What Are the Different Parts of the Female Reproductive System?

The female reproductive system includes internal and external reproductive organs and their related tissues. Female internal genitalia, including vagina, uterus, fallopian tubes and ovaries. Female genitalia refers to the exposed part of the reproductive organs, also known as vulva. Including the clitoris, labia majora, labia minora, clitoris, vaginal vestibule.

Basic Information

English name: female reproductive system
Visiting department: Gynecology

Common locations: Internal and external genitalia
Contagious: no

Female genitalia

Range of vulva

Female genitalia refers to the exposed part of the reproductive organs, also known as the vulva, which refers to the tissue that the pubic bone joins to the perineum and between the two medians.

2. Composition of the vulva

(1) Yinfu is located in front of the pubic symphysis, and there is rich fatty tissue under the skin. At the beginning of puberty, the skin on it begins to grow curly pubic hair, which is one of the second sexual characteristics.

(2) The labia majora is a pair of raised skin folds on both sides of the vulva. It is followed by the Yinfu and the perineum. The labia majora is rich in adipose tissue and venous plexus. It is easy to form hematoma after local injury.

(3) The labia minora is located inside the labia majora. It is a pair of vertical skin folds, with a moist surface, exactly like a mucous membrane, brown, hairless, and rich in nerve endings, so it is extremely sensitive.

(4) The clitoris is located at the front of the labia minora. It is a cavernous tissue. The clitoral head is rich in nerve endings and is extremely sensitive.

(5) The vaginal vestibule is a diamond-shaped area between the two labia minora. There is a urethral opening in front of the vestibule and a vaginal opening in the rear. urethral opening: located between the clitoris and vaginal opening, is an irregular oval hole. There are a pair of glands on both sides of the posterior wall of the urethral orifice, which are called paraurethral glands, which are often the place where bacteria are latent. vestibular gland: also known as the Pap glands. Located behind the labia majora, are glands on both sides of the vaginal opening. Much like soybeans; the glandular duct is slender 1 to 2 cm, opening in the ditch between the labia minora and the hymen. During sexual excitement, yellow-white mucus is secreted for lubrication. This gland cannot be touched during normal conditions. It can be seen or palpable if an abscess or cyst is formed due to occlusion of the glandular duct due to infection. Vestibular bulb: also known as bulbocavernosus, located on both sides of the anterior lip is composed of erectile venous plexus, the surface is covered with bulbocavernosus. Vaginal opening and hymen: The vaginal opening is located below the urethral opening. The vaginal opening is covered with a thin film called hymen. There is an opening in the center of the membrane. Menstrual menstrual blood flows out of this.

Female genitalia

The female genitalia includes the vagina, uterus, fallopian tubes, and ovaries, and the latter two are called attachments.

Vagina

It is the channel for sexual intercourse organs, menstrual blood excretion and fetal delivery.

(1) The location and shape are located in the center of the lower part of the true pelvis, and it is a wide and narrow tube. The anterior wall is 7-9cm in length, adjacent to the bladder and urethra, and the posterior wall is 10-12cm in length. The upper end of the vagina surrounds the cervix, and the part surrounding the cervix is called the vaginal vault. According to its location, it is divided into front, back, left, and right parts, of which the posterior fornix is the deepest and is closely adjacent to the rectal uterine depression. It is the lowest part of the pelvic cavity and can be punctured or drained clinically. The lower end of the vagina opens at the back of the vestibule.

(2) Tissue structure The vaginal wall is composed of mucous membrane, muscular layer and fibrous tissue membrane. The vaginal mucosa is pale red and is covered by stratified squamous epithelial cells without glands. The vaginal muscle layer is composed of two layers of smooth muscle fibers. The outer layer runs longitudinally and the inner layer loops. There is a fibrous tissue membrane outside the muscle layer, which contains a large amount of elastic fibers and a small amount of smooth muscle fibers.

The vaginal mucosa is affected by sex hormones periodically. In young girls and postmenopausal women, the vaginal mucosa epithelium is very thin, with less wrinkles, less extensibility, trauma and bleeding. The vaginal wall is rich in venous plexus, so there is a lot of bleeding or hematoma formation after local damage.

2. uterus

Organs with thick walls, small cavities, and mainly muscles. The mucosa covered by the cavity is called the endometrium. After puberty, it is affected by sex hormones to change periodically and produce menstruation. The fetus is conceived during pregnancy.

(1) Morphology The uterus of the adult is a slightly flat inverted pear shape, weighing 50 g, 7 to 8 cm in length, 4 to 5 cm in width, 2 to 3 cm in thickness, and 5 ml in uterine cavity. The upper part of the uterus is wider, the uterine body is the upper part of the uterus, the sides of the uterus are horns, and the lower part of the uterus is cylindrical. The upper and lower uterine cavity is narrow, and the narrowest part between the uterine body and the cervix is the isthmus. It is 1cm in length during non-pregnancy, and its upper end is narrower in shape and becomes the anatomical inner mouth. It is called the histology inside mouth. The cervical canal is 2.5 to 3 cm long and the lower end is the external cervix. The part of the lower end of the cervix that penetrates into the vagina is called the cervical vagina, and the part above the vagina is called the upper part of the cervical vagina. The maternal outer cervix is round, and the maternal cervix is affected by childbirth to form a transverse fissure.

