A&P Chapter 14 - Brain

  1. brain
    • protected by meninges
    • floats in CSF
    • weighs 3lbs
  2. CSF
    • located in ventricles
    • produced by choroid plexus
    • drains into thorax
    • mechanical protection
    • ideal chemical environment
    • exchanges nutrients and waste between blood and brain
  3. choroid plexus
    • network of capillaries that hangs off the 3rd ventricle
    • produces CSF
  4. hydrocephalus
    production of more CSF than is drianed
  5. ventricles
    • cavities within the brain
    • 4 ventricles: lateral (2), 3rd, 4th
  6. lateral ventricles
    midline of the brain
  7. 3rd ventricle
    small slit between R/L thalamus
  8. 4th ventricle
    space between brain stem and cerebellum
  9. parts of the brain
    • brainstem
    • diencephalon
    • cerebellum
    • cerebrum
  10. brainstem
    • medulla oblongata
    • pons
    • midbrain
  11. diencephalon
    • thalamus
    • hypothalamus
  12. medulla oblongata
    • continuation of the spinal cord that begins at the foramen magnum and ends at the pons
    • 1-2" long
    • pyramids on front surface
    • olive on front surface
    • all ascending and descending nerves pass through
  13. pyramids
    two bulges on front surface of MO where ascending and descending nerves decussate
  14. decussate
    nerve fibers cross over
  15. olive
    elevated region on front of MO that relays proprioceptive sensations up to cerebellum
  16. proprioception
    awareness of position and location of body parts without having to look
  17. medulla oblongata functions
    • cardiac center: regulates rate and strength of heartbeat
    • basic rhythm of breathing (2 sec in/3 sec out)
    • vasomotor center: regulates diameter of blood vessels
    • controls swallowing, vomiting, coughing, sneezing
    • reticular formation
    • origin of cranial nerves C8-C11
  18. pons
    • bridge or relay station that connects spinal cord to the upper parts of the brain
    • major regulator of breathing
    • 2 breathing centers: apneustic and pneumotaxic
    • origin of cranial nerves C5-C8
    • all motor signals coming from cerebrum or cerebellum pass through pons
  19. apneustic center
    keeps lungs from overfilling
  20. pneumotaxic center
    allows you to hold breath
  21. midbrain
    • connects upper and lower brain
    • origins of cranial nerves C3 and C4
  22. cerebral peduncles
    part of the midbrain that anchors cerebrum to brainstem
  23. tegmentum
    part of midbrain that helps both frontal lobe of cerebrum and cerebellum with fine motor control
  24. cerebral aqueduct
    small tube in midbrain that connects 3rd and 4th vesicles
  25. lemniscus
    white matter region of midbrain that helps convey sensations of touch, pressure, vibration
  26. tectum
    • posterior midbrain
    • contains corpora quadrigemina, superior colliculi, inferior colliculi
  27. corpora quadrigemina
    part of tectum that controls movements of the eyes, head, neck, trunk
  28. superior colliculi
    part of tectum that controls eye movement in response to visual stimulation
  29. inferior colliculi
    part of tectum that controls head movement in response to sound
  30. thalamus
    • part of the brain where sensations such as pain, temperature, touch, vision, and sound are first interpreted
    • gateway to the cerebrum
    • controls emotion and some memory
    • plays a role in cognition
    • contains 2 hemispheres connected by intermediate mass
  31. hypothalamus
    • directly below the thalamus
    • 4 regions: mammillary, tuberal, supraoptic, preoptic
  32. mammillary region
    region of hypothalamus that controls reflexes
  33. tuberal region
    region of hypothalamus that contains infundibulum
  34. infindibulum
    connects hypothalamus to pituitary
  35. supraoptic region
    region of hypothalamus where optic nerves cross over on way to upper brain
  36. preoptic region
    region of hypothalamus that controls all autonomic functions
  37. functions of the hypothalamus
    • HR
    • gland secretion
    • smooth/cardiac muscle contraction
    • peristalsis and gastric juice secretion
    • body temp
    • appetite and thirst
    • sleep
    • blood glucose levels
    • memory
    • sex drive
    • rage, aggression, and fear
    • pleasure and pain
  38. cerebellum
    • little brain
    • mostly gray matter
    • contains arbor vitae (white matter region)
    • separated from cerebrum by transverse fissure
  39. arbor vitae
    tree shaped region of white matter in the cerebellum
  40. functions of the cerebellum
    • gross body movements and coordination
    • posture and balance
    • skilled movements of the finger
    • emotional development
    • controls feelings of anger and pleasure
