Back and Vertebral Column Flashcards
How many vertebrae do we have
33 plus intervertebral discs
Functions of vertebral column
- weight-bearing
- protection
- movement
- site of muscle attachements
How does the vertebral column allow for weight bearing
- Carries and transmits weight from upper body down to lower limbs
- Vertebral bodies increase in size from superior to inferior
- Cutvatures and intervertebral discs provide shock absorption
How is the spine curved as a fetus
1 big inwards curve
Spinal curves (names and positions/regions they occur in)
Cervical and lumbar lordoses (
Thoracic and sacral kyphoses )
scoliosis
spine curves sideways
Basic anatomy of typical vertebra
see sheet
Types of vertebrae and briefely outline their distinguishable characteristics)
3 main but 2 others too
- Cervical ( foramen transversarium, bifid spineous process)
- Thoracic (big fin thinngy)
- Lumbar - vertebral arch
Sacral
Coccygeal
function of intervertabral discs
shock absorption and movement
Components of intervetebral discs
nucleus pulposus - central core with high water content - shock absorbant
annulus fibrosus - tough cartilage which can resist high forces/compression
what is a “slipped disc”
herniated nucleus pulposus - compressing the nerve roots
What protects the spinal cord/spinal nerves
spinal cord protected by vertebral canal (vertebral foraman)
spinl nerves protected by intervertebral foramen
What are the meninges
3 layes/membranes that protect the spinal cord/brain
Name the 3 mininges and describe their relative locations
Dura mater - outermost
Arachnoic mater - middle
Pia mater - inner
Where is cerebrospinal fluid (CSF) found
in subarachnoid space (below arachnoic mater)
Flexion of spine
bend forwards
extension of spine
bend backwards
lateral flexion of spine
move outwards (sideways)
lateral extension of spine
move back inwards (sideways)
Rotaion of spine
circular rotational movement
5 joints of the vertebral column
- Intervertabral discs (symphasis 2ndry cartilegenous joints)
- Facet joints (synovail plane)
- Joints with ribs (synovial plane)
- Skull and atlas (synovial ellipsoid) - more mobile so can nod head
- Atlas and axis (synovial plane) - rotation so can shake head
What is the orientation of facet joints like for cervical, thoracic and lumbar vertebrae
Cervical: slanty which allows fro largest range of movement
Thoracic - coronal plane
Lumbar - like fins ( \ / )
Name the 5 ligaments of the vertebral column
- posterior longitudinal
- anterior longitudinal
- liganmentum flavum
- interspinous
- supraspinous
Give functions of 5 ligaments of vertebral column
- posterior longitudinal - limits hyperflexion
- anterior longitudinal - limits hyperextension
- liganmentum flavum - holds vertebrea together and preserves posture
- interspinous - links whole length of spine and limits flexion
- supraspinous - only posterior tips of spines, keeps head up?
locate each ligament of the vertebral column
(lable it)
see sheet
What do extrinsci mucles of the back attach to
- head
- limbs
- thorax
- abdomen
Explain the erector spinae
location, function…
Intrinsci back muscle
Extension, lateral flexion and “controlling” flexion
generally what do the anterior spinal muscles do
flexion of spine
generally what do the posterior spinal muscles do
(erector spinae)
extension of spine
osteoarthritis
pain/stiffness of joints
osteoporosis
compression fractures altering the curvature of the spine - linked to Ca2+ absorption and capacity
what does dehydration of intervertabral discs lead to
reduced shock absorption
what do weakened back muscles cause
- imbalance loading of spine
- back pain
What are the 6 muscle attachment sites for the back
just general
- Head
- Upper limb
- Thorax
- Abdomen
- Hips
- Lower limbs
function of extrinsic back muscles
2 functions
Upper limb movement and respiration
Functions of intrinsic back muscles
- maintain posture
- control movement of the vertebral column
(superficial, intermediate (erector spinae) and deep layers)
Flexion (bilateral)
where are the muscles - name them
Muscles anterior to the spine
* rectus abdominis
* psaos major
Extension (bilateral)
where are the muscles - name them
Muscles posterior to the spine
* erector spinae
what does bilateral mean in terms of muscle flexion and extension
muscles flex together either side of the column
Rotation (unilateral)
which muscles (name them)
Muscles with oblique fibre orientation
* external oblique
* internal oblique (opposite side)
* erector spinae
lateral flexion (inilateral)
muscles to do this movement…
- erector spinae
- exteranl and internal obliiques
Location and function of recturs abdominis
- 3 large and flat muscles with different fibre orientation - anterior abdonimal wall muscles
- Anterior flexion, lateral flexion and rotation of the trunk
posterior abdominal wall muscles
3 main ones:
* illiacus
* psosas major
* quadratus lumborum
Anterior flexion (psoas) and laterl flexion of spine
Intrinsic back musles: erector spinae functions
- extension of vertebral column (bilaterally)
- Lateral flexion of vertebral column (unilaterally)
older people: weakened back muscles/disability
loss of muscle mass, muscle strength and physical function
Where does the spinal cord begin and end
Begins at medulla oblongata (brain stem) and extends up to L1/L2 vertebral level
Cervical and lumbar enlargement
accomodate for nerve plexuses leaving at arms/legs
i think???
