This chapter evaluates the types of blood cell found within peripheral blood. It begins by explaining blood cell production and the structure of the bone marrow. The red colouration of our blood is derived from the red blood cells, also called erythrocytes, and in particular the intracellular respiratory pigment haemoglobin. Meanwhile, our capacity to fight infection comes from heterogeneous populations of white blood cells, also called leucocytes, with each population having a different function. Under the umbrella term of white blood cells are three types of cell characterized by the types of granule within their cytoplasm. These cells are broadly called granulocytes, and more specifically are neutrophils, eosinophils, and basophils. The chapter then looks at stem cells, haemopoiesis, erythropoiesis, thrombopoiesis, haemostasis, granulopoiesis, and monopoiesis.
Chapter
Blood cell genesis: red cell, white cell and platelet families
Gavin Knight
Book
Edited by Guy Orchard and Brian Nation
Cell Structure & Function starts by introducing cell structure, molecular construction, and communication strategies. It looks at techniques for studying cells; anatomy, embryology, and cell families; blood cell genesis; nerves; and lungs. Next it turns to the alimentary canal, cells and commercial bacteria of the alimentary canal, and the cells of the vascular and lymphatic systems. There is then a chapter on connective tissue, bones, cartilage, and muscle. Next, the text deals with the cells of the liver and kidney, reproductive cells and gametogenesis, and the endocrine system. Finally, the book looks at the cells of the skin.
Chapter
Cells and microbial flora of the gastrointestinal tract
Kathy Nye
This chapter describes the cells and microbial flora of the gastrointestinal (GI) tract. Around 10 billion human cells, which are replaced every three to four days, interact with an even greater number of microorganisms, a ratio of around one cell to ten microorganisms. This interaction is key to the proper development and functioning of the GI tract and the immune system, as well as to the assimilation and production of essential nutrients. However, scientists are only just beginning to understand the full extent of this vital, symbiotic relationship. The chapter considers these complex interactions, in health and disease, and how an understanding of these mechanisms may lead to improvements in health and the management of some types of illness.
Chapter
Cells of the cardiovascular and lymphatic systems
Andrew Blann
This chapter outlines the cells and organs of the cardiovascular and lymphatic systems, and looks at how together they form the circulation. Almost all of the cells that make up the vessels and organs are endothelial cells, smooth muscle cells, heart muscle cells (cardiomyocytes), macrophages, and fibroblasts. In various combinations they make up vessels (arteries, veins, capillaries, and lymphatics) and the organs of the heart, thymus, spleen, and lymph nodes. The chapter then examines the different types of disease that affect the cells, vessels, and organs of the cardiovascular and lymphatic systems. These include atherosclerosis (involving arteries), venous thromboembolism or VTE (involving veins), and tumour-associated lymphadenopathy (affecting lymph nodes).
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
Tony Warford and Tony Madgwick
This chapter addresses the digestive system, which is a complex association of different integrated anatomical components with the primary task of extracting nutrients, water, and electrolytes from ingested food before collecting and excreting the indigestible waste. Thus, the system can be divided into a region for mechanical disruption and initial digestion of food (the oral pharynx), with delivery of this mass via the oesophagus to the stomach for further processing by extracellular digestion. Most nutrient uptake occurs in the small intestine (further divided into the duodenum, jejunum, and ileum), while water and electrolyte absorption occurs mainly in the colon. Finally, the undigested remnants are collected in the distal colon and rectum before expulsion by defaecation. A secondary, but important, function is that of immune surveillance provided by aggregates of lymphoid tissue associated with the entire alimentary tract.
Chapter
Introducing the cell: the unit of life
Carole Hackney and David Furness
This introductory chapter provide an overview of cells, which are the basic unit of life and, with the exception of certain particulate forms that can reproduce under some conditions (viruses), make up all living things. The two main types of cell are prokaryotes, which lack a nucleus, and eukaryotes, which possess a nucleus. Eukaryotes may have evolved from prokaryotes acting together in a communal way initially, until eventually they became associated together within a single membrane. The modern eukaryotic cell is encapsulated in a plasma membrane, which contains a watery cytoplasm within which are a number of organelle types and a nucleus containing the genetic material of the cell. The chapter then looks at membrane systems, cell division, and tissue formation.
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Introduction to anatomy and embryology
Joanne Murray and Ian Locke
This chapter begins by examining anatomy and physiology. Anatomy defines the spatial/structural relationships between the various components and organ systems of the body. Meanwhile, physiology is the study of the function of the body and the systems within it. Fine anatomy is the detailed, microscopical structure of individual organs or tissues. The chapter then describes the gross features of the human body and differentiates between fine and gross anatomy. The human body is composed of 11 major organ systems; each of these systems is composed of various cell and tissue types. The chapter also looks at fertilization and implantation, before considering foetal development. Finally, it studies the continued development of the ageing human through childhood, adolescence, adulthood, and into old age.
