Pathophysiology Exam #3 Flashcards
How many total vertebra are in the spinal column?
33
How many vertebra in the cervical region of the spinal column?
7
How many vertebra in the thoracic region of the spinal column?
12
How many vertebra in the lumbar region of the spinal column?
5
How many vertebra in the sacral region of the spinal column?
5
How many vertebra in the coccygeal region of the spinal column?
4
Is the word vertebrae plural or singular?
plural, vertebra is singular
How many curvatures of the spine is seen normally and describe each curvature.
There are 4 curvatures(from an anterior perspective)
- cervical convexity-curved towards the ANTERIOR part of the body
- thoracic concavity-curved towards the POSTERIOR part of the body
- lumbar convexity-curved towards the ANTERIOR part of the body
- sacral concavity-curved towards the POSTERIOR part of the body
What is the purpose of the body of the vertebra?
BODY: weight bearing and protection of spinal cord
o Largest and the thickest part of the SCol
o In between sits the intervertebral disk
§ separates and cushions
§ integrity is important for the disk,
§ keeps the intervertebral foramen the same size
What makes up the vertebral arch of the vertebra, and where does it attach in relation to the other structures of the spinal column?
(1) Two pedicles, attached to body
(2) Two laminae, joins lamina from opposite half of
arch
§ lamina from one side and the lamina from the
other, form the SPINOUS PROCESS
Describe the traverse process of the spinal column.
o Extends laterally from each side of arch between
lamina and pedicle
o Attachment for skeletal muscles
Describe the spinous process of the spinal column.
o Junction between TWO lamina o Attachment for skeletal muscles o Sometimes curved down, sometimes they’re horizontal o What you are palpating down the spine
What is the purpose of the vertebral foramen?
foramina of all vertebrae;It forms the vertebral canal for the entire spinal cord
• This is where the SCord sits
• The vertebral foramen size is different, in
different segments of the vertebral columns
because the SCord is not the same diameter all the
way down
Describe the intervertebral foramina(notch).
o Exit for spinal nerves and blood vessels
o Formed by superior and inferior intervertebral
notches in pedicles of adjacent vertebrae
o INFERIOR and SUPERIOR INTERVERTEBRAL NOTCH
§ WHERE THE SPINAL NERVE ROOTS EXIT
o DO NOT CONFUSE VERTEBRAL FORAMEN WITH INTERVERTEBRAL FORAMEN
What is the pedicle of the spinal column?
Foot of the arch with one on each side; forms the lateral wall of the vertebral foramen
What is the lamina of the spinal column?
Posterior part of the vertebral arch; forms the posterior wall of the vertebral foramen
What is the function of the articular processes of the spinal column?
Superior and inferior projections containing articular facets where vertebrae articulate with each other; strengthen the vertebral column and allow for movement.
What is different about C1(atlas) from the rest of the cervical region of the spinal column?
§ ATLAS (C1): - no body -no spinous process -large superior articular facets for base of skull (occipital condyles) to sit -large vertebral foramen v supports the skull v facet is where the DENS sits v allows the head and neck to move up and down (to nod)
What is different about C2(axis) from the rest of the cervical region of the spinal column?
§ AXIS (C2): dens that fits into vertebral foramen of atlas
v DENS (projection upwards) aka the ODONTOID PROCESS
Ø allows for the rotation of the neck
§ Superior articular facet on C2 sits into the inferior articular facet of C1
What is a bifid spinous process of the spinal vertebra?
o Bifid spinous processes
§ bifid: split at the end of the spinous processes
§ muscles of the neck connect here
§ most cervical vertebrae are bifid, for muscle attachment
What are the characteristics of the cervical region of the spinal column?
• CERVICAL(7 vertebrae)
o Small bodies
o Bifid spinous processes
o Horizontal spinous processes
o Transverse foramina (located in the transverse processes) for vertebral arteries(except C7)
§ very important: the cervical transverse foramina have
vertebral arteries that pass through the foramen magnum
that supply the base of the brain
o Relatively large vertebral foramina for cervical
enlargement of spinal cord
What is special about C7?
