Back Flashcards
What is the first vertebra?
Atlas C1
What is the 2nd vertebra?
Axis C2
How many cervical vertebrae?
7
What kind of curvature does the cervical portion of the spine has?
Concave posteriorly - Cervical lordosis
What kind of curvature does the thoracic portion of the spine has?
Concave anteriorly - Cervical kyphosis
How many thoracic vertebrae?
12
What kind of curvature does the lumbar portion of the spine has?
Concave posteriorly - Cervical lordosis
How many lumbar vertebrae does the spine have?
5
How many sacral vertebrae does the spine have?
5 fused
How many vertebrae composes the coccygeal region?
variable 3-5
What passes through the intervertebral foramen?
Spinal nerve to enter the spinal cord
What is another name for vertebral facets?
Zygapophyseal joint
What kind of vertebrae often has a bifid spinous process?
Cervical vertebrae
What is the vertebral arch composed of?
pedicles + laminae
What kind of vertebrae has uncinate processes?
cervical
What kind of vertebrae have a transverse costal facet?
thoracic
What part of the spine do stabilizing muscles attach to?
Lumbar
What specific features can we find on lumbar vertebrae?
- Mammilary process
- Accesory processes
- Lumbar transverse process
What kind of vertebrae have a promontory, ala, and anterior and posterior sacral foramina?
Sacral
What kinds of sacral crest does sacral vertebrae have?
Median and lateral
Where can we find the auricular surface
Sacral vertebrae
What kind of vertebrae don’t have intravertebral discs?
C1-C2 and saccral
What are the two parts of an intervertebral disc?
Anulus fibrosus (sclerotome) and nucleus pulposus (notochord)
During compression where does pressure go to in the intravertebral disc?
nucleus pulposus
What is another name for a slipped disc?
Herniated nucleus pulposus (HPN)
During examination, what are we look for in the spinal curvatures?
Check for normal or abnormal spinal curvatures, and may indicate muscle spasms, damage, or fractures
What does atlas C1 supports?
The skull
What is the difference between a facet and a Demi-facet?
Facet: a single rib head articulated with one vertebral body
Demi-facet: a rib head shared between two vertebral bodies
What kind of disc herniation is most common?
Posterior herniation
Where does the nucleus pulposus go during flexion?
posteriorly
Where does the nucleus pulposus go during extension?
anteriorly
What causes excessive thoracic kyphosis?
Osteoporosis and compression fractures
What causes excessive lumbar lordosis?
Pregnancy, carrying access belly fat lack of abdominal muscle tone
What kind of abnormal curvature does scoliosis exhibit?
Lateral
What kind of ligament is locater anterior to vertebrae?
anterior longitudinal ligament
Name the ligaments found posterior to vertebrae
- supraspinous ligament
- interspinous ligament
- Intertransverse ligament
What is the most posterior ligament of the spine?
supraspinous ligament
Name the two ligaments found inside the spine
- Posterior longitudinal ligament
- Ligamentum flavum
Name the Broad midline ligament out from the skull that covers the cervical in upper thoracic spine is processes
Nuchal ligament
Where does the nuchal ligament arises from?
The supraspinous ligament
Why is the nuchal ligament so broad?
It’s the side for multiple muscle attachment at the cervical area of the spine
Name the ligament that holds the head of the rib to the vertebral, facet and Demifacets
Radiate ligament
Where does the costotransverse ligaments found?
Thoracic region
Name the ligament that connects the transverse processes of L4 and L5 to the ilium
iliolumbar ligaments
Which muscles stretch between the C2 and C1 vertebrae?
Suboccipital muscles affecting primarily the atlanto-axial in atlanto-occipital joints
What movement is produced by the atlanto-occipital joint?
Flexion and extension
= yes
What movement is induced by the atlanto-axial joint?
Rotation
What composes the atlanto-occipital joint?
Superior articular facets of the atlas and occipital condyles
Where is CSF found within the spinal cord?
The subarachnoid space
What covers the spinal cord directly?
Pia mater
What is the outermost covering of the spinal cord?
Dura and arachnoid matter
What substance surrounds the vertebral venous plexus in the vertebral canal?
Fat
What kind of neurons are found in the anterior horn of a spinal nerve?
Lower motor neuron cell bodies
What is the gray matter composed off in the spinal cord?
Posterior and anterior Horns
What are the anterior roots made out of?
Lower motor axons
What kind of neurons are found in the posterior horn’s?
Sensory neuron cell bodies
What are the posterior roots made out off?
Sensory axons
What can we find in the posterior root ganglion?
Sensory neuron cell bodies
What is a spinal nerve made out of?
Mixed motor and sensory axons
Where does the anterior rami send information to?
Motor and sensory axons to muscles and skin of anterior trunk and limbs
Where does the posterior rami send information to?
