1.03k likes | 4.61k Views
Comparative Anatomy Urogenital System. Note Set 11 Chapter 15 . Urogenital System. Ducts of excretory and reproductive systems are intimately associated. Figure 14.1: Embryonic and evolutionary development of kidneys in vertebrates (handout). Primitive Kidney.
E N D
Comparative AnatomyUrogenital System Note Set 11 Chapter 15
Urogenital System • Ducts of excretory and reproductive systems are intimately associated Figure 14.1: Embryonic and evolutionary development of kidneys in vertebrates (handout).
Primitive Kidney • Archinephros- primitive excretory kidney organ • Holonephros • Filtration system • Archinephric duct- drains to cloaca or bladder Figure 14.2: Hypothetical archinephros (book figure 15.7).
Primitive Kidney (con’t) • Pronephros • 1st tubules to appear • Anteriorly located; head kidney • Involutes to form lymphoidal mass • Only functions temporarily • All tubules associated with pronephros • Pronephric (archinephric) duct drains pronephros Figure 14.3: Pronephros region of primitive kidney.
Primitive Kidney (con’t) Figure 14.4: Fate of nephrogenic mesoderm (red) (book figure 15.8). Figure 14.5: Pronephric, mesonephric, and metanephric system relationships.
Primitive Kidney (con’t) • Mesonephros (opisthonephros)- kidney mass caudal to pronephric region • Functional adult kidney of fish and amphibians • Opisthonephros in sharks • Drained by mesonephric (archinephric) duct Figure 14.6: Mesonephros of Urodele (book figure 15.8) Figure 14.7: Mesonephric duct of opossum embryo (book figure 15.19).
Primitive Kidney (con’t) • Ductus efferens: • Pronephric duct • Mesonephric duct • Archinephric duct • Anterior portion of mesonephric tubules used in male reproductive system Figure 14.8: Urogenital system and adrenal glands of male frog.
Primitive Kidney (con’t) Figure 14.9: Mesonephric kidneys with mesonephric duct (black) carrying sperm and/or urine (book figure 15.25).
Primitive Kidney (con’t) • Accessory urinary ducts • Tubules also in reproductive sys. • Path for sperm to enter mesonephric duct (sperm duct) Figure 14.10: Mesonephric kidneys with separate sperm duct (red) (book figure 15.25).
Amniote Kidney • Pronephros • Lost • Mesonephros • Mainly an embryonic kidney • Involutes at birth • Metanephric kidney • Takes over functions of mesonephros • Ureter- new duct drains met. kidney Figure 14.11: Metanephric kidney assuming superior position to remainder of urogenital system.
Amniote Kidney (con’t) • Mesonephric duct • Sperm duct in males • Ductus deferens in amphibians • Vas deferens in mammals • Terminate at cloaca • Most amniotes • Not higher vertebrates Figure 14.12: Male teleost, caudal end of urogenital system (book figure 15.18).
Embryonic Amniotes • Pronephros involutes • Mesonephros involutes • Metanephric kidney develops • Vas deferens
Urinary Bladder • Most vertebrates • Formation varies • Fish- terminal segment of mesonephric duct • Large bladders- turtles and lizards • Turtles- accessory bladder
Gonads • Elevated ridges medial to kidneys • Gonads enlarge, suspended by mesenteries • Mesorchium- males • Mesovarium- females Figure 14.13: Urogenital ridge in developing embryo. Figure 14.14: Ovary of hagfish.
Gonads (con’t) • Bidder’s organ • Rudimentary ovary of toads (Bufo) • If testes removed, become functional ovary • Ovotestes in fish • Both ovary and testis in lizards • Multi-lobed testis in some species Figure 14.15: Left bidder’s organ of male Bufo (book figure 15.23).
Copulatory Organs • Claspers in cartilagenous fish • Gonopodium in teleost • Intromittent organ • Hemipenes • Single penis Figure 14.16: Gonopodium on male guppy.
Copulatory Organs (con’t) • No copulatory organs • Sperm pocket- some salamanders • Rudimentary copulatory organ • Some amniotes (tuatara) • Cloacal apposition • Male and female cloacas come together Figure 14.17: Urogenital system of female sphenodon.
Copulatory Organs (con’t) • Muellarian ducts • In males, ducts are nonfunctional • In females, ducts give rise to female reproductive tract • Only left reproductive tract • Birds and crocodiles • Raptors have vestigial right reprod. tract Figure 14.18: Mullerian ducts and gonads of male amphibians. Figure 14.19: Rudimentary oviduct of pigeon.
