Immunity refers to protection against infections. The immune system is the collection of cells and molecules that are responsible for defending the body against the countless pathogens that individuals encounter. Defects in the immune system are the cause of immunodeficiency…
In this chapter we discuss genetic and pediatric diseases together, because many disorders of childhood are of genetic origin. However, it must be borne in mind that not all genetic disorders manifest in infancy and childhood, and, conversely, many pediatric…
The health of cells and tissues depends on the circulation of blood, which delivers oxygen and nutrients and removes wastes generated by cellular metabolism. Under normal conditions, as blood passes through capillary beds, there is little net movement of water and…
Inflammation is a response of vascularized tissues to infections and tissue damage that brings cells and molecules of host defense from the circulation to the sites where they are needed, in order to eliminate the offending agents. Although in common…
Introduction to Pathology The field of pathology is dedicated to understanding the causes of disease and the changes in cells, tissues, and organs that are associated with development of disease. Thus, pathology provides the scientific foundation for the practice of…
Although this chapter comes at the end of the book, it is not an afterthought. Vision is a major quality-of-life issue. Before the public awareness of acquired immunodeficiency syndrome (AIDS) and Alzheimer disease, the most feared disease among Americans was…
The principal functional unit of the central nervous system (CNS) is the neuron . Neurons of different types and in different locations have distinct properties, including diverse functional roles, patterns of synaptic connections, neurotransmitters used, and metabolic requirements, which vary…
Neuromuscular diseases are a complex group of disorders that typically present with weakness, muscle pain, or sensory deficits and may be inherited or acquired. They can be grouped according to anatomy, disease course, and pathogenesis. Physicians keep all these characteristics…
Bone Basic Structure and Function of Bone The adult human skeleton is composed of 206 bones that account for ~12% of body weight. Bone functions include mechanical support, force transmission, internal organ protection, and mineral homeostasis, and it also serves…
The Skin: More Than a Mechanical Barrier More than a century and a half ago, the noted pathologist Rudolph Virchow described the skin as a mere protective covering for more delicate and functionally sophisticated internal viscera. Subsequently, the skin was…