313263515组胚课件06留.ppt

Female Reproductive System 2 Lei Lei July, 2006 Today’s points Oviduct Structural and functional changes of the uterus during the menstrual cycle Mammary gland Ⅰ. Oviducts One end is adjacent to the ovary and opens into the peritonea, the other end communicates with the uterine cavity. Functions: Transport ovum from the ovary to the uterus; Provide environment for fertilization and early cleavage. Four segments of the oviduct Infundibulum is funnel-shaped part near ovary with fimbriae Ampulla is dilated part Isthmus is narrow, adjacent to uterine wall Intramural part is in uterine wall The wall of the oviduct is composed of three layers Ⅱ.Uterus Ⅱ.Uterus Hollow pear-shaped organ located between the bladder and rectum; 30~40g, 7.5×5×2.5 cm; Consists of a body (corpus), the cervix, and the fundus; Three layers of the wall, the endometrium, the myometrium, and the perimetrium. 1. Myometrium Four poorly defined layers; Inner and outer layers are mostly longitudinal in orientation; Middle layers are more circular (venous plexuses) and thicken in pregnancy with more smooth muscle cells and increased collagen. Myometrium changes during pregnancy Pregnancy Smooth muscle cells increase in number--Hyperplasia, increase in cell size--Hypertrophy Increase in uterine collagen content ● Recover Destruction of some smooth muscle cells Enzymatic degradation of the collagen Uterus is reduced in size 2. Endometrium The functional layer proliferates and then degenerates during a menstrual cycle The vasculature of the endometrium also proliferates and degenerates during each cycle. Endometrium Vasculature Arcuate arteries in the myometrium give rise to the straight arteries of the basal layer which give rise to the coiled arteries of the functional layer The spiral arteries degenerate and regenerate during the cycle under the effect of E and P. 3. The menstrual cycle Estrogen and progesterone from ovary stimulate changes in the endometrium. 28 day cycle on average. Be