Key Points ▪ The alveolar anesthetic concentration (F A ) or partial pressure (P alv ) is important because it is the driving force determining anesthetic uptake into blood and target tissues in the central nervous system, and it can…
Key Points ▪ Anesthesia consists of separable and independent components, each of which involves distinct, but possibly overlapping, mechanisms at different sites in the central nervous system. ▪ The potencies of general anesthetics correlate with their solubility in oil, indicating…
Key Points ▪ Pharmacokinetics describes the relationship between drug dose and drug concentration in plasma or at the site of drug effect over time. For anesthetic drugs, the processes of distribution and elimination (metabolism and excretion) govern this relationship. ▪…
Key Points ▪ A molecule in the plasma must pass in succession through the endothelial fenestration, glomerular basement membrane (GBM), and epithelial slit diaphragm to cross the filtration barrier and enter the tubular fluid. The capillary endothelium restricts the passage…
Key Points ▪ The liver is the largest abdominal organ and carries out a number of vital functions including metabolism and detoxification. ▪ The liver receives approximately 25% of the resting cardiac output. The hepatic artery is responsible for 25%…
Key Points ▪ The gastrointestinal (GI) tract forms a long tube from mouth to anus and its main functions are motility, digestion, absorption, excretion, and circulation. Each component of the GI tract has specific functions. ▪ The layers of the…
Key Points ▪ The cardiac cycle is the sequence of electrical and mechanical events during a single heartbeat. ▪ Cardiac output is determined by the heart rate, myocardial contractility, and preload and afterload. ▪ The majority of cardiomyocytes consist of…
Key Points ▪ Removal of carbon dioxide (CO 2 ) is determined by alveolar ventilation, not by total (minute) ventilation. ▪ Dead space ventilation can be dramatically increased in patients with chronic obstructive pulmonary disease and pulmonary embolism to more…
Key Points ▪ The neuromuscular junction contains the distal nerve terminal, Schwann cell, synaptic cleft, and muscle end plate, which together provide an array of receptors and substrates for drug action. Neuromuscular transmission is predominantly dependent on acetylcholine as the…
Key Points ▪ The brain has a high metabolic rate and receives approximately 12% to 15% of cardiac output. Under normal circumstances, cerebral blood flow (CBF) is approximately 50 mL/100 g Gray matter receives 80% and white matter receives 20%…