ABSTRACT
Serial sections of the rabbit embryos measuring 4-14 mm. were carefully studied to compare the developing eye with 36 somites chick embryos and 10-15 mm. pig embryos. The eyes of the 4-5 mm. rabbit embryos were at an earlier stage than those of the 36 somites chick embryos, but at about the same stage as the fifth-week human embryos. At this stage, the optic cups had already formed but some of the lenses had incompleted double fusion. The eye of the 12-14 mm. rabbit embryos were somewhat identical to the 15 mm. pig embryos and can be compared to the sixth week human embryos. At this stage the optic cups were divided into the outer pigment and inner nervous layers; the lens was characterized by a thinner anterior lens epithelium and the longer posterior lens fiber. The mesenchyme surrounding the optic cups of this stage showed a slight condensation to from the vascular and fibrous coats of the eyeball. The rabbit embryos of 4-14 mm. were more suitable for use as laboratory models in studying eye development than of the pig embryos since the latter were no longer available for slide preparation.
ABSTRACT
The aim of this study was to examine in detail the course and location of lateral femoral cetaneous nerve (LFCN) as it emerges from the pelvis in Thais. The anatomy of the LFCN was studied through the dissection of 107 halves of formalin-embalmed Thai cadavers ranging in age from 37 to 94 years. The LFCN is formed by the union of posterior divisions of ventral rami of the second and third lumbar spinal nerves (L2 – L3). The site at which the nerve exits the pelvis is quite variable. Depending on the anatomical location which varies from superficial and posterior, to medial and deep, to anterior superior iliac spine (ASIS) and origin of the sartorius muscle, five different types as identified by Aszman et all1 were confirmed : type A, posterior to the anterior superior iliac spine across the iliac crest (1.86%); type B, medial to the anterior superior iliac spine and ensheathed in the inguinal ligament (9.34%); type C, medial to the anterior superior iliac spine and ensheathed in the tendinous origin of the sartorius muscle (46.72%); type D, medial to the anterior superior iliac spine located in the interval between sartorius muscle and iliopsoas muscle deep to the inguinal ligament (40.18%); type E, medial to the anterior superior iliac spine, deep to the inguinal ligament, overlying the iliopsoas fascia, and contributing the femoral branch of genitofemoral nerve (1.46%). The majority of the LFCN course and location as it exits the pelvis are type C (46.72%), and type D (40.18%). There is no statistical difference with regard to either gender or side of thigh.
ABSTRACT
Background : Embryology studies require good quality embryonic images. In addition, many teratology studies require the critical gross examination of embryos to determine the exact stage of embryonic development, or the extent of malformations. Objectives : The present study was designed to develop an improved method for preparing embryos. Materials and Methods : Sixty fertilized chicken eggs were divided into 6 groups of 10 and incubated at 38 oC foe various time periods (18, 20, 25, 30, 55, 72 hrs) depending on the developmental stage of the embryos. After incubation, the embryos were removed from the shells and yolk sacs. In each group, 5 embryos were stained using the Mayer’s carmine technique and the remaining 5 embryos were stained using the improved method. By the new method, the embryos were macerated in 3% potassium hydroxide for different length of time before the Mayer’s carmine staining. Results : It was found that the whole mount chick embryos which were stained with Mayer’s carmine after maceration were of better quality than those stained using the routine Mayer’s carmine technique. The new method gave superior preservation, clarity and contrast of the normal embryonic details. Interestingly, the advantage of the new method was clearly noted in the later stage of embryonic development, at the 30-somite and 30-somite stages. Using the routine Mayer’s carmine technique, the development of heart, circulation, and nervous system were not clearly differentiated, since those structures were concealed by soft tissues and/or many structures. In contrast, the new technique facilitated identification and allowed us to understand the whole development process of those structures. Conclusions : The new method improves the visibility of embryonic details normally seen or not seen with the Mayer’s carmine technique. It permits good quality photographs to be produced rapidly and consistently for the standard gross embryo analyses in embryology and teratology.