C7 (VERTEBRA PROMINENS); usually (but not always) has no transverse foramina
*sometimes associated with an extra “cervical rib”
What are the characteristics of the thoracic region of the spinal column?
• THORACIC VERTEBRAE(12 vertebrae)
o Long, thin spinous processes, which become more vertical from above downward
o Vertebral foramina smaller than in cervical vertebrae
o Bodies larger than cervical vertebrae and increase in size from above downward
§ more weight bearing
o Only the first 10 (thoracic vertebrae) have costal facets on transverse processes and bodies for articulations with rib heads and tubercles
§ Superior articular facet for rib head
§ Inferior articular facet for rib head
§ Articular facet for tubercle of rib
o Does not have any transverse foramina in the transverse processes (not arteries)
o Spinous processes are no longer bifid and are fairly
vertical
o Vertebral foramen smaller
o Superior articular facet articulates with the inferior
articular facet above that
o Inferior intervertebral notch: where nerve roots exit
What are the characteristics of the relationship between the thoracic column and the rib articulations?
• THORACIC VERTEBRAE AND RIB ARTICULATIONS
o 12 ribs in man and woman
o 1st seven ribs are called TRUE
RIBS
§ posteriorly they articulate with the vertebral column
§ continue out posteriorly then laterally
§ then curve anteriorly
§ joined with cartilage SEPARATELY, that then joins
to the body of the sternum
o Rib #1 articulates with the manubrium
o Rib #2 joins at the sternal angle
o Ribs #3-7 articulate with the sternum
o Ribs 8-12 are called the FALSE RIBS
§ each rib does not directly join to cartilage that attaches to sternum
§ cartilage to cartilage
o Ribs 11-12 do not join at all and are called the FLOATING RIBS
What is the significance of the “sternal angle”?
o Sternal angle (significance): to properly find the proper correct anatomical landmarks for assessing heart
sounds(T2)
What are the characteristics of the lumbar region of the spinal column?
• LUMBAR VERTEBRAE(5 vertebrae)
o large, thick vertebral bodies
o heavy transverse and spinous processes for HEAVY WEIGHT BEARING and limited rotation;
o no transverse foramina and no costal facets;
o almost horizontal spinous processes
What are the characteristics of the sacral region of the spinal column?
• SACRAL VERTEBRAE
o 5 vertebrae fused to form sacrum
§ no disk between the vertebral bodies
o Intervertebral foramina: Dorsal and ventral foramina
(where nerve roots exit)
o Anterior edge of body of first sacral vertebra bulges to
form sacral promontory
o 1st sacral vertebra is called the SACRAL PROMONTORY
( that was used to measure the diameter of the birth canal -unknown if this is stilled used)
o SACRAL HIATUS (posterior): used for caudal blocks
What are the characteristics of the coccyx region of the spinal column?
• COCCYX à
o 3-5 (average 4) fused bones; no vertebral foramina or transverse processes
o the opening or junction between the sacrum and coccyx is where the coccygeal spinal nerve exits
What is the purpose of the intervertebral disks of the spinal column?
Provides cushion
Adds length to SC in the adult
• Fibrocartilaginous structures between adjacent vertebral bodies from AXIS TO SACRUM; prevent vertebrae from rubbing against each other
• There is not a disk between the skull and C1; or
between C1 and C2; no disk in the sacral either
• 25% of length of adult vertebral column; thickest in
lumbar region
What are the two parts of the intervertebral disk and their function?
o ANULUS FIBROSUS (can be spelled with one or
two N’s): outer concentric fibrous tissue
o NUCLEUS PULPOSUS: central, springy, pulpy
zone(§ provides cushioning between vertebral bodies
and adds a significant percentage to the length of the vertebral column
WITH AGE THE DISC LOOSE WATER AND COLLAGEN CAUSING SHRINKAGE AND DECREASE IN ABILITY OF MOVEMENT(or painful movements)
Why is it important that the disk remain a consistent size?