Motor and sensory axons to muscles and skin of the back
What is a dermatome?
Sensory region of the skin supplied by a single spinal nerve
Dermatome C4
Top of shoulder
Dermatome at C6
thumb
Dermatome at C8
Fifth digit of hand
Dermatome at T4
Nipple
Dermatome at T10
Umbilicus
Dermatome at L1
Inguinal region
Dermatome at L4
Medial heel and ankle
Dermatome at L5
Antero-lateral leg in dorsum of the foot
Dermatome at S1
Posterior lateral lower, limb
Dermatome at S2
Posterior medial lower limb
What is a myotome?
Muscle fibers supplied by a single spinal nerve
How many spinal nerves does the cervical region have?
Eight
How many thoracic spinal nerves
12
How many lumbar spinal nerves
5
How many sacral spinal nerves
5
Do spinal nerves, exit the vertebrae superiorly or inferiorly?
Superiorly by the cervical nerves and inferiorly by all the other nerves
What tethers the pia matter, and the spinal cord to the Dura matter?
Denticulate ligaments
When analyzing injury to the spinal cord between two vertebrae, which is spinal nerve is likely to be affected, the superior or inferior one?
Inferior
What is the adequate portion of the spine to perform a spinal tap?
Lumbar
Where does the spinal cord extends to in adults?
L2 vertebrae
What forms the cauda equina?
anterior and posterior roots of the spinal cord
What is the name of the tip of the spinal cord?
Conus medullaris
Where can anesthetic be injected in the spine?
Epidural space, or sacral hiatus
Where can we sample CSF?
Inserting a needle into the subarachnoid space
Where does every spinal nerve exits from the vertebrae?
Intervertebral Foramen
What is radicular pain radiates along?
Dermatome
Difference between radicular and not radicular pain
Radicular pain radiates causes, numbness, tingling and weakness, while non-radicular pain is localized
Which type of back muscle did not originate in the back?
Extrinsic back muscles
Where is the triangle of auscultation and the lumbar triangle found?
In the back made out of extrinsic back muscles
What makes the triangle of auscultation?
Latissimus dorsi, scapula and trapezius
What triangle of the back can we use to look for herniations?
Lumbar triangle
What makes the lumbar triangle?
Latissimus dorsi, iliac crest, external abdominal oblique
List all the extrinsic back muscles
- latissimus dorsi
- Trapezius
- Levator scapulae
- Rhomboid, minor and major
- Serratus posterior inferior
- Thoracolumbar fascia
What is the thoracolumbar fascia?
Acts as aponeurosis for the latissimus dorsi and serratus posterior inferior muscles
What muscles origin from the thoracolumbar fascia?
Erector spinae muscles
What are the proximal attachment of the trapezius?
- External occipital protuberance
- Cervical to mid thoracic spinous processes
What are the distal attachment of the trapezius?
- Clavicle
- acromion
- Spine of scapula
Major functions of the trapezius?
Upper fibers: elevate the scapula
Middle fibers: retract scapula
Lower fibers: depressed scapula
Proximal attachments of the latissimus dorsi?
- Mid thoracic to sacral spinous processes
- Iliac crest
Distal attachment of latissimus dorsi
Intertubercular sulcus (proximal humerus)
Major functions of the latissimus dorsi
- Adduct arm from an abducted position
- Extend arm from a flex position
What are the proximal attachment of the levator scapulae?
Transverse processes of upper cervical vertebrae
What are the distal attachments of the levator scapulae?
Superior angle of scapula
What is the major function of the levator scapulae?
Elevate scapula
What are the proximal attachment of the rhomboid major and minor?
Lower cervical to upper thoracic spinous processes
What is the distal attachment of the rhomboid major and minor?
Medial border of the scapula
What makes a superficial layer of intrinsic back muscles?
Splenius muscles
What is the major function of the rhomboid major and minor?
Retract scapula
What are the two kinds of splenius muscles?
- splenius capitis muscle
- Splenius cervicis muscle
Where does splenius muscles originate?
From cervical and upper thoracic spinous processes
Where does the splenius cervicis muscle attach to?
To the transverse processes of the upper cervical vertebrae
Where does the splenius capitis muscle attaches to?
To the mastoid process and occipital bone
What muscles make the intermediate layer of intrinsic back muscles?
The erector spinae muscle group
1. Iliocostalis
2. Longissimus
3. Spinalis
Where does the Erector spinae muscle group originate from?
The iliac crest, sacrum and superior spinous and transverse processes
List the attachments of the erector spinae muscle group
- Iliocostalis – attach lateral to costal angle
- Longissimus – attach medial to costal angle
- Spinalis - attach to more superior spinous process
What makes the deep intrinsic back muscle layer?
The transversospinalis muscle group
What makes the transversospinalis muscle group?
- Rotatores
- Multidifi
- Semispinalis
Where do the transversospinalis muscle group attached to?
