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What does a spinal reflex require?

What does a spinal reflex require?

A reflex does not require any thought input. The path taken by the nerve impulses in a reflex is called a reflex arc. In higher animals, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord.

What are the characteristics of a spinal reflex?

Spinal reflexes are investigator-evoked artifacts arising from connections of stretch receptors in the muscle or nociceptors in the skin that activate a spinal motor neurons to evoke contractions/twitches in particular somatic muscles (e.g., the quadriceps muscle in a patellar tendon reflex).

What are the spinal cord reflexes?

Introduction. Spinal cord reflexes are simple behaviors produced by central nervous system (CNS) pathways that lie entirely within the spinal cord. The sensory afferent fibers that evoke these reflexes enter the spinal cord and activate spinal motor neurons directly or through a chain of one or more spinal interneurons …

What is the simplest type of reflex?

First let’s examine the neural circuitry of one spinal reflex: the stretch reflex. This is the simplest reflex known; it depends only in the monosynaptic connection between primary afferent fibers from muscle spindles and motor neurons innervating the same muscle.

What is the minimum number of neurons needed for a reflex arc?

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

What does the blinking reflex involve?

The corneal blink reflex is caused by a loop between the trigeminal sensory nerves and the facial motor (VII) nerve innervation of the orbicularis oculi muscles. The reflex activates when a sensory stimulus contacts either free nerve endings or mechanoreceptors within the epithelium of the cornea.

What is somatic reflex?

Somatic reflexes involve specialized sensory receptors called proprioceptors that monitor the position of our limbs in space, body movement, and the amount of strain on our musculoskeletal system. The effectors involved in these reflexes are located within skeletal muscle.

What are the spinal reflexes?

The Spinal Reflexes are the most basic of all reflexes, but other parts of the central nervous system also contain reflex pathways.

How many neurons are in the monosynaptic reflex?

The monosynaptic reflexes consist of two neurons. The first is located within the spinal ganglion. This is the sensory neuron (afferent) whose peripheral process detects the stimuli from the muscle. Then, the central process of the first neuron conducts this signal to the ventral horn of the spinal cord, where the second neuron is situated.

Are spinal reflexes hard-wired or Unwired?

Spinal reflexes traditionally have been viewed as hard-wired, unchanging neural circuits. Studies of learning-like changes in spinal reflex excitability have shown that spinal reflex circuits are capable of long-lasting alterations under varying stimulus conditions.

What is a reflex movement?

Reflex movements are movements initiated by sensory receptors, which, by having synaptic contacts within the spinal cord, are a basic level of regulation of muscles or glands. The Spinal Reflexes are the most basic of all reflexes, but other parts of the central nervous system also contain reflex pathways.

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