Introduction As described in Chapter 8 , the immune system is a complex cellular network that defends the body against danger. To do so, the immune system must distinguish between safe and dangerous substances. Safe or nonthreatening substances can be…
Introduction The kidney modifies the contents of the plasma by filtering its components into the urine, whereas the liver modifies the blood contents by metabolically transforming them. The liver is where drugs, hormones, and toxic waste products, such as ammonia,…
Introduction In Chapter 24 , we saw that the acquisition of energy and building blocks requires digestion and absorption. We now focus on two other critical gastrointestinal (GI) capabilities, without which digestion and absorption could not occur: Motility is the…
Introduction The gastrointestinal (GI) system supplies the fuel and the building blocks for the functioning of the body through the digestion and absorption of nutrients. Its machinery for doing so is the alimentary canal, also called the gastrointestinal tract, a…
C.J. is a 52-year-old male with chronic hypertension (HTN) managed both with lifestyle changes and pharmacologically. He presented yesterday morning to an outside hospital with malignant HTN, headache, and complaints of “tearing” chest pain. His only past medical history is…
Introduction Micturition is the process by which the urinary bladder empties its contents, and it is more commonly known as urination. This process involves two steps: (1) the bladder fills until wall tension exceeds a certain threshold level and (2)…
Introduction Bodily processes are exquisitely sensitive to pH. Deviations from the normal range of blood pH of 7.35 to 7.45 may have serious consequences. Low pH (<7.2) causes significant clinical manifestations, including impaired growth, decreased cardiac output, decreased blood pressure,…
Introduction In the past few chapters, we made several observations about extracellular fluid (ECF) volume and osmolality: The stability of these parameters is critical for normal physiologic functioning These parameters are subject to daily changes The kidney counters these changes…
Introduction Osmolality (or concentration of the solutes in the body fluids) is critical to organ function and must be closely regulated. Disturbances in the osmolality of the body fluids arise from the gain or loss of water, or from the…
Introduction Organ perfusion, and therefore function, is dependent on blood pressure (BP). The cardiovascular system does not govern BP by itself; equally important to the regulation of BP is the kidney’s control over the volume of the extracellular fluid (ECF).…