Psychology
Nervous System Divisions
The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord, while the PNS includes all the nerves outside the CNS. The PNS further divides into the somatic and autonomic nervous systems, which control voluntary and involuntary bodily functions, respectively.
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11 Key excerpts on "Nervous System Divisions"
eBook - PDF- Ann Scott, Elizabeth Fong(Authors)
- 2018(Publication Date)
- Cengage Learning EMEA(Publisher)
Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 144 CHAPTER 8 Central Nervous System The Nervous System The study of body functions reveals that the body con- sists of millions of small structures that perform a mul- titude of different activities. These are coordinated and integrated by the nervous system into one harmoni- ous whole. The two main communications systems are the endocrine system and the nervous system. They send chemical messengers and nerve impulses to all of the structures. The endocrine system and hormonal regulation are discussed in other chapters. Hormonal regulations are slow, whereas neural regulation is com- paratively rapid. Divisions of the Nervous System The nervous system can be divided into three divi- sions: the central, peripheral, and autonomic nervous systems. 1. The central nervous system consists of the brain and spinal cord. 2. The peripheral nervous system consists of nerves of the body: 12 pairs of cranial nerves extending out from the brain and 31 pairs of spinal nerves extending out from the spinal cord. 3. The autonomic nervous system is part of the peripheral nervous system. It includes peripheral nerves and ganglia (a group of cell bodies outside the central nervous system that carry impulses to involuntary muscles and glands). When a decision is called for and action must be considered, the central and peripheral nervous systems are involved. They carry information to the brain, where it is interpreted, organized, and stored. An appropriate command is then sent to organs or muscles. The autonomic nervous system supplies heart muscle, smooth muscle, and secretory glands with nervous impulses as needed.
No longer available |Learn more- Ann Scott, Elizabeth Fong(Authors)
- 2016(Publication Date)
- Cengage Learning EMEA(Publisher)
144 CHAPTER 8 Central Nervous System The Nervous System The study of body functions reveals that the body con- sists of millions of small structures that perform a mul- titude of different activities. These are coordinated and integrated by the nervous system into one harmoni- ous whole. The two main communications systems are the endocrine system and the nervous system. They send chemical messengers and nerve impulses to all of the structures. The endocrine system and hormonal regulation are discussed in other chapters. Hormonal regulations are slow, whereas neural regulation is com- paratively rapid. Divisions of the Nervous System The nervous system can be divided into three divi- sions: the central, peripheral, and autonomic nervous systems. 1. The central nervous system consists of the brain and spinal cord. 2. The peripheral nervous system consists of nerves of the body: 12 pairs of cranial nerves extending out from the brain and 31 pairs of spinal nerves extending out from the spinal cord. 3. The autonomic nervous system is part of the peripheral nervous system. It includes peripheral nerves and ganglia (a group of cell bodies outside the central nervous system that carry impulses to involuntary muscles and glands). When a decision is called for and action must be considered, the central and peripheral nervous systems are involved. They carry information to the brain, where it is interpreted, organized, and stored. An appropriate command is then sent to organs or muscles. The autonomic nervous system supplies heart muscle, smooth muscle, and secretory glands with nervous impulses as needed. It is usually involuntary in action. Central Nervous System (CNS) The central nervous system consists of the brain and spinal cord. The central nervous system is the most highly organized system of the body. Functions of the CNS include the following: 1. It is the communication and coordination system in the body. ■ It receives messages from stimuli all over the body.
- Ian Peate, Muralitharan Nair, Professor Ian Peate, OBE, Professor Muralitharan Nair, Ian Peate, Muralitharan Nair(Authors)
- 2011(Publication Date)
- Wiley-Blackwell(Publisher)
The nervous system is a major communicating and control system within the body. It works with the endocrine system to control many body functions. The nervous system provides a rapid and short acting response and the endocrine system provides a slower but often more sustained response. The two systems work together to maintain homeostasis.The nervous system interacts with all of the systems of the body. This system is large and complex. In order to facilitate understanding of the nervous system it has to be divided into smaller functional and anatomical parts. This chapter outlines the divisions of the nervous system; it discusses the structure and function of the nervous system and how it influences other structures of the body. Having such an important role in maintaining homeostasis, the nervous system possesses additional protection and that too will be investigated.Organisation of the nervous systemThe nervous system can be divided into two parts: the central nervous system and the peripheral nervous system. The central nervous system consists of the brain and spinal cord and is the control and integration centre for many body functions.The peripheral nervous system carries sensory information to the central nervous system and motor information out of the central nervous system. The direction of information flow to and from the nervous system is important and is shown in Figure 6.1 .Figure 6.1 Organisation of the nervous systemSensory division of the peripheral nervous systemSensory information is gathered from both inside and outside of the body. This sensory input is delivered to the central nervous system via the peripheral nerves. Sensory nerve fibres are also called afferent fibres. Sensory information always travels from the peripheral nervous system towards the central nervous system. An example of sensory information is temperature. Temperature receptors in the skin called thermoreceptors detect changes in temperature and this information is relayed to the central nervous system.
- Werner Kahle, Michael Frotscher(Authors)
- 2011(Publication Date)
- Thieme(Publisher)
The Nervous System Introduction The Nervous System—An Overall View 2 Development and Structure of the Brain 6 2 Introduction Introduction The Nervous System—An Overall View Development and Subdivision (A–D) The nervous system serves processing infor-mation within the body in the interest of adapting its reactions. In the most primitive forms of organization (A) , this function is assumed by the sensory cells ( A – C1 ) them-selves. These cells are excited by stimuli coming from the environment; the excita-tion is conducted to a muscle cell ( A – C2 ) through a cellular projection, or process . The simplest response to environmental stimuli is achieved in this way. (In humans, sensory cells that still have processes of their own are only found in the olfactory epithelium.) In more differentiated organisms ( B ), an ad-ditional cell is interposed between the sensory cell and the muscle cell – the nerve cell, or neuron ( BC3 ) which takes on the transmission of messages. This cell can transmit the excitation to several muscle cells or to additional nerve cells, thus form-ing a neural network ( C ). A diffuse network of this type also runs through the human body and innervates all intestinal organs, blood vessels, and glands. It is called the au-tonomic ( visceral , or vegetative ) nervous system (ANS), and consists of two com-ponents which often have opposing func-tions: the sympathetic nervous system and the parasympathetic nervous system . The interac-tion of these two systems keeps the interior organization of the organism constant. In vertebrates, the somatic nervous system developed in addition to the autonomic nervous system; it consists of the central nervous system (CNS; brain and spinal cord), and the peripheral nervous system (PNS; nerves of head, trunk, and limbs). It is re-sponsible for conscious perception , for vol-untary movement , and for the processing of information ( integration ).
eBook - PDF- Laurie Kelly McCorry(Author)
- 2008(Publication Date)
- Routledge(Publisher)
they.are.interconnected.in.a.given.circuit.that.distinguishes.one.region.of.the. brain. from. another,. and. the. brain. of. one. individual. from. that. of. another . . In. addition,. plasticity ,. the. ability. to. alter. circuit. connections. and. function. in.response.to.sensory.input.and.experiences,.adds.further.complexity.and. . distinctiveness.to.our.neurological.responses.and.behavior . The.nervous.system.is.divided.into.two.anatomically.distinct.regions:.the. central nervous system .(CNS).and.the. peripheral nervous system .(PNS) . .The. CNS . • • • • • • • • • • • • • • Essentials of human physiology for pharmacy consists.of.the.brain.and.the.spinal.cord . .The. PNS .consists.of.the.12.pairs. of. cranial. nerves. that. arise. from. the. brainstem. and. the. 31. pairs. of. spinal. nerves.that.arise.from.the.spinal.cord . .These.peripheral.nerves.carry.infor-mation.between.the.CNS.and.the.tissues.of.the.body . .The.PNS.consists.of. two.divisions:.the. afferent division .and.the. efferent division . The. afferent division .carries.sensory.information.toward.the.CNS,.and.the. efferent division . carries. motor. information. away. from. the. CNS. toward. the. effector.tissues.(muscles.and.glands) . .The.efferent.division.is.further.divided. into.two.components:.the.somatic.nervous.system.that.consists.of.the.motor. neurons.that.innervate.skeletal.muscle,.and.the.autonomic.nervous.system. that.innervates.cardiac.muscle,.smooth.muscle,.and.glands . .2 Classes of neurons There.are.three.functional.classes.of.neurons.in.the.human.nervous.system: . 1 . .Afferent.neurons . 2 . .Efferent.neurons . 3 . .Interneurons Afferent neurons .lie.predominantly.in.the.PNS.(see.Figure.6 .1). .Each.has.a. sensory.receptor.that.is.activated.by.a.particular.type.of.stimulus,.a.cell.body. located.adjacent.to.the.spinal.cord,.and.an.axon . .The. peripheral axon .extends. from.the.receptor.to.the.cell.body,.and.the. central axon .continues.from.the. cell.body.into.the.spinal.cord .