how many pairs of spinal nerves exit from the spinal cord
31 pairs
Number of verterae and nerves at each spinal segment
Cervical (7) - 8 spinal nerves
Thoracic (12) - 12 spinal nerves
Lumbar (5) - 5 spinal nerves
Sacral (5) - 5 spinal nerves
Coccygeal (4ish) - 1 spinal nerve
Explain the development of the spinal cord and why it does not exent the full length of the spine
- spinal cord and vertebral canal length almost equal in fetus
- vertebral canal grows and spinal cord ends at L1-L2 vertebral levels in adults
- Remaing spinal nerves forms cauda equina seeking their intervertebral (IV) foramen to exit
vertebral colum grows, but spinal cord doesnt, so stops
conus medullarise
conical inferior end of the spinal cord - typically at L1
Cauda equina
bundle of spinal nerve roots - all spinal nerves looking for exit
filum terminale
what is it + function
continuation of pia mater (internum) - attach to coxyx so gives stability to cord
Dural cistern
dilated dural sac ends at S2 vertebral level - contains CSF
histology of spinal cord
sheet
grey matter
H shaped - cell bodies located here
White matter
axons (+schwann cells?)
Nissl bodies
rough ER in the neurone cell bodies
How do spinal nerves exit the vertebral canal
through intervertebral foramen
WHat do bentral rami of the spinal nerves from
Nerve plexuses that supplies the limbs:
* brachial plexus to upper limb C5-T1
* lumbosacral plexus to lower limb T12-L5
dorsal root
sennsory
ventral root
motor
spinal nerve
motor/sensory
mixed
dorsal rami
motor/sensory
mixed
ventral rami
motor/sensory
mixed
where is CSF found
between arachnoid and pia mater
Give the properties of the 3 coverings/membranes of the spinal cord
e.g. toughness/appearance
- dura mater - tough/fibrous
- arachnoid mater - clear/fibrous
- pia mater - delicate/vascular/thin
what is the dural sac + location
The membranous sheath of dura mater that surrounds the spinal cord and the cauda equina
terminates at S2 and attached to tip of coccyx by filum terminale externum
where are sensory neuron cell bodies located
dorsal root ganglia
where are motor neuron cell bodies located
grey matter in ventral horm
outflow of sympathetic NS
Thoracolumbar: T1-L2
Where are sympathetic neuron cell bodies located
At the lateral horn of the grey matter
parasympathetic NS outlow
Craniosacral: brain and pelvic splanchnic nerve (S2-S4)
Where are cell bodies of preganglionic parasympathetic fibres found
lateral horm
Spinal Cord Ischemia
no idea what this is about??? - relevance?
- Deficinecy of blood supply to spinal cord: muscle weakness and paralysis
- venous drainage: internal vertebral venous plexuses. Drains to the cerebral dural venous sinuses
- Infection and cancer can spread to vertebrae/spinal cord/brain/skull from other parts of the body
Where could bleeding occur in the spinal cord (what spaces)
- epidural space
- subduroid space
- subarachnoic space
briefly summarise some common spinal cord injuries
more just general knowledge/understanding
- blunt trauma and penetrating injuries —> paralysis
- Cord compression from disc prolapse or bone metastasis from primary cancer/stenoisis of the vertebral canal -> chronic back pain
- May lead to coplete/partial loss of motor function and sensation (including disruption to autonomic function)
Where does lumbar puncture occur
L3-L4 of subarachnoic space (CSF collection)
Epiidural anesthesia: epidural space
structural differences between somatic and autonomic NS
Somatic: 1 motor neurone
Autonomic: 2 motor neurons
Where are ANS cell bodies located
lateral horn of spinal cord
Somatic motor neuron
myelinated - white?
autonomic pre- and post-ganglionic neurons
Pre: myelinated
Post: unmyelinated - grey?
