Lecture 5: Back Flashcards
4 functions vertebral column
- Protection: encloses and protects the spinal cord within the spinal canal
- support: carries weight of body above pelvis
- Axis: forms the central axis of the body
- Movement: rods in both posture and movemeent
5 Divisions
- cervical (7)
- Thoracic (12)
- Lumbar (5)
- Sacrum (5, fused)
- coccyx (4 fused)
Normal Curvatures of the back (4)
- cervical concavity (lordosis)
- Thoracic Convexity (kyphosis)
- Lumbar concavity (lordosis)
- Sacral Convexity (kyphosis)
Lordosis
inward curvature of the spine
Kyphosis
outward curvature of spin
Abnormal curvature of spine (3)
- kyphosis
- scoliosis
- lordosis
Abnormal curvature: Kyphosis
excessive outward curvature of spine, utusllay T spine
-hunchback
Abnormal curvature: solciolosis
abnormal *lateral curvature of the spine
-test for this in school -aged children
Abnormal Curvature: Lordosis
excessive inward curvature of the spine
-usually L spine
*swayback
C spine (4)
- C1-C7
- C1= atlas: holds head on neck
- C2= Axis: where the head turns on the neck providing axis of rotation
- Dens: projects superiorly attaching it to the atlas and functions as a pivot, permits rotation - fairly mobile portion of the spine
**Concave/lordosis
Dens
projection on Axis (C2) supperiorly attaching it to the atlas and functions as a pivot that permits rotation
Joints unique to C spine (2)
- Atlanto-occipital
- Atlanto-axial
* both synovial
Atnlanto-Occipital
between the atlas and the occipital bone
-allows you to nod “yes”
Atlanto-axial
between the atlas and the axis
allows you to shake “no”
C spine ROM (4)
- flexion (bend head forward, look down)
- Extension (look up)
- Lateral flexion (ear to shoulder)
- Roatary movements: left and right
T spine (3)
- thoracic spine composed of 12 vertebrae
- 12 pairs of ribs articulate with thoracic vertebrae
- this region of the spine is more rigid and inflexible than the cervical region
* convex kyphosis
L Spine (3)
- 5 lumbar vertebrae
- comparatively large for bearing weight of trunk
- fairly motile, but not nearly as mobile as the cervical vertebrae
* concave/lorsosis
Lumbar Puncture
purpose
where?
- cerebrospinal fluid may be sampled and examined clinically by lumbar puncture/spinal tap
- spinal needle inserted into the subarachnoid space of the lumbar cistern in midline
- between L3 and L4 or L4 and L5 vertebral spinal processes - because the spinal cord ends at approximately the L1 or L2 vertebral level, the needle will not pierce and damage the cord**
Epidural
Purpose
Where?
- anesthetic agents may be directly delivered into the epidural space (above the dura mater) to anesthetize the nerve fibers of the caudal equine; this common form of anesthesia is used during childbirth in most western countries
- epidural anesthetic infiltrates dural sac to reach the nerve roots and its usually administered at the same levels as the lumbar puncture
Sacrum (3)
- collection of 5 fused vertebra
- inverted triangle
- apex point inferiorly - lateral walls facets for articulation with pelvis as sacroiliac joints
- remember it is convex/kyphosis
Coccyx (2)
- small bone articulates with apex of sacrum
- recognized by lack of vertebral arches
- no vertebral canal
T-L Spine ROM (4)
- flexion- touch toes
- extension- bend back
- rotation-twist at waist
- lateral flexion-reach down on sides of body to touch lateral legs
Osteoporosis (5)
def
cause
complications
- thinning of bones
- results from imbalance in bone resorption and formation
- bones become fragile which places bones at great rx for fracutre
- loss of height common as back bones collapse
- most common bone disease
Vertebral body*
weight bearing component of vertebrae
pedicle of vertebrae*
paired portion of vertebral arch
-attach at transverse processes to the body
transverse process vertebrae*
lateral extensions from the joining of the pedicel and lamina
articular process of vertebrae*
form joints between one vertebrae and its superior and inferior counterparts
-articular processes are located at the intersection of the laminae and pedicles
lamina of vertebrae*
paired portions of the vertebral arch that connect the transverse processes to the spinous processes
Spinous process of vertebrae*
projection that extends posteriorly from the union of two laminae
Vertebral foraminen*
opening formed by vertebral notches that contains spinal nerve roots and associated vessels
Landmarks of Vertebrae (7)*
- vertebral body
- pedicle
- transverse process
- articular process
- lamina
- spinous process
- vertebral foramen
Ligaments of back (2)
- nuchal ligament
2. supraspinous ligament
Nuchal ligament
extends from external occipital protuberance along the spinous processes C1-C7
Supraspinosus Ligament
Connects the apices of the spinous processes from C7 to the sacrum
Ligaments of Spine (4)
- interspinal ligament
- ligamentum flavus
- anterior longitudinal ligament
- posterior longitudinal ligament
interspinal ligament
connects adjoining spinal processes
ligamentum flavum
connected paired laminae of adjacent vertebrae
anterior longitudinal ligament (2)
purpose?
