BIOLOGY II NAME______URINARY SYSTEM ACTIVITY #2 DATE______HOUR_____
THE NEPHRON AND URINE FORMATION
OBJECTIVES: 5. Describe the structure and functions of the nephron. (pp. 519 – 523) 6. List and describe the processes involved in urine formation. (pp. 524 – 531)
NEPHRON LOCATION
Renal Cortex Blood supply
Nehpron
Collecting duct Renal Medulla
Urine
NEPHRON FUNCTIONS Filtration · Formation of filtrate – Bowman’s capsule · Waste, nutrients, water, ions, proteins move from blood into nephron Reabsorption · Nutrients, ions, water move from filtrate back into blood
Secretion · Ions, wastes, toxins move from blood into filtrate
Urinary System Activity #2 page 1
NEPHRON STRUCTURE Distal Convoluted
Tubule Bowman’s Capsule · Secretion · Bowman’s capsule · Reabsorption · Site of filtration · Formation of filtrate
Proximal Convoluted Tubule · Reabsorption Collecting Duct · Carries urine to
renal pelvis · Reabsorption Loop of Henle · Secretion · Reabsorption
NEPHRON BLOOD SUPPLY
From renal Afferent arteriole artery
Glomerulus
Efferent arteriole
Peritubular
capillaries
Urinary System Activity #2 page 2 #4 Distal Convoluted Tubule URINE FORMATION · Secretion of ions, acids, drugs, toxins #2 Proximal Convoluted Tubule · Variable reabsorption of water and Na+ Reabsorption of water, ions, and all organic nutrients
#5 Collecting Duct
· Variable reabsorption of water, K+, Na+, H+, - #1 Bowman’s Capsule HCO3
· Variable secretion of · Filtrate production water, K+, · Blood pressure forces small solutes, water, Na+, H+, HCO - ions from blood into 3 capsule
#6 Urine Contents #3 Loop of Henle · Water · Reabsorption of · Urea, creatine, uric acid water (descending · Various ions limb) · Reabsorption of Na+ and Cl- (ascending limb)
KEY:
à filtrate à water Urinary System Activity #2 page 3 à solute