Autonomic reflexes are not subject to conscious control, are mediated by the autonomic division of the nervous system, and usually involve the activation of smooth muscle, cardiac muscle, and glands. Somatic reflexes involve stimulation of skeletal muscles by the somatic division of the nervous system.

The PNS can be broken down into two systems: the autonomic nervous system, which regulates involuntary actions such as breathing and digestion, and the somatic nervous system, which governs voluntary action and body reflexes.

somatic nervous system

Well, reflexes are functions of the nervous system, which coordinates our actions. The nervous system is the network of neurons that transmits the action potentials. The sensor and neurons are outside the spinal cord, in what is called the peripheral nervous system (PNS).

The PNS consists of the nerves and ganglia outside the brain and spinal cord. The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body….External links.

Nervous system – Reflexes A reflex action often involves a very simple nervous pathway called a reflex arc. A reflex arc starts off with receptors being excited. They then send signals along a sensory neuron to your spinal cord, where the signals are passed on to a motor neuron.

Receptors

somatic system

The peripheral nervous system refers to parts of the nervous system outside the brain and spinal cord. It includes the cranial nerves, spinal nerves and their roots and branches, peripheral nerves, and neuromuscular junctions.

The nervous system has two main parts: The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.

The peripheral nervous system is subdivided into nerves, the autonomic system, and the somatic system. The autonomic nervous system is further subdivided into the parasympathetic and sympathetic nervous systems.

Schwann cells (SCs) are the main glial cells of the peripheral nervous system which wrap around axons of motor and sensory neurons to form the myelin sheath.

Schwann cells are excluded from the CNS during development by the glial limiting membrane, an area of astrocytic specialisation present at the nerve root transitional zone, and at blood vessels in the neuropil. Extensive Schwann cell CNS myelination may have therapeutic significance in human myelin disease.

Schwann cells make myelin in the peripheral nervous system (PNS: nerves) and oligodendrocytes in the central nervous system (CNS: brain and spinal cord). In the PNS, one Schwann cell forms a single myelin sheath (Figure 1A).

Central nervous system (CNS) is composed of two major cell types: neuron and glia. Consistently, the CNS houses oligodendrocytes for myelin synthesis. On the other hand, Schwann cells are the myelinating cells in the peripheral nervous system (PNS).

Neuroglia in the CNS include astrocytes, microglial cells, ependymal cells and oligodendrocytes. Neuroglia in the PNS include Schwann cells and satellite cells. Astrocytes support and brace the neurons and anchor them to their nutrient supply lines.

The central nervous system (CNS) consists of the brain and the spinal cord. It is in the CNS that all of the analysis of information takes place. The peripheral nervous system (PNS), which consists of the neurons and parts of neurons found outside of the CNS, includes sensory neurons and motor neurons.

The CNS consists of the brain and the spinal cord, while the PNS is composed of nerves and groups of nerve cells (neurons), called ganglia.

the vagus

Parasympathetic preganglionic neurons have cell bodies located in the brainstem and in the sacral (toward the bottom) spinal cord, as shown in Figure 16.27. The axons of the preganglionic neurons release acetylcholine on the postganglionic neurons, which are generally located very near the target organs.

There are eight pairs of cervical nerves, twelve pairs of thoracic nerves, five pairs of lumbar nerves, five pairs of sacral nerves, and one pair of coccygeal nerves. The spinal nerves are part of the peripheral nervous system….

Because the lumbar spine has no spinal cord and has a large amount of space for the nerve roots, even serious conditions—such as a large disc herniation—do not typically cause paraplegia (loss of motor function in the legs).

Sensory (afferent) – carry information INTO the central nervous system from sense organs or motor (efferent) – carry information away from the central nervous system (for muscle control). Cranial – connects the brain with the periphery or spinal – connects the spinal cord with the periphery.