Functionally Oriented Regional Anatomy Chapter 2
Vertebrae of the human body
7 cervical
12 thoracic
5 lumbar
5 sacral
4-5 coccygeal
Spinal regions
cervical, thoracic, lumbar, sacral, coccygeal
Primary Spinal Curves
Sacral and Thoracic
Secondary Spinal Curves
Cervical and Lumbar
Movements of the Vertebral Column
Flexion, extension, lateral flexion, and rotation
How many curvatures are in the adult vertebral column?
4
What is Kyphosis?
anteriorly concave curvatures in the vertebral column
What is lordoses?
anteriourly convex curvatures in the vertebral column
When does the cervical curvature become pronounced?
at three months when an infant is able to hold its head erect
When does the Lumbar curvature become apparent?
When the toddler tries to stand at the age of 9-10 months
body of a vertebrae
connects posteriorly with two vertebral arches
Vertebral foramen
formed by the fusing together of the two V.arches, contains the spinal cord, meninges, roots, vessels, and other tissue
Spinous Process
extends posteriorly from the point of fusion of the two V. arches
Pedicle
adjascent part of the body of the vertebra
Lamina
Continues posteriorly from the pedicle
Vertebral arches
made of up of the Pedicle and the Lamina
Transverse Process
a bony extension on each one of the vertebral arches
Superior Articular Process
found at the junction of the pedicle and lamina, on each side, projecting UPWARD
Inferior Articular process
found at the junction of the pedicle and lamina, on each side, projecting DOWNWARD
facet
Found on each articular process, it is an aticular surface made of hyaline cartilage, and is the site of articulation b/t the vertebrae
Vertebral notch
found b/t the articular process and the vertebral body, the bone has an indentation or depression
Vertebral foramen
formed from the articulation of the vertebral notches of vertebrae to vertebral column, and transmit nerve roots
Transverse Foramen
Transmit the vertebral artery on each side, develops as a result of incomplete fusion of the vertebral and costal elements of the transverse process of the cervical vertebrae during development
Vertebral Artery
originates from the subclavian arteries on each side, & provide the major blood supply to the spinal cord & brain stem, as well as partial blood supply to the brain
Cervical Vertebra
have smaller bodies
larger vertebral foramen
have transverse foramen
have bifid spinous processes
Atlas
C1
NO body
large vertebral foramen for DENS
NO spinous process
Axis
C2
Has an odontoid process
has an apex and two articular facets
What are the contents of the Verterbral Foramen?
the spinal cord and its surrounding meninges, nerve roots and spinal vessels, CSF (cerebral spinal fluid) and fat tissue
What are the different meningeal layers surrounding the spinal cord and the brain?
The meninges consist of three membranes, dura, pia, and arachnoid mater.
Meningeal membranes
Dura mater, Pia Mater, and arachnoid Mater
Dura Mater
outer layer of the meningeal membranes
Extends down to S2
Pia Mater
innnermost meningeal membrane, closely attached to the spinal cord
Extends to the Coccyx
Covers blood vessels
Arachnoid mater
middle meningeal membrane
denticulate ligaments
entension of pia mater from the surface of the spinal cord to the arachnoid mater, and supports the spinal cord in the vertebral canal, and separate the ventral and dorsal roots of the spinal nerves
contents of the IF (Intervetebral foramen)
DRG (dorsal root ganglion) on each side, and the spinal roots and vessels pass through the foramen
contents of the transverse foramen (only cervical vertebra have transverse foramen)
Verterbral artery, on each side, and veins
C7 TF- contains the accessory vertebral vessels
how do transverse processes develop?
asa result of incomplete fusion of the vertebral and costal elements of the transverse process of the cervical vertebrae during development
characteristics of cervical vertebrae
-smaller bodies, or no body (Atlas C1)
-larger vertebral foramen
-have transverse foramen
-have bifid spinous process
How many cervical nerves and how many cervical vertebrae are there?
There are 8 cervical nerves and 7 cervical vertebrae
special features of cervical vertebra 7
C7- has a vertebral prominence that we can feel when we bend out necks forward, the first protrusion on our necks
-anterior tubercle on transverse process is missing
contents of the I.F. (intervertebral Foramen)
-DRG- Dorsal root ganglion (at the sides of the foramen)
-The three menengial layers:
a. Dura Mater
b. Arachnoid Mater
c. Pia Mater
-The spinal Cord
-blood vessels
how many parts does the vertebral artery have?
3 parts
part one of the Vertebral artery
extends from the point of origin (at the subclavian artery) to the transverse foramen
insertion point is C6
Part two of the Vertebral artery
found ascending in the transverse foramina of the cervical vertebrae
c6-c1
Part three of the Vertebral Artery
turns medially on the posterior arch of the atlas and is found in the sub occipital triangle
Angle of the Spinous process of the Thoracic Verterbrae
Postinferior Slope
Distinguishing feature of the Thoracic vertebrae
body of the thoracic vertebrae have two costal facets that articulate with the head of the rib
Muscles that make up the sub occipital triangle
-rectus capitis posterior major
-oblique capitis superior
-oblique capitis inferior
Origin of the Spinal Cord
extends form the foramen magnum in the occipital lobe of the skull to L1 at the conus medullaris
Termination of the spinal cord
the spinal stops at the film terminale (the spinal cord roots), which insert into the coccyx
Swellings of the spinal cord
- at the cervical region -which innervates the upper limbs
-at the lumbar region- which innervates the lower limbs
epidural space
space between the vertebra and the dura mater- which contains adipose tissue
Subdural Space
space between the dura and arachnoid mater
Subarachnoid space
space between the arachnoid mater and the Pia mater, this space contains CSF
CSF (cerebral spinal Fluid)
Clear fluid produced in the ventricles (the Coroid Plexus) of the brain, contains almost NO blood cells.
