This chapter discusses the development of the nervous system. It recognizes the complexity of the nervous system in comparison to all the organ systems in the animal embryo. Moreover, the chapter mentions the divide between the central nervous system (CNS) and peripheral nervous system (PNS). It explores the different types and connections of neurons. In addition, the chapter explains how the nervous system is superficially similar to other developmental systems, except that it involves the acquisition of individual cell identities. It looks into how neural activity plays a major role in refining connections, such as those between the eye and the brain.
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Chapter
Development of the nervous system
Chapter
Nerves: the cells of the central and peripheral nervous systems
Rosalind King and Richard Mathias
This chapter focuses on the cells that make up the structures of the nervous system, and looks at how they act together to facilitate all the functions of human life. The nervous system is often thought of as having two main components. The central nervous system (CNS) comprises the brain and spinal cord. From the CNS, nerve fibres project to the receptors and effectors in every other organ and tissue throughout the body, forming the peripheral nervous system (PNS). The chapter then describes the cells that make up the nervous system and their functions, looking at neurons and glial cells. It also explains the mechanisms of neuronal communication and outlines the arrangement and integration of the central and peripheral nervous systems.
Chapter
Nervous System Organisation and Biological Clocks
This chapter examines the correlation between the organisation of the nervous system and biological clocks. It cites how the organisation of behavioural adaptation results from the function of the nervous system. The organisation of neurons into functional nervous systems allows for the complexity of neural control of animal physiology and behaviour. The chapter cites the central nervous system (CNS) and peripheral nervous system (PNS) as the major division in the nervous system in most animals. It explains how biological clocks endow animals with an intrinsic temporal organisation, which is a timed pattern of change in physiology or behaviour independent from a change in environment.
Chapter
Neurons, nerves and nervous systems
This chapter evaluates the nervous systems in animals. All animals except Placozoa and Porifera (sponges) have a well-defined nervous system, which is the main means of communication between the animal and the outside world. Animals with bilateral symmetry have a central and a peripheral nervous system. The central nervous system (CNS) in invertebrates is organized in ganglia close to sensory structures, while the CNS in vertebrates consists of the brain and the spinal cord. The chapter then looks at the ionic basis of electrical activity in neurons, before considering how neurons communicate with each other. Signal transmission between neurons takes place at synapses, which are of two types: electrical synapses and chemical synapses.
Chapter
The Seat of Self and Neurosurgery
This chapter examines the inner workings of the nervous system and some ways to repair any damage to it. The nervous system is composed of the central and peripheral systems that provide control and communication to the body. The nervous system is as susceptible as any other organ to damage through trauma and its risk goes higher due to the inability of the nervous system to repair damaged neurones. Even though neurosurgery offers ways to manage acute and subacute damage to the brain and spinal cord, it is still a high-risk procedure. The chapter considers the extensive field of reconstructive neurology and bionics to improve the outcomes of brain and nerve damage.
Chapter
The endocrine system
This chapter reviews how the endocrine system, together with the nervous system, controls the multitude of physiological processes in the body and ensures that homeostasis is achieved. It discusses the formation of hormones from derivatives of amino acids, peptides and proteins, and lipids. It also analyszes the chemical nature of the process by which anan individual hormone determinesing where its receptor is located. The chapter clarifies how the overall plasma levels are maintained at the appropriate level proportion by negative feedback mechanisms, although hormone secretion may display circadian rhythms. It mentions the pituitary gland. This is described as the master endocrine gland by virtue of the number of physiological processes it controls.
Chapter
Nerve cells and their connections
This chapter examines the nervous system. The nervous system is adapted to provide rapid and discrete signalling over long distances. It is divided into the central nervous system (CNS) comprising the brain and spinal cord, and the peripheral nervous system comprising the peripheral nerves, the enteric nervous system, and autonomic nervous system. The chapter describes the two main types of cells that make up the nervous system: the nerve cells or neurons and the satellite cells. The chapter clarifies that the satellite cells in the brain and spinal cord are called glial cells or neuroglia, while elsewhere they have different names, such as Schwann cells, Müller cells, or pituicytes. The neurons are the fast-signalling elements of the nervous system.