• Its important that the intervertebral disks remain at a
consistent size because of the intervertebral foramen; so
the opening will remain the same size
o if the intervertebral disk loses volume/ water, becomes dehydrated, that area will be narrowed,
o placing pressure on the sensory nerves that enter
and motor nerves that exit.
o Which can cause problems in the periphery, in terms
of sensations; loss of sensations/ painful sensations
o Can also cause alterations in motor movement
What are herniated disc?
o Many people have herniated disks
o As I mentioned the outer part is the annulus fibrosis.
o The center is the nucleus pulposus; a pulpy area
§ Sometimes the integrity of the annulus fibrosus is lost, allowing the nucleus pulposus to herniate.
§ It usually herniates POSTERIORLY
§ It compresses the intervertebral foramen, compressing that nerve root that exits there
§ Loss of sensations, loss of muscle activity, painful sensations, etc.; to the various parts of the body that is innervated
o Repair:
§ old approach: laminectomy
§ modern approach: use of a cushioned disk to supplement that area
Where does the Anterior Longitudinal Ligament extend from, towards what and what does it connect?
• ANTERIOR LONGITUDINAL
LIGAMENT:
o extends from ANTERIORLY tubercle of ATLAS TO SACRUM;
o increases in width from above downward;
o CONNECTS THE ANTERIOR VERTEBRAL BODIES AND
INTERVERTEBRAL DISKS
Where does the Posterior Longitudinal Ligament extend from, towards what and what does it connect?
o extends from AXIS TO SACRUM
o CONNECTS THE POSTERIOR VERTEBRAL BODIES AND INTERVERTEBRAL DISKS
o broader above than below;
o lies within vertebral canal behind vertebral bodies
What is the function of the Ligamenta Flava
• LIGAMENTA FLAVA: o JOIN ADJACENT LAMINAE; o small gap in midline between right and left ligamentum flavum for passage (exit) of (small) veins o LIGAMENTUM FLAVUM = SINGULAR (talking about either the one on the L or the R); LIGAMENTA FLAVA = PLURAL (talking about both) SPELLING IS IMPORTANT!!!
Where does the Supraspinal Ligaments extend from and to, and what are their function?
• SUPRASPINAL LIGAMENTS: o INTERCONNECT TIPS OF SPINOUS PROCESSES FROM 7TH CERVICAL VERTEBRA TO SACRUM; o continuous with ligamentum nuchae above and interspinal ligaments in front; o increase in thickness from above down
Where does the Interspinal Ligaments extend from and to, and where are they best developed?
• INTERSPINAL LIGAMENTS:
o EXTEND BETWEEN ROOTS AND APEXES OF
SPINOUS PROCESSES;
o best developed in lumbar region
What do the Inter-transverse Ligaments adjoin, and where do they extend from and to?
• INTERTRANSVERSE LIGAMENTS:
o ADJOIN ADJACENT TRANSVERSE PROCESSES
o Run the length of the Spinal Column
What separates the inferior medulla oblongata from the superior SC?
foramen magnum
How long is the spinal cord? Where does the spinal cord terminate?
SPINAL CORD
• Continuation of medulla oblongata; foramen magnum divides spinal cord from medulla oblongata
• About 46 cm long
• Extends from foramen magnum/atlas to where it terminates at the conus medullaris at vertebrae
L1 – L2
What are the two enlargements of the spinal cord?
cervical enlargement
lumbosacral enlargement
- The diameter of the SCord is not the same all the way down
- There is an ENLARGEMENT IN THE CERVICAL AREA because that is the ORIGIN OF THE NERVES THAT INNERVATE THE ARMS, HANDS AND FINGERS
- There is also an ENLARGEMENT OF the SCord in the LUMBAR SEGMENT because that is the ORIGIN OF NERVES THAT INNERVATE THE HIPS, LEGS, FEET, AND TOES
At what structure does the SC terminate(L1,L2)?
conus medullaris
Whats the name of the ligament that anchors the spinal cord to the coccyx?
From conus medullaris, there’s a ligament called the FILUM TERMINALE that extends to coccyx and anchors spinal cord to coccyx
What nerves supply the upper limbs?
C4-T2
What nerves supply the lower limbs?
L3-S3
How many total pairs of nerves are there?
31
How many cervical nerves?
