vertebral column, bony thorax Flashcards
intervertebral discs- pad between vertebrae
cushion like pad composed of 2 parts. nucleus pulposus- inner gelatinous nucleus that gives the disc its elasticity and compressibility. anulus fibrosus- outter collar composed of collagen and fibrocartilage
vertebral column
chain of 33 vertebrae and intervertebral discs. cervical (7)- vertebrae of neck. thoracic(12)- vertebrae of thoracic cage. lumbar(5)- vertebra of lower back. sacral(5)- bone inferior to lumbar vertebrae. coccygeal(4)- terminus of vertebral column. functions: supports skull and trunk, allows movement, protects spinal cord, absorbs stress from walking, running and lifting. provides attachment for limbs, thoracic cage, and postural muscles. transmits weight of trunk to lower limbs. surrounds and protects spinal cord. flexible curved structure containing 26 irregular bones (vertebrae). birth c shaped. 3 s shaped. secondary curvatures; cervical and lumbar curvatures that develop after crawling and walking.
body (centrum)
anterior weight bearing region
vertebral arch
composed of pedicles and laminae that along with centrum enclose vertebral foramen
vertebral foramina
together make up vertebral canal for spinal cord
intervertebral foramina
lateral openings between adjacent vertebrae for spinal nerves
seven processes per vertebra
spinous process, transverse processes, superior articular processes, inferior articular processes
spinous process
projects posteriorly
transverse processes(2)
project laterally
superior articular processes(2)
protrude inferiorly
c1 and c2= atlas and axis
have unique features
atlas c1
no body or spinous process, consists of anterior and posterior arches and 2 lateral masses, superior surfaces of lateral masses articulate with occipital condyles. “yes” motion, flat, no body, supports the skull
axis c2
dens projects superiorly into the anterior arch of the atlas, dens is a pivot for the rotation of the atlas, “no” motion, dens (odontoid process) provides rotational movement
cervical vertebrae
seven total, smallest and lightest, transverse foramina- holes in, transverse processes- passage of the vertebral arteries, bifid spinous process for the nuchal ligament
thoracic vertebrae
t1- t12, all articulate with ribs at facets and demifacets, long spinous process, location of articular facet allows rotation of this area of spine, twelve total, costal facets- attachment points for the 12 pairs of ribs, spinous process is pointed and angled downward
lumbar vertebrae
L1-L5, short, thick pedicles and laminae, flat, hatchet shaped spinous processes, orientation of articular facets, locks lumbar vertebrae together, so as to prevent rotation, five total, thick stout bodies, blunt squarish spinous process, largest of all vertebrae, articular processes face laterally and medially
sacrum (fusion of s1-s5)
fusion begins by age 16 and finishes by age 26, 5 fused vertebrae, forms posterior wall of pelvis, articulates with L5 superiorly, and with auricular surfaces of hip bones laterally. articulates with pelvic bones and forms posterior wall of pelvic cavity
coccyx (c01- c04)- tailbone
fuse by age 20, 3-5 (4) fused vertebrae, articulates superiorly with sacrum, provides attachment point for muscles of the pelvic floor
thoracic cage
composed of thoracic vertebrae, sternum, ribs, and their costal cartilages. function is to protect vital organs of thoracic cavity. supports shoulder girdle and upper limbs, provides attachment sites for many muscles, including intercostal muscles used during breathing. conical enclosure for lungs and heart, attachment point for pectoral girdle and upper limbs, expands and contracts for respiration.
sternum (breast bone)
3 fused bones, manubrium-clavicular notches, jugular (suprasternal) notches, and sternal angle (angle of Louis) articulates with clavicle and ribs 1 &2, body-(gladiolus) articulates with costal cartilages of ribs 2-7, xiphoid process- site of abdominal muscle attachment (not ossified until age 40)
ribs
12 pairs, all attach posteriorly to thoracic vertebrae, pairs 1-7- true (vertebrosternal) ribs attach directly to the sternum by individual costal cartilages. false (vertebrochondral) ribs 8-12- lack independent connection to sternum, ribs 8-10 attach to costal cartilage of rib 7. Ribs 11-12 floating (vertebral) ribs, no attachment to sternum
structure of a rib (main parts)
head- articulates posteriorly with facets(demifacets) on bodies of 2 adjacent vertebrae, neck, tubercle- articulates posteriorly with transverse costal facet of same numbered thoracic vertebra, shaft
