Embryology Tutor

Urinary System Lesson

© 1997
by
Thomas F. Fletcher, DVM, PhD
Department of Veterinary Biology
University of Minnesota
St.Paul MN 55108

Contents:
         Lesson Objectives
         Lesson Content Outline
         Student Evaluations
         Platform requirements
         Download instructions

Lesson Objectives:

• Understand principles involved in urine production.
• Describe the origin and significance of the urogenital ridge.
• State the names given to kidneys formed during each of the three progressive stages of kidney development.
• Report the embryonic significance of kidney cells formed at each of the three stages of development, i.e., what is the ultimate fate of the cells.
• Describe the stages of formation of the definitive (adult) kidney.
• Describe developmental changes undergone by the cloaca and list the definitve structures derived from different regions of the cloaca.
• Undertand how cystic kidneys, patent urachus, and ectopic ureter anomalies could develop in the course of development.
• Describe the embryonic origin of the adrenal cortex.

Detailed Outline of Lesson Content:

I. Urine production overview
A. Preview of kidney structure

II. Urogenital ridge (intermediate mesoderm)
A. Origin of intermediate mesoderm

III. Kidney (derived from nephrogenic cord of urogenital ridge)
A. Pronephros (7-8 tubules; typically non-functional)
1] pronephric duct
B. Mesonephros (70-80 tubules; functional temporarily)
1] mesonephric duct
C. Metanephros (the definitive kidney)
1] ureteric bud & metanephrogenic mass
2] nephron formation

IV. Cloaca
A. Urogenital sinus & urachus
1] pelvic (cranial) region
2] phallic (caudal) region
B. Ureter
C. Urinary bladder
1] urachus
D. Urethra
1] female
2] male

V. Clinical anomalies
A. cystic kidneys
B. patent urachus
C. ectopic ureter
D. double ureters (kidneys)
E. horseshoe-shaped kidney

VI. Adrenal cortex

Student Evaluations:

Platform Requirements:

      Embryology Tutor 0.9.8 is a HyperCard stand-alone application. Minimal requirements are a Macintosh computer with a 9-in. black & white screen and 2 MB of RAM available to run the application. Disc size is 4.5 MB (including all lessons).

Download Instructions:

      A Macintosh computer is required to run Embryology Tutor 0.9.8. When you click "Download Now" (below), a 2.2 MB compressed, self-extracting, binary file "Embryology Tutor 0.9.8.sea" will be transmitted to the location on your hard disk where your browser downloads files. Double-click the downloaded file icon to extract a 4.3 MB folder "Embryology Tutor 0.9.8" (your browser may extract this file automatically). Inside the folder, double-click the HyperCard application entitled "Begin Embryology Tutor" to view the courseware (the application and lessons frolder must remain in the same parent folder). You can trash "Embryology Tutor 0.9.8.sea" to conserve disk space.) Download Now