Most reflexes are polysynaptic (involving more than two neurons) and involve the activity of interneurons (or association neurons) in the integration center. Some reflexes; however, are monosynaptic ("one synapse") and only involve two neurons, one sensory and one motor.

What is the minimum number of neurons that are present in a Polysynaptic reflex arc?

Reflexes require a minimum of two neurons, an sensory neuron (input) and a motor neuron (output) (see Figure 1) The sensory neuron (such as a pain receptor in the skin) detects the stimuli and sends a signal towards the CNS.

How many neurons are involved in a reflex arc?

The motor neuron carries efferent impulses to the effector, which produces the response. Three types of neurons are involved in this reflex arc, but a two-neuron arc, in which the receptor makes contact directly with the motor neuron, also occurs.

What are the parts of a Polysynaptic reflex arc?

The reflex arc consists of 5 components:

• sensory receptor.
• sensory neuron.
• integration center.
• motor neuron.
• effector target.

How many neurons comprise a Monosynaptic reflex arc?

When a reflex arc consists of only two neurons, one sensory neuron, and one motor neuron, it is defined as monosynaptic. Monosynaptic refers to the presence of a single chemical synapse.

Introduction to how reflexes work - reflex arc, monosynaptic and polysynaptic reflexes

24 related questions found

What is a Polysynaptic reflex?

Any reflex with more than one synapse (1), not counting the synapse between neuron and muscle, and hence involving one or more interneurons. In humans, all reflexes except stretch reflexes are polysynaptic.

What are the 5 components of the reflex arc in order?

Reflex Arc Components. Most reflex arcs have five main components: receptors, sensory neurons, interneurons, motor neurons and muscles.

What are Polysynaptic neurons?

Most reflex arcs are polysynaptic, meaning multiple interneurons (also called relay neurons) interface between the sensory and motor neurons in the reflex pathway.

How does a Polysynaptic reflex work?

Contrary to monosynaptic reflexes, polysynaptic reflexes are accomplished with the participation of one or more interneurons, meaning that the communication between the afferent and efferent neurons is indirect. ... Typically, these reflexes cause some muscle groups to contract, while others simultaneously relax.

What is a Polysynaptic reflex quizlet?

What is a polysynaptic reflex. A reflex action that involves an electrical impulse being transferred from a sensory neuron to a motor neuron via at least one connecting neuron (interneuron) in the spinal cord.

What neurons are involved in a reflex arc?

There are three main types of neuron: sensory, motor and relay. These different types of neurons work together in a reflex action . A reflex action is an automatic (involuntary) and rapid response to a stimulus, which minimises any damage to the body from potentially harmful conditions, such as touching something hot.

Is the stretch reflex Monosynaptic or Polysynaptic?

The stretch reflex consists of a monosynaptic response from the direct connection between Ia afferents and motor neurons, that may be followed by polysynaptic reflex activity.

What are the three neurons in a reflex arc and in what order are they activated?

What are the three neurons in a reflex arc, and in what order are they activated? the signal to the efferent neuron, and finally the efferent neuron stimulates the muscle to contract. 25. Where can you find the association neuron in the reflex arc?

Why is this reflex classified as a Polysynaptic reflex?

It is like a polysynaptic spinal reflex because it is a motor response to sensory stimulation that is repeated the same way each time the “hardwired” reflex circuit is activated.

What is an example of Polysynaptic reflex?

An example of a polysynaptic reflex arc is seen when a person steps on a tack—in response, their body must pull that foot up while simultaneously transferring balance to the other leg.

Why are Polysynaptic reflexes slower?

Polysynaptic reflexes are slower than monosynaptic reflexes for 2 reasons: This specific type of sensory fiber that carries in the information in the dorsal root for monosynaptic reflexes is very large, fast, heavily myelinated fibers. They conduct faster. slowest conducting of all fibers.

Why is the withdrawal reflex Polysynaptic?

The withdrawal reflex (nociceptive flexion reflex or flexor withdrawal reflex) is a spinal reflex intended to protect the body from damaging stimuli. A withdrawal reflex is mediated by a polysynaptic reflex resulting in the stimulation of many motor neurons in order to give a quick response. ...

Do Polysynaptic reflexes involve the brain?

By contrast, in polysynaptic reflex pathways, one or more interneurons connect afferent (sensory) and efferent (motor) signals. All but the most simple reflexes are polysynaptic, allowing processing or inhibition of polysynaptic reflexes within the brain.

What is the Polysynaptic pathway?

As the pathway of this reflex system is polysynaptic, it allows the integration of inputs from muscle, joint, and cutaneous afferents, and convergence with commands from supraspinal centers to common spinal interneurons. ... A polysynaptic pathway also mediates the effects of flexor-reflex afferent (FRA) fibers.

Which of the following is the best example of a Polysynaptic reflex?

A stimulation of pain receptors in the skin initiates a withdrawal reflex, which is an example of polysynaptic reflex.

Which is faster Monosynaptic or Polysynaptic reflex?

Monosynaptic reflexes are faster compared to polysynaptic reflexes. This is because of the type of sensory fiber that carries information.

What are the 5 components of a reflex arc quizlet?

Terms in this set (5)

• receptor. Sense organ in skin, muscle, or other organ.
• sensory neuron. Carries impulses towards CNS.
• interneuron. Carries impulses within CNS.
• motor neuron. Carries impulse away from CNS.
• effector. Structure by which animal responds (muscle, gland, etc.)

Are the autonomic integrating centers Monosynaptic or Polysynaptic?

Are the autonomic integrating centers monosynpatic or polysynaptic? Can the autonomic integrating centers be influenced by higher brain area? Yes, the autonomic integrating centers can be influenced by higher brain areas. Describe the function of sensory receptors.

What are inter neurons?

Interneurons (also known as association neurons) are neurons that are found exclusively in the central nervous system. ... This abundance of interneurons is due to the complexity of integrating the sensory and motor segments of the nervous system and the diversity of functions that exist in the brain and spinal cord.