- courses longitudinally along the anterior surface of the vertebral bodies
- limits vertebral extension
posterior longitudinal ligament (3)
Purpose?
- courses longitudinally down the posterior surface of the vertebral bodies *within the vertebral canal
- supports the intervertebral disc poteriorly
- reducing incidence of herniations that may compress the spinal cord and cauda equina
Intervertebral discs (2 components)
- annulus fibrosus
2. nucleus pulposus
Annulus fibrosus (4)
- tough and collagenous ring of ligament fibers
- surrounds nucleus pulpous
- securely connects the spinal vertebrae above and below the disc
- prevent nucleus pulposus from herniating or leaking out of the disc by
- hydraulically sealing the nucleus
- evenly distributing any pressure and force imposed on intervertebral disc
Nucleus pulposus (2)
- surrounded by annulus fibrosus
- prevented from leaking or herniating out of the disc by annulus fibrosus
- can become herniated and cause neurological and muscular complications
Intervertebral Disc Herniations (3)
def.
occurs in what direction?
complications?
- herniation of an intervertebral disc occurs when nucleus pulposus ruptures, breaking through the annulus fibrosis
- rupture usually occurs in a posterior-lateral direction, after which the nucleus pulposis can irritate nearby spinal nerves
- causes variety of neurological and muscular symptoms
2 Groups muscles of back
- extrinsic
2. intrinsic
extrinsic back muscles movements
involved in movements of upper limb and respiration
intrinsic back muscle movements
involved in movements of the spine and maintenance of posture
Extrinsic/Superficial back muscles (5)
- trapezius
- levator scapulae
- rhomboid major
- rhomboid minor
- latissimus dorsi
*involved in movement of upper limb
Extrinsic/intermediate back muscles
- serratus posterior superior
2. Serratus posterior inferior
Serratus posterior superior
shape
location
movement
extrinsinc/intermediate back muscles
- thin, rectangular muscle
- lies deep to rhomboid muscles on upper back
- elevates ribs 2-5 and assists with respiration
Serratus posterior inferior
characteristic
location
movement
extrinsic/intermediate ack muscles
- serratus posterior inferior is broad and strong
- lies underneath the latissimus dorsi
- depresses ribs 9-12 and assists with respiration
Intrinsic back muscles-superior (2)
- splenius capitis
2. splenius cervicis
splenius capitis
movement
O
I
superior intrinsic back muscle
extend the head
O: spinus process C7-T3
I: posterior mastoid process
splenius cervicis
movement
O
I
superior intrinsic back muscle
extends the neck
O: SPINOUS processes T3-T6
I: TRANSVERSE processes C1-C3
intrinsic muscles of the back (3)
2 types + movement
- assoc. with movement of vertebral column
- erector spinae muscles
- transverso-spinal muscles
erector spinae muscles
3 muscles
purpose (3)
intrinsic muscles of back
- iliocostalis
- longissimus
- spinalis
*maintain posture, extend the spine, lateral bend spine
Transverso-spinal muscles
2 muscles
intrinsic muscles of back
- semispinalis
- multifundus
*often called paravertebral muscles and travel down spine
Spinal cord * (3)
- tubular bundle of nervous tissue and supporting cells
- extends from brainstem to lumbar vertebrae
- spinal cord + brain= CNS
Spinal cord components * (7)
- medulla oblongata
- cervical enlargement
- vertebral canal
- lumbar enlargement
- conus medullaris
- cauda equina
- filum terminale
Arterial vasculature of spinal cord (3 main arteries)
- supply via 3 longitudinal arteries
A. anterior spinal artery
B. Posterior spinal arterieS
C. Additional anterior & posterior segmental medullary arteries
Anterior spinal artery
formed from
travel where?
- formed from branches of vertebral arteries
2. travel in anterior median fissure
Posterior spinal arteries
Originate from?
