structure and function of nervous system pdf

Structure and function of nervous system pdf

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Nervous System Anatomy

What Are Neurons?

Nervous tissue

The Human Nervous System

Nervous tissue , also called neural tissue , is the main tissue component of the nervous system.

Nervous System Anatomy

The picture you have in your mind of the nervous system probably includes the brain , the nervous tissue contained within the cranium, and the spinal cord , the extension of nervous tissue within the vertebral column. The brain is contained within the cranial cavity of the skull, and the spinal cord is contained within the vertebral canal of the vertebral column. The peripheral nervous system is so named because it is in the periphery—meaning beyond the brain and spinal cord. In addition to the anatomical divisions listed above, the nervous system can also be divided on the basis of its functions. The nervous system is involved in receiving information about the environment around us sensory functions, sensation and generating responses to that information motor functions, responses and coordinating the two integration.

That suggests it is made of two organs—and you may not even think of the spinal cord as an organ—but the nervous system is a very complex structure. Within the brain, many different and separate regions are responsible for many different and separate functions. It is as if the nervous system is composed of many organs that all look similar and can only be differentiated using tools such as the microscope or electrophysiology. In comparison, it is easy to see that the stomach is different than the esophagus or the liver, so you can imagine the digestive system as a collection of specific organs. Figure 1. Central and Peripheral Nervous System The structures of the PNS are referred to as ganglia and nerves, which can be seen as distinct structures. The equivalent structures in the CNS are not obvious from this overall perspective and are best examined in prepared tissue under the microscope.

Fred H. He studies the unanticipated plasticity and complexity represented in the brain. Any man could, if he were so inclined, be the sculptor of his own brain. Neuroscience is the scientific study of the nervous system the brain, spinal cord, and peripheral nervous system and its functions. The belief that the brain is the organ that controls behavior has ancient roots, dating to early civilizations that connected loss of function to damage to parts of the brain and spinal cord. But the modern era of neuroscience began — and continues to progress — with the development of tools, techniques, and methods used to measure in ever more detail and complexity the structure and function of the nervous system. We now know that the human brain contains approximately one hundred billion neurons and that these neurons have some one hundred trillion connections, forming functional and definable circuits.

What Are Neurons?

The central nervous system CNS is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric animals —i. It consists of a large nerve running from the anterior to the posterior, with the anterior end is enlarged into the brain. Not all animals with a central nervous system have a brain, although the large majority do. The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals. In vertebrates the brain and spinal cord are both enclosed in the meninges. Within the meninges the brain and spinal cord are bathed in cerebral spinal fluid which replaces the body fluid found outside the cells of all bilateral animals.

Skip to main content Skip to table of contents. Advertisement Hide. This service is more advanced with JavaScript available. Front Matter Pages i-xiii. Gross Anatomy of the Brain. Pages Neurons and Associated Cells.

Thank you for visiting nature. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. IN no part of the body is the relation of form and function so clear as in the central nervous system.

Nervous tissue

Neurons, also known as nerve cells, send and receive signals from your brain. Specialized projections called axons allow neurons to transmit electrical and chemical signals to other cells. Neurons can also receive these signals via rootlike extensions known as dendrites. At birth, the human brain consists of an estimated billion neurons.

The nervous system consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body. Together, these organs are responsible for the control of the body and communication among its parts. The brain and spinal cord form the control center known as the central nervous system CNS , where information is evaluated and decisions made. The sensory nerves and sense organs of the peripheral nervous system PNS monitor conditions inside and outside of the body and send this information to the CNS. Efferent nerves in the PNS carry signals from the control center to the muscles, glands, and organs to regulate their functions.

Nervous system , organized group of cells specialized for the conduction of electrochemical stimuli from sensory receptors through a network to the site at which a response occurs. All living organisms are able to detect changes within themselves and in their environments. Changes in the external environment include those of light , temperature , sound , motion, and odour , while changes in the internal environment include those in the position of the head and limbs as well as in the internal organs.

12.1 Structure and Function of the Nervous System

The central nervous system consists of the brain and spinal cord. This article gives a brief overview of the central nervous system CNS. We will look at the types of cells involved, different regions within the brain, spinal circuitry, and how the CNS can be affected by disease and injury.

The Human Nervous System

The nervous system transmits signals between the brain and the rest of the body, including internal organs. The human brain contains about billion neurons. Bundles of axons, called nerves, are found throughout the body. Axons and dendrites allow neurons to communicate, even across long distances. Different types of neurons control or perform different activities.

NCBI Bookshelf. Parker E. Ludwig ; Vamsi Reddy ; Matthew Varacallo.

 - Беккер улыбнулся и достал из кармана пиджака ручку.  - Я хотел бы составить официальную жалобу городским властям.

Central nervous system

Introduction

Стратмор задумался. - С какой стати он должен на него смотреть? - спросил. Сьюзан взглянула ему в. - Вы хотите отправить его домой. - Нет.

Не в силах сдержать нетерпение, Беккер попытался позвонить снова, но по-прежнему безрезультатно. Больше ждать он не мог: глаза горели огнем, нужно было промыть их водой. Стратмор подождет минуту-другую. Полуслепой, он направился в туалетную комнату. Смутные очертания тележки все еще виднелись у двери в мужской туалет, поэтому Беккер снова подошел к дамской комнате. Ему показалось, что внутри звучали какие-то голоса.

 - Кроме всего прочего, вирус просто не может проникнуть в ТРАНСТЕКСТ. Сквозь строй - лучший антивирусный фильтр из всех, что я придумал. Через эту сеть ни один комар не пролетит. Выдержав долгую паузу, Мидж шумно вздохнула. - Возможны ли другие варианты.

2 comments

  • Victoria W. 24.04.2021 at 04:52

    The central nervous system consists of the brain and spinal cord.

    Reply
  • Archaimbau C. 25.04.2021 at 14:02

    tional units of the nervous system. Neurons transmit messages to and from the brain. They consist of a cell body and processes (nerve. StruCture aNd FuNCtioN​.

    Reply

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