Unit 1 - III. Vertebral Column / Spinal Column Flashcards
What is the number of vertebrae in a typical adolescent?
33 segments
What is the number of vertebrae in a typical adult?
26 segments
What is the number of vertebrae in the typical spine?
24 segments
What constitutes the spine?
the 24 presacral segments; the cervical, thoracic and lumbar vertebrae
How many segments unite to form the typical sacrum?
5 segments
How many segments unite to form the typical coccyx?
4 segments
What does the term “cervical” refer to?
the region of the neck
What is the typical number of segments in the cervical region?
7 segments
What does the term “thoracic” refer to?
breast plate or chest; it referred to the armor bearing region of the torso
What other term is often used to identify the vertebral segments of the chest?
the dorsal segments; the dorsals
What is the typical number of segments in the dorsal or thoracic region?
12 segments
What does the term “lumbar” refer to?
the loin; the region between the rib and the hip
What is the typical number of segments in the lumbar region?
5 segments
What does the term “sacrum” refer to?
the holy bone or holy region
What does the term “coccyx” refer to?
a cuckoo birds’ bill or cuckoo birds’ beak
Which region of the spine is more stable in terms of the number of segments/vertebrae?
the cervical region
Which variations account for the disparity in number and morphology of vertebrae within the population?
sexual dimorphism or gender variation, ontogenetic variation (growth variation or age variation), geographic variation or population-based variation, and idiosyncratic variation (individual variation)
What is the length of a typical male spinal column?
about 70 centimeters or 28 inches
What is the length of a typical female spinal column?
about 60 centimeters or 25 inches
What is the difference in length between a typical male and typical female spinal column?
about 3 inches
What is the length of the male cervical region (both measurements)?
about 12 centimeters or 5 inches
What is the length of the male thoracic region (both measurements)?
about 28 centimeters or 11 inches
What is the length of the male lumbar region (both measurements)?
about 18 centimeters or 7 inches
What is the length of the male sacrum (both measurements)?
about 12 centimeters or 5 inches
Based on the numbers for individual regions of the vertebral column, what is the length of the male spine (both measurements)?
about 58 centimeters or 23 inches
How does the vertebral column participate in protection of neural tissues?
the spinal cord and beginning PNS are located within the vertebral segments
How does the vertebral column participate in protection of the viscera?
ribs are attached to vertebrae to form the thorax thus protecting the heart and lungs
What parts of the body are supported by the vertebral column?
the head, upper extremities, ribs, viscera, and pelvis
How does the vertebral column participate in skeletal formation?
ribs are formed from the costal process of the embryonic vertebral template
What levels of the vertebral column specifically accommodate weight-bearing transfer?
S1-S3 at the auricular surface
Distinguish between motion and locomotion.
motion is movement without travel; locomotion is movement to a new site or location
What is specifically responsible for shape and position of the human frame?
comparative anterior vs. posterior height of the vertebral body and comparative anterior vs. posterior height of the intervertebral disc
How does the vertebral column accommodate transmission?
the peripheral nerve communicates with the central nerve system via the intervertebral foramen
What organ(s) is (are) specifically associated with the horizontal axis of the skull?
the eye and the vestibular apparatus of the inner ear
How is the vertebral column involved in stabilization of visceral function?
integrity of the spinal column enhances appropriate nerve system control of viscera
When does the embryonic disc form?
second week in utero
When does gastrulation occur or a 3-layered embryo form?
third week in utero
What are the 3 layers of the embryo called?
ectoderm, mesoderm, endoderm
Invagination of ectoderm along the primitive streak gives rise to what embryonic structure?
notochord
What is the name given to the mesoderm that will give rise to the vertebral column?
paraxial mesoderm
What does paraxial mesoderm give rise to that will form the vertebral column?
somites
Name the areas of cellular differentiation formed within the somite.
sclerotome, myotome and dermatome
What part of the somite will give rise to the vertebral column?
sclerotome
List, in order, the names of the succesive vertebral columns formed during development?
membranous, cartilaginous, skeletal or osseous
Migration of sclerotomes to surround the notochord forms what developmental feature?
the perichordal blastema
The perichordal blastema gives rise to what processes?
neural processes and costal processes
What is the name of the artery located between adjacent perichordal blastemae?
intersegmental artery
Cell proliferation within the perichordal blastema will result in what features?
a loose cranial sclerotomite and a dense caudal sclerotomite
What forms between the sclerotomites of a perichordal blastema?
the intrasclerotomal fissure (fissure of von Ebner)
The intrasclerotomal fissure (fissure von Ebner) gives rise to what developmental feature?
the perichordal disc
The perichordal disc is in the presumptive location of what adult feature?
the intervertebral disc
What is the earliest embryonic feature that will identify the position of the adult intervertebral disc?