Chapter
Introduction to the nervous system
This chapter focuses on the nervous system. This includes motor control and the basis of sensation. It outlines the organization of the nervous system and the nature of its constituent cells. The nervous system may be divided into five main parts: the brain, the spinal cord, peripheral nerves, the autonomic nervous system, and the enteric nervous system. The chapter discusses how the brain and spinal cord constitute the central nervous system (CNS), while the peripheral nerves, autonomic nervous system, and enteric nervous system make up the peripheral nervous system. The autonomic nervous system is the part of the nervous system that is concerned with the innervation of blood vessels and the internal organs, which includes the autonomic ganglia that run parallel to the spinal column and their associated nerves.
Chapter
Repair and Regeneration in the Nervous System
Edited by George J. Augustine, Jennifer Groh, Scott Huettel, Anthony-Samuel LaMantia, Leonard E. White, and Dale Purves,
This chapter reviews the three types of cellular repair in the adult nervous system, in addition to the functional reorganization of surviving neurons and circuits that typically follows brain damage. The first and most effective is the regrowth of severed peripheral axons either from peripheral sensory neurons or central motor neurons, usually via the peripheral nerve sheaths once occupied by their forerunners. A second, and far more limited, type of repair is local sprouting or longer extension of axons and dendrites at sites of traumatic damage or degenerative pathology in the brain or spinal cord. A third type of repair is generation of new neurons in the adult brain. In most mammals, the olfactory bulb and the hippocampus are the only sites of adult neurogenesis in the central nervous system (CNS).
Chapter
Cholinergics, anticholinergics, and anticholinesterases
This chapter describes drugs that have an effect on the cholinergic nervous system, citing several clinically important drugs that act on the peripheral and the central nervous system (CNS). It examines the involvement of CNS with nerves through the use of the neurotransmitter acetylcholine as a chemical messenger. It also covers drugs that influence the activity of motor nerves, which take messages from the CNS to various parts of the body, such as skeletal muscle, smooth muscle, cardiac muscle, and glands. The chapter details how motor nerves innervate skeletal muscle, nerves that synapse with other nerves in the peripheral nervous system, and the parasympathetic nerves innervating cardiac and smooth muscle. It reviews two types of cholinergic receptor: muscarinic receptors that are present in smooth and cardiac muscle and nicotinic receptors that are present in skeletal muscle and in synapses between neurons.
Chapter
Digestive System
This chapter argues that the digestive system is one of the most important systems of the human body. The digestive system aims to break down complex molecules into smaller ones in an effort for them to be absorbed in the bloodstream to provide nutrients for the body. The digestive tract produces a range of enzymes that are responsible for the digestion of macronutrients. The chapter details the histology and regulation of the digestive tract with reference to its four main layers: mucosa, submucosa, muscularis externa, and serosa. It shows how the nervous and endocrine systems contribute to the control of the digestive tract.
Chapter
Communication and Control 3
Controlling Organ Systems
This chapter discusses communication and control within organ systems. Organs and tissues work together as groups to facilitate varying physiological processes necessary for life. The organ systems work together in concert to achieve specific goals and maintain homeostasis. Homeostasis occurs in many forms, such as the regulation of body temperature, blood pressure, blood volume, acid-base balance, and glucose concentration. The chapter then details how the autonomic nervous system and endocrine system control the activity of different organ systems. It cites the hypothalamus as the major control and integration centre for both systems and provides a functional link between the two.
Book
Gillian Pocock, Christopher D. Richards, and David A. Richards
Human Physiology provides clear explanations of the principles that govern the body’s physiological processes and shows how these can be applied. It is made up of eleven sections. Section 1 is about basic concepts. The second section covers the organization and basic functions of cells. The third section looks at the excitable tissues, nerve, and muscle. The fourth section goes into detail about the nervous system and special senses. The section which follows is about the endocrine system and it includes details on the pituitary gland, hypothalamus, the thyroid and parathyroid glands, the adrenal gland, and the endocrine pancreas. The text also looks at blood and the immune system, before turning to the cardiovascular and respiratory systems. There follows a section of the regulation of the internal environment. Towards the end the text turns to the gastrointestinal system. Finally, the text looks at reproduction and growth.
Chapter
Communication and Control 3
Controlling Organ Systems
This chapter discusses communication and control within organ systems. Organs and tissues work together as groups to facilitate varying physiological processes necessary for life. The organ systems work together in concert to achieve specific goals and maintain homeostasis. Homeostasis occurs in many forms, such as the regulation of body temperature, blood pressure, blood volume, acid-base balance, and glucose concentration. The chapter then details how the autonomic nervous system and endocrine system control the activity of different organ systems. It cites the hypothalamus as the major control and integration centre for both systems and provides a functional link between the two.
