Quiz 2- Lectures 5-6 Flashcards
cervical spine (lordosis/kyphosis)
lordosis
thoracic spine (lordosis/kyphosis)
kyphosis
lumbar spine (lordosis/kyphosis)
lordosis
sacral spine (lordosis/kyphosis)
kyphosis
lordosis: define
normal inward CONCAVE curvature of the lumbar and cervical regions of the human spin
kyphosis: define
normal outward CONVEX curvature in the thoracic and sacral regions; means “bent backward”
fetus: spinal stage
primary curve; large curve
newborn: spinal stage
start seeing concavity in POSTERIOR CERVICAL region and in lumbar region; when patient starts holding up their head, the curves become more pronounced
why doesn’t it take much muscular activity to keep adult body upright?
line of gravity passes through curve of vertebral column
two main segments of the typical vertebrae
arch and body
orientation of facets: cervical
oblique/ horizontal plane
orientation of facets: thoracic
coronal plane
orientation of facets: lumbar
sagittal plane
describe LUMBAR vertebrae
(shape, superior/inferior surfaces, and discs)
- shape: kidney bean vertebral bodies
- superior/inferior surfaces of L1-L3 are parallel**, and L4/L5 are **wedge-shaped
- Discs are wedge-shaped and contribute to most typical lumbar curve (lordosis)
describe venous drainage of vertebrae
*(check)
- basivertebral veins
- anterior & posterior external vertebral venous plexus
- anterior & posterior internal (epidural) vertebral venous plexus
basivertebral veins
- emerge from the foramina on the posterior surfaces of the vertebral bodies.
- communicate through small openings on the front & sides of vertebral bodies with the anterior external vertebral plexuses, and converge behind to the principal canal, and open by valved orifices into the transverse branches which unite the anterior internal vertebral plexuses
ANTERIOR EXTERNAL vertebral venous plexus
- lie in front of the bodies of the vertebrae
- communicate with the basivertebral and intervertebral veins
- receive tributaries from the vertebral bodies
- In cervical region, these anastomose with the vertebral, occipital, and deep cervical veins
POSTERIOR EXTERNAL vertebral venous plexus
- placed partly on the posterior surfaces of the vertebral arches and their processes, and partly between the deep dorsal muscles.
- In cervical region, these anastomose with the vertebral, occipital, and deep cervical veins
ANTERIOR INTERNAL vertebral venous plexus
- consist of large veins on the posterior surfaces of vertebral bodies and IV fibrocartilages on either side of the posterior longitudinal ligament (PLL);
- under cover of PLL they are connected by transverse branches into which the basivertebral veins open
- opens into the vertebral veins and is connected above with the occipital sinus, the basilar plexus, the condyloid emissary vein, and the rete canalis hypoglossi.
POSTERIOR INTERNAL vertebral venous plexus
- one on either side of the middle line in front of the vertebral arches and ligamenta flava
- anastomose by veins passing through those ligaments with the posterior external plexuses.
- opens into the vertebral veins and is connected above with the occipital sinus, the basilar plexus, the condyloid emissary vein, and the rete canalis hypoglossi.
how many processes are there?
what if you include the mammillary processes?
7 processes; but 9 total if you count the mammillary processes
what are the 7 articular processes on the vertebrae?
1 spinous process
2 transverse processes,
4 articular processes (=2 superior/2 inferior)
which processes “arise from junction of pedicles & laminae, except for L5”
transverse process
how do transverse processes change in the lumbar region?
From L1-L3:increasein size fromL1-L3, whereas
L4/L5: decrease in size of transverse processes
where does transverse process arise?
from the vertebral body
where are articular processes located?
at junction of pedicle and lamina
what muscle attaches to the mammillary processes?
multifidous muscle
- (consists of a number of fleshy and tendinous fasciculi, which fill up the groove on either side of the spinous processes of the vertebrae, from the sacrum to the axis.
- Very thin but importnat in stabilizing the joints within the spine.
- One of the transversospinales)
which direction do the following face?
superior articular facets
face medially
which direction do the following face?
inferior articular facets
face laterally
in which plane do the articular facets lie?
sagittal/median plane
how do superior and inferior articular processes differ?
- Spacing: superior articular proc. are further apart (except L5) than inferior articular processes
- Facet Orientation:
- Superior articular facets: face MEDIALLY
- Inferior articular facets: face LATERALLY
How is L5 different than the other lumbar vertebrae?