the intrasclerotomal fissure (fissure of von Ebner)
The union of a dense caudal sclerotomite and a loose cranial sclerotomite from adjacent perichordal blastemae gives rise to what feature?
the vertebral blastema
What vessel will be identified adjacent to the vertebral blastema?
the segmental artery
When will cartilage first form in the membranous vertebral blastema?
beginning in the 6th embryonic week
What is the name given to the replacement of mesoderm by cartilage?
chondrification
Chondrification is first identified in which region of the embryonic vertebral column?
the cervical region
What are the names given to the centers of chondrification within the vertebral blastema?
centrum center, neural arch center, transverse process center
How many centers of chondrification typically appear in the vertebral blastema?
six… 2 for the centrum, 2 for the neural arch, 2 for each transverse process
What is the earliest time that centers of ossification appear in the cartilaginous vertebra?
during the 7th embryonic week
Ossification begins in which region of the embryonic vertebral column?
the lower cervical-upper thoracic region
What is the name given to centers of ossification based on time of appearance?
primary centers appear in utero, secondary centers appear after birth
What is the name given to centers of ossification appearing in utero?
primary centers
What is the name given to centers of ossification appearing after birth?
secondary centers
What is the ratio of primary to secondary centers of ossification for a typical vertebra?
3 primary centers: 5 secondary centers
What are the names of the primary centers of ossification for a typical vertebra?
centrum centers and neural arch centers
How many primary centers of ossification appear in the typical vertebra?
three… 1 for the centrum, 2 for the neural arches
What is the classification of the joint forming between primary centers of ossification?
cartilage synchondrosis / amphiarthrosis synchondrosis
What are the names of the synchondroses forming between primary centers of ossification in the typical vertebra?
neurocentral synchondrosis and neural arch synchondrosis
What are the names of the five secondary centers of ossification for a typical vertebra?
tip of the transverse process, tip of the spinous process, epiphyseal plate centers
How many secondary centers of ossification appear in the typical vertebra?
five… 1 for the tip of each transverse process, 1 for the tip of the spinous process, 1 for each epiphyseal plate
What is the classification of the joint forming between secondary centers of ossification and the rest of the typical vertebra?
cartilage synchondrosis / amphiarthrosis synchondrosis
What are the names of the synchondroses forming between secondary centers of ossification and the rest of the typical vertebra?
tip of the transverse process synchondrosis, tip of the spinous process synchondrosis, and epiphyseal ring synchondrosis
What is the range of appearance for secondary centers of ossification of a typical vertebra?
during puberty, typically ages 11-16 years old
What are the three basic osseous parts of a vertebra?
the vertebral body, vertebral arch, and the apophyseal regions
What is formed by the vertebral body and vertebral arch?
the vertebral foramen
What is the general shape of the vertebral body at each region of the spine?
cervical - rectangular; thoracic - triangular; lumbar - reniform
What is the name given to the compact bone at the superior and inferior surfaces of the vertebral body?
superior epiphyseal rim, inferior epiphyseal rim
What is the central region at the superior and inferior surfaces of the vertebral body called?
cancellous or spongy bone
What is the name given to the cartilage found at the superior and inferior surface of a developing vertebral body?
superior epiphyseal plate, inferior epiphyseal plate
What are the names of the openings found around the margins of the vertebral body?
nutrient foramina or vascular foramina
What large opening is usually observed at the back of the vertebral body?
the basivertebral venous foramen
What is the name of the vessel entering the nutrient or vascular foramen?
osseous artery
What is the name given to the large vessel exiting the back of the vertebral body?
the basivertebral vein
What is the semicircular region of bone attached to the back of the vertebral body called?
the vertebral arch
What is the name given to the anterior part of the vertebral arch?
the pedicle
What is the name given to the posterior part of the vertebral arch?
the lamina
What is the name given to the intermediate part of the vertebral arch where the transverse process and articular processes attach?
the lamina-pedicle junction
What is the name of the feature located at the upper and lower surfaces of the pedicle?
the superior vertebral notch or superior vertebral incisure; the inferior vertebral notch or inferior vertebral incisure
What is the generic orientation of the pedicle at each region of the spine?
cervical - posterolateral
thoracic - posterior, slight lateral
lumbar - posterior
All lamina are oriented in what direction?
posterior and median
What is the name given to the overlap of laminae seen on X-ray?
shingling
What ligament will attach to the lamina?
the ligamentum flavum
What is the name given to abnormal bone at the attachment site of the ligamentum flavum?
para-articular process
What classification of bone will para-articular processes represent?
accessory bone
What is the name given to the lamina - pedicle junction at each region of the spine?
cervical - articular pillar; thoracic and lumbar - pars interarticularis
What is the name given to the junction of the vertebral arch - spinous process on lateral X-ray?
the spinolaminar junction