8
How many thoracic nerves?
12
How many lumbar nerves?
5
How many sacral nerves?
5
How many coccygeal nerves?
1
How are the nerve rootlets named?
- The various segments of the SCord are named according to the vertebrae beside which they originated during fetal development.
- In adulthood, those SCord segments no longer lie adjacent to those vertebrae, but they still carry the same names as they always did.
spinal cord segments move up in relation to the spinal column
What is the name of the group of rootlets that extend below the level of the SC and terminating at the Filum terminale called?
Cauda equina(horses tail)
Where does the first cervical nerve exit the spinal column?
above C1 and below the skull
What nerves make up the Brachial plexus?
v BRACHIAL PLEXUS: from ventral rami of C5,
C6, C7, C8, T1 (with contributions from C4 and T2)
What does the gray matter of the spinal cord consist of(2) and what happens there?
- nerve cell bodies
- and their dendrites
axons synapse with those dendrites
The gray matter is divided into what two sections?
- Dorsal(posterior) horn
2. Ventral(anterior) horn
Only those segments of the SC associated with the autonomic nervous system have _____ _____ in the gray matter of the SC.
lateral horns(primarily T1-L2 and the sacral segments of the SC) sympathetic and parasympathetic
What is located in the central canal of the SC?
CSF
What is the area within the gray matter called where it crosses from one side of the SC to the other?
gray commissure
The central canal communicates with what structure at its most superior point?
the 4th ventricle
What does the white matter consist of(2)?
Bundles of axons and their myelin sheaths or we could say consist of tracts that ascend and descend
What separates the right and left sides of the SC on the posterior side?
posterior median sulcus
What separates the right and left sides of the SC on the anterior side?
anterior median fissure
Whats the difference between a sulcus and a fissure
fissure is a fairly wide and deep separation, whereas a sulcus is not as wide or deep although it still separates
Is there a posterior white commissure?
No just an anterior white commissure
What structure runs the length of the anterior median fissure?
The anterior spinal artery
What types of information is transferred via the dorsal root(column) of the spinal cord?
sensory
What types of information is transferred via the ventral root(column) of the spinal cord?
motor
What types of infuriation is transferred via the lateral root(column) of the spinal cord?
autonomic
The dorsal, ventral and lateral roots or columns of the spinal cord is a part of the _____ _____.
white matter
The sensory information is transported from the _____ to the _____ _____ via the _____ _____.
peripheral, spinal cord, dorsal root
What makes up the dorsal root ganglion?
contain a cluster of nerve cell bodies (and their associated dendrites) of these afferent sensory
neurons
What type of neurons make up the dorsal root ganglion?
unipolar or pseudo-unipolar neurons
Where do sensory impulses terminate?
§ AFFERENT SENSORY PATHWAYS:
v Sensations are conducted from the periphery toward the SCord, first through a sensory spinal
nerve
v then they follow the DORSAL ROOT
v then the dorsal root divides into the DORSAL ROOTLETS
v THEN THEY TERMINATE IN THE POSTERIOR HORN OF THE GRAY MATTER IN THE SCORD
The cross section of the spinal cord is both _____ and _____.
bilateral and symmetrical
What is the function of the ventral rootlets?
Ventral (anterior)
§ VENTRAL ROOTLETS exit the spinal cord near anterior (ventral) horns, and transmit efferent nerve impulses (action potentials) away from the cord;
§ Ventral rootlets then converge into the VENTRAL ROOT (NO VENTRAL ROOT GANGLION)
v these nerve impulses consist of somatic motor impulses to skeletal muscles and
v autonomic (sympathetic and parasympathetic) impulses to smooth muscles, thoracic and abdominal organs, glands, etc.
What is the Efferent somatic motor pathway?
EFFERENT SOMATIC MOTOR PATHWAYS:
- impulse comes from the brain down the SP
- Nerve cell body will be somewhere in the anterior horn
- the axon exits through the ventral rootlets to the ventral root
- joins to with the dorsal root ganglion to form the common spinal nerve
- terminates on skeletal muscle fibers
What is the Efferent autonomic pathways?
