Download THE NEPHRON AND URINE FORMATION

BIOLOGY II
URINARY SYSTEM
ACTIVITY #2
NAME_____________________
DATE___________HOUR_____
THE NEPHRON AND URINE F ORMATION
OBJECTIVES:
5.
6.
Describe the structure and functions of the nephron. (pp. 519 – 523)
List and describe the processes involved in urine formation. (pp. 524 –
531)
NEPHRON LOCATION
Renal Cortex
Blood supply
Nehpron
Renal Medulla
Collecting duct
Urine
NEPHRON F UNCTIONS
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
Bowman’s Capsule
• Bowman’s capsule
• Site of filtration
• Formation of
filtrate
Proximal Convoluted
Tubule
• Reabsorption
Loop of Henle
• Reabsorption
Distal Convoluted
Tubule
• Secretion
• Reabsorption
Collecting Duct
• Carries urine to
renal pelvis
• Reabsorption
• Secretion
NEPHRON BLOOD SUPPLY
From renal
artery
Afferent arteriole
Glomerulus
Efferent arteriole
Peritubular
capillaries
To renal vein
Urinary System Activity #2 page 2
Vasa recta
#4 Distal Convoluted Tubule
URINE FORMATION
•
#2 Proximal Convoluted Tubule
•
Reabsorption of water, ions, and
all organic nutrients
Secretion of ions, acids,
drugs, toxins
Variable reabsorption of
water and Na+
#5 Collecting
Duct
•
#1 Bowman’s Capsule
•
•
•
Filtrate production
Blood pressure forces
small solutes, water,
ions from blood into
capsule
#6 Urine Contents
#3 Loop of Henle
•
•
•
•
•
Reabsorption of
water (descending
limb)
Reabsorption of
Na+ and Cl(ascending limb)
KEY:
Urinary System Activity #2 page 3
Variable
reabsorption
of water, K+,
Na+, H+,
HCO3Variable
secretion of
water, K+,
Na+, H+,
HCO3-
à
à
à
filtrate
water
solute
Water
Urea, creatine, uric acid
Various ions