How Many Types of Nerves are There

Introduction

Nerves are functional and structural units of the peripheral nervous system (PNS). They consist of groups of individual specialised cells called neurons (or nerve cells) that exchange motor and sensory information between the PNS and the central nervous system (CNS). Transmission occurs via an electrochemical impulse known as an action potential. By definition, a nerve is a bundle of axons (or nerve fibres) located in the PNS. Within the central nervous system, axons form units known as pathways. Nerves are simple in structure, but their function, innervation, and nomenclature can be complex. This article describes different types of nerves and their morphological features and functions.

Structure of nerves

• Your nerves are made up of axons, groups of cord-like fibres that run down the middle of the nerve.

• Dendrites are branches that carry electrical impulses.

• Indonesia, the layer of connective tissue that surrounds the axons.

• The perineurium is a layer of connective tissue that surrounds groups of axons called fascicles.

• Epithelium, the layer of connective tissue that covers the outer surface of nerves.
  Within the brain, cells called oligodendrocytes surround axons. Outside the central nervous system (brain and spinal cord), cells called Schwann cells surround axons.
  Both oligodendrocytes and Schwann cells contain fatty tissue called myelin. Myelin surrounds axons with a layered covering (coating). The myelin sheath is like an insulator around the wire. When damaged, nerves can no longer send electrical signals quickly. It may even stop sending electrical signals altogether.

Types of nerves

There are several ways to classify nerves. The first and most common classification of nerves is based on how they transmit information.

• Afferent (Sensory) Nerves

Nerves that carry signals from the periphery to the central nervous system are called afferent or sensory nerves. These nerves can be further divided into somatosensory (carrying information from the skin, skeletal muscles, and joints) and visceral (internal organs such as the liver and kidneys). All these sensory impulses are sent to the central nervous system via ascending pathways.

• Efferent (Motor) Nerves

Efferent, or motor, nerves, on the other hand, are nerves that carry signals from the central nervous system to the periphery. Different nerves carry motor impulses from the CNS to effector organs such as muscles and glands. They are divided into two types: somatic motor neurons (which provide innervation for skeletal muscles) and visceral motor neurons (which are part of the autonomic nervous system and innervate smooth muscle, cardiac muscle, and glands). Can do. All motor impulses are sent to the PNS via the descending pathway.

The term is easy to remember because signals leave the central nervous system from different nerves and enter the central nervous system from afferent nerves. Finally, there are mixed nerves that contain both sensory and motor fibres.

• Mixed Nerves

So far, we have discussed sensory afferents and motor efferents and their somatic and visceral divisions. Nerves that have both sensory afferents and motor fibres efferent are called mixed nerves. They send messages in both directions at the same time.

Functions of nerves

• Nerves help the two parts of the nervous system to communicate with each other.
  The peripheral nervous system is a network of nerves that carry signals throughout the body to the spinal cord, part of the central nervous system.

• The central nervous system is the brain and spinal cord. Receives and interprets nerve signals from the peripheral nervous system. Your brain integrates these messages (inputs) to inform everything you do: how you move, how you feel, what you do, and how you think. Some reactions are reflexive and occur below the level of consciousness, such as removing hands from a hot stove.

• When nerves send electrical impulses. Signals travel down axons, which are the "wiring" connections of nerves

• Messages are converted into chemical signals at nerve endings called axonal hillocks.

• This chemical releases molecules called neurotransmitters into the space that bridges the space between one neuron and another. These bridges are called synapses.

• Neurotransmitters bind to receptors in muscles or connecting neurons and convert them into different electrical signals.