BMS 360 Lecture Notes - Macula Densa, Urinary Incontinence, Afferent Arterioles
Document Summary
The amount of metabolites, ions, and water that is excreted is dependent in part on the rate of gfr) Blood pressure at the glomerulus determines gfr rate. Gfr increases flow through tubule increases flow past macula densa increases paracrine diffuses from macula densa to afferent arteriole afferent arteriole constricts resistance in afferent arteriole increases hydrostatic pressure in glomerulus decreases . Macula densa cells sense distal tubular flow and release paracrines. Urinary incontinence is inability to voluntarily control urination (micturition). Urethral external sphincter muscle pressure is normally > bladder detrusor muscle pressure. Stress incontinence: sneeze, cough, or exercise can cause detrusor pressure > sphincter pressure. Often due to reduced strength of supportive pelvic floor muscles. Incontinence in diabetes: diabetic autonomic neuropathy; atonic bladder; incomplete voiding. Functional incontinence: functional disturbance prevents getting to bathroom in time. Regulating input/output of nacl and water to maintain a steady-state is important for maintaining blood volume and pressure. Proximal tubules: (reabsorbs most of metabolites and water).
