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Pregnancy and Parturition - Horse Anatomy (view source)
Revision as of 17:27, 26 November 2012
, 17:27, 26 November 2012no edit summary
* Basal lamina of the endothelium
* Basal lamina of the endothelium
* Endothelium of the fetal placental capillary in the teriary villus
* Endothelium of the fetal placental capillary in the teriary villus
====Macroscopic Physiology====
The physical contact surfaces used within the process of circulatory exchange are the fetal membranes and the endometrium and this exchange takes place via microscopic chorionic villi that invade the endometrium. These chorionic villi are covered by epithelium. Horses have many small contacts spread over the entire surface of the fetal membranes and this form of placenta is termed a '''diffuse placenta'''.
====Microscopic Physiology====
The horse has an '''epitheliochereal''' placenta. This type of placenta can be said to be the most complete form, where the interface between the chorion (chorionic epithelium)and uterus (endometrial epithelium) consists of intact layers of epithelial cells with a basal laminae on each side. Both sides of the placenta have supporting connective tissue and a high density of blood capillaries.
====Placental Blood Supply====
====Placental Blood Supply====
Maternal blood carrying oxygen and nutrient substrate to the placenta must be transferred to the foetal compartment and this rate of transfer is the rate limiting step in the process. Therefore the placenta has a significant blood to facilitate improved exchange. Foetal blood enters the placenta via a pair of '''umbilical arteries''' which have numerous branches resulting in '''foetal chorionic villi''' within the placenta, terminating at the '''chorionic plate'''. The foetal chorionic villi are then surrounded by maternal tissues. This physiology is referred to as "invasive decidualisation" as the fetal chorionic villi effectively invade the maternal tissues. <br />
Maternal blood carrying oxygen and nutrient substrate to the placenta must be transferred to the foetal compartment and this rate of transfer is the rate limiting step in the process. Therefore the placenta has a significant blood to facilitate improved exchange. Foetal blood enters the placenta via a pair of '''umbilical arteries''' which have numerous branches resulting in '''foetal chorionic villi''' within the placenta, terminating at the '''chorionic plate'''. The foetal chorionic villi are then surrounded by maternal tissues. This physiology is referred to as "invasive decidualisation" as the fetal chorionic villi effectively invade the maternal tissues. <br />