What neurotransmitters to sympathetic pathways use
Ach and norepinephrine
What neurotransmitters to parasympathetic pathways use
Ach only
What part of the spinal cord contains the cell bodies of sympathetic neurons
lateral horn
Where is the lateral horn only present
In spinal cord betweeen T1-L2/3 vertebrae: therefore sympathetic outflow - thoracolumbar outflow
How do we get nerves coming out of S2/3/4 if spincal cord ends at L1/2
Differential growth of vertebral column vs spinal cord.
Neurons named according to where they emerge from the vertebral column, not the spinal cord
Where is parasympathetic outflow
nerves from lateral horn between S2-S4 spinal segments
- synapse in a parasympathetic ganglion in pelvis - sacral outflow
What does the lateral horn consist of
sympathetic nerve cell bodies from T1-L2/3 sdpinal segments but also parasympathetic nerve cell bodies from S2-S4 spinal segments
If all 31 pairs of spinal nerves have sympathetic fibres in them, but they only emerge between T1-L2/3 how to other spinal nerves above/below this recieve their sympathetic fibre
Sympathetic fibres from T1-L2/3 are spread through bilateral sympathetic chains which run paravertebrally from C1-Cc1. Thus, mass distribution mechanism for sympathetic supply to all parts of the body
Explain the colour/myelination of sympathetic neurons
White rami communicates: (myelinated, preganglionic) - from spinal nerve to SC
Synapses in SC
Grey rami communicates (unmyelinated, postganglionic) - from SC back to spinal nerve
How do spinal nerves communicate with the sympathetic chain
through white and grey rami communicates
If sympathetic fibres originate between T1-L2/3 how do parts of the body aboove/below this recieve sympathetic innervation
Some preganglionic fibres (from T1-L2/3) can travel up or down the sympathetic chain without synapsing there to synapse at a sympathetic ganglion lying at a level higher/lower than T1/L2/3 and only enter the spinal nerve at that level (e.g. at C4 or L4 etc.)
what does the sympathetic chain allow for
like general overview
all parts of the body to recieve sympathetic supply, every spinal nerve (C1 to Cc1) contains sensory, motor and sympathetic fibres
3 options of sympathetic fibres leaving lateral horn of spinal cord
- synapse in chain at the same level
- can run up or down the chain and synapse at a higher or lower level
- can pass right through the sympathetic chain without synapsing and synpase in an autonomic ganglion in the abdomen lying outside the SC. Known as splanchnic nerves and supply only abdominal organs - are preganglionic
splanchnic
supply organs
how does the face/head recieve sympathetic supply
after synapsing at 1 of 4 cervical ganglia, sympathetic fibres utilise blood vessels going to the head/face by “climbing up” them
Horner’s syndrome
not sure if need to know???
sympathetic fibres damaged along course to head/face:
- partial ptosis (drooping of upper eyelid)
- Miosis C(constriction of pupil)
- Anhydrosis (dec sweating)
does the autonomic NS have sensory supply
Yes, although primarily motor system
Autonomic sensory supply
Pain (nociceptive) and sensory impulses from organs run back to spinal cord mainly in sympathetic afferent fibres (parasympathetic afferent fibres in pelvis) via the dorsal root
Parasympathetic nerves - craniosacral outflow
summarise key points/anatomy of outflow
- Parasympathetic nerve fibres arise from the CNS with the S2, S3, and S4 spinal nerves and also cranial nerves - craniosacral outflow
- the S2, S3, and S4 spinal nerves carrying parasympathetic fibres to pelvic organs are commonly referred to as the pelvic splanchnic nerves - pelvic splanchnic nerve cell bodies reside in the lateral horn of the spinal cord in the L2-3 spinal segments, but emerge from the vertebral column between S2-S4
- These axons are preganglionic and synapse in a parasympathetic ganglion close to or within the pelvic target organ. Postganglionic fibres then supply the organ
where would a C4 emerge
between C3 and C4 vertebbrae - like nerve number=number of lower vertebr
Name C1 vertebrae
atlas
name C2 vertrbrae
Axis
facet joint
joints located on the top and bottom of each vertebra that connect the vertebrae to each other and permit back motion
name parts of cervical vertebrae
see sheet
name parts of thoracic vertebrae
see sheet
name parts of lumbar vertebrae
see sheet
what motions occur at atlas and axis joints
Lateral rotation/flexion/pivots occur here
what lies within the vertebral foramen
spinal canal
what lies within the intervertebral foramen
(ventral) roots of spinal nerves
what joint occurs between the bodies of adjacent vertebrae
Intervertebral joint: symphysis (secondary cartilaginous joint)
