columna vertebral y medula espinal Flashcards
cuantas vertebras cervicales tiene un humano en promedio
7
C1 = ATLAS
C2 = AXIS
cuantas vertebras toracicas tiene un humano en promedio
12
each articulating with a pair of ribs
cuantas vertebras lumbares tiene un humano en promedio
5
large vertebrae to support the body’s weight
cuantas vertebras del sacro tiene un humano en promedio
5 fused vertebrae
cuantas vertebras del coccix tiene un humano en promedio
4
name the curvatures of the vertebral column
cervical curvature
thoracic curvature
lumbar curvature
sacral curvature
name the primary curvatures of the vertebral column
thoracic curvature
sacral curvature
- both present in the fetus
name the secondary curvatures of the vertebral column
cervical curvature: acquired when the infant can support the weight of its own head
lumbar curvature: acquired when the infant assumes an upright posture
name the key ligaments of the vertebral column
- anterior longitudinal ligament: connects adjacent bodies and the IVD along their anterior aspect
- posterior longitudinal ligament: connects adjacent bodies and IVD along their posterior aspect
- supraspinous ligament: between adjacent spinous processes
- interspinous ligament: between adjacent spinous processes
- ligament flava (ligamento amarillo): connect adjacent laminae; contain elastic fibers.
characteristics of C1 (atlas)
- doesn’t have a body or spinous process
- ringlike bone; superior facet articulates with occipital bone
whats the strongest cervical vertebra
C2 (axis)
characteristics of thoracic vertebrae
- heart-shaped body, with facets for rib articulation
- small circular vertebral foramen (the spinal cord passes through the vertebral foramen)
- long transverse processes (which have costal facets for rib articulation; T1-T10 only)
- long spinous processes (slope posteriorly and overlap the next vertebra below)
what is the largest vertebrae
L5
characteristics of the lumbar vertebrae
- kidney-shaped body, massive for support
- facets face medial or lateral direction, which permits good flexion and extension
- spinous process is short
characteristics of the sacrum
- large, wedge-shaped, which transmits body weight to pelvis
- five fused vertebrae, with fusion complete by puberty
characteristics of the coccyx
- Co1 often not fused
- Co2 to Co4 fused
- no pedicles, laminae, spines
- remnant of our embryonic tail
cuales son las costillas verdaderas
ribs 1 - 7; they articulate with the sternum directly
cuales son las costillas falsas
ribs 8 - 10; they articulate with costal cartilages of the ribs above
cuales son las costillas flotantes
ribs 11 - 12; they articulate with vertebrae only
cuantas costillas tenemos
12
caracteristicas de una costilla tipica
contienen cabeza, cuello, tuberculo, cuerpo y angulo
son las costillas 3 al 9
cuales son las costillas atipicas y porque
1: es la mas ancha, corta y curvada, tiene 2 surcos para los vasos subclavios, tiene solo 1 cara articular para T1
2: tiene la tuberosidad del musculo serrato anterior
10 - 12: tiene solo 1 cara articular
11 y 12: no presentan cuellos ni tuberculos
partes del esternon
manubrio
cuerpo
apofisis xifoides
what is the spinal cord
it is a direct continuation of the medulla oblongata, extending below the foramen magnum at the base of the skull and passing through the vertebral (spinal) canal formed by the articulated vertebrae
name the features of the spinal cord
- 31 pairs of spinal nerves (8 cervical pairs, 12 thoracic pairs, 5 lumbar pairs, 5 sacral pairs and 1 coccygeal pair)
- each spinal nerve is formed by dorsal and ventral roots
- motor neurons reside in the spinal cord gray matter (anterior horn)
- sensory neurons reside in the spinal nerve dorsal root gangla
- ventral rami of spinal nerves often converge to form plexuses (a mixed network of nerve axons)
where does the spinal cord end
at a tapered region called the conus medullaris, which is situated at about the level of the L1-L2 vertebrae
where is the gray matter located in the spinal cord and the cerebral cortex
spinal cord: lie in the center of the cord, where they form a butterfly or H shaped region
cerebral cortex: surface of the brain
how is the grey matter divided in the spinal cord
posterior horn: receives sensory axons from the periphery
anterior horn: efferent axons exit the cord to enter a spinal nerve
characteristics of the white matter of the spinal cord
- it decreases as one continues inferiorly from rostral to caudal
- divided into dorsal, lateral and anterior funiculi (bundles) that contain multiple fiber tracts
characteristics of the dorsal (posterior) funiculus tract
ascending pathways that, generally speaking, convey proprioception (muscle and joint position), touch and tactile discrimination (size and shape discrimination) from the leg (fasciculus gracilis) and arm (fasciculus cuneatus)
characteristics of the lateral funiculus tract
ascending pathways that convey proprioception, pain, temperature, and touch sensations to higher centers, and convey descending pathways concerned with skilled movements and autonomic information to preganglionic neurons
characteristics of the anterior funiculus
some ascending pathways that convey pain, temperature, and touch, and descending pathways that convey information that facilitates or inhibits flexor and extensor muscles; reflex movements that control tone, posture, and head movements; and some skilled movements
what are lower motor neurons
they are the neurons of the anterior horn that innervate skeletal muscle.
lesions of these neurons or their axons in the peripheral nerve results in the loss of voluntary and reflex responses of the muscles and cause muscle atrophy. The denervated muscles exhibit fibrillations (fine twitching) and fasciculations (brief contractions of muscle motor units)
what are upper motor neurons
they are the neurons at higher levels in the CNS that send axons either to the brainstem or spinal cord.
in general, lesions of these neurons or their axons result in spastic paralysis, hyperactive muscle stretch reflexes, clonus (a series of rhythmic jerks), a “clasp-knife” response (muscle hypertonia) to passive movements, and lack of muscle atrophy (except by disuse)
what is ALS
it is a progressive and fatal disease that results in the degeneration of motor neurons in the cranial nerves and in the anterior horns of the spinal cord. Muscle weakness and atrophy occur in some muscles, whereas spasticity and hyperreflexia are present in other muscles.
