Summary
The fetal microvascular architecture of the feline near-term placenta was investigated using scanning electron micrographs of partially fractured corrosion casts from plastic-filled vessels. The findings were compared with those on corresponding semithin histological sections.
The branches of both umbilical arteries and veins roughly follow a course parallel to the zonary girdle on the allantochorionic side of the feline placenta in an acute-angled pattern of ramifications. They join the double-layered capilary networks in the chorionic lamellae of the labyrinth, which generally exhibit a chorio-uterine orientation and are partially twirled. On the allantochorionic side of the labyrinth, these fetal capillary networks are “suspended” on the maternal stem-artery-system of the placenta; on the uterine side, they have peduncular or tuft-like endings of capillary loops and are flattened by the uterine septa, which at this level converge into the maternal veins. The chorionic capillary lamellae have a variable breadth and length and therefore need shorter or longer arterioles and venules from the allantochorionic side to become irrigated at any level of the labyrinth.
As a result, the feline placenta is characterized by a generally one-way crosscurrent type of materno-fetal blood flow.
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References
Faber JJ (1977) Steady-state methods for the study of placental exchange. Fed Proc 36:2640–2646
Faber JJ, Hart FM (1966) The rabbit placenta as an organ of diffusional exchange. Comparison with other species by dimensional analysis. Circ Res 19:816–833
Habashi S, Burton GJ, Steven DH (1983) Morphological study of the fetal vasculature of the human term placenta: Scanning electron microscopy of corrosion casts. Placenta 4:41–56
Kaufmann P, Davidoff M (1977) The guinea-pig placenta. Adv Anat Embryol Cell Biol 53/2. Springer, Berlin Heidelberg New York
Kehrer A (1973) Zur Entwicklung und Ausbildung des Chorions der Plazenta zonaria bei Katze, Hund und Fuchs. Z Anat Entwickl Gesch 143:25–42
Kohler T, Leiser R (1983) Blood vessels of the bovine chorioidea. Acta Anat 116:55–61
Leiser R (1980) Funktionelle Morphologie der Implantation und der frühen Plazentation bei der Hauskatze; Licht- und elektronenmikroskopische Untersuchungen mit histocytochemischer Ergänzung. Habil-Schrift Bern: 1–162
Leiser R (1984) Fetal vasculature of the human placenta: Scanning electronmicroscopy of microvascular casts. Contr Gyn and Obst [in press]
Leiser R, Enders AC (1980) Light and electron-microscopic study of the near-term paraplacenta of the domestic cat. I. Polar zone and paraplacental junctional areas. Acta Anat 106:293–311
Leiser R, Kohler T (1983) The blood vessels of the cat girdle placenta. Observations on corrosion casts, scanning electron microscopical and histological studies. I. Maternal vasculature. Anat Embryol 167:85–93
Leiser R, Kaufmann P, Luckhardt M (1984) Materno-fetal vessel interrelationship in different types of placenta [in preparation]
MacDonald AA (1981) The vascular anatomy of the pig placenta: A scanning electron microscope study. Acta Morphol Neerl Scand 19:171–172
Malassiné A (1974) Evolution ultrastructurale du labyrinthe de placenta de chatte. Anat Embryol 146:1–20
Martin CB, Jr (1981) Models of placental blood flow. In: Wallenburg HCS, van Kreel BK, van Dijk JP (eds) Transfer across the primate and non-primate placenta, chapt 5. Saunders & Co, London Philadelphia Toronto
Moll W (1972) Gas exchange in concurrent, countercurrent and crosscurrent flow systems. The concept of the fetoplacental unit. In: Longo LD, Bartels H (eds) Respiratory gas exchange and blood flow in the placenta. 281–294 US Department of Health, Education and Welfare DHEW Pub No (NIH) 73-361
Moll W (1981) Physiologie des fetalen plazentaren Kreislaufs. In: Becker V, Schiebler TH, Kubli F (eds) Die Plazenta des Menschen. Thieme, Stuttgart New York, pp 195–198
Risco JM, Nopanitaya W (1980) Ocular microcirculation. Scanning electron microscopic study. Invest Ophthalmol Vis Sci 19:5–12
Schultze O (1897) Grundriss der Entwicklungsgeschichte des Menschen und der Säugetiere, 1. Aufl. Engelmann, Leipzig
Spörri H (1976) Blutkreislauf. In: Scheunert A, Trautmann A (eds) Lehrbuch der Veterinär-Physiologie, chapt 8. Parey, Berlin Hamburg
Thiriot M, Panigel M (1978) Microcirculation. — La microvascularisation des villosités placentaires humaines. CR Acad Sci [Paris] Ser D 287:709–712
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Supported by the “Stiftung zur Förderung der wissenschaftlichen Forschung an der Universität Bern”
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Leiser, R., Kohler, T. The blood vessels of the cat girdle placenta. Observations on corosion casts, scanning electron microscopical and histological studies. Anat Embryol 170, 209–216 (1984). https://doi.org/10.1007/BF00319006
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DOI: https://doi.org/10.1007/BF00319006