Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ INTRODUCTION ++Table Graphic Jump LocationTABLE A2-1Physiologic Changes with AgingView Table||Download (.pdf) TABLE A2-1 Physiologic Changes with Aging Organ System Manifestation Balance and gait ↓ Stride length and slower gait ↓ Arm swing ↑ Body sway when standing Body composition ↓ Total body water ↓ Lean body mass ↑ Body fat ↔ or ↓ Serum albumin ↑ α1-Acid glycoprotein (↔ or ↑ by several disease states) Cardiovascular ↓ Cardiovascular response to stress ↓ Baroreceptor activity leading to ↑ orthostatic hypotension ↓ Cardiac output ↑ Systemic vascular resistance with loss of arterial elasticity and dysfunction of systems maintaining vascular tone ↑ Afterload ↓ Coronary perfusion Central nervous system ↓ Size of the hippocampus and frontal and temporal lobes ↓ Number of receptors of all types and ↑ sensitivity of remaining receptors ↓ Short-term memory, coding and retrieval, and executive function Altered sleep patterns Endocrine ↓ Estrogen, testosterone, thyroid-stimulating hormone, and DHEA-S levels Altered insulin signaling Gastrointestinal ↓ Motility of the large intestine ↓ Vitamin absorption by active transport mechanisms ↓ Splanchnic blood flow ↓ Bowel surface area Genitourinary Atrophy of the vagina with decreased estrogen Prostatic hypertrophy with androgenic hormonal changes Detrusor hyperactivity may predispose to incontinence Hepatic ↓ Hepatic size ↓ Hepatic blood flow ↓ Phase I (oxidation, reduction, hydrolysis) metabolism Immune ↓ Antibody production in response to antigen ↑ Autoimmunity Oral Altered dentition ↓ Ability to taste salt, bitter, sweet, and sour Pulmonary ↓ Respiratory muscle strength ↓ Chest wall compliance ↓ Arterial oxygenation and impaired carbon dioxide elimination ↓ Vital capacity ↓ Maximal breathing capacity ↑ Residual volume Renal ↓ Glomerular filtration rate ↓ Renal blood flow ↓ Filtration fraction ↓ Tubular secretory function ↓ Renal mass Sensory Presbyopia (diminished ability to focus on near objects) ↓ Night vision Presbycusis (high-pitch, high-frequency hearing loss) ↓ Sensation of smell and taste Skeletal ↓ Skeletal bone mass (osteopenia) Joint stiffening due to reduced water content in tendons, ligaments, and cartilage Skin/Hair Thinning of stratum corneum ↓ Langerhans cells, melanocytes, and mast cells ↓ Depth and extent of the subcutaneous fat layer Thinning and graying of hair due to more hairs in the resting phase and shortening of the growth phase as well as changes in follicular melanocytes Source: Data from Cefalu CA. Theories and mechanisms of aging. Clin Geriatr Med. 2011;27:491–506; Alvis BD, Hughes CG. Physiology considerations in geriatric patients. Anesthesiol Clin. 2015;33:447–456. ++Table Graphic Jump LocationTABLE A2-2Age-Related Changes in Drug PharmacokineticsView Table||Download (.pdf) TABLE A2-2 Age-Related Changes in Drug Pharmacokinetics Pharmacokinetic Phase Pharmacokinetic Parameters Gastrointestinal absorption Unchanged passive diffusion and no change in bioavailability for most drugs ↓ Active transport and ↓ bioavailability for some drugs ↓ First-pass metabolism, ↑ bioavailability for some drugs, and ↓ bioavailability for some prodrugs Distribution ↓ Volume of distribution and ↑ plasma concentration of water-soluble drugs ↑ Volume of distribution and ↑ terminal disposition half-life (t1/2) for lipid-soluble ... Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth