Embryology, Vertebral Column and Spinal Cord Flashcards
Life has two basic characteristics. What are they?
Metabolism and reproduction
The two types of human cells are
somatic cells for metabolism and sex cells for reproduction
Cell membrane is made up of
double layer membrane and proteins embedded or attached, cross talking with other cells
Remember stability vs. mobility
What is the nucleus of a cell?
the structure in the cell that contains the chromosomes, compresses the genetic information into the chromosomes
The mitochondria does what?
produces ATP, the power factory, have their own genetic material
Diploid cells refer to cells with…
two complete sets of chromosomes, one from each parent.
haploid cells refers to cells with…
the presence of a single set of chromosomes in an organism’s cells
sex cells replicate through
meiosis
how long does it take for an egg cell to go through meiosis?
2 weeks
how long does it take sperm cells to go through meiosis
64 days
What happens during week one of embryology
fertilization
cleavage is…
the equal distribution of cytoplasm from 2 to 8 cells, mainly replication
Blastocysts start what
differentiation, unequal distribution of cytoplasm
What happens during week 2 of embryology
implantation ( trophoblast cells invade endometrium and start to recruit cells for blood vessels to form placenta)
Inner cell mass develops into epiblast and hypoblast
What percentage of blastocysts fail to implant in the 1st two weeks?
30%
What happens in Embryology week 3?
- Formation of placenta
- Gastrulation (germ layers formed: Ectoderm, Mesoderm, and Endoderm)
-Formation of notochord
START EMBRYO PHASE
What happens in Embryology week 4?
Establishment of body plans, formation of somites: mesoderm, notochord as the axis
- segmental interaction of nervous system and somites
- primitive organs still nonfunctional
The dorsal somite gives rise to what?
the sclerotome and dermomyotome
-segmental distribution, muscles and bones develop independently: no origin and insertion at the beginning
Muscles have origins and insertions when they first form. True or False.
False
A lack of caudal neuropore closure during the closure of the neural tube causes what?
spina bifida
What happens with no closure of the neural tube in the cranial/rostal neuropore?
acephaly
the neural tube is part of which nervous system?
CNS
Motor neurons have two types. What are they?
somatic - axons expand outward to somites
visceral- axons expand to visceral motor ganglia
Neural crest is part of what?
the PNS
Somatic sensory neurons expand into whta?
the neural tube and somites
Autonomic nervous system is made up of what?
visceral motor ganglia
Which limb is formed first?
upper limb
By what week is an embryo almost fully formed?
week 9
Myotome and dermatome do what during development?
rotate with the limb rotation
Dermatomes are…
- map, huge variations among people and even within the same individual
When is the EMBRYO formed?
week3
When is the embryo considered a fetus?
week 9
Four curvatures of the spine are
-Cervical lordosis
-Thoracic kyphosis
- lumbar lordosis
-sacral kyphosis
Which two curvatures of the spine flex
thoracic kyphosis and sacral kyphosis
Which two curvatures of the spine extend
cervical lordosis, lumber lordosis
Curvatures do what?
provide flexibility, support, protection and shock absorption
C1 is the …
atlas
the atlas has no….
vertebral body or spinous process
c2 is the …
axis
the axis and the c1 vertebral body form the …
dens
*happens during development
Vertebral body is a
uncinate process
uncinate processes have what shape?
hook
The transverse process is
a groove and a foramen transversarium
Which cervical vertebra has no bifurcated spinous process?
C7
The Thoracic vertebrae body has/does what?
has a superior/inferior rib demi-facets, articulates with ribs
Which thoracic vertebrae are unique?
T1, T9-T12
The transverse process is the articulating facet of the thoracic vertebrae. True or false?
True
Lumbar vertebrae have the largest what?
Body
Mammillary process is the what?
superior process on costal process connected in the lumbar region with the back part of the superior articular process
Accessory process is the what?
an inferior tubercle of the lower thoracic vertebrae situated at the back part of the base of the costal process, which forms the beginnings of the original transverse process.
atlanto-occipital joint is during which movement of the head
yes
atlanto-odontoid joint is moved during which movement of the head
no
atlanto-axial joint has no what?
no disc
Between the vertebral bodies there are:
Intervertebral discs, uncovertebral joints
Discs are named according to what?
the superior vertebrae
ex. C4 disc is between C4 and C5
What is an anatomic landmark in the cervical region?
Dens
How do you know if an image is a CT scan?
bones are white
How do you know if a MRI is T1 or T2?
T1 - only the fat is white, under the skin is subcutaneous tissue/ fat
T2- both fat and water/fluid are white
What is the thinnest disc along the spine?
intervertebral discc
Zygapophyesal joints are also known as
facet joints
What percent of the population has a 6th lumbar vertebra?
10%
X-rays are usually in which view?
Anterior-posterior (AP) view
Anterior longitudinal ligament is _____ caudally and _____ cranially.
Broad, narrow
if opposite - lumbar disc herniation or tectorial membrane
Posterior longitudinal ligament is in the
vertebral canal
The tectorial membrane is the
specialized posterior longitudinal ligament in the cervical region
the ligament nuchae runs from
C6 to external occipital protuberance
Specialized ligaments in the cervical region are
Tectorial membrane, transverse ligament of atlas, apical ligament, alar ligament, ligament nuchae
Specialized ligaments in the lumbosacral region are
iliolumbar and lumbosacral ligaments
Functional spinal unit is
adjacent two vertebrae and 3 joints
The anterior column of the vertebral body withholds what percentage of stress along the spine?
70%
The posterior column arch witholds what percentage of stress along the spine?
30%
The anterior column of the FSU controls the
degrees of motion EXCEPT IN THE CERVICAL REGION
The posterior column arch controls the
types of motion
Facet joints do what in the sagittal plane?
FLX/EXT
Facet joints do what motion in the coronal plane?
L or R side bend
Facet joints do what motion in the transverse plane?
L or R rotation
Nucleus pulposus is
degenerated from notochord, difficult to heal after injury
Impingement of the ligamenta flava causes
spinal stenosis, Flx decrease the compression
Facet joint hypertrophy causes
degenerative change and nerve root impingement
Disk herniation has what types and grades
Buldge
Protrusion
Extrusion
Sequesteration
Increase in severity from top to bottom of list
Which two types of disc herniation benefit from Mckenzie extension and traction?
Buldge and protrusion
further grades of herniation do not benefit
In which two regions is it easiest to herniate a disc?
Cervical and Lumbar
Why do lumbar discs have a higher risk of herniation?
70% vs 30% or stress in lumbar, discs are so thin, don’t have much to be herniated.
- posterior and anterior ligament don’t provide enough support for lateral underside part of the disc
Nervous system has hundreds of subsystems. True or false?
True
Both the CNS/PNS have:
efferent (information issues out) and afferent (information flows in)
PNS divides into
Afferent:
sensory somatic
sensory motor
Efferent:
motor somatic - to skeletal muscles
motor visceral - cardiac and smooth muscles
- motor visceral has sympathetic and
parasympathetic
What is a ganglion?
a cluster of neuron cell bodies outside the CNS
What is a nucleus in relation to the nervous system?
A cluster of neuron cell bodies in the CNS
The CNS is made up of
Neurons, astrocytes, microglia, oligodendrocyte (myelin sheath), ependymal cells
The PNS is made up of
Neurons, satellite cells, and schwann cells (myelin sheath)
Spinal cord is developed from -
neural tube
Grey matter contains
dendrites and cell bodies of neurons. NON MYELINATED
- dorsal horn for sensory
-ventral horn for motor
- intermedial lateral horn
White matter is
axonal tracts - mainly myelinated
The central canal contains
CSF for nutrition and protection
The spinal canal is made up of
The vertebral canal which is the foramina from cervical vertebrae:7, Thoracic vertebrae:12, lumbar vertebrae:5. and the sacral canal which contains the sacrum:1
How many axon can a neuron have?
One. No matter how complicated.
Where does the spinal cord end?
T12~L2
Where does the spinal cord initiate?
the foramen magnum
The conus medullaris is the
cone shape at the end of the spinal cord
The cauda equina is the
end of the spinal cord where nerves go elsewhere. means quite literally horse tail.
Meninges from Deep to Superficial
Pia mater is inner, then arachnoid mater, then dura mater
Which meninge is strongest?
dura mater
What are the specialized ligament(s) in the dura mater
filum terminale externum
What are the specialized ligament(s) in the pia mater
denticulate ligament and filum terminal internum
What is the epidural space between?
the dura mater and the vertebral bony wall
What is the subdural space between?
the dural mater and the arachnoid mater
What is the subarachnoid space filled with?
CSF
Enlargements of the cervical region names and what they are for
the cervical plexus and brachial plexus
for neck and upper limbs
Enlargements of the lumbosacral region and what they are for
lumbar plexus and sacral plexus
for gluteal/groin areas and lower limbs
Which ligaments are formed by pia mater and where are they located?
Denticulate ligament and fulum terminale internum
*run longitudinally between the dorsal and ventral roots of the spinal cord and serve to suspend the spinal cord from side to side in the dural sac. The pia continues inferiorly from the end of the spinal cord (at the level of the second lumbar vertebra) as the filum terminale internum.
From superficial to deep, what’s the order of the meninges?
Dura, arachnoid, pia
