What is Supraspinal?

What is Supraspinal?

Medical Definition of supraspinal : situated or occurring above a spine especially : situated above the spine of the scapula.

What is Supraspinal motor control?

Abstract. The control of spinal reflex mechanisms from supraspinal structures is exerted in the most developed form (in mammals) by four descending systems (cortico-, rubro-, reticulo- and vestibulo-spinal).

What are the 4 types of spinal reflexes?

Spinal reflexes include the stretch reflex, the Golgi tendon reflex, the crossed extensor reflex, and the withdrawal reflex.

What are Supraspinal structures?

Supraspinal means above the spine, and may refer to, above the spinal cord and vertebral column: brain.

What is the function of the supraspinal descending inhibitory motor pathways?

briefly explain the function of the supraspinal descending inhibitory motor pathways. they modulate reflex arc sensitivity, normally preventing hypereflexia, or exaggerated reflexes. there are two pathways by which the jendrassik maneuver facilitates alpha motor neuron output.

What is GREY and white matter?

The tissue called “gray matter” in the brain and spinal cord is also known as substantia grisea, and is made up of cell bodies. “White matter”, or substantia alba, is composed of nerve fibers.

What are Renshaw cells?

Renshaw cells are the specialized population of spinal inhibitory interneurons that receive the output from motoneurons (Renshaw, 1946) through excitatory collateral branches (Eccles et al., 1961).

What is Disynaptic reflex?

As a result of this reflex, activation of the Ib afferent causes the muscle to cease contraction, as the alpha motor neuron becomes inhibited. Because this reflex contains an interneuron between the sensory afferent and the motor neuron, it is an example of a disynaptic reflex.

Why does UMN lesion cause spasticity?

How does UMN lesion cause spasticity and associated phenomena? The major problem is a loss of control of the spinal reflexes. Spinal reflex activity is normally tightly regulated and if inhibitory control is lost, the balance is tipped in favor of excitation, resulting in hyperexcitability of the spinal reflexes.

What is the descending inhibitory pathway?

The descending pain pathway is a critical modulator of nociception and plays an important role in mediating endogenous and exogenous opioid-induced analgesia. Because of this, it is highly implicated in allostatic cellular and molecular changes following repeated opioid use that lead to the development of tolerance.

What is the difference between grey matter and white matter in the brain?

The central nervous system of the brain is made up of two kinds of tissue: grey matter and white matter. The grey matter contains the cell bodies, dendrites and the axon terminals, where all synapses are. The white matter is made up of axons, which connect different parts of grey matter to each other.

What are sensory cortices?

Sensory cortex refers to all cortical areas associated with sensory function. In the case of vision, this includes virtually all of the occipital cortex and much of the temporal and parietal cortex.

What stimulates the Renshaw cells?

Renshaw cells are interneurons that are stimulated by the alpha motor neuron and then, by a feedback mechanism, inhibit the alpha motor neuron, causing auto inhibition.

What do Renshaw cells release?

It has also been shown that glycine is the inhibitory transmitter released by the Renshaw cells. In essence the Renshaw cells regulate the firing of the alpha motor neuron leaving the ventral horn.

What is somatic and visceral reflexes?

Somatic reflex is the nerve circuit of the somatic nervous system. It is responsible for the contraction of skeletal muscles. On the other hand, the visceral reflex is the nerve circuit of the autonomic nervous system. It is responsible for the contraction of smooth muscles and organs inside the body.