Introduction The body faces multiple challenges met by the kidneys, including acid base balance, regulation of the concentrations of electrolytes such as potassium, and control of blood pressure. Two of the most critical are (1) the management of extracellular fluid…
Introduction The kidney is the principal organ of homeostasis. The kidney’s filtration of blood, and modification of that filtrate by epithelial transport, produces urine to accomplish the following functions: Control of the composition of body fluids, the concentration of electrolytes,…
A.Y. is a 33-year-old woman with a history of severe asthma requiring multiple admissions and intubations, who initially presented to the emergency room with shortness of breath, wheezing, and chest pain. Presentation: History A.Y. had been in her usual state…
Core concepts ( figs. 16.1 and 16.2 ) To function properly, the human respiratory system must: Respond to oxygen demands. Maintain a constant range of oxygen and carbon dioxide in blood. Respiration is governed by both voluntary and involuntary neural…
Introduction For successful cell respiration to occur, multiple systems must work in unison for the transport of oxygen (O 2 ) and carbon dioxide (CO 2 ): Respiratory system Hematologic system Cardiovascular system Both O 2 and CO 2 traverse…
Introduction Why do we breathe? The vital importance of breathing was clear even in ancient times, when people believed that the air we breathe, or pneumo , gives rise to the spirit. Oxygen in the air enables active cellular metabolism,…
Introduction The use of oxygen for energy extraction is called aerobic respiration. In humans, gas exchange occurs in the air-filled lungs, which exposes the blood of the circulatory system to the air. Oxygen in the air of the lungs diffuses…
L.B. is a 68-year-old retired accountant who has noticed worsening shortness of breath while mowing his lawn. Presentation: History L.B. was well until 6 months ago, when he noticed extreme fatigue and lightheadedness when moving from a sitting or lying…
Introduction Whether running a marathon or toting a hefty biochemistry book up a staircase, exercising muscle places demand on the body through three mechanisms: Increased oxygen and nutrient demand Increased waste products of metabolism Increased heat generation The cardiovascular, respiratory,…
Introduction The heart contains specialized tissue for: (1) generating rhythmic action potentials and (2) conducting those action potentials precisely across the heart. This ensures correct timing of atrial and ventricular contraction. System structure Fig. 11.1 depicts the typical pathway of…