- largest body
- *wedge-shaped body
- *INF. ARTIC. PROC. are further apart than superior
- transv. proc (TP): thick, arise partly from vertebral body; and shortest TP
- spinous processes: shortest, but thickest
- narrow lateral recesses
- INF ART Facets (IAF): oriented in frontal/coronal plane, whereas the SAF are mostly oriented sagittally
*Movement is possible at L5 due to position of facets
boundaries of vertebral foramen
- formed by the anterior segment (the body),
- and the posterior part, the vertebral arch:
- Pedicle
- Transverse process
- Laminae
- Spinous process
what is shape of LUMBAR vertebral foramina?
triangular in shape; often w/ sharp lateral recesses (esp. L5)
CC: osteoarthritic lipping around vertebral bodies posteriorly can cause…
lateral or central spinal stenosis (narrowing of vertebral canal)
the contents of the vertebral canal or intervertebral foramen can be compressed
CC: Facet joint hypertropy (facet syndrome, osteoarthritis) anteromedially can cause…
lateral spinal stenosis; and anteriorly in foraminal stenosis
the contents of the vertebral canal or intervertebral foramen can be compressed
CC: Spondylosis
(What is it, and what are the sxs)
- any degenerative osteoarthritic change in the spine
- causes impingement upon contents of spinal canal or intervertebral foramen
CC: Lumbar spondylosis w/o acute disc herniation
how common?
nearly as common cause of lumbar nerve root encroachment as disc disease (particularly in the elderly)
In L3/L4, why is there a large interlaminar space between adjacent laminae?
Because laminae in the lumbar region are *not as tall as the vertebral bodies
describe the lumbar spinous processes of L3/L4;
what is the clinical implication?
- lumbar spinous processes are stout, squared off, and do not overlap; these project straight posteriorly
- CC: these make the lumbar spine a good level to do a spinal tap or lumbar puncture
what are the red arrows pointing to? green arrows?
Red arrows: intervertebral foramen
Green arrow: pedicle
boundaries of intervertebral foramen
anterior: disc & body of vertebrae
roof/floor: pedicles
posteriorly: facet joints
posterior longitudinal ligament
- Syndesmosis of vertebral body
- Found w/in vertebral canal, extends along posterior surfaces of bodies of the vertebrae
- Prevents hyperflexion of vertebral column
- Hourglass shape: more narrow at the vertebral bodies and wider at the intervertebral disc space which is more pronounced
CC: plays a role in spinal disc herniation; much weaker than anterior longitudinal ligaments
CC: herniated discs
- the disc involved with be the disc above the vertebrae of the same name/number as the affected spinal nerve
development of vertebrae: week 6
by end of 6th week, there is mesenchymal primordium and chondrification centers form –> then it forms cartilaginous vertebrae
development of vertrebae: weeks 9-10
- ossification center for neural arch
- ossification in costal processes
- and ossification center for vertrebal body (centrum)
Based on cartilaginous model of vertebrae
development of vertebrae: at term
ossified: vertebral body, rib, and most of arch
*CARTILAGINOUS SPINE remains
lumbar vertebrae development:
when do ossification centers for arch and body form?
Ossification center appears in 9-10th week, and vestige of notochord remains w/in body
when do the superior/inferior annular epiphysis of lumbar vertebrae fuse?
around age 20 y/o
CC: transitional lumbosacral vertebrae
abnormal fusion of vertebrae in which S1 vertrebrae is partly free; could also have L5 be prtly fused to sacrum
CC: maldeveloped sacrum
left side of sacrum is imperfectly developed
CC: spina bifida
“split spine”; result of nerual tube defects and problems in develpoment of spine
*occulta = “hidden”, aperta = “open
Factors include genetics and environment (deficiency of folic acid)
sacrum: ventral (pelvic) surface
- faces anterioinferiorly,
- concave
- trasnverse ridges are remnants of IV joints
- ventral rami (S1-S4) travel through paired ventral foramina
- lateral parts represent fused transverse processes & costal elements
sacrum: dorsal surface
- faces posterosuperiorly
- convex
- rough/narrow
- Surface features:
- median sacral crest
- sacral groove
- sacral hiatus
- intermediate sacral crest
- lateral sacral crest
- (Dorsal sacral foramina transmit dorsal rami of S1-S4)
what connects the dorsal and ventral sacral foramina to the sacral canal?
intervertebral foramen
lateral surface features of sacrum
auricular surface and tuberosity
(sacroiliac joint (auricular surface; ear-like shape) is the articulation between the sacrum and the os coxae.
how many primary and secondary ossification centers have been identified in sacrum?
58 total, and 35 of which are held constant
pelvic girdle (axial or appendicular)
appendicular skeleton
bony pelvis (axial or appendicular)
BOTH (bc os coxae are appendicular, and sacrum/coccyx are axial)
name the 3 parts of the hip bone; when do these fuse?
3 bones: ilium, ischium, pubis
Fuse during adolescence (forming synostosis)
Prior to fusion, the joints are cartilaginous (synchondroses)
joints between 3 parts of the hip bone
Prior to fusion, the joints are cartilaginous (synchondroses)
Fuse during adolescence (forming synostosis)
2 parts of ilium
- ala (wing)
- body (contributes to acetabulum - lunate surface and fossa & has a pelvic part as well)
2 sides of BODY of ilium
external (acetabular)
internal (pelvic)
on which bone(s) is the arcuate line of the pelvic inlet?
on the ilium and part of pubis bones
(*though TECHNICALLY, the part on the pubis is called the “pectin pubis”, and the arcuate line + pectin pubis is called hte iliopectineal line)
2 sides/surfaces of ALA of ilium
internal (pelvic)
external (gluteal)
auricular surface of the ilium
The anterior surface (auricular surface), so called from its resemblance in shape to the ear, is coated with cartilage in the fresh state, and articulates with a similar surface on the side of the sacrum.
2 key ligaments we focused on that attach to the ILIUM?
- sacroILIAC
- sacroTUBEROUS
interossesous sacroiliac ligament
- **It is the strongest ligament in the body
- lies deep to the posterior ligament
- consists of a series of short, strong fibers connecting the tuberosities of the sacrum and ilium, which keeps sacrum and ilium together
- nearly horizontal direction of fibers from sacrum to ilium
which is strongest ligament in the body?
interosseous sacroiliac ligament
sacrotuberous ligament
- Situated at the lower and back part of the pelvis
- Flat, and triangular in form; narrower in the middle than at the ends
- Runs from sacrum to tuberosity of the ischium (remnant of biceps femoris muscle)
- contains the coccygeal branch of the inferior gluteal artery
clinical significance of sacrotuberous ligament
If the pudendal nerve becomes entrapped between this ligament and the sacrospinous ligament causing perineal pain, the sacrotuberous ligament is surgically severed to relieve the pain.
Which is the anteroinferior part of the os coxae?
pubis, which is fused internally and externally w/ ilium and ischium
pubis has 3 parts. what are they?
- body
- superior ramus
- inferior ramus
which part of PUBIS has both ventral and dorsal sides/surfaces, in addition to internal (pelvic) and external sides?
only the BODY of the pubis has ventral/dorsal sides/surfaces;
but all parts of pubis have internal and external sides
which parts of the pubis have internal (pelvic) and external sides?
all parts of pubis
(body, superior rami, inferior rami)
the inferior ramus of the pubis is not unique, but what is the ischiopubic/conjoined ramus?
the inferior pubic ramus and ischial ramus fuse to form conjoined/ ischiopubic ramus
superior pubic ramus and landmarks
- pectin pubis (of iliopectineal line)
- pubic tubercle
- pubic crest
- obturator groove
- obturator crest
obturator groove (w/in membrane, contributes to obturator cana) & helps transmit
obturator nerve, artery, and vein into medial thigh
2 parts of ischium
- body - large and incl part of acetabulum and ischial tuberosity
- ramus - part of conjoined ramus
obturator groove: part of which bone, and what does it transmit
- a groove in the inferior surface of the superior ramus of the pubis
- converted to the obturator canal when covered over by part of the obturator membrane; and the obturator canal is patent opening that transmits obturator nerve, artery, vein, into medial thigh)
which parts of the ischium have internal (pelvic) and external (femoral) facing sides?
both the BODY and the RAMUS have the internal/external sides/surfaces
acetabulum: what is it, and which bones contribute?
- “little vinegar cup”; concave surface of a pelvis.
- the head of the femur meets with the pelvis at the acetabulum, forming the hip joint
- Lunate surface (of acetabulum): incl. ilium, ischium, and pubis (not a complete circle
- Acetabular fossa is surrounded by lunate surface, and the acetabular notch forms bc the lunate surface is not a complete circle
Development of os coxae: comparing at birth to 12-13 y/o pt
Key concepts
- Lots of bone in ilium at birth, and less bone in ischium and pubis at birth
- Week of gestation during which ossification centers develop (9th - ilium, 15th- ischium, 20th- pubis)
- Some 2º ossification centers that develop in puberty (approx 12-13 y/o) –> usually fused by mid-20s (except for end of clavicle, which fuses a bit later)