Chapter
Digestive System
This chapter argues that the digestive system is one of the most important systems of the human body. The digestive system aims to break down complex molecules into smaller ones in an effort for them to be absorbed in the bloodstream to provide nutrients for the body. The digestive tract produces a range of enzymes that are responsible for the digestion of macronutrients. The chapter details the histology and regulation of the digestive tract with reference to its four main layers: mucosa, submucosa, muscularis externa, and serosa. It shows how the nervous and endocrine systems contribute to the control of the digestive tract.
Chapter
The autonomic nervous system
This chapter deals with the autonomic nervous system (ANS). This regulates the operation of the internal organs and supports the activity of the body as a whole. The autonomic nervous system is not a separate nervous system but is the efferent pathway that links those areas within the brain concerned with the regulation of the internal environment to specific effectors such as blood vessels, the heart, and the gut. The chapter points out that the ANS does not pass directly to the effector organs, but rather they synapse in autonomic ganglia, which are located outside the CNS. The chapter looks at fibres. These project from the CNS to the autonomic ganglia. The latter are called preganglionic fibres, and those that connect the ganglia to their target organs are called postganglionic fibres. The sensory nerves of the internal organs are known as visceral afferents.
Chapter
The endocrine pancreas and the regulation of plasma glucose
This chapter examines the cells of the body which have continuous access to glucose to carry out their normal metabolism, the major fuel used to produce cellular energy. It also looks at certain tissues, notably the central nervous system, the retina, and the germinal epithelium. These rely almost entirely on glucose metabolism for the generation of adenosine triphosphate (ATP). The nervous system alone requires around 110 g of glucose each day to meet its metabolic needs. The chapter discusses the concentration gradient for glucose between the blood and the extracellular environment of the brain cells that is maintained. Blood glucose levels are normally maintained between 70 and 125 mg glucose dl-1 blood despite wide fluctuations in dietary intake and regulation takes place continuously over a timescale of minutes.
Chapter
Introduction
This chapter gives an overview of neuroethology, the biological discipline that attempts to understand how the nervous system controls the natural behavior of animals. It emphasizes that this area of study has its roots in both neurobiology and ethology, and that its success is based on the incorporation of a blend of the neurobiological and ethological approaches into its own scientific armory. The chapter introduces ethogram, which refers to the entire behavioral repertoire of an animal species. Then it discusses how behavioral patterns are quantified using their rate of occurrence, duration, and/or intensity. The chapter also considers how to select a suitable model system for neuroethological research. These systems are characterized by behavioral patterns that, although simple, robust, and readily accessible, are also ethologically relevant.
Chapter
Communication systems in the body: neural
Neil Henney and Peter Penson
This chapter details the role, structure and function of the peripheral nervous system. It cites that when things go wrong with the peripheral nervous system, the result is often severe movement disorders. Drugs that act on the somatic part of the peripheral nervous system can be useful in preventing pain or relaxing muscles during surgery. The chapter provides an overview of drugs that affect neurotransmission. Neurotransmission occurs from cell to cell across narrow gaps called synapses. Drugs that effect the peripheral nervous system include local anaesthetics and muscle relaxants. The chapter also looks into pain and sensory neurotransmission.
Chapter
Early Brain Development
Edited by George J. Augustine, Jennifer Groh, Scott Huettel, Anthony-Samuel LaMantia, Leonard E. White, and Dale Purves,
This chapter explores early brain development. The elaborate architecture of the adult brain is the product of cell-to-cell signals, genetic instructions, and their consequences for stem cells that are set aside in the embryo during the earliest steps of development to generate the entire nervous system. These events include the establishment of the primordial central and peripheral nervous systems, the initial formation of the major brain regions, the generation of multiple classes of neurons and glial cells from undifferentiated neural stem or progenitor cells, and the migration of neurons or their immediate precursors from sites of generation to their final positions. These processes set the stage for the subsequent local differentiation of dendrites, axons, and synapses, as well as the growth of long-distance axon pathways and synaptic connections. When any of these processes goes awry, the consequences can be disastrous.
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