  41. reticular formation
    • vague region of the brain throughout the MO, pons, midbrain, thalamus, hypothalamus, and cerebellum
    • plays a role in sleep
    • controls HR and muscle tone
    • pain modulation
    • habituation
  42. pain modulation
    how a person deals with pain
  43. habituation
    ability to block out repeated stimuli related to sound
  44. cerebrum
    • large brain
    • controls all memory
    • speak and calculate
    • taste and smell
    • remember past and plan for future
    • shape, color, movement
    • translate words to thoughts and vice versa
    • interprets sound
  45. cortex
    • outside gray matter of the brain
    • folded
    • contains convolutions and fissures
  46. convolutions
    folds in the cortex of the cerebrum
  47. fissures
    deep grooves
  48. longitudinal fissure
    most prominent fissure that separates the cerebrum into R/L hemisphere
  49. sucli/gyri
    shallow grooves in the cortex
  50. corpus callosum
    fiber of the cerebrum that connects R/L hemisphere
  51. association fibers
    fibers of the cerebrum that transmit info between regions in the same hemisphere
  52. projection fibers
    fibers of the cerebrum that transmit info from cerebrum down to spinal cord and vice versa
  53. commissural fibers
    fibers of the cerebrum that transmit info from a point in one hemisphere to the exact same point in the opposite hemisphere
  54. main cerebral regions
    • motor
    • sensory
    • association
  55. motor area
    • entirely in frontal lobe
    • controls all motor activity in the body
    • 2 subregions: primary motor and motor speech
  56. primary motor area
    • controls voluntary contraction of every muscle in the body
    • almost all fibers decussate in MO
    • damage to this region causes paralysis
  57. motor speech area
    • aka Broca's area
    • allows translation of thought to speech
    • controls muscles of mouth and throat
  58. sensory area
    • sensory
    • visual
    • auditory
    • gustatory
    • olfactory
  59. primary sensory area
    • aka somatosensory
    • parietal lobe
    • localization of sensations
    • (sensory area)
  60. primary visual area
    • occipital lobe
    • interprets sensations of shape, color, movement
    • (sensory area)
  61. primary auditory area
    • temporal lobe
    • receives sensations of sound, rhythm, pitch
    • (sensory area)
  62. primary gustatory area
    • parietal lobe
    • receives all sensation related to taste
    • (sensory area)
  63. primary olfactory area
    • temporal lobe
    • receives all sensations related to smell
    • (sensory area)
  64. association areas
    • somatosensory
    • visual
    • gnostic
    • auditory
    • premotor
    • frontal eye field
  65. somatorsensory area
    • parietal lobe
    • analyzes sensation received from the primary sensory area and allows reaction
    • determines size, shape, texture of an object without actually seeing it
    • (association area)
  66. visual area
    • occipital lobe
    • uses past visual experiences and relates them to the present
    • (association area)
  67. gnostic area
    • occipital, temporal, parietal lobes
    • receives, interprets, allows reaction to input from vision, sound, taste, smell
    • (association area)
  68. auditory area
    • aka Wernicke's area
    • temporal lobe
    • translates words to thoughts
    • differentiates between music, noise, speech
    • (association area)
  69. premotor area
    • frontal lobe
    • controls complex sequental learned motor activities and forms a memory bank
    • (association area)
  70. frontal eye field area
    • frontal lobe
    • controls voluntary scanning movement of the eye
    • (association area)
  71. limbic system
    • aka emotional brain
    • found throughout the brain stem
    • controls feelings of anger, fear, pleasure
    • contains hippocampus
  72. hippocampus
    region of limbic system that converts short term memory to long term memory
  73. blood brain barrier
    • membrane that surrounds entire brain (excluding hypothalamus)
    • protects brain from toxins
    • hypothalamus must sample body fluids
  74. electroencephalogram (EEG)
    • measures electrical activity of the brain
    • 4 waves: alpha, beta, theta, delta
  75. alpha wave
    awake but resting with eyes closed
  76. beta wave
    • brain extremely active
    • lots of sensory input
  77. theta wave
    • normal in young children and in adults with emotional stress
    • brain tumor if seen in stress-free adults
  78. delta wave
    • sleeping adult or infant < 1 if away
    • brain damage if seen in awake adult
Card Set
A&P Chapter 14 - Brain
A&P Chapter 14 - Brain