Spinal Cord

• Where is gray matter located in the spinal cord?

  Inner butterfly shape
• What are the two main sensory pathways in the spinal cord?

  Dorsal column system and spinothalamic tract
• What are the key differences between white matter and gray matter?

  • White Matter:
  • Composition: Myelinated axons
  • Location: Outer regions
  • Function: Signal transmission

  
  

  • Gray Matter:
  • Composition: Neurons & dendrites
  • Location: Inner butterfly shape
  • Function: Local processing
• Where is white matter located in the spinal cord?

  Outer regions
• What type of sensation does the dorsal column system convey?

  Fine touch and proprioception
• What type of sensation does the spinothalamic tract convey?

  Pain and temperature
• What role does the spinal cord play in reflex actions?

  Facilitates quick reflexes without brain involvement
• Where do second-order neurons cross to the opposite side?

  In the spinal cord
• What happens to signals after they travel through first-order neurons?

  They synapse with second-order neurons
• Describe the pathway of sensory signals from the spinal cord to the brain.

  1. First-order neurons carry signals to the spinal cord.
  2. They synapse with second-order neurons.
  3. Second-order neurons cross to the opposite side.
  4. Third-order neurons carry signals to the thalamus.
  5. Signals are processed in the postcentral gyrus.
• What controls the reflex arc?

  The spinal cord
• What is a reflex arc?

  A rapid stimulus-response pathway
• Where do signals go after the thalamus?

  To the postcentral gyrus for processing
• What do third-order neurons carry signals to?

  The thalamus
• What role does white matter play in reflex arcs?

  Enables quick transmission through the circuit
• What happens when you touch something hot?

  Your hand pulls away instantly
• How can the spinal cord be analogized?

  • It is like a highway for communication
  • Connects the brain to the rest of the body
  • Allows signals to travel quickly and efficiently
• What is the spinal cord?

  A long bundle of nerve tissue
• What is the overall structure of the spinal cord and its functions?

  • Butterfly shape in cross-section
  • White matter surrounds gray matter
  • Pairs of spinal nerves extend from the cord
  • Dorsal roots for sensory neurons
  • Ventral roots for motor neurons
  • Efficient signal entry and exit
• What are the steps in a reflex arc?

  1. Pain receptors detect stimulus
  2. Sensory neurons send signals to dorsal root
  3. Signal crosses gray matter to relay neuron
  4. Motor neurons carry response signal
  5. Muscles contract (effector)
• What type of neurons first carry signals to the spinal cord?

  First-order neurons
• What extends from the spinal cord?

  Pairs of spinal nerves
• What are the sections of the spinal cord and their nerve pairs?

  • Cervical: 8 nerve pairs
  • Thoracic: 12 nerve pairs
  • Lumbar: 5 nerve pairs
  • Sacral: 5 nerve pairs
• What shape does the spinal cord have in cross-section?

  Butterfly shape
• What is the primary function of the spinal cord?

  Transmits signals between the brain and body
• Where does the spinal cord extend to?

  To the lower back
• Where does the spinal cord extend from?

  From the base of the brain
• What surrounds the gray matter in the spinal cord?

  White matter
• Where do sensory neurons enter the spinal cord?

  Dorsal horns
• What is the primary function of the spinal cord?

  Signal relay system connecting brain to body
• Through which roots do spinal nerves extend from the cord?

  Dorsal and ventral roots
• How does the structure of the spinal cord facilitate signal transmission?

  It allows efficient entry and exit of signals
• What are the key aspects of the spinal cord?

  • Definition: A long bundle of nerve tissue
  • Function: Transmits signals between brain and body
  • Location: Extends from brain base to lower back
  • Analogy: A highway for communication
• Where do motor neurons exit the spinal cord?

  Ventral horns
• How does the spinal cord provide protection?

  Through three layers: pia, arachnoid, dura mater
• What does white matter consist of?

  Myelinated axons
• What is the primary function of white matter?

  Signal transmission
• What are the two main tissue types in the spinal cord?

  White matter and gray matter
• What are the features of the dorsal column system and spinothalamic tract?

  • Dorsal Column System:
  • Sensation: Fine touch, proprioception
  • Signal Path: Medial lemniscus
  • Crossing Point: Medulla
  • Spinothalamic Tract:
  • Sensation: Pain, temperature
  • Signal Path: Lateral spinothalamic tract
  • Crossing Point: Spinal cord
• What is the primary function of gray matter?

  Local processing