This chapter talks about complex multicellular organisms which require coordinating systems that can regulate and integrate the functions of different cell types. Two coordinating systems have evolved: the nervous system and the endocrine system. It details how the endocrine system uses chemical signalling to regulate the activity of particular cell populations. The chapter looks at chemical agents known as hormones, which are produced by cells within endocrine tissues and travel in the bloodstream to other cells upon which they exert a regulatory effect. Therefore, a hormone is usually defined as a blood-borne chemical messenger, and endocrinology is defined as the study of the endocrine glands, their hormones, and their target tissues.
Chapter
Introduction to the endocrine system
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
Cells of the endocrine system
Judy Brincat
This chapter discusses the cells of the endocrine system, which are scattered throughout the body. They occur either within an epithelial surface such as the endocrine cells of the respiratory tract and alimentary canal, or within the stroma of another organ such as the C- or parafollicular cells of the thyroid, or the cells comprising the islets of Langerhans situated among the glands of the exocrine tissue of the pancreas. Endocrine cells also aggregate to form discrete organs or endocrine glands such as the adrenal glands, parathyroids, thyroid, pituitary, and pineal gland. The functions of the endocrine system are essential for maintaining homeostasis and the coordination of body growth and development, and are similar to those of the nervous system. Both systems communicate information to peripheral cells and organs, and because their functions are interrelated they are often referred to as the neuroendocrine system.
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
Communication and Control 1
The Nervous and Endocrine Systems
This chapter covers the processes of signalling in the nervous system and the endocrine system. Cells respond to environmental changes and communicate to coordinate processes, such as growth, differentiation, metabolism, and even cell death. Thus, signalling within the body involves communication between neurons. The chapter also looks at the conduction of an action which has the potential to align the length of a neuron's axon. Signal transmission between neurons occurs most commonly through the release of a chemical neurotransmitter at the synaptic terminal. The chapter then notes the four main types of receptors of cellular signalling: ionotropic and metabotropic receptors, kinase-linked receptors, and steroid receptors.
Chapter
Communication and Control 1
The Nervous and Endocrine Systems
This chapter covers the processes of signalling in the nervous system and the endocrine system. Cells respond to environmental changes and communicate to coordinate processes, such as growth, differentiation, metabolism, and even cell death. Thus, signalling within the body involves communication between neurons. The chapter also looks at the conduction of an action which has the potential to align the length of a neuron's axon. Signal transmission between neurons occurs most commonly through the release of a chemical neurotransmitter at the synaptic terminal. The chapter then notes the four main types of receptors of cellular signalling: ionotropic and metabotropic receptors, kinase-linked receptors, and steroid receptors.
Chapter
Nutrition and the skeleton
Ian R. Reid
This chapter explains how nutrition plays a key role in the maintenance of bone health. Since the skeleton is the principal structural element of the body necessary for all movement, it plays a key role in the metabolism of the minerals calcium and phosphate. Additionally, bone density directly correlates to body weight throughout a person's life. The chapter looks into the structure of bone and the cellular events that provide remodelling and renewal of bone before considering the regulation of calcium metabolism and the vitamin D endocrine system. It then details the nature, pathogenesis, and management of osteoporosis, osteomalacia, and rickets.
Chapter
Introducing hormones
This chapter provides an overview of hormones, which constitute a range of different compounds, including peptides and steroids. Oversimplification of information about hormones can lead to some misleading ideas. For example, not all hormones are slow acting as is often assumed. The endocrine and nervous systems are closely connected, and hormones are released by a range of different tissues in the body, not just the 'classical' endocrine organs. Steroid hormones are all made from cholesterol by a process called steroidogenesis, while peptide hormones are made just like any other protein. The effects of hormones are all as a result of the hormone binding to its receptor. These receptors are found in target tissues, and their cellular location depends on the chemical type of hormone. The chapter then looks at negative feedback control, which is the most effective means of regulating blood levels of hormones and their effects.
Book
Ian Kay and Gethin Evans
Thrive in Human Physiology provides an initial introduction to human physiology. It then looks at control and co-ordination in terms of the nervous system and the endocrine system. It moves on to musculoskeletal physiology and movement, cardiovascular physiology, respiratory physiology, renal physiology, gastrointestinal physiology, reproductive physiology, and integrative physiology.
