Figure 36–1 Calcium and bone metabolism. Vitamin D facilitates calcium absorption from the gut. Parathyroid hormone (PTH) decreases calcium excretion in the urine but increases phosphorus excretion (not shown). Endogenously…
Figure 33–1 Biosynthetic pathways for adrenal steroids. (A) Major pathways for mineralocorticoid, glucocorticoid, and androgen biosynthesis are shown. Important enzymes include 3β-hydroxysteroid dehydrogenase (3β-HSD), steroid 21-hydroxylase (P45021), steroid 11β-hydroxylase (P45011β),…
Figure 15–1 Comparison of normal (A) and atherosclerotic (B) arterial walls. Steps in the pathogenesis of atherosclerosis are as follows: (1) Damage to the endothelium is followed by invasion of…
Figure 28–1 Physiology of gastric acid secretion and sites of drug action. Gastric acid is secreted by the proton pump (H+,K+-ATPase) located in the luminal membrane of parietal cells. H+,K+-ATPase…
Figure 32–1 The hypothalamic-pituitary-thyroid axis. Thyroid hormone synthesis is initiated by the release of thyroid-releasing hormone (TRH) from the hypothalamus, which stimulates the pituitary to release thyroid-stimulating hormone (TSH). TSH…
Figure 40–1 Mechanisms of action of antifolate drugs. Sulfonamides inhibit the action of dihydropteroate synthase and thereby block the synthesis of dihydrofolate. Trimethoprim inhibits the action of dihydrofolate reductase and…
Figure 11–1 Classification and pathophysiology of ischemic heart disease. Variant angina, also called Prinzmetal’s angina, is considered a form of unstable angina if the angina attacks occur with increasing severity…
Many antifungal drugs act by impairing plasma membrane function in fungal cells. The selective toxicity of these drugs is caused by the difference in the sterols found in fungal and…
The M2 and M4 receptors are coupled with Gαi proteins and their activation decreases cyclic adenosine monophosphate (cyclic AMP, or cAMP) levels, by inhibiting adenylate cyclase, or increases potassium efflux….