All attach from transverse process two more superior spinous processes
What muscles make the minor deep intrinsic muscles of the back?
- suboccipital muscles
- Interspinalis
- Levatores costorum
- Intertransversarii
What’s a major role of minor deep, muscles of the back?
Involved more with Proprioception than movement
What is proprioception?
When a muscle is in charge of telling the brain about our position when moving – the smaller the muscle, the more proprioceptor
What makes the suboccipital triangle?
- Rectus capitis posterior minor: C1-Skull
- Obliquus capitis superior: C2-Skull
- Rectus capitis posterior major
- Obliquus capitis inferior
What is the Myodural bridge?
Sheet of connective tissue –> originate from –> rectus capitis posterior minor –> pierces the posterior atlanto-occipital membrane –> to the Dura matter
responsible for headaches
Which muscles assist in standing upright?
- Erector spinae
- Multifidus lumborum
- Semispinalis muscles
- Abdominal muscles
- Psoas major
What mature structure originate from ectoderm?
Central nervous system and epidermis
What mature structure originates from endoderm?
Lining of Gut, respiratory and urogenital tracts
White mature structure originates from the mesoderm?
Muscles, bones, connected tissue, fat
What structure in the mesoderm signals the ectoderm to fold to form the neural groove? - neurulation
Notochord
List what makes the trilaminar embryo
- Primitive groove in ectoderm
- Extraembryonic mesoderm
- Embryonic endoderm
What structure is formed by the folding of the neural groove?
Neural tube
What does the neural tube give rise to?
Central nervous system (CNS= the brain, brainstem, and spinal cord)
What does the neural crest cells give rise to?
posterior root ganglia
What gives rise to somites?
mesoderm
What do somites give rise to?
Muscles, bones, and dermis
How many occipital somites?
4
How many cervical somites?
8
How many thoracic somites?
12
How many lumbar somites?
5
How many sacral somites?
5
How many coccygeal somites?
2-3
Name the parts of a somite
- Sclerotome
- Myotome
- Dermatome
What does the sclerotome of a somite give rise to?
vertebrae and axial bones
What does the myotome of a somite give rise to?
muscle of body wall and limbs
What does the dermatome of a somite give rise to?
deep dermis of body
What does the neural tube differentiates to?
It thickens and differentiates into anterior and posterior horns
How do sensory neurons reach dermatomes?
By following motor axons that have reached the corresponding myotomes
Which sign reaches the brain first when a nerve is pinched and why?
Sensory - because sensory axons are on the outside of the nerve
Describe the process of origin of a spinal nerve
anterior horn axon –>myotome
posterior root ganglion axons –> dermatome –> posterior horn
Sclerotomes split in half –> so axons can pass
How do vertebrae develop from sclerotomes?
when sclerotomes divide, the remnants fuse to form vertebrae
Describe intervertebral discs development
These form at the sites of fissures from sclerotomes splitting
- Annulus fibrosus = sclerotome
- Nucleus pulposus = mature remnant of notochord
Where and when chondrification takes place?
In week 6th at the sclerotome and start replacing with cartilage
When are ossification centers developed and what do they replace?
On week 7 and cartilage is replaced by bone at the vertebral body, pedicles and lamina
What part of vertebrae is the last to ossify?
Spinous processes
What happens with ossification in spina bifida?
Ossification fails or the spinous process does not form at all
What can you test in utero to determine if baby has spina bifida?
test for alpha-fetoprotein in maternal blood
Spina bifida oculta
neural arch - spinous process fail to ossify
defect is not large
Meningocele
Type of spina bifida when meninges and CSF herniate through hole left by failed neural arch
Meningomyelocele
Type of spina bifida when meninges, CSF, spinal cord and roots herniate
Rachischisis
Type of spina bifida where neural tube fails to fold properly = neural arch cannot form
Why does the spinal cord end at L2?
Because the growth after the embryonic stage increases to the point the spinal cord cannot keep up
Which myotomes and dermatomes migrate to upper limb bud?
From C4-T2 region
Which myotomes and dermatomes migrate to Lower limb bud?
From L4-S3 region
Do limb bones come from somites?
No, they come from lateral mesoderm
Define the cause of syndactyly
Caused by the failure of apoptosis of the interdigital areas that carve out the digits
Define the cause of sirenomelia
Failed formation of rescind of tail segment resulting in fusion of the rear limb buds
Define the cause of muscle agenesis
Failure of anterior rami to form complex plexi before reaching target muscles.
The muscles resulting from this process fail to form
Define the cause of Amelia and phocomelia
When the FGF8 gene in not produced or expressed = limbs dont form (amelia) or are disrrupted (phocomelia)
Define de cause of polydactyly
Mutation in the Shh gene interferes with signals in the medio-lateral patterning that defines number or pattern of digits
