Ganongs Review of Medical Physiology

‘Ganongs Review of Medical Physiology’ Summary of the book
The detailed study of physiologic system structure and function has its foundations in physical and chemical laws and the molecular and cellular makeup of each tissue and organ system. This first section provides an overview of the basic building blocks that provide the important frame- work for human physiology. It is important to note here that these initial sections are not meant to provide an exhaustive understanding of biophysics, biochemistry, or cellular and molecular physiology, rather they are to serve as a reminder of how the basic principles from these disciplines contrib- ute to medical physiology discussed in later sections. In the first part of this section, the following basic building blocks are introduced and discussed: electrolytes; carbohy- drates, lipids, and fatty acids; amino acids and proteins; and nucleic acids. Students are reminded of some of the basic principles and building blocks of biophysics and biochemi- stry and how they fit into the physiologic environment. Examples of direct clinical applications are provided in the Clinical Boxes to help bridge the gap between build- ing blocks, basic principles, and human physiology. These basic principles are followed up with a discussion of the generic cell and its components. It is important to realize the cell is the basic unit within the body, and it is the collec- tion and fine-tuned interactions among and between these fundamental units that allow for proper tissue, organ, and organism function. In the second part of this introductory section, we take a cellular approach to lay a groundwork of understanding groups of cells that interact with many of the systems dis- cussed in future chapters. The first group of cells presented contribute to inflammatory reactions in the body. These individual players, their coordinated behavior, and the net effects of the”open system” of inflammation in the body are discussed in detail. The second group of cells discussed are responsible for the excitatory responses in human physiol- ogy and include both neuronal and muscle cells. A funda- mental understanding of the inner workings of these cells, and how they are controlled by their neighboring cells helps the student to understand their eventual integration into individual systems discussed in later sections. In the end, this first section serves as an introduction, refresher, and quick source of material to best understand systems physiology presented in the later sections. For detailed understanding of any of the chapters within this section, several excellent and current textbooks that pro- vide more in depth reviews of principles of biochemistry, biophysics, cell physiology, muscle and neuronal physiol- ogy are provided as resources at the end of each individ- ual chapter. Students who are intrigued by the overview provided in this first section are encouraged to visit these texts for a more thorough understanding of these basic principles. CHAPTER SUMMARY
■ Olfactory sensory neurons, supporting (sustentacular) cells, and basal stem cells are located in the olfactory epithelium within the upper portion of the nasal cavity.
■ The cilia located on the dendritic knob of the olfactory sensory neuron contain odorant receptors that are coupled to G-proteins. Axons of olfactory sensory neurons contact the dendrites of mitral and tufted cells in the olfactory bulbs to form olfactory glomeruli.
■ Information from the olfactory bulb travels via the lateral olfactory stria directly to the olfactory cortex, including the anterior olfactory nucleus, olfactory tubercle, piriform cortex, amygdala, and entorhinal cortex.
■ Taste buds are the specialized sense organs for taste and are composed of basal stem cells and three types of taste cells (dark, light, and intermediate). The three types of taste cells may represent various stages of differentiation of developing taste cells, with the light cells being the most mature. Taste buds are located in the mucosa of the epiglottis, palate, and pharynx and in the walls of papillae of the tongue.
■ There are taste receptors for sweet, sour, bitter, salt, and umami. Signal transduction mechanisms include passage through ion channels, binding to and blocking ion channels, and GPCRs requiring second messenger systems.
■ The afferents from taste buds in the tongue travel via the seventh, ninth, and tenth cranial nerves to synapse in the NTS. From there, axons ascend via the ipsilateral medial lemniscus to the ventral posteromedial nucleus of the thalamus, and onto the anterior insula and frontal .