泌尿系統 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Urinary System Organization Functions of the Urinary System Eliminate organic wastes Regulate plasma ion levels Regulate blood volume and blood pressure Adjust water loss Release cardiovascular hormones Stabilize blood pH Conserve nutrients Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Urinary System Organization 腎臟 輸尿管 膀胱 尿道 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

The Kidneys Anatomy of the Kidney Kidneys are retroperitoneal Left kidney superior to right左高於右 Fibrous capsule腎被膜 surrounds the kidney Renal artery and renal nerve enter at hilum腎門 每分鐘腎血流量1.2~1.3L (20%總血量) Renal vein and ureter exit at hilum Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

An Overview of Kidney Anatomy The Kidneys An Overview of Kidney Anatomy Figure 18-2a

The Kidneys Internal Anatomy of the Kidney Nephrons腎元 Renal pelvis腎盂 Urine produced by nephrons About a million nephrons per kidney Renal pelvis腎盂 Urine collects here from calyces腎盞 Input from two major calyces Each major calyx is fed by four to five minor calyces Urine leaves pelvis to ureter 皮質 髓質 腎錐體

The Structure of the Kidney The Kidneys The Structure of the Kidney 近曲小管 腎小體 遠曲小管 亨利氏環 集尿管 Figure 18-3(c)

The Kidneys Kidney Blood Supply Renal artery腎動脈 Interlobar arteries葉間動脈 Arcuate arteries弓狀動脈 Interlobular arteries小葉間動脈 腎靜脈 小葉間靜脈 弓狀靜脈 葉間靜脈

The Blood Supply to the Kidneys Figure 18-4(b)

The Blood Supply to the Kidneys 輸入小動脈 腎小管周圍血管 輸出小動脈 腎絲球 Figure 18-4(c)

The Kidneys The Blood Supply to the Kidneys 腎絲球 直血管 Figure 18-4(d)

The Kidneys The Nephron腎元 Basic functional unit of the kidney Two parts to the nephron Renal corpuscle 腎小體 Renal tubule 腎小管 Feeds into collecting system Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

The Kidneys Pathway of Urine through the Nephron First, filtered in the renal corpuscle鮑氏囊 Urine begins as filtrate Next, filtrate flows into renal tubule First, into the proximal convoluted tubule (PCT)近曲小管 Next, the loop of Henle亨利氏環 Finally, the distal convoluted tubule (DCT)遠曲小管 Last, exits to collecting duct集尿管 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

A Representative Nephron and the Collecting System The Kidneys A Representative Nephron and the Collecting System Figure 18-5

Principles of Urine Production Primary Purpose of Urine Production Excretion of dissolved solutes Metabolic wastes Urea (21 g per day) Creatinine肌酸酉干 (1.8 g per day) Uric acid (480 mg per day) Excess ions Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Principles of Urine Production Processes in Urine Formation Filtration過濾 Reabsorption再吸收 Secretion分泌 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Principles of Urine Production Water Balance in the Kidney More than 99% of water is reabsorbed from the filtrate by the renal tubules Water content of normal urine ranges from 93% to 97% Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Principles of Urine Production

Transport, Storage, & Excretion Ureters 輸尿管　(30 cm) Ureters extend from renal pelvis to urinary bladder Push urine toward bladder Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Transport, Storage, & Excretion Urinary Bladder 膀胱 Distensible muscular sac for urine storage (1L/time) Internal features include Trigone膀胱三角 Neck Internal urethral sphincter尿道括闊約肌 Detrussor muscle逼尿肌 Contraction forces urine into urethra尿道 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Transport, Storage, & Excretion Organs for the Conduction and Storage of Urine Figure 18-10(a)

Transport, Storage, & Excretion Organs for the Conduction and Storage of Urine Figure 18-10(b)

Transport, Storage, & Excretion Organs for the Conduction and Storage of Urine Figure 18-10(c)

Transport, Storage, & Excretion The Urethra　尿道 Longer in males (18~20 cm) than females (2.5~3 cm) External urethral sphincter formed by a circular band of skeletal muscle of pelvic floor 骨盆底 Under voluntary control Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Transport, Storage, & Excretion Micturition Reflex and Urination Urination coordinated by micturition reflex 排尿反射 Initiated by stretch receptors in the bladder wall 200 ml urine Voluntary urination couples reflex with relaxation of external urinary sphincter Permits internal urinary sphincter to open (極限500 ml urine) Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings

Transport, Storage, & Excretion The Micturition Reflex Figure 18-11

Fluid, Electrolyte, & Acid-Base

Aging and the Urinary System Age-Related Changes in Urinary System Loss of functional nephrons Reduced GFR Reduced response to ADH Urinary retention in men with prostate enlargement前列腺肥大 Drop in body water and mineral content Disorders of fluid, electrolyte, or acid-base balance Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings