What are the functions of the urinary system? **__________ – water and salts ____________ metabolic wastes (N) If water is plentiful then NH 3 If water is limited then Urea If water is scarce then Uric acid _______________ – blood cell formation as a result of erythropoeitin secretion. Urinary System
What are the “rules of thumb” regarding water and salts for different classes of vertebrates? ____________________– excrete water and conserve salt _____________________– excrete salt and conserve water _____________________– modify salt and water loss appropriately Urinary System
What is the basic pattern and what is an archinephros? ___________ – functional unit of kidneys Renal corpuscle: 1) ____________ 2) ____________ 3) ____________ Urinary System
What is the basic pattern and what is an archinephros? Nephron – functional unit of kidneys Renal corpuscle – Urinary System
What are the 3 basic processes involved with urine formation? 1) ____________ – glomerulus 2) ____________ – renal tubules 3) ____________ – renal tubules Other processes include: 4) ______________ – renal tubules and collecting ducts 5) _____________ – bladder 6) ____________ – bladder, sphincters & urethra Urinary System
Renal corpuscle = Bowman’s capsule = Where does filtration take place? Urinary System
Filtration Pressure… Flow depends on … Fluids and solutes move from … Why is there a difference in pressure? GCP = Glomerular capillary pressure CP = Capsule pressure COP = Colloidal osmotic pressure What is involved with producing filtrate? Urinary System
What is the route of blood flow through the kidney and how does this fit with REABSORPTION? Afferent arteriole to glomerulus to Efferent arteriole to peritubular capillaries to vasa recta, then back out Urinary System
Moving wastes into nephron both passive and active Passive … Active …. What is the role of secretion in urine production? Urinary System
How is urine concentrated? Urinary System
How do kidneys form embryologically? _______________________– lateral to mesodermal somites Where are the kidneys in Necturus? Tubules appear at cephalic end Paired ducts develop and form caudad until they reach posterior and form opening Posterior tubules Urinary System
What is an archinephros? _______________– Believed to be the prototype from a segmented ancestor Urinary System
Why would glomeruli be larger in freshwater fish and aquatic amphibians… and smaller in marine fishes and tetrapods (especially in tetrapods of arid environments)? Urinary System
How are kidneys organized? Urinary System
Location: Size: Surrounded by connective tissue (_________________) Protected by renal fat pad (_____________) Where can one find a kidney? Urinary System
Gross anatomy! Urinary System
What is extrarenal salt excretion and how does it occur? ________ – actively transport across lamellar membranes ____________ – can empty into nasal canals or mouth Urinary System
_________ & _________ Contract = What other anatomy is significant? Transitional epithelium lines the …
Stratified & Stretchy Contract = peristaltic movements What other anatomy is significant? Transitional epithelium lines the ureters & urinary bladder