EFFERENT AUTONOMIC PATHWAYS:
v Nerve cell bodies are located in the lateral horn
v Autonomic nerve cell bodies will exit the same as Efferent somatic motor pathways
v Axon continues from that nerve cell body and then terminates on organs and tissues that have autonomic innervation
Dorsal (posterior) and ventral (anterior) root unite to form ?
The common spinal nerve
What is the difference between Afferent and Efferent nerves?
Afferent is sensory while Efferent is motor or autonomic
How many Laminae of Rexed are located in gray matter?
10
Laminae Rexed 1-6 are located where? What impulse information do they transmit?
- Dorsal horns of the gray matter;
- Laminae 1 =fast pain/acute pain(A-alpha)
- Laminae II and III (together are often referred to as the substantia gelatinosa): associated with Type C neurons and slow pain transmission
- Laminae III, IV, V, VI: primary neurons that are transmitting other sensations will terminate in one of these laminae of Rexed
Laminae Rexed 7-9 are located where? What impulses do they transmit?
Laminae VII – IX of ventral (anterior) horn contain cell bodies of efferent somatic motor neurons to skeletal muscles
- Lamina of Rexed VII is located in the LATERAL horn: AUTONOMIC PATHWAY
- the ventral horn is where nerve cell bodies for LOWER MOTOR NEURONS that exit the SCord and
transmit efferent somatic motor pathways to skeletal muscle fibers
Where is Laminae Rexed 10 located, and what is it associated with?
v Neurons that are going to cross from one side of the SCord to the other are going to cross here at the lamina of Rexed X. A point of crossover(gray comminsure).
v Notice that the lamina of Rexed X is right around the central canal of the SCord
What is another name for Laminae Rexed 1?
(aka, lamina marginalis)
Laminae 2 and 3 together are called?
the substantia gelatinosa
Small tract of white matter just off the dorsal horn is called the?
tract of Lissauer-specifically related to pain pathways
the meninges surrounding the spinal cord is continuous with?
the meninges surrounding brain
Characteristics of the Dura mater?
o around the SCord, the dura mater is only one
single layer that DOES NOT ADHERE TO VERTEBRAE
o unlike the brain, the SCord dura mater has a
space between the DURA MATER and the
VERTEBRAL SPACE that is called the EPIDURAL SPACE
Under the Dura mater is the?
Underneath the dura mater is the subdural space: more of a potential space (than a real space) with thin film of fluid
What space lies under the subdural space of the meninges of the SC?
Arachnoid mater;
o Has extensions of the arachnoid
o has lots and lots and lots of small, fragile vessels and CSF in the subarachnoid space
how does CSF enter the Subarachnoid mater?
§ from the 3 foramina, from the 4th ventricle;
§ moves into the subarachnoid space around
the brain;
§ and the subarachnoid space around the brain
is continuous with the subarachnoid space around the SCord.
o Subarachnoid space: continuous with cranial
subarachnoid space; filled with cerebrospinal
fluid and weblike extensions of arachnoid
o Ends at level of S2 vertebra along with dura
mater
Below the Subarachnoid mater lies the?
Pia mater
What are the characteristics of the Pia mater?
o Firmly attached to the SCord
o Thin vascular, connective tissue covering spinal
cord and nerve roots
o Below conus medullaris, pia mater continuous
with filum terminale, pierces dura mater and
arachnoid, and blends with connective tissue
behind coccyx
o On each side, pia mater attached to dura mater
by 22 denticulate (means tooth-like) ligaments, which anchor the cord
§ The denticulate ligaments: is where the pia mater extends outward and attaches to the dura mater
§ Extension of the pia mater, out through the arachnoid mater, that attaches to the dura mater.
§ That’s sort of a way of attaching the SCord, holding it in place, giving it a foundation
Cervical nerves 1-8 lie approximately at what level of the spinal column in the adult?
Nerve/vertebrae C: 1 - C : 1 C: 2 - C: 2 C: 3 - C: 2-3 C: 4 - C: 3-4 C: 5 - C: 4-5 C: 6 - C: 5 C: 7 - C: 6 C: 8 - C: 6-7
