Reflex Arc and Reflexes Quiz

Study Notes

Reflexes Overview

Reflex: Involuntary, instantaneous movement triggered by a stimulus.
Often mediated through a reflex arc, enabling automatic responses.

Reflex Arc Components

Sensory Receptor: Detects the stimulus.
Afferent Nerve: Carries the sensory signal to the spinal cord or brain.
Integrative Center: Integrates sensory input and generates motor output.
Efferent Nerve: Transmits the motor signal to the body.
Motor Effector: Executes the response.

Classification of Reflexes

By Effector:
- Autonomic Reflexes: Regulate internal organs (e.g., glands, heart).
- Somatic Reflexes: Control skeletal muscle movements.
By Number of Synapses:
- Monosynaptic Reflex: Involves 2 neurons and 1 synapse.
- Polysynaptic Reflex: Involves multiple neurons connected by interneurons with 2 or more synapses.
By Type of Sensory Receptor:
- Exteroceptive: Receives stimuli from the external environment.
- Interoceptive: Receives stimuli from within the body.
- Proprioceptive: Receives information on body position and movement.

Reflex and Reaction Times

Reflex Time: Interval between the stimulus onset and reflex response.
Reaction Time: Delay between stimulus onset and a voluntary response.

Laterality

Refers to the human preference for one side of the body over the other.

Somatic Proprioceptive Reflexes

Utilize sensory fibers from joints, tendons, and muscles, integrating info in the spinal cord.
Primarily unconscious, providing feedback on joint position and muscle tension.
Includes important stretch reflexes.

Somatic Exteroceptive Reflexes

Utilize skin receptors reacting to external stimuli (pain, temperature).
Mostly polysynaptic, integrating protective mechanisms (withdrawal, coughing, sneezing).

Stretch Reflex

A monosynaptic reflex that maintains muscle length and responds to muscle stretching.
Relies on muscle spindle and Golgi tendon receptors for information.

Muscle Spindle Functionality

Monitors muscle length and the rate of change in length.
Central region acts as a sensory receptor; peripheral region contains muscle fibers that respond to neural stimulation.
Steps:
- Detects muscle stretch.
- Sends impulse via Ia afferent fibers to the spinal cord.
- Activates alpha motor neurons, causing contraction.

Golgi Tendon Organ

Senses tension within muscle tendons.
Prevents excessive tension through an inhibitory reflex mechanism.
Steps:
- Detects muscle tension.
- Sends impulses via Ib sensory fibers to the spinal cord.
- Engages inhibitory interneurons, leading to alpha motor neuron inhibition.
- Results in muscle relaxation and reduced tension.

Description

Test your knowledge on the reflex arc and the classification of reflexes with this engaging quiz. Dive into key terms and definitions that help explain how reflex actions occur in response to stimuli. Perfect for students studying biology or physiology.