Copulatory Organs (con’t) • Duplex uterus • Monotremes and marsupials • Separated female reprod. tracts • Bipartite uterus • Rabbit • Body of uterus seems unpaired yet has two lumens • Bicornuate uterus • Cat • Two uterine horns and single lumen Abnormal human bicornuate uterus
Copulatory Organs (con’t) • Bicornuate uterus • Cat • Two uterine horns and single lumen • Simplex uterus • Primates • Large body and horns Figure 14.21: Mammalian uteri; muellerian ducts (blackened regions) and cloaca (red) (book figure 15.47).
Cloaca • Receives digestive, reproductive, and urinary products and tracts • No cloaca • Fish- three separate openings • Mammals above monotremes • Cloaca subdivisions: • Coprodaeum • Urodaeum • Proctodaeum Figure 14.22: Cloacal cavities and urogenital structures in salamanders.
Cloaca Subdivisions • Coprodeum • Receives alimentary canal • Simple columnar • Urodeum • Receives urinary and reproductive products • Transitional epithelium • Proctodeum • Associated with excretory • Stratified squamous Figure 14.23: Subdivisions of cloaca shown in bird.
Cloaca (con’t) • Bursa of Fabricius • Lymphoid evagination off cloaca Figure 14.24: Bursa of Fabricius on young bird. Figure 14.25: Histology of Bursa of Fabricius and cloaca.
Reproduction • Some vertebrates require both sexes • Some verts. are asexual • Reproduce parthenogenetically • Some fish and lizards • Embryonic humans are asexual • Until differentiation of sexual structures
Differentiation of Sexual Structures Figure 14.26: Mesonephros contributions to male and female reproductive tracts.
Differentiation of Sexual Structures (con’t) • Genital Tubercle • Male- penis • Female- clitoris • Genital Folds • Male- penis contribution • Female- labia minora • Genital Swellings • Male- scrotum • Female- labia majora Figure 14.27: external genitalia of bisexual stage of human embryo (book figure 15.48).
Differentiation of Sexual Structures (con’t) • Mesonephric Duct • Male- vas defferens • Female- gartner’s duct • Muellerian Duct • Male- portions are retained • Female- reproductive tract Figure 14.28: Changes in female, mammalian urogenital system (book figure 15.13).
Differentiation of Sexual Structures (con’t) • Mesonephric Tubule • Male- vasa efferentia • Female- epoophoran and paraophoran • Genital Ridge • Male- testes • Female- ovaries
Homologous Urogenital Structures Figure 14.29: Homologous urogenital structures in male and female mammals (book tbl 15.3).
Literature Cited Figure 14.1- Trauth, Stan. Handout. Figure 14.2, 14.4, 14.6, 14.7, 14.9, 14.10, 14.12, 14.15, 14.21, 14.27, 14.28, 14.29- Kent, George C. and Robert K. Carr. Comparative Anatomy of the Vertebrates. 9th ed. McGraw-Hill, 2001. Figure 14.3- http://people.eku.edu/ritchisong/342notes10.html Figure 14.5- http://connection.lww.com/Products/sadler/imagebank.asp Figure 14.8- http://www2.vscc.cc.tn.us/MSD/BIO/1020/Lab7ChordateII.htm Figure 14.11- http://www.med.unc.edu/embryo_images/unit-genital/genital_htms/genital018.htm Figure 14.13, 14.14, 14.17, 14.18, 14.19- Kardong, Kenneth V. Vertebrates: Comparative Anatomy, Function, Evolution. 4th ed. McGraw-Hill, 2006. Figure 14.16- http://www.th.physik.uni-frankfurt.de/~brandste/aqua/fauna/zucht.html Figure 14.20- http://137.222.110.150/calnet/vetrep7/page2.htm Figure 14.22- Sever, David. Reproductive Biology and Phylogeny of Urodela. Vol 1. Science Publishers, Inc, 2003. pg 334 Figure 14.23- http://member.rivernet.com.au/balehirs/Bishyp6nroBirdNests.htm Figure 14.24- http://www.uic.edu/classes/dh/dh110/Immunology_files/ Figure 14.25- http://www.upei.ca/histology/html/bursa_fabricus.html Figure 14.26- http://www.mun.ca/biology/desmid/brian/BIOL3530/DB_Ch12/DBNGerm.html