there?
12
How many thoracic vertebrae are there?
12 (T1-T12)
When does the sacrum become completely fused?
25
how many movable parts are in your vertebral column
26
How many vertebrae are there?
33
How many coccygeal vertebrae are there?
4 (Co1-4)
how many spinal curves are in your vertebral column and what are they?
4; cervical curvature, thoracic curvature, lumbar curvature, and sacral curvature
How many lumbar vertebrae are there?
5 (L1-L5)
How many fused vertebrae make up the sacrum?
5 (S1-S5)
How many cervical vertebrae are there?
7 (C1-C7)
Anatomy of hanging
A hangman's knot is ideally placed behind the ear on one side of the head so when the person to be executed galls through the trapdoor of the gallows, the sideways pressure will dislocate or fracture the cervical vertebrae, sever the spinal cord, and cause rapid death.
What are costal notches?
A single pair represent articulations for the first ribs' costal cartilages
Which cervical vertebrae has superior articular facets?
C1--atlas
Which cervical vertebrae lacks a spinous process?
C1--atlas
Which cervical vertebrae have inferior articular facets?
C2-C7
What are ribs 8-12?
False ribs, because their costal cartilages, if present, do not attach directly to the sternum. The costal cartilages or 8-10 fust to the costal cartilage of rib 7, and thus indirectly articulate with the sternum.
What are ribs 11-12?
Floating ribs (and false ribs) bceause they have no connection at all with the sternum
What is paradoxical motion?
Fractured segment of ribs moves in an opposite direction from the rest of the chest wall
What happened to Christopher Reeves?
He got injured in a horseback riding accident and became paralyzed from the neck down. He died from bed sores or decubitus ulcers
What was wrong with Otzi's ribs?
He lacked a 12th pair of ribs--T12 was vestigial. It didn't impair him in any way. Rib fractures were observed on both sides: while that on the right side had healed, the fractures on the left side were recent.
What are the unique features of C2?
It has the odontoid process, or dens, which is a superior peg-like projection. This projection acts as a pivot for the rotation of both the atlas and the skull in a side-to-side motion.
What is the coccyx?
It's composed of four small vertebrae that become fused at about 25 years of age to form a triangular shaped structure. It serves as an attachment site for several ligaments and some muscles. In very old individuals the coccyx may fuse with the sacrum.
What happens if you break your xiphoid process?
Most likely you'll have an injury to your liver or heart
Can you have a L6 vertebrae?
Rarely. Occasionally, the L6 vertebra can become sacralized, or attached to the sacrum by a rudimentary joint that creates additional motion, and therefore greater potential for motion-related stress that can lead to lower back pain, herniated disc, osteoarthritis, or spinal stenosis
atlanto-occipital joint
The articulation between the occipital condyles and the atlas, allows us to nod "yes"
What are the largest vertebrae in the body?
The lumbar (L1-L5), they are easily identified by their heavy bodies and thick. blunt spinous processes used for attachment by powerful back muscles.
Jugular notch
The shallow bony curve between the clavicular notches, just superior there is a depression in the skin called the suprasternal fossa
What forms the thoracic cage?
The thoracic vertebrae posteriorly, the ribs laterally, and the costal cartilages and sternum anteriorly
What are transverse foramina?
The transverse process of the first 6 (sometimes 7th) cervical vertebrae are unique because they contain prominent round foramina, which provide a bony passageway for the vertebral arteries and veins that serve the brain.
What is spina bifida?
This is a congenital defect of the vertebral column resulting from a FAILURE OF THE LAMINAE OF VERTEBRAE TO FUSE, exposing the meninges, spinal cord, or both. The lumbar area is mainly affected, often with only a single vertebra involved. Over 50% of these defects can be prevented!
What are ribs 1-7?
True ribs, because they connect individually to the sternum by separate cartilaginous extensions called costal cartilages
What is the name of C7?
Vertebra prominens, because its relatively large and long spinous process (which is typically not bifurcated) is easy seen and palpated through the skin where the neck connects with the torso.
What is Flail Chest?
When 3 or more adjacent ribs are fractured, each in TWO places, the segment of the chest wall between fractures becomes a free-floating segment. The injured area demonstrates paradoxical motion. This injury is particularly dangerous because the underlying lungs may be damaged.
What are the costal demifacets of the thoracic vertebrae for?
When the head of a rib attaches between two thoracic vertebrae, a portion of the facet will be on the body below.
How does whiplash occur?
When the stress is too great on the cervical vertebrae, causing possible injury with damage to the muscles and ligament and potential injury to the spinal cord.
