Lecture 3: Axial Skeleton Flashcards
What are the 5 regions of spine
1.Cervical
2. Thoracic
3. Lumbar
4. Sacral
Coccygeal
How many vertebrae in cervical region?
7
How many vertebrae in thoracic region?
12
How many vertebrae in lumbar region?
5
How many vertebrae in sacrum?
1! it is 5 fused together before birth
How can we classify curvatures of spine?
in two ways:
A)
1. primary- present at birth (thoracic, sacral)
2. secondary- not present at birth (cervical, lumbar)
B)
1. Dynamic- can change based on body position (cervical, thoracic, lumbar)
2. Static- can’t change (sacral)
what is the purpose of dynamic curvatures?
INCREASE resistance of vertebral column against compressive forces up to 10 fold!
When does a baby acquire cervical curvature?
when it can hold its head/neck
3 months
when do we acquire lumbar curvature
when begin walking. 18 mnths
Kyphosis
exaggeration of thoracic curvature only
Lordosis
exaggeration of lumbar/cervical curvature
Scoliosis
: side curvature develops in spine or vertebral column
when is scoliosis considered a pathology?
above 5 degrees
btw 5-30= physio
above 30 = surgery
Vertebral foramina
contain CSF
when u stack vertebrae, these foramina form the vertebral canal. in the middle of a typical vertebra
what is the vertebral arch composed of?
- Pedicle: thick piece of bone
- lamina: flat, thin bone
also has bony processes attached on both sides (transverse processe)
Where the two laminae join together = spinous process = palatable for most vertebrae
transverse process articulate with costal tubercle of rib
spinous process
where two laminae join together. can feel this on most vertebrae
articular process
connect adjacent vertebrae
typical vertebrae have superior and inferior articular process
articular facet
smooth concave surface of process
what features does a typical cervical vertebra have?
Bifid spinous process (split in 2)
Transverse forman on transverse process. an artery travels through theseq
Atlas
first cervical vertebra
ATYPICAL
no vertebral body, instead it has an anterior arch
instead of vertebral arch, have a posterior arch
lateral masses where anterior and posterior arches join. on these are articular facets which articulate CI to occipital bone (occipital condyle) and CII
CII
spinous process is almost bifid
has dens: process whicih projects from body of CII superiourly, articulates with atlas
=axis of rotation btw CI and CII
unique features of thoracic vertebrae
spinous process is very long and points inferiourly
unique features of lumbar vertebrae
large body
relatively short spinous process
sacrum
○ 5 bones fused. Remnants of 5 pieces is visible by the transverse ridges (remnants of intervertebral discs which have ossified (turned into bones) no more sign of discs, just horizontal ridges)
○ Body of SI at top, other ridges repesent SII, SIII, SIV, SV
○ Sacral Ala (means wing)- two wings on each side
○ Apex= distal end
○ Superior border of SI is Sacral Promontory (means nose) promotes into pelvic cavity****
§ Promontory is border of SI INTO PELVIC CAVITY
○ Foramina = exit point of spinal nerves. Present in front and back -= ANTERIOR or POSTERIOR SACRAL FORAMINA (depends on view)
transverse ridges
(remnants of intervertebral discs which have ossified (turned into bones) no more sign of discs, just horizontal ridges)
3 main parts of sternum
- Manubrium-top
- Body
- Xiphoid process- most distal
jugular notch
above manubrium
- pt at which manubrium articulates with body
- horiztonal ridge
sternal angle
below jugular notch
where trachea ends
where aorta makes big arch
horizontal plane thru passes thru TIV and TV disk
true ribs
first 7 pairs
directly articulate with sternum
false ribs
bottom 5 pairs
3 still connect to sternum via cartilage of rib 7
free ribs
last 2 ribs which have no attachment to sternum
costal angle
point at which rib bends sharply
Costal groove
inferior border of body. Shallow groove
○ Nerves and blood vessels travel thru groove
- Head of rib
articulates with 2 vertebrae
costal tubercle
carries an articular facet, which articulates with transverse process of thoracic vertebra
which vertebrae is this
atlas
CI
which vertebrae is this
cII
dens
Articulates with atlas
Enables us to rotate our neck
Dens = axis of rotation between CI and CII
what type of vertebrae is this
thoracic
which type of vertebrae is this
lumbar
left side-sacral ala
right side-sacral promontory**border into pelvic cavity
what is the distal end of the sacrum called
apex
articulates with coccyx
left=auricular surface. articulates wit hip
right- sacral canal
left=sacral crests
right=posterior sacral foramina
l=sacral hiatus
r=coccyx
top to bottom:
1. manubrium
2/ body
3/ xiphoid process
sternal angle
xiphesternal joint
jugular notch
2 inches below jugular notch= sternal angle ** VERY IMPORTANT
* Sternal angle is where trachea ends
* Where aorta makes a big arch
* If u pass horizontal plane through sternal angle it passes through intervertebral disc of TIV and TV DISK
label these and which type of vertebrae is this?
thoracic
top:
left= transverse process
right= costal tubercle
bottom
left=body
right=head