indications of a hemorrhage
too much blood in the CSF-most easily seen during a lumbar puncture
Dorsal Root ganglion (DRG)
sensory only
made up of the dorsal root and the ventral root coming together
NOT inside the Intervertebral foramen
dorsal ramus
go towards the back and innervate the back muscles
Types of Anesthesia
Spinal Block
Caudal Epidural Anesthesia
Spinal Block
This kind of anesthesia will paralyze from iliac crest down. (anesthesia goes into the CSF)
Caudal (Epidural) Anesthesia
Administered through the sacral hiatus
will anesthetize up to S2, maximum S1 (hocks the pelvic nerves)
Will maintain motor ability
Usually only administered for labor and delivery
Intervertebral Discs (I.D.)
made up of two parts:
Anulous Fibrosus- tough, made of fibrocartilage
Nucleus Pulposus- inner part of the I.D. remnants of embryonic tissue (starlight cells)
make up 20-25% of vertebral height
Anencephaly
birth defect, where the babies are born without parts of the brain & skull, a type of neural tube defect. The upper part of the neural tube must close by the 24th day of conception, if not this results in the baby missing the forebrain, and the cerebellum (the thinking, and coordinating parts)
Prominense
the name for C7
Muscles of the Suboccipital Triangle
rectus capitis major
oblique capitis superior
oblique capitis inferior
Vertebral Basilar ischemia
temporary set of symptoms due to decreased blood flow in the posterior circulation of the brain.
Site of circulation for the dens to C1
Atlanto-occipital articulation
Where is the basilar artery found?
in the anterior aspect of the brain stem
inside the sub occipital triangle
the suboccipital cranial nerve
the 3rd part of the vertebral artery
C2 Sensory Nerve- Runs OVER the triangle
Cruciate ligament
keeps the dens from posterior displacement
Exit points of cranial nervers
the cranial nerves will exit ABOVE the corresponding vertebra
i.e. CN1 exits about C1 and below the occipital bone.
Characteristics of the Lumbar Vertebra
5 vertebra
mammallary process on the posterior surface of the superior articulating process
Spinous process extends in the sagittal direction
Characteristics of the Sacrum
located between the two hip bones
has a concave anterior
has a convex dorsal surface
Sacral promontory
anterior edge of the S1 vertebra
Sacral Canal
Exit point for the Cauda Equina and the surrounding meninges, to continue downward
Sacral hiatus
located in the lower part of the dorsal surface of the sacrum
Cornua
2 sacral horns, that flank the sacral hiatus
Characteristics of the Coccyx
4 rudamentary vertebrae that are fused together
Herniation of a disc
happens in the nucleus pulposus, and usually lateral and posterior
Characteristics of Thoracic Vertebrae
longer spinous processes
body of the vertebrae have articular facets that articulate with the ribs
Osteophytes
bony processes that appear superiorly on the articulating surfaces of the vertebrae, can cause pain and pinch nerves (osteoarthritis)
uncinate processes
a raised area on the body of vertebrae that over time can cause a crack on I.D.
Coccydynia
Pain in the coccyx
Endochondral ossification
Formation of bone via hyaline cartilage model
Intermembranous Ossification
Formation of bone from mesenchyme cells, from within the bone
When does ossification of the epiphyseal plate happen?
During puberty, once all growth is completed
Unconvertebral Joint
AKA Secondary joints-occur b/t the uncinate processes and the inferolateral surfaces of the vertebral bodies superior to them in the cervical region
Zygapophysial joints
articulations between the facets of the vertebral articular processes
atlanto occipital articulation
consist of the medial and lateral atlanto-axial articulations between the atlas and the axis
ALL- anterior longitudinal ligament
prevents hyperextension of the vertebral column, extends from atlas to sacrum
How many layers does the PLL- Posterior longitudinal ligament have?
2- Superficial and Deep
Superficial layer of PLL
continuation of the tectoral membrane originating from the foramen magnum in the skull, starts on the body of the axis
Deep layer of PLL
continuation of the cruciate ligament from the atlas & down to into the sacral canal
What does the PLL do?
prevents hyperextension of the VC
Helps protect agains Posterior disc herniation
Functions of the Ligamentum Flavum (active ligament)
Brings the VC back to an erect position
Location of the Ligamentum Flavum
Between the vertebral arches
loation of the Interspinous ligaments
b/t the spinous process of the vertebrae
location of the supraspinous ligaments
spinous process of the vertebrae
location of the intertransverse ligaments
b/t the transverse processes of the vertebrae
location of the ligamentum nuchae
originates from the occipital bone, extends to the spinous processes of the cervical vertebrae and become continuous with the supraspinous ligaments
Location of the Cruciate ligaments
formed by the superior and inferior longitudinal bands, and the transverse ligament of the atlas
Apical ligament of the dens
extends from the head of the odontoid process to the aneroid border of the foramen magnum
Alar ligaments
originate form both sides of the Odontoid process to the lateral borders of the foramen magnum