anatomy final

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anatomy final
2014-05-08 00:33:16
angelica cute

for some cute girl angelica
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  1. what is the spinal cord? what does it do?
    “information highway”cylinder of nervous tissue that connects the brain and the lower body
  2. where (anatomically) is the spinal cord? how big is it?
    spans from the brainstem at the foramen magnum, through the vertebral canal to the inferior margin of L1

    45 cm long, 1.8cm thick & occupies ⅔ of vertebral canal
  3. what does the spinal cord contain?
    the neural routes
  4. what are the 4 functions of the spinal cord?
    • conduction
    • neural integration
    • locomotion
    • reflexes
  5. what is conduction?
    the nerve fiber bundles CONDUCT info up & down the cord, connecting the body to other parts of itself and to the brain
  6. what is neural integration?
    the spinal neurons receive input from many sources, integrate (aka combine) the information and perform some action/function

    --they get info from different nerves, they combine this information from each nerve to figure out what is happening to the body and respond to it!
  7. what is locomotion?
    repetitive, coordinated contractions of several muscle groups of the limbs.

    central pattern generators provides the basic motions by integrating (aka combining!) input from nerves.

    examples of simple repetitive movements are WALKING!!! EATING!!!! you dont have to think about walking or the process of eating.
  8. what are reflexes?
    involuntary stereotyped responses to stimuli

    ---automatic responses to certain environmental stimuli for example fire... when you feel something hot like fire, you move away from it instantly without thinking.
  9. how many PAIRS of spinal nerves are there? where do they pass through?
    31 pairs

    first pair passes between the skull and C1

    the rest pass through intervertebral foramina
  10. segment
    ONE pair of nerves in the spinal cord makes up a segment
  11. anterior median fissure
    a groove along the anterior midline of the spinal cord (a groove that basically goes right down the center from top to bottom)

    deeper than posterior median sulcus
  12. posterior median sulcus
    a groove that goes down the midline of the spinal cord that's SHALLOW (this Sulcus = Shallow)
  13. what are the regions of the spinal cord?
    • cervical
    • thoracic
    • lumbar
    • sacral

    (same as the back :) )
  14. in what two areas is the spinal cord a little bit thicker than everywhere else? what makes them so special?
    • cervical enlargement
    • --the nerves of the upper limbs come from here so it has to be thicker

    • lumbar enlargement
    • --the nerves of the Lower (L for lower and lumbar) and pelvic region come from here
  15. medullary cone
    inferior to the lumbar enlargement the cord tapers (goes from big to thinner)
  16. cauda equina
    means a horse's tail in latin 

    named that because it looks like one

    a bundle of nerves that occupy the vertebral canal from L2 to S5
  17. meninges
    three fibrous connective tissue membranes that encloses the brain and spinal cord that protect them

    ---meningitis is the infection of this tissue and its so deadly because it's supposed to protect your brain and spinal cord
  18. what are the 3 layers of the meninges from superficial (outside) to deep?
    • Dura mater 
    • Arachnoid mater
    • Pia mater

    (Damn Angie's Pussy :P)
  19. dural sheath
    sheath is another word for a cover

    its a loose fitting sleeve around the spinal cord formed by the dura matter
  20. epidural space
    space between the dural sheath and the vertebral bones (epi= above.. above dural)

    filled with blood vessels, adipose tissue & loose connective tissue
  21. gray matter
    internal and butterfly shaped

    contains little myelin, somas, dendrites and proximal parts of the axons of neurons
  22. why is the gray matter important?
    center of all neural integration (combination of all of the nerves signals) in the spinal cord
  23. what does the core of the gray matter consist of?
    2 posterior horns

    2 anterior horns

    2 lateral horns

    one of each on each side
  24. gray commissure
    connects left and right sides of the gray matter

    Commissure Connects
  25. posterior dorsal root
    carries sensory nerve fibers
  26. posterior horns contain
    sensory soma and interneurons

    Posterior= Interneurons, Sensory Soma

    (PISS, i know gross)
  27. Anterior horns contain
    the Large somas of the somatic motor neurons

    (you got a LARGE Anterior ma ;) )
  28. Lateral horns contain
    autonomic- sympathetic motor neurons

    visible from each side of T2 to L1
  29. white matter
    its external, surrounds the grey matter

    contains a lot of myelin

    composed of tracts
  30. tracts
    subdivisions of the columns that are made up of bundles of axons that carry signals from one part of the central nervous system to another

    compose the white matter
  31. the white matter is arranged in:
    3 pairs called columns or funiculi

    they are the posterior, lateral and anterior COLUMNS

    (white matter has columns, grey has horns; same names)
  32. ascending tracts
    ascending means to the top

    carries SENSORY info up the spinal cord
  33. descending tracts
    descending means down

    conducts MOTOR impulses down
  34. decussation
    crossing over of the tracts from one side of the body to the other
  35. contralateral
    opposite sides of the body
  36. ipsilateral
    same side of the body
  37. sensory signals typically travel across how many neurons from their origin?
  38. first order neurons
    detects stimuli and transmits signals to the spinal cord or brain stem
  39. second order neurons
    continues from first order up to the gateway called the thalamus at the top of the brainstem
  40. third order neurons
    carries the signal from the thalamus to the sensory region of the cerebral cortex
  41. gracile fasciculus
    carries signals from the midthoracic and lower parts of the bodies 

    composes from T6 down the entire posterior column

    carries signals for vibration, visceral pain, deep and discriminative touch and proprioception from the lower limbs and trunk
  42. proprioception
    nonvisual sense of the position and movements of the body

    ---eyes closed you know you're laying on the bed and you can pick up your phone without opening your eyes
  43. cuneate fasciculus
    joins the gracile fasciculus at the T6 level

    carries the same signals from the T6 UP.
  44. spinothalamic tract

    anterolateral system that carries signals for pain, temp, pressure, tickle, itch and light touches

    here, the first order neurons go up to the posterior horn of the spinal cord

    sensory signals arrive at the cerebral hemishphere
  45. spinoreticular tract

    travels up the anterolateral system and carries pain signals from tissue injury
  46. how do signals travel through the neurons in the spinoreticular tract?
    first order neurons enter the posterior horn and immediately synapse to the second order neurons

    decussate to the opposite anterolateral system, travel up the cord and end in the RETICULAR FORMATION (loosely organized core of grey matter) in the medullar and pons

    third order go from pons to thallamus

    fourth complete the path to the cerebral cortex