Ch2-Back: Key features Flashcards
-Long vert col and short spinal cord:
- In adults; spinal cord ends between LI and LII or to TXII or LII and LIII
- In neonates; extends to LIII or LIV
- Conus medularis-distal end
- Spinal nerves orig from spinal cord at oblique angles.
- filum terminale
- Cervical enlargment
- External surface marked by:
- Ant median fissure- Posterior median sulcus
- Posterolateral sulcus
-Intervertebral foramina and spinal nerves
- Exits vert canal laterally through interv. Foramina
- Pathology that occludes or reduces size of foramen can affect function of cord.
- Foramen bordered by zygapophysial joint-post, intervertebral disks-ant
-Innervation of back
- Post spinal nerves innervate intrinsic muscles
- extends into gluteal region and post head.
-Posterior spaces bet vert arches
-Wide gaps bet LI to LV
-Types of Joints
- Synovial: separated by cavity
- hyaline cartilage covering
- joint capsule consisting of inner vascular synovial membrane and outer fibrous (dense conn tiss) membrane
- articular discs, fat pads, tendons
- plane, hinge, pivot, bicondylar, condylar, saddle, ball&socket
- uni-axial, bi-axial, mult-axial
-Solid: no cavity but connective tissue linking adj surfaces.
- Fibrous:
- Sutures: skull, sutural ligament
- gomphoses: teeth, periodontal ligament
- syndesmoses: ligamentum flavum
- Carilaginous:
- synchondroses: 2 ossification centers in developing bones remain separate by cartilage.
- symphyses: 2 separet bones interconnected by cartilage. Intervertebral disks, pubic symphyses.in
-Joints between vert in back:
-A typical vert has 4 synovial-bet articular process, 2 symphyses-between vert bodies
- Symphyses bet vert bodies: by hyaline cart on each body and intervertebral disc
- anulus fibrosus, nucleus pulposus
-Movements of Joints bet vert arches (zygapophysial joints)
- Cervical: flexion, extention
- Thoracic: rotation
- Lumbar: limited flexion, extenstion
-Ligaments
- Anterior and Posterior longitidunal ligaments
- Ligamenta flava: on each side, pass bet laminae of adj vertebra.
- Supraspinous ligament-connects and passes along spinous process
- from CVII to sacrum
- Ligamentum nuchae-
- from CVII to skull- supports head, resists flexion, return head to anatomic, provide attachment for adj muscles.
-Interspinous Ligaments: pass bet adjacent vert spinous process. From base to apex of each spinous process, blending with supraspinous ligament post, ligament flava-ant on each side.
-Back Musculature-
-Superficial group: Superior appendicular to axial skeleton (Table 2.1)
- Deep group
- Spinotranversales: splenius capitis & cervicis (Table 2.3)
- erector spinae and tranversospinales (Table 2.4) (2.5)
- interspinales and intertransversarii (Table 2.6)
- Suboccipital muscles
- connect CI to CII and to base of skull. (Table 2.7)
-Thoracolumbar fascia
-Intro to Nervous System-
- gray matter- outer cell bodies
- white matter- axons and ventricles
Arteries
- Longitudinal vessels → segmental medullary arteries → arteria radicularis magna (artery of Adamkiewicz)
- 1 anterior spinal artery
- 2 posterior spinal artery
-Feeder arteries (segmental spinal arteries) → ant/post radicular arteries
→ seg medullary arteries
Veins (drain cord)
- 2 pairs on each side connect ant/post roots to cord
- 1 midline channel ll ant median fissure
- 1 mid passes along post med. sulcus
-Functional Subdivision of CNS–Somatic (sensory afferent, motor efferent): skin, skeletal muscle, voluntary muscle. Info from external:
-arise from somites
-cells that migrate anteriorly, give rise to limb & trunk muscles-Hypaxial
“ posteriorly, “ intrinsic muscles-Epaxial
- motor neurons-develop from spinal cord. All motor leave anteriorly.
- sensory neurons-develop from neural crest cells. All sensory info pass to posterior aspect of cord.
-Functional Subdivision of CNS–
Visceral (autonomic division of PNS-Sympathetic & Parasympathetic): guts, organs sys, smooth musc, glands. Info from internal.
-Visceral sensory neurons(gen visc afferent fibers)-arise from neural crest to medial tube and lateral developing body. Changes in viscera.
- Visceral motor neurons(g vis eff fib)-from cells in lateral tube and out of ant of tube to smooth muscle,cardiac,and glands.
- Preganglionic fibers-axons located inside cord
- Postganglionic fibers-axons outside cord.
- ganglion-cell bodies outside
- @ T1 to L2-sympathetic system. Innervates peripheral body and viscera
- @ cranial/sacral-parasympthetic system-only viscera.
- In cranial, associated w/ 4/12 cranial nerves (CN III, VII, IX, X)
- In spinal cord, T1 to L2, S2 to S4
Visceral sensory Innervation(Viseral afferents)-accompany visc motor.
- may follow symp fibers course entering cord @ levels same or diffrt.
- concerned w/ detecting pain w/ sympathetic
- w/ parasympathetic: mainly in IX and X, S2 to S4
- Viseral sensory fibers in IX-neck, pharynx - ” X-cervical viserca, thorax, abs - “ S2 to S4-pelvic, distal colon - involved w/ status of normal physiologic processes and reflex activities