what type of oint occurs between articular facets of adjacent vertebrea
synovial joints
C7 - vertebrae name
vertebra prominens
distinguishing features of cervical vertebrae
Bifid spinous process, Transverse process (foramina)
distinguishing features of thoracic vertebrae
Demi facets for ribs, spinous processes of thoracic vertebrae oriented obliquely inferiorly and posteriorly, vertebral foramen of thoracic vertebrae is circular
distinguishing features of lumbar vertebrae
Large with kidney shaped vertebral bodies, no costal facets/bifid spinous processes
costal facet
site of connection between rib and vertebral body
type of cartilage found in intervertebral disc
fibrocartilage cartilage
In what direction with an intervertebral disc herneate and why
Posterolateral: herniates in this direction as softest part/easiest/weakest gap to outside intervertebral disc - spinal cord is directly lateral and is “harder”
what does a herniated disc generely compress on
Nerve roots - cause pain/numbness
ligaments of spine
see sheet
ligamentum flavum
connects lamina of adjacent vertebrae
anterior longitudinal ligament
connects the anterior surface of vertebral bodies
posterior longitudinal ligament
connects the posterior surface of vertebral arches
supraspinous ligament
connect the spinous tips of adjacent vertebrae
interspinous ligaments
connects the spinous processes of adjecent vertebrae
primary curvature of spine
like as foetus - kyphosis
secondary curvature of spine
happens in adults in cervical and lumbar regions of spine
scoliosis
abnormal twisting and curvature of the spine
what is key to remember about facet joints of different types of vertebral bodies
they are all in different places/angles in comparison with each other - allows for different range/types of movement
What movements are permitted at cervical, thoracic and lumbar vertebrae
flexion, extension, lateral flexion and rotation
However, range dec as we go down spine
where is the vertebral prominence found
spinous process of C7
spine of scapula location
spine of T3
Summit of iliac crest
spine of L4
inferior angle of scapula
spine of T7/8/9?
lumbar puncture location
between L3 and L4
Where does a lumbar puncture occur in children and why is this different to as in adults
between L4 and L5 - spinal cord stops growing in kids whereas spine continues to lengthen as age. Means spinal cord protrudes lower down spine in children
what are transverse foramen
an opening that is occupied by the vertebral artery and vein in the first six vertebrae and only the vertebral vein in the seventh
conus medullaris
terminal end of the spinal cord
L1 (ish)
cauda equina
bundle of nerve roots located at the lower end of the spinal cord - once spinal cord has “ended”
filum terminale
location/function
fibrous band that extends from the conus medullaris to the periosteum of the coccyx, and its functions are to fixate, stabilize, and buffer the distal spinal cord from normal and abnormal cephalic and caudal traction.
Why does the spinal cord show an enlargement in the cervical and lumbar regions
Due to enlargement for grey matter necessary to supply the limbs
vertebral level spinal cord terminates in adults and kids
- adults = L1-L2
- Kids = L3
What type of nerve impulses are associated with the anterior horn cells
motor
What type of nerve impulses are associated with the posterior horn cells
sensory
What type of nerve impulses are associated with the lateral horn cells
Autonomic (sympathetic)
dural sac
/thecal sac
the membranous sheath of dura mater that surrounds the spinal cord and the cauda equina
where does the dural sac terminate caudally
S2
where is the epidural space found
between the dura mater and the vertebral bones
Where is CSF found
subarachnoid space
what is meant by “sentinel node”
The first lymph node to which cancer cells are most likely to spread from a primary tumour
how does the sympathetic nervous system connect to the sympathetic chain
via white and grey rami communicates
how is lymph returned to the venous system
Lymphatic vessels empty the lymph into the right lymphatic duct and left lymphatic duct (also called the thoracic duct). These ducts connect to the subclavian vein, which returns lymph to your bloodstream.
main movement of thoratic vertebrae
rotation (and lateral flexion but to lesser extent)
main movement of lumbar verterbrae
flexion and extension (but with some lateral flexion and some rotation)
main movement of cerviacal vertebrea
All (flexion, extension, lateral flexion, rotation)
2 broad ways to divide a vertebrae
like 2 sections of a vertebrae
vertebral body and vertebral arch
what are extrinsic back muscles innervated by
mostly ventral rami