Nucleus Pulposus has...
a high water content
"Thin layer" of the vertebrae
arched laminae
Spinal taps
are used to collect spinal fluid and are typically preformed by inserting a needle between L3 and L4 (also a common site for epidurals)
When does the xiphoid process ossify?
around age 40
The tubercle of the rib...
articulates with costal facet on the transverse process of a thoracic vertebra (except for ribs 11 and 12, which lack tubercles)
What is the atlantoaxial joint?
articulation between the atlas and axis
What is C2's name?
axis
What can be used to treat lumbar pain?
bed rest, spinal manipulation by a chiropractor, and back and abdominal exercises to strengthen postural muscles. Surgery is the last resort!!!
Where are the most common rib fractures?
between ribs 3-10
Vertebral Arch (Neural Arch)
composed of pedicles, laminae, and a spinous process, it represents the junction of all posterior extensions from the vertebral body
What makes thoracic vertebrae unique?
costal facets/costal demifacets on the lateral sides of the body and on the lateral sides of the transverse processes
The cervical vertebrae...
form the flexible framework of the neck region and support the head and are bifid. This allows for the nuchal ligament to fall centrally.
vertebral canal
formed by vertebral column and contains spinal cord and the beginnings of spinal nerves
The vertebral end of a rib typically articulates with the costal facet (or demifacet) of a thoracic vertebra by the...
head of the rib
The angle of the rib...
indicates the site where the tubular shaft beings curving anteriorly towards the sternum
which processes interlock with the superior articular processes adjacently?
inferior articular processes
The neck of the rib...
is between the head and the tubercle--it is constricted
Fractures of the vertebrae can occur following...
lateral displacement or following compression
intervertebral foramina
lateral openings between adjacent vertebrae for spinal nerves
What are the three parts of the sternum?
manubrium, gladiolus, xiphoid process
What the auricular surface of the upper lateral portions of the sacrum do?
marks the site of articulation with the os coxae of the pelvic girdle, forming the strong, nearly immovable sacroiliac joint
what does the spinous process do?
muscle attachment
what is the purpose of transverse processes?
muscle attachment and rib attachment for T1-T10
What is spinal stenosis?
narrowing of the vertebral canal and pressure on the spinal nerves
"small foot" of the vertebrae
pedicles
What is the purpose of the thoracic cage?
protect vital organs--such as the heart, lungs, trachea and esophagus. It provides attachment points for muscles supporting the pectoral girdle, the chest, neck, the shoulders, the back and muscles involved in respiration. Hematopoiesis occurs in the ribs, vertebrae and the sternum.
what are the functions of the vertebral column
protects the spinal cord, supports the head and body, helps maintain upright position, helps transfer weight to appendicular skeleton, provides pathway for spinal nerves to connect to spinal cord, attaches to skeletal muscles of the back
What is the Latin word for sacrum?
sacred bone, thought to be where the soul resides
Thoracic Vertebrae (T1-T12) typically have a spinous process that...
slant obliquely downward
what projects posteriorly and inferiorly from the laminae of the vertebral arch?
spinus process
what is lumbar pain caused by?
strained muscles (most common cause), herniation of the cartilage disc between lumbar vertebrae (most frequently between L4/L5 or L5/S1), dislocation of articular facets between two vertebrae, etc.
which processes interlock with the inferior articular processes adjacently?
superior articular processes
what does breaking of femur indicate when old?
that you are probably gonna die soon within the next year. cause your bones start to go down cause you get down
What is the body of the vertebrae?
the anterior portion which is the weight bearing structure also where the intervertebral disc is attached
what do the superior and inferior articular processes do?
the interlocking limits the twisting of the vertebral column
What are intervertebral discs?
these discs are composed of an outer ring of fibrocartilage (ANULUS FIBROSUS) and an inner circular core with a gelatinous consistency (NUCLEUS PULPOSUS). Make up approximately 1/4 of the height of the entire vertebral column. They act as shock absorbers and allow for flexibility between vertebrae, and also allow the vertebral column to bend.
What are the costal facets on the body of thoracic vertebrae for?
they are the sites where the head of each rib attach to the body
What are the costal facets on the transverse process of the thoracic vertebrae for?
they are the sites where the tubercle of each rib attaches to the transverse process.
what protrudes laterally from the vertebral arch?
transverse processes
hollow space formed by the neural arch and the body
vertebral foramen
If you traumatize above C3 in your spinal cord...
you can't breathe and will be paralyzed from the neck down