Chapter
Kidney and urinary tract
Guy Orchard, David Muskett, and Brian Nation
This chapter highlights the cells of the kidney and urinary tract. The kidneys and urinary system provide the basis for homeostatic regulation of the body's water level, controlling electrolytes and fluid balance. The kidneys operate by a series of active and passive transport mechanisms to ensure efficient production of urine. They have numerous hormonal functions; for example, controlling blood pressure through the renin-angiotensin function, the production of red blood cells via the production of erythropoietin, processing vitamin D, and the production of antihypertensive lipids. The urinary system comprises two kidneys, two ureters, the bladder, and a single draining urethra. Anatomically, the kidneys are located on the posterior wall of the abdomen at around waist height. The chapter also looks at urinary system disease and kidney transplantation.
Chapter
Liver
Anne Rayner and Alberto Quaglia
This chapter studies the cells and microscopic structures found within the liver. The liver is a large, solid organ situated in the upper right quadrant of the abdomen, below and partly behind the lower rib cage, separated from the thoracic cavity by the diaphragm. At the microscopical level, the liver parenchyma consists of a main epithelial cell population (hepatocytes) arranged in cords (hepatic plates) in close contact with a network of capillary-like vascular structures (sinusoids) containing a mixture of oxygenated arterial blood and venous blood carrying nutrients from the gastrointestinal tract. Other cell components include biliary epithelial cells lining the biliary tree ducts, endothelial cells lining the sinusoids, stellate cells involved in vitamin storage and fibrogenesis, and lymphocytes and macrophages providing an immunological barrier against circulating antigens. The chapter then looks at the main types of pathology affecting the liver and biliary tract.
Chapter
Lungs: the cells of the respiratory system
Behdad Shambayati and Andrew Evered
This chapter assesses the tissues and cells involved in respiration. Respiration is the transport of oxygen into cells and tissues, and the removal of carbon dioxide. The respiratory system consists of two parts: a system of tubes and passages for conduction of the air, and a respiratory portion in which gaseous exchange occurs. The conduction portion includes the nose, pharynx, trachea, and bronchi, while the respiratory portion includes respiratory bronchioles, alveolar ducts, and alveoli. Alveoli are sac-like structures that make up the majority of lung tissue and are the sites where exchange of O2 and CO2 takes place. The very thin wall of the alveoli and their close proximity to a dense network of capillaries allows the diffusion of oxygen from inspired air into arterioles, and the removal of carbon dioxide from venules into the alveolar space for removal during expiration.
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Musculoskeletal system
Suha Deen
This chapter explores the skeletal system, including skeletal muscles, bones, and cartilage. The musculoskeletal system provides the body with mechanical support. It is composed of skeletal muscles, tendons, bones, joints, and ligaments, with all the different components working together as a unit. The main functional attribute of bone is its specialized extracellular matrix, which is hardened by the deposition of calcium, enabling it to function as a rigid lever, articulating with other bones through joints that are kept in relationship by ligaments. Bone also contains blood-forming marrow. Meanwhile, skeletal muscles act as contractile levers and are connected to bones by tendons. The chapter then describes the microscopic and ultrastructural features of muscle fibres, as well as the different types of ossification.
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.
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Reproductive cells and gametogenesis
Andrew Evered and Behdad Shambayati
This chapter reviews the cells and tissues that make up the reproductive tract. The reproductive system is unique in possessing a population of cells that contain half the amount of genetic material normally found in other cells of the body. These germ cells, or gametes as they are sometimes called, are created by a process known as gametogenesis and give humans their reproductive capacity. The chapter then looks at how the cells of the testes and associated duct system support spermatogenesis, as well as how the cells of the ovary and associated ducts and cavities support oogenesis. It also explains how the structure of spermatozoa and ova facilitates reproduction, before describing the structure and function of tissues that comprise the external genitalia.
Chapter
Skin and breast
Guy Orchard
This chapter examines the main cell types that compose the skin, which represents the largest organ of the human body. The skin has homeostatic and regulatory functions that protect and regulate the body systems. It also has a sensory perceptive role. It is the largest sensory organ of the human body and has receptors for touch, pain, pressure, and temperature. The structures responsible for this role are called corpuscles. Finally, the skin also has a metabolic role. The subcutaneous fat provides the body with triglycerides for energy, if required; in addition, the epidermal cells synthesize vitamin D (previtamin D3), which is primarily important in bone structure. The chapter also considers breast tissue, which is a specialized form of apocrine glands.
Chapter
Studying cells: essential techniques
Gavin Knight
This chapter discusses the role technology plays in furthering our understanding of cells, with particular emphasis on those found in the human body. It begins by describing the historical aspects of cells and cell theory. It was not until the use of microscopy by Robert Hooke, curator of experiments at the Royal Society in London, that the composition of organisms and their fine structure was reported. Since the introduction of microscopy in 1595, huge technological advances have seen progress made, from the typical compound microscope to the assembly of small, powerful machines that help us visualize the ultrastructure of cells. The chapter then looks at cytometrics, cytogenetic analysis, and molecular biology.
