Ultrastructural Studies of Chicken Embryo Chorioallantoic Membrane during Incubation

Abstract

SummaryStructural changes taking place in the chorioallantoic membrane (CAM) of embryonated hen's eggs during incubation were followed up by histological, histochemical and electron microscopic methods. The allantoic sac surrounds the amnionic sac and also the yolk sac by the 7th to 11th day, respectively, and forms together with the chorion the CAM. The mesenchymal layer placing between the chorion of ectodermal and the allantoic layer of entodermal origin develops from the somatic and splanchnic‐pleure of the parietal mesoderm.The CAM is composed of three different layers, i.e. chorionic epithelium, mesenchyme and allantoic epithelium. The chorion comprises 2 layers of cubical epithelial cells. In between the 2 layers capillaries and directly under the shell membrane vascular sinuses can be found. Blood circulating in the sinuses is separated from the air in the pores of the shell membrane by the adacent epithelial cell‐projections of 0,2 μm thickness, the basal membrane (0.1 μm) and the sinus endothelial layer of 0.2 μm thickness. The mesenchymal cells are of star‐like form. The allantioc epithelium is built of one layer of fusiform cells with oval‐shaped or rod‐like nuclei.

Effects of Prebiotics and Synbiotics Delivered <I>In Ovo</I> on Broiler Small Intestine Histomorphology During the First Days After Hatching

“…A greater number of bifidobacteria appeared in the feces when the injection was done on the 12 day of incubation (VILLALUENGA et al 2004). On the other hand, after 12 days of incubation, the completely developed and highly vascularized allantochorion serves as a more efficient transport route from the air cell to the blood (FÁNCSI & FEHÉR 1979). Injection of FOS and RFO in increasing doses of 0.1763, 0.8815, 1.763 and 8.815 mg/egg on the 12th day of embryo development significantly influences embryo body weight and the number of bifidobacteria in the chicken colon.…”

The Chick Chorioallantoic Membrane as a Model Tissue for Surgical Retinal Research and Simulation

“…Directly above the basal lamina of the thin layer lies the ISM, an approximately 20 m thick, acellular, calcium-rich membrane containing peptidoglycans and collagen types I, V, and X. 15,18 The thin layer's basal lamina contains extensive microvilli that penetrate into the ISM 12 and contain calcium transporters that transfer calcium stored in the ISM to the developing embryo via the extraembryonic tissue. 19 -21 …”

“…12 Structurally, the outer epithelial layer of the chorion is derived from the trophoblast, which opposes the allantois. This structure forms a supportive matrix for the extensive vascular network that courses through the CAM, analogous to the retina and its vasculature (Figure 1, inset).…”

Providing Glucose to Turkey Hatching Eggs Via Pressure Differential Antibiotic Dipping: Effects on Hatchability, Poult Quality, and Subsequent Performance

“…Subsequent alterations in albumen osmotic pressure clear these channels and a concurrent development of the chorioallantoic membrane permits gas exchange and aerobic respiration ensues (Fancsi and Feher, 1979).…”