Đang chuẩn bị liên kết để tải về tài liệu:
Fluids and Electrolytes Demystified - part 2

Tế bào là đơn vị cơ bản của cấu trúc và chức năng của cuộc sống. Nhiều sinh vật bao gồm chỉ một tế bào đơn lẻ. Tế bào này thực hiện tất cả các chức năng quan trọng đối với sinh vật đó. Mặt khác, nhiều sinh vật đa bào, bao gồm cả con người, có cơ quan bao gồm khoảng 70 nghìn tỷ tế bào trong môi trường riêng của họ. | CHAPTER 1 Underlying Fluid and Electrolyte Balance to allow essential chemical reactions to occur. What is fluid balance What are the electrolytes of life This chapter will address these questions beginning with a basic overview of select anatomy and physiology of the human body. The Cell Cells are the basic unit of structure and function of life. Many organisms consist of just one single cell. This cell performs all the vital functions for that organism. On the other hand many organisms are multicellular including humans whose bodies are composed of about 70 trillion cells in their own environment. Cells make up tissues tissues form organs and organs form organ systems and these all interact in ways that keep this internal environment relatively constant despite an everchanging outside environment. With very few exceptions all body structures and functions work in ways that maintain life. All cells are bounded by a plasma membrane. This membrane is selectively permeable allowing certain things in and out while excluding others. Useful substances like oxygen and nutrients enter through the membrane while waste products like carbon dioxide leave through it. These movements involve physical passive processes such as Osmosis water movement across a membrane from an area of low concentration to an area of high concentration Diffusion movement of molecules from an area of high concentration to an area of low concentration Facilitative diffusion movement of molecules from an area of high concentration to an area of low concentration using a carrier cell to accelerate diffusion Filtration selective allowance or blockage of substances across a membrane wherein movement is influenced by a pressure gradient The movement of substances across a membrane also includes physiologic or active processes such as Active transport molecules moving against a concentration gradient with the assistance of energy. Sodium and potassium differ greatly from the intracellular to the .