Nervous Tissue

Introduction

The nervous tissues are considered the primary tissue in the nervous system. The nervous tissue is the part of the cellular unit that helps in the basic functionalities of the body. These tissues help in monitoring and controlling basic bodily functions in living organisms. Nervous tissues are made of two cells: neurons which are also called nerve cells and glial cells, these cells transmit nerve impulses and provide nutrients to neurons.

What is Nervous Tissue?

The nervous tissue is the primary tissue of the nervous system. It helps in the coordination process and controls overall functioning of the body muscles.

Figure 1: Nerve cell

It consists of two cells: The nerve cells and the glial cells, these units help in transmitting nerve impulses and also enrich the neurons with nutrients. The brain, spinal cord and nerves are made up of nervous tissue. They possess the capability the transmission of stimulus from one part of the body to another.

Structure of Nervous Tissue

Figure 2: Structure of a neuron

• The nervous tissue consists of nerve cells or neurons and all of these tissues are made of axons. These axons are long stem-like projections that emerge out of cells. These units are responsible for communicating with other cells which is called the target cells.

• The main part of these tissues is the cell body which contains the nucleus, cytoplasm, and various organelles.

• Dendrite functions in a branched mechanism, it is responsible to receive information from other neurons and synapses.

Location of Nervous Tissue

The nervous tissue can be found in the peripheral nerves throughout the body and it is also found in the organs of the central nervous system. For example, the spinal cord and brain. These neurons react to the stimuli by generating signals through the axons, these are the elongated structures that arise from the cell body.

Nervous Tissue Characteristics

• The nervous tissue is functional to the CNS and the PNS of the nervous system.

• It is made of two particular cellular units, that is, neurons and the glial cells

• It is made of dendrites, cell bodies, axons and nerve endings.

• Neurons are responsible for the secretion of chemical neurotransmitters which helps in the stimulation of other neurons.

• The nerve cell tends to live long and cannot be divided or replaced, depending on any further factors except the memory cells.

Nervous Tissue Functions

• Neurons helps in the generation of nerve impulses and execution of certain impulses. These help in the production of electrical signals which are transmitted over long distances it occurs by secreting neurotransmitters of chemical products

• The nervous tissue reacts to various stimuli.

• It is useful in integration and communications.

• These tissues help in providing electrical insulations to the nerve cells.

• It is useful in carrying messages from other neurons and the cell body.

Types of nervous tissue

The functioning of the nerves is brought forth by channelling electrochemical signals or impulses that are obtained from other nerves, brains, tissues or organs, the sites at which the nerves end. The nerves, based on their functionality can be classified into the following sections:

• Motor nerves: The motor neurons are also called motor nerves which are useful in the transmission of impulses or signals to various muscles from the spinal cord to the brain. If the motor neuron gets damaged it is responsible for causing muscle weakness and muscle shrinkage.

• Sensory nerves: The sensory nerves are important in the generation of impulses or signals in different directions from the motor neurons. The sensory neurons helps in gathering information such as pressure, pain, and temperature these are present in muscles, skin, and other organs which are further redirected back to the brain.

Figure 3: Types of nervous tissues

Autonomic nerves: The autonomic nervous system controls various actions of heart muscles and smooth muscles. As opined in Becker et al. (2019), these nerves are also useful in renal function. These are located in the stomach and interlining of glands.

Cranial nerves: These are crucial for smell, eyesight, and movement of the face and eyes. It is also useful in salivation and tongue movement.

Conclusion

The nervous system is a very crucial unit in the body of various organisms. It is useful in various ranges of motion in the human body. The nervous tissue is the primary component of two major parts that is the Central Nervous system (CNS) which is formed by the spinal cord, the brain and the branching peripheral nerves belonging to the peripheral nervous system (PNS), it helps in controlling and regulating body functions.

FAQs

Q1. What are the main functions of the nervous system?

Ans. The main function of the nervous tissue is to obtain stimuli from various organs and send signals to the brain and spinal cord. These signals are further sent back to the muscles with the help of nerves. These are also helpful in digestion. The nervous system is sub-classified into two categories, the neurons help in the transmission of electrical signals. The glial cells provide support and defence to the neurons

Q2. What is the sciatic nerve?

Ans. The nerve that joins the lower back to the buttocks is the sciatic nerve. The sciatic nerve permits the movement entire leg that has a collection of nerves. Some of these motor nerves are functional in the hamstrings, feet, and thighs.

Q3. What are the different sections of cranial nerves?

Ans. Cranial nerves are found in twelve distinct pairs. The cranial nerves to be found are olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, spinal accessory and hypoglossal nerves.

Q4. What is a synapse?

Ans. It is referred to the junction between the neuron, from where a message from one neuron is transmitted to another. The synapses are formed between axons and dendrites.