- originate from vertebral artery or posteroinferior cerebellar artery
- anastomose with anterior spinal artery in the pia matter
anterior & posterior segmental medullary arteries
- enter where?
- notable segment? why?
- small vessels enter via nerve roots
2. largest anterior segmental medullary artery=Artery of Adamkiewicz
Venous drainage of spine
- composition (6)
- characteristics veins (2)
- receive?
- drain to?
- empty to?
- 3 anterior spinal veins
- 3 posterior spinal veins
- vains valveless
- form anastomosing network along surface of spinal cord
- receive venous blood from radicular veins
- spinal veins drain into the internal and external vertebral plexuses
- empty into the systemic segmental veins
+ dural venous sinus (internal vertebral plexus)
Spinal nerves (3)
Originate?
form what part of nervous system?
- spinal nerves are mixed nerves that
- originate in spinal chord
- forming peripheral nervous system
Posterior rami (3)
supplies nerve fibers to
- the synovial joints of the vertebral column
- deep muscles of the back
- overlying skin
anterior rami
supplies nerve fibers to much of the remaining area of the body, both motor and sensory
Spinal nerve roots
4 segments
- cervical: 8** nerve roots
- thoracic: 12 nerve roots
- lumbar: 5 nerve roots
- sacral: 5 fused segments, 5 nerve roots
Spinal nerve roots: C spine (3)
- spinal nerves exit the cervical spine ABOVE their corresponding vertebral body level
- C7 nerve root exits above C7 through C6-C7 neural foramen
- C8 exits between T1, and C7, since there is no C8 vertebral body level
Spinal nerve roots: T-L spine
2
- orientation (roots exiting ABOVE corresponding vertebrae) REVERSES in the thoracic and lumbar spine
- T-L spinal nerve roots exit BELOW their corresponding vertebral body level
- ex) L3 nerve root exits below the L3-L4 foramen
Dermatomes (4)
what kind nerves?
- region of skin innervated by somatic sensory nerve axons assoc. with single spinal chord level
- encircle the body in segmental fashion, corresponding to spinal cord level that received sensory input from that segment of skin
- sensation conveyed by touching the skin is largely that of pressure and pain
- knowledge of the dermatome pattern is useful in localizing specific spinal cord segments and in assessing the integrity of the spinal cord at that level
- intact or lesioned
Herpes Zoster
- shingles, most common infection of peripheral nervous system
- reactivation previous infection of dorsal root or sensory ganglion by varicella-zoster virus (causes chicken pox)
- acute neuralgia confined to a dermatome distribution of specific spinal or cranial sensory nerve root
Atlas
C1
holds head on neck
axis
C2 provides axis of ration for neck
Epidural Space
above dura mater
space were epidural injecteted to anesthetize nerve fibers of cad equina
Sacroliac joints
lateral edges sacrum articulate with pelvis/iliac bone
Artery of Adamkiewicz
Arrises from?
Supplies?
- largest anterior segmental medullary artery
- Arises from inferior intercostal or upper lumbar arteries
- supplies inferior 2/3 of the spinal cord
Internal Vertebral Plexus
Venous drainage into the dural venous sinuses superiorly
AND to systemic segmented veins
Spinal Nerve Roots (3)
- Anterior- motor
2. posterior-sensory
anterior spinal nerve root
motor
posterior spinal nerve root
sensory
Nerve Roots…
…arise from spinal cord (anterior motor/ posterior sensory) and unite at intervertebral foramina
and form a single spinal nerve
Spinal nerves…
…leave vertebral canal via intervertebral foramina, and divide into
a. posterior rami
b. anterior rami
C1-C4 nerve functions (2)
- breathing
2. C2 - head and neck movements
C4-C6 nerve functions (2)
- heart rate
2. shoulder movement (C5)
C6-C7 nerve function
elbow and wrist movement
C7-T1 nerve function
Hand and finger movement
T1-12 nerve function (2)
- sympathetic tone
2. temperature regulation and trunk stability (T2-12)
T11-L2 nerve function
ejaculation
L2 nerve function
Hip motion
L3 nerve function
Knee Extension
L4-S1 nerve function
- foot motion
2. L5- knee flexion
S2-S4 nerve function
- penile erection
S2-S3 nerve function
bowel and bladder activity
Importance of knowing location of spinal nerves in relation to their vertebrae
- important to know which nerve root exits which foramen in order to understand patient’s radiculopathy symptoms can be explained by specific anatomic derangement
L5 nerve function
Knee flexion