- Ian Peate, Muralitharan Nair(Authors)
- 2015(Publication Date)
- Wiley-Blackwell(Publisher)
2. 1. 5. 14 Peripheral nervous system 31 Chapter 14 Peripheral nervous system PNS The peripheral nervous system includes all the tissues that lie out- side the CNS. These include cranial nerves, spinal cord, spinal nerves and autonomic system (see Chapter 13). There are two types of cells in the peripheral nervous system. These cells carry information to (sensory nervous cells) and from (motor nervous cells) the central nervous system (CNS). Cells of the sensory nerv- ous system send information to the CNS from internal organs or from external stimuli. Motor nervous system cells carry information from the CNS to organs, muscles and glands. The motor nervous system is divided into the somatic nervous system and the autonomic nervous sys- tem. The somatic nervous system controls skeletal muscle as well as external sensory organs such as the skin. This system is said to be voluntary because the responses can be controlled consciously. Reflex reactions of skeletal muscle however are an exception. These are involuntary reactions to external stimuli. Peripheral nervous system connections Peripheral nervous system connections with various organs and structures of the body are established through cranial nerves and spinal nerves. There are 12 pairs of cranial nerves (see Chapter 9) in the brain that establish connections in the head and upper body, while 31 pairs of spinal nerves (see Chapter 11) do the same for the rest of the body. While some cranial nerves contain only sensory neurons, most cranial nerves and all spinal nerves contain both motor and sensory neurons. Sensory division The sensory (afferent) division carries sensory signals by way of afferent nerve fibres from receptors in the central nervous system (CNS). It can be further subdivided into somatic and visceral divisions. The somatic sensory division carries signals from recep- tors in the skin, muscles, bones and joints.
eBook - PDF- Julianne Zedalis, John Eggebrecht(Authors)
- 2018(Publication Date)
- Openstax(Publisher)
The PNS can be broken down into the autonomic nervous system, which controls bodily functions without conscious control, and the sensory-somatic nervous system, which transmits sensory information from the skin, muscles, and sensory organs to the CNS and motor commands from the CNS to the muscles. The autonomic nervous system can be further divided into the parasympathetic and sympathetic pathways. “Rest and digest” responses are activated by the parasympathetic division, whereas “fight or flight” responses are activated by the sympathetic division. In other words, these two systems often have opposing effects on target organs; for example, activation of the parasympathetic system slows heart rate, whereas activation of the sympathetic system increases heart rate. (If, as you’re reading this information, a Tyrannosaurus rex barged into the room, which division would be activated?) The sensory-somatic nervous system is made up of cranial and spinal nerves with both sensory and motor neurons. The peripheral nervous system (PNS) is the connection between the central nervous system and the rest of the body. The CNS is like the power plant of the nervous system. It creates the signals that control the functions of the body. The PNS is like the wires that go to individual houses. Without those “wires,” the signals produced by the CNS could not control the body (and the CNS would not be able to receive sensory information from the body either). The PNS can be broken down into the autonomic nervous system, which controls bodily functions without conscious control, and the sensory-somatic nervous system, which transmits sensory information from the skin, muscles, and sensory organs to the CNS and sends motor commands from the CNS to the muscles. Chapter 26 | The Nervous System 1137 Autonomic Nervous System Figure 26.26 In the autonomic nervous system, a preganglionic neuron of the CNS synapses with a postganglionic neuron of the PNS.
eBook - PDF- Thomas Brown(Author)
- 2012(Publication Date)
- Academic Press(Publisher)
INTRODUCTION GENERAL FEATURES OF THE BRAIN SUMMARY: GENERAL FEATURES OF THE BRAIN SUBDIVISIONS OF THE BRAIN SUMMARY: SUBDIVISIONS OF THE BRAIN THE SPINAL CORD SUMMARY: THE SPINAL CORD THE PERIPHERAL NERVOUS SYSTEM SUMMARY: THE PERIPHERAL NERVOUS SYSTEM Anatomical Terms Cells in the Brain Blood Supply of the Brain Cerebrospinal Fluid and the Brain's Ventricles Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon Chemical Pathways in the Brain Dorsal and Ventral Horns White Matter in the Cord Somatic Nerves Autonomic Nerves Cranial Nerves 4 overview of the nervous system KEY TERMS SUGGESTED READINGS Neuroanatomy! The very word strikes terror into the hearts of most students, fearful of having to memorize long lists of strange Latin names. But we can't proceed very far into the brain without learning some of its parts. We can't begin to find out what this physical basis of mind is and how its function relates to our behavior without a road map of some kind. In this chapter we will provide a simplified road map of the nervous system (although even a simple one is rather com-plicated—the human nervous system is the most complicated piece of machinery on Earth). As we go through each of the behavioral systems in later chapters we will add more detail. The anatomical study of the nervous system began with a sharp knife and the naked eye, and has progressed to the point where it is possible to see incredibly fine details of synapses and neuron struc-ture. Early anatomists often gave parts of the nervous system a name based on the structure's appearance. Functional names might have simplified the task of studying physiological psychology, but early anatomists did not know what the functions of these structures might be. To complicate things still further, different anatomists called the same structure by different names, and sometimes both names survived.
