The uterus is the cradle of life. It is like an inverted pear. It is a thick-walled, muscular organ located between the rectum and the bladder. It is connected to the fallopian tubes on both sides above and to the vagina below. The upper 2/3 of the uterus is called the uterine body, which is higher than the fallopian tubes. It is called the fundus of the uterus, the lower 1/3 of the uterus is cylindrical, called the cervix, and the inner cavity is triangular, called the uterine cavity. There is the narrowest part between the body of the uterus and the cervix, called the uterine isthmus. When not pregnant, the isthmus is only 1 cm long; after pregnancy, it can gradually become longer as the uterus increases, slowly forming the lower uterine segment; by the time of full-term pregnancy, it can reach 7 to 10 cm. Therefore, the uterine isthmus is a very important part for pregnancy and childbirth.
The ratio of the uterus to the cervix is 1:2 in infancy and 2:1 in adulthood. The inner wall of the uterus is divided into 3 layers: endometrium, myometrium and adventitia. The intima is composed of a single layer of columnar epithelium and connective tissue. The epithelial lamina propria stretches to form tubular glands called uterine glands. There are abundant small blood vessels and lymphatic vessels in the middle of the lamina propria. The muscular layer is composed of smooth muscles arranged in a criss-cross pattern, with blood vessels running through it. This layer is still very stretchable. For example, during pregnancy, the smooth muscle cells increase in size to adapt to the needs of pregnancy. During childbirth, smooth muscle rhythmically contracts and becomes the driving force for the delivery of the fetus. Because of its contraction, it can also compress blood vessels and prevent postpartum bleeding.
The uterus, as the fetal room, is not spacious, but this beautiful palace needs to be decorated once a month. It turns out that the endometrium is a layer of pink, soft velvet tissue, which is like a mattress for fertilized eggs. If the fertilized eggs fail to arrive after the due date, the \”mattress\” will be replaced regularly, stripped clean, and replaced with a new layer of \”mattress\”. The \”decoration\” work in the uterus is controlled and directed by the ovaries. The ovaries control the growth or shedding of the endometrium by periodically secreting estrogen and progesterone. Repeatedly, this results in a woman\’s monthly menstrual cramps, indicating that the uterus has the ability to give birth to life and is only waiting for fertilization. Once the east wind of eggs arrives, everything will be successful.
The endometrium is a pink mucosal tissue that undergoes cyclic changes under the influence of ovarian hormones, forming menstruation. The myometrium is the thickest layer, only 0.8 cm thick when not pregnant; after pregnancy, muscle fibers proliferate and the uterine wall thickens, reaching 2 to 2.5 cm. The uterine muscles have three layers, the outer layer is vertical, the inner layer is circular, and the middle layer is intertwined. There are blood vessels in the middle of the muscles. When the uterus contracts, the blood vessels compress, which can prevent postpartum bleeding. The uterine serosa layer is the peritoneum covering the surface of the uterus. It is connected to the bladder and rectum in the lower part of the uterus, forming the vesico-uterine reflexed peritoneum and utero-rectal trap.Concave, the latter is of great significance in diagnosis and treatment.
The cervix is mainly composed of connective tissue, but also contains muscles and blood vessels. The cervical mucosa has many glands that secrete mucus, which is alkaline. This mucus forms mucus plugs and plays a role in defense against diseases.
The uterus relies on the support of four pairs of ligaments, pelvic floor muscles and fascia to maintain its normal position.
This article is provided by Baidu Reading and is excerpted from \”The Clear \”Conception\” Plan\” Author: Sun Jianqiu and Xie Yingbiao