Vertebral Column Flashcards
What movements can the vertebral column do?
- flexion
- extension
- lateral bending
- rotation
primary curvatures of spine?
- thoracic
- sacral
- formed prenatal
- concave anteriorly
secondary curvatures of spine?
- cervical (6 months)
- lumbar (1 year)
- develop after birth
- concave posteriorly
kyphosis?
- excessive rounding of thoracic curvature
- hunchback
- roundback
lordosis?
- lumbar curvature excessive curving
- swayback
what passes through the vertebral foramen?
spinal cord
what is the zygapophyseal joint?
- joint between articular processes of vertebrae
- limits and guides movement
what passes through the intervertebral foramen?
- dorsal root ganglion
- spinal nerves run through
what makes cervical vertebrae unique?
- small vertebral body and large foramen to accommodate cervical enlargement of spinal cord
- transverse process includes anterior and posterior tubercles and transverse foramen (C1-C6 for vertebral artery)
- short and bifid spinous processes (C2-C5)
- C6 and C7 (longest) have long spinous processes
Unique characteristics of Atlas (C1)?
- no body or spinous process
- has anterior and posterior arches
- superior articular process is flat and strong, holds cranium, articulates with occipital condyles
what is the lateral atlanto axial joint?
-joint between the inferior articular facets of C1 and the superior articular facets of C2
what is the median atlanto axial joint?
-joint between facet for dens of C1 and the facet for atlas on the dens of C2
what is the transverse ligament of C1?
- divides foramen in two
- foramen for dens holds the dens of C2 in place
- posterior is the vertebral foramen for spinal cord
why is the dens important?
-provides the pivot of C1 to rotate the head
what is the course of the vertebral artery in the cervical region?
- vertebral artery branches off the subclavian artery
- it ascends to base of C6, skips C7
- runs through transverse foramina from C6 to C1
- exits C1 and passes posteriorly on posterior arch of C1 and enter foramen magnum to cranium
- the two vertebral arteries unite in brain to form basilar artery
Unique characteristics of thoracic vertebrae?
- superior and inferior costal facets on the body to articulate with ribs
- demi facets articulate with the same head of rib
- long transverse processes with transverse costal facets which articulate with the tubercle of rib
Unique characteristics of lumbar vertebrae?
- accessory process on posterior surface of transverse process
- mammillary process on posterior surface of articular processes
- these serve as muscle attachments
Unique characteristics of sacrum?
- 5 vertebrae fused
- superior surface of S1 is the base, anterior edge is the promontory
- Ala articulate with hip bone
- 4 pairs of sacral foramina are for the passage of anterior and posterior rami of S1 to S4 spinal nerves
- median crest is the fusion of spinous processes
- intermediate crest is the fusion of articular processes
- lateral crest is the fusion of transverse processes
- sacral hiatus is the formed by lack of lamina of S4 and S5, leads to sacral canal
- auricular surface forms the sacral iliac joint
what are intervertebral discs and their parts?
- provide shock absorption between vertebrae, disc compresses to move
- outer concentric fibrous rings are the annulus fibrosis, degenerate with aging
- gelatinous central mass is the nucleus pulposus, most of it is water, dehydrates with aging (disc herniation)
- no IV discs between C1 and C2 because of the dens
- lowest IV disc is between L5 and S1
Ligaments of spine?
- anterior longitudinal ligament
- attach to anterior surface of sacrum and anterior and lateral sides of vertebrae
- attaches to anterior arch of C1
- prevents hyper extension - posterior longitudinal
- attaches to posterior side of vertebral body and runs in vertebral foramen
- at base of cranium, continues with tectorial membrane
- limits hyper flexion of spine - ligamentum flavum
- between adjacent lamina
- yellow ligament - interspinous ligament
- in between adjacent spinous processes
- weak - supraspinous ligament
- attaches adjacent tip of spinous processes
- becomes nuchal ligament
Three layers of meninges?