eBook - PDF- Gerard J. Tortora, Mark Nielsen(Authors)
- 2020(Publication Date)
- Wiley(Publisher)
694 CHAPTER 19 Shawn Miller and Mark Nielsen The Autonomic Division of the Peripheral Nervous System Introduction It is the end of the semester, you have studied diligently for your anatomy final, and now it is time to take the exam. As you enter the crowded lecture hall and take a seat, you sense ten- sion in the room as the other students nervously chatter about last-minute details they think will be important to know for the test. Suddenly you feel your heart race with excitement—or is that apprehension? You notice that your mouth becomes somewhat dry, and you break out in a cold sweat. You also notice that your breathing is a little bit faster and deeper. As you wait for the professor to pass out the test, these symptoms become more and more pronounced. Finally the test arrives at your desk. As you slowly flip through the exam to get a feel for the questions being asked, you recognize that you can answer them all with confidence. What a relief! Your symptoms begin to disappear as you focus on transferring your knowledge from your brain to the paper. Most of the effects just described fall under the control of the autonomic division of the peripheral nervous system. The autonomic division has three parts—the sympathetic, para- sympathetic, and visceral parts. In this chapter, we compare structural and functional features of the autonomic division of the peripheral nervous system with those of the somatic division of the peripheral nervous system, which was introduced in Chapter 16. Then we discuss the anatomy of the autonomic division of the periph- eral nervous system and compare the organization and actions of its two major parts, the sympathetic and parasympathetic parts. A third part of the autonomic division, the visceral part, is described in greater detail in the discussion of the digestive system in Chapter 24 (Section 24.2).
eBook - PDFDiscovering Psychology
The Science of Mind
- John Cacioppo, Laura Freberg(Authors)
- 2015(Publication Date)
- Cengage Learning EMEA(Publisher)
These functions are carried out by the 31 pairs of spinal nerves serving the torso and limbs and the 12 pairs of cra-nial nerves serving the head, neck, and some internal organs (see ● Figure 4.16). Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Chapter 4 | THE BIOLOGICAL MIND: THE PHYSICAL BASIS OF BEHAVIOR 130 The Autonomic Nervous System The function of the autonomic nervous system is the control of tissues other than the skeletal muscle (Langley, 1921)—in other words, our glands and organs. The term autonomic has the same root as the word autonomy, or independence. You might think of this system as the cruise control of the body, because it ensures that your heart keeps beating and your lungs continue to inhale and exhale without your conscious direction. The autonomic nervous sys-tem contains three subdivisions: the sympathetic, the parasympathetic, and the enteric. The sympathetic and parasympathetic divisions are active under different circumstances. The sympathetic nervous system prepares the body for situations requir-ing the expenditure of energy, while the parasympa-thetic nervous system directs the storage of energy. You have probably experienced sympathetic arousal, perhaps because of a close call on the highway. In the aroused state produced by the sympathetic nervous system, our hearts race, we breathe rapidly, our faces become pale, and our palms sweat. All these activities are designed to provide the muscles with the nutrients they need for a fight-or-flight reaction.
eBook - PDF- Spencer Rathus, , , (Authors)
- 2021(Publication Date)
- Cengage Learning EMEA(Publisher)
FIG. 2.4 THE BRANCHES OF THE AUTONOMIC NERVOUS SYSTEM Weiten, W. Psychology, 8e. 2010 Cengage Learning. Copyright 2022 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 40 CHAPTER 2: Biology and Psychology In some reflexes, a third neuron, called an interneuron , transmits the neural impulse from the sensory neuron through the spinal cord to the motor neuron. The spinal cord and brain contain gray matter and white matter. Gray matter consists of nonmyelinated neurons. Some of these are involved in spinal reflexes. Others send their axons to the brain. White matter is composed of bundles of longer, myelinated (and thus whitish) axons that carry messages to and from the brain. A cross-section of the spinal cord shows that the gray matter, which includes cell bodies, is distributed in a but-terfly pattern (see Figure 2.5). The spinal cord is also involved in reflexes. We blink in response to a puff of air in our faces. We swal-low when food accumulates in the mouth. A physician may tap below the knee to elicit the knee-jerk reflex, a sign that the nervous system is operating adequately. Sexual response involves many reflexes. Urinating and processes, but the sympathetic branch, which can be acti-vated by fear, inhibits digestion. Thus, fear can give you indigestion. The ANS is of particular interest to psycholo-gists because its activities are linked to various emotions such as anxiety and love. 2-2b THE CENTRAL NERVOUS SYSTEM: THE BODY’S CENTRAL PROCESSING UNIT The CNS consists of the spinal cord and the brain.
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