Structure and Function of Cells

Structure and Function of Cells

Shazia Ali (Sher-I-Kashmir Institute of Medical Sciences (SKIMS), India), Sumit Kumar (Jawaharlal Nehru University, India), Asma Ali (Independent Researcher, India) and Syed Irtiza (Sher-I-Kashmir Institute of Medical Sciences (SKIMS), India)
Copyright: © 2020 |Pages: 17
DOI: 10.4018/978-1-7998-2860-0.ch003

Abstract

Neurons are the elementary structures that process information in the CNS. They are electrically excitable cells that process and transmit information around the nervous system. Neurons communicate information either by electrical or by chemical signaling that occurs through synapses. Neurons are the main part of nervous system consisting of a number of specialised types. Neuronal structure is similar to other body cells, having common features: Neurons are enclosed in a cell membrane known as a plasma membrane. The nucleus of a neuron compromises of chromosomes and genetic information. Neurons comprise of cytoplasm, mitochondria, and other organelles. The cellular processes take place in a neuron. Ribosomes are used for production of proteins, and mitochondria are for metabolic action acting as powerhouse of cell. Neurons comprise a Golgi complex that has a system of vesicles that secretes hormones and other products. The difference in neurons or nerve cells from other body cells is that extensions originate from the central body of the neuron.
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Neuron Structure

A distinctive neuron possesses a cell body (soma), dendrites and axon. Dendrites are filaments in nature, originate from the cell body, they branch several times forming a complex dendritic tree. Small protrusions present in dendrites called dendritic spines, which further increase the surface area require for synaptic connection. An axon is like rob in an electrical cable. The axon mound is the site where cell body starts and explorations to the site in the nervous system connecting with another nerve cell or different type of cell, such as muscle (Fig. 1).

Figure 1.

Neuronal structure

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The cell body possess cytoplasm as like other cells with granules called as Nissl’s granules. It frequently gives rise to several dendrites but only to one axon formation. A layer of fatty cells called the myelin sheath segmentally encloses the fibres of several neurons which increases the transmission speed of neutral impulses. The periodic gaps present along axon over myelin sheath called nodes of Ranvier. It is “recharged” signal as it travels along axon.

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Neuron And Its Characteristics

The neuron compromises of cell body (or soma) that contains a nucleus, smooth and rough endoplasmic reticulum (ER), Golgi apparatus, lysosomes, mitochondria and other cellular components (Fig. 2).

Key Terms in this Chapter

GABA: Gamma-aminobutyric acid, or ?-aminobutyric acid, or GABA, is the principal inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its prime role is reducing neuronal excitability throughout the nervous system. GABA is sold as a dietary supplement.

Neurotransmitters: Neurotransmitters are endogenous chemicals that allow neurotransmission. It is a type of chemical messenger which transfers signals crosswise a chemical synapse, such as a neuromuscular junction, from one neuron (nerve cell) to another target neuron, muscle cell, or gland cell.

Neuron: A neuron (also called neurone or nerve cell) is a cell that transmits electrical impulses. Neurons are the elementary (functional and structural) units of our nervous system. Every neuron is made of a cell body (also called soma or cyton), dendrites and an axon. Dendrites and axons are nerve fibers.

Cells: Cells are the elementary building slabs of living things. The human body is composed of trillions of cells, all with their own focussed function. Cells are the basic structures of all living organisms. Cells deliver structure for the body, take in nutrients from food and carry out significant function.

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