- dura mater
- thick and fibrous
- tapers inferiorly at S2 level and forms as a cord called filum terminale externum, attaches to coccyx
- spinal nerves have dural sleeves - arachnoid mater
- thin and avascular
- close with dura mater, CSF underneath presses top two layers together - pia mater
- thinnest layer
- denticulate ligament is lateral extension of pia, 21 pairs, alternates with spinal nerves, posterior to anterior nerve rootlets, anterior to posterior rootlets
- filum terminale (L1-L2), pia mater becomes this and anchors cord to dural sac inferiorly
- cauda equina is bundle
intermeningeal spaces?
- epidural space
- between bone and dura
- filled with fat and veins around spinal cord - subdural space
- between dura and arachnoid
- small space due to CSF but can bleed in this space - subarachnoid space
- CSF filled space between arachnoid and pia
where does spinal cord end?
- L1 or L2
- forms conus medullaris as it tapers
- continues with filum terminale and cauda equina
two enlargements of spinal cord?
- cervical enlargement
- C4 to T1 - lumbosacral
- L1 to S3
-these correspond to segments that innervate upper and lower limbs
Gray and white matter of spinal cord?
- gray matter on the inside contains nerve cell bodies
- anterior horn contains motor neurons (efferent, ventral)
- posterior horn contains sensory neurons (afferent, dorsal)
- lateral horn is found between T1-L2 (IML- intermedial lateral cell column) - white matter on outside contain myelinated axons
Dorsal root ganglion?
- groups of neurons outside of CNS
- pseudo unipolar neurons
- synapse with sensory neurons in dorsal horn of spinal cord
Where does the dorsal and ventral rami go?
- dorsal
- innervates deep back muscles and overlaying skin - ventral
- innervates rest of body, anterior lateral of body and wall and upper and lower extremities
- usually thicker
How many spinal nerves are there?
31 pairs of spinal nerves:
- 8 cervical (C1 is above C1 vertebrae, C8 nerve is below C7 vertebrae)
- 12 thoracic (T1 nerve is below T1)
- 5 lumbar
- 5 sacral
- 1 coccygeal
- they exit intervertebral foramen
- the higher the cord, the shorter the spinal nerves
Peripheral vs central nervous system?
- central
- brain and spinal cord - peripheral
- somatic (voluntary)
- autonomic (involuntary) includes sympathetic and parasympathetic (controls organs in rest or stress)
Responses of sympathetic nervous system?
- fight or flight
- dilate pupils
- inhibit salvation
- increase heartbeat
- relax airways
- inhibit stomach
- stimulate release of glucose, inhibit gall bladder
- inhibit intestines
- secrete epinephrine and nor
- relax bladder
- promote ejaculation and vaginal contraction
Responses of parasympathetic system?
- rest and digest
- constrict pupils
- stimulate saliva
- slow heartbeat
- constrict airways
- stimulate stomach
- inhibit release of glucose, stimulate gall bladder
- stimulate intestines
- contract bladder
- promote erection of genitals
Two neuron chain in autonomic system?
- first neuron
- sympathetic IML (T1-L2)
- parasympathetic (brainstem, gray matter of S2-S4) - second neuron
- sympathetic ganglia
- parasympathetic ganglia
- pre ganglionic or post ganglionic
Sympathetic ganglia?
- paravertebral (sympathetic chain) ganglia
- meets inferiorly to form ganglion impar - pre vertebral ganglia (pre aortic)
- associate with celiac ganglion, superior mesenteric ganglion, and inferior mesenteric ganglion
Pre and post ganglionic fibers of sympathetic nervous system?
- pre fibers
- white ramus (T1-L2)
- myelinated
- fibers go through ventral root and synapse with neurons in sympathetic ganglia - post fibers
- gray ramus (all levels of sympathetic chains)
- unmyelinated
- paravertebral ganglia
Rami communicantes?
- white ramus, communication between spinal nerves and paravertebral sympathetic ganglia
- gray ramus, fibers from ganglion back to nerves
Abdominopelvic splanchnic nerves?
- T5-T12 preganglionic fibers form splanchnic nerves
- greater
- lesser
- least
- runs through diaphragm into abdomen
Parasympathetic ganglia?
- S2 to S4 contain first neurons, sacral origin, not spinal nerves, but from pelvic splanchnic nerves
- nerves are very long to parasympathetic ganglion to inside of target organs, post synaptic fibers are short and run inside organs