In this chapter, we discuss general principles of gene structure and expression as well as mechanisms underlying the regulation of tissue-specific and inducible gene expression. We will see that proteins (transcription factors) control gene transcription by interacting with regulatory elements…
Even single-cell organisms must respond to environmental challenges, which necessitated the development of signal-transduction mechanisms. The evolution of multicellular organisms required the evolution of cell-to-cell communication within the organism to coordinate between cells activities ranging from the induction of embryonic…
In the minds of many students, the discipline of physiology is linked inextricably to images from its past. This prejudice is not surprising because many experiments from physiology's proud history, such as those of Pavlov on his dogs, have transcended…
What is physiology? Physiology is the dynamic study of life. Physiology describes the “vital” functions of living organisms and their organs, cells, and molecules. For centuries, the discipline of physiology has been closely intertwined with medicine. Although physiology is not…
Endothelium The endothelium is the single-cell-thick lining of all blood vessels that is in direct contact with the blood stream. In arteries and veins, the endothelium is the inner most surface of the vessel, overlying the deeper wall components, such…
Cell-cell communication It is no surprise that cells communicate with each other. Signaling is essential for coordinating the function and differentiation of nearby cells. Cells located close to one another communicate in three main ways: If the cells are connected…
Signal transduction The cell membrane is a barrier to the free movement not only of matter (molecules, ions), but also to that of information . Just as living cells must maintain an internal environment chemically separate from but in regulated…
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Cell membrane structure and transport functions The contents of cells are sealed off from the extracellular environment by a lipid barrier called the plasma membrane that protects the cell’s interior from the changing conditions of the extracellular environment and helps…
Presentation: History and physical examination J.B is a 38 year old woman who presents to her primary care physician with a chief complaint of fatigue and weight gain. She was in her normal state of health until about 6 months…