Study Notes on Reflexes and Sensory Pathways

Stress Reflex

  • Definition: An involuntary muscle contraction that occurs in response to stressors.

Cross-Extentor Reflex

  • Definition: A spinal reflex that activates the opposite leg to extend when the other leg withdraws from a painful stimulus.

Pupillary Reflex

  • Definition: The involuntary constriction of the pupil occurring in response to light exposure.

Instinct vs Learned Reflex

  • Instinct Reflex: Refers to genetically pre-determined behaviors that occur without prior learning.
  • Learned Reflex: Involves behaviors that are acquired through experience and practice rather than being innate.

Monosynaptic Reflex

  • Definition: An involuntary, rapid response involving a single synaptic connection between a sensory neuron and a motor neuron. This type of reflex is characterized by its speed due to the minimal synaptic transmission time.

Polysynaptic Reflex

  • Definition: A reflex involving multiple synapses in a more complex pathway, allowing for more multifaceted responses to stimuli. This results in a slower response compared to monosynaptic reflexes due to the involvement of interneurons.

Receptive Fields

  • Definition: The area of sensory reception where stimuli can be detected by nervous tissues. Receptive fields determine the sensitivity and accuracy of sensory perception in specific regions.

Interceptors

  • Definition: Sensory receptors that process information about the internal state of the body, running or functioning before or after events are executed. These are crucial for homeostatic mechanisms.

Exteroceptors

  • Definition: Sensory receptors located on or near the body's surface, which respond to external stimuli such as touch, temperature, and pain.

Automatic Movement

  • Definition: Types of movements that occur without conscious thought and are typically controlled by reflex arcs and the autonomic nervous system.

Somatic Movement

  • Definition: Movements that are voluntary and controlled by the somatic nervous system, allowing conscious interaction with the environment.

Afferent Pathways

  • Definition: Neurons that carry sensory information toward the central nervous system (CNS), facilitating perception and response to stimuli.

Efferent Pathways

  • Definition: Neurons that carry signals away from the central nervous system to effectors like muscles and glands, involved in executing responses to stimuli.