(2) Organizational structure The structure of the uterine cervix and the cervix are different. The uterine body wall consists of 3 layers of tissues, the outer layer is the serosa layer (visceral peritoneum), the middle layer is the muscular layer, and the inner layer is the endometrium. The endometrium is a layer of pink mucosal tissue that has been affected by ovarian hormones since puberty. The surface can be changed cyclically on two-thirds of which is called the functional layer; the remaining 1/3 of the endometrium near the uterine muscle layer has no periodic changes. Bottom. Myometrium is thick, about 0.8cm thick when not pregnant. The muscular layer consists of smooth muscle bundles and elastic fibers. The muscle bundles are crisscross like a net, roughly divided into three layers: the outer layer is more longitudinal, the inner layer is circular, and the middle layer is intertwined. It is also called "outer longitudinal, inner ring, and middle cross". The muscle layer contains blood vessels, which are compressed when the uterus contracts, which can effectively prevent postpartum uterine bleeding. Cervix: It is mainly composed of connective tissue, and also contains smooth muscle fibers, blood vessels and elastic fibers. The mucosal epithelial cells of the cervical canal have a single layer of high columnar shape. There are many glands in the mucosal layer that can secrete alkaline mucus, forming a mucus plug in the cervical canal, which separates the cervical canal from the outside. The cervix and vagina are covered by stratified squamous epithelium with a smooth surface. The junction of the columnar epithelium and squamous epithelium of the external cervix is a common site of cervical cancer, and it is periodically shifted out due to the effects of hormones. Location The uterus is located in the center of the pelvis, between the bladder and the rectum, and the lower end is connected to the vagina. There are fallopian tubes and ovaries on both sides. The normal position of the uterus is slightly forward leaning forward, mainly relying on the ligament of the uterus and the pelvic floor muscles and fascia support. There are 4 pairs of uterine ligaments: round ligament, broad ligament, main ligament and uterine sacral ligament. If the aforementioned ligaments, pelvic floor muscles, and fascia are weak or damaged, the uterus can be abnormally positioned, and pelvic organ prolapse can be formed to varying degrees.

3. Fallopian tube

The fallopian tube is the place where the eggs meet with the sperm, and it is also the conduit for fertilized eggs to the uterine cavity. It is a pair of slender and curved tubes, located in the upper edge of the broad ligament of the uterus, communicating with the uterine horn on the medial side, free on the outer end, and close to the ovary. Approximately 8 to 14 cm in total length. According to the shape of the fallopian tube, it can be divided into 4 parts from the inside to the outside, the interstitial part, the isthmus part, the ampulla part and the umbrella part.

The fallopian tube wall consists of 3 layers: the outer layer is the serosa layer, the middle layer is the smooth muscle layer, and the inner layer is the mucosal layer. The inner layer is rich in ciliated cells, whose ciliary swings help transport eggs.

4. Ovary

It is a pair of flat oval gonads with reproductive and endocrine functions, producing and discharging egg cells, and secreting sex hormones. Before puberty, the surface of the ovaries is smooth; after ovulation begins, the surface gradually becomes uneven; adult women's ovaries are about 4cm × 3cm × 1cm large, weighing 5-6g, and are grayish white; after menopause, the ovaries shrink and become hard. The outer ovary is connected to the pelvic wall by the pelvic funnel ligament, and the inner ovary is connected with the uterus by the inherent ovarian ligament.

There is no peritoneum on the surface of the ovary, which is covered by a single layer of cubic epithelium called germinal epithelium; there is a layer of fibrous tissue inside it called the ovarian leukomembrane. Further inside is the ovarian tissue, divided into cortex and medulla. The cortex is in the outer layer, which contains tens of thousands of primitive follicles (also known as primordial follicles) and dense connective tissue; the medulla is in the center, there are no follicles, containing loose connective tissue and abundant blood vessels, nerves, lymphatic vessels and a small amount of ovarian suspension Continuous smooth muscle fibers that have an effect on ovarian movement.

The above-mentioned internal reproductive organs play an important role in the embryogenesis process during pregnancy: mature eggs are discharged from the ovary during ovulation, the umbilical end of the fallopian tube "picks up", and the eggs enter the ampulla of the fallopian tube. At this time, the cervical mucus plug becomes thin, suitable for sperm to enter. After intercourse, the semen enters the posterior fornix of the vagina, and some of the sperm migrate through the cervical canal and uterine cavity and enter the fallopian tube. At the junction of the fallopian tube isthmus and ampulla, sperm and egg cells fuse into a new syncytial cell. This process is called fertilization. Although one ejaculation can discharge hundreds of millions of sperm, it can rarely reach the fertilized site in the end. The ability of sperm to fertilize in the female reproductive tract can only be maintained for about 48 hours. The fertilized egg gradually moves to the uterine cavity under the action of the tubal peristalsis and cilia, and simultaneously undergoes cell division of the fertilized egg. The development and operation of fertilized eggs occur simultaneously. Due to the peristaltic muscles of the fallopian tube wall and the cilia of the fallopian tube mucosa, the fertilized eggs gradually move towards the uterine cavity and reach the uterine cavity 3 to 4 days after fertilization. On the 7th to 8th day after fertilization, the fertilized egg develops into a blastocyst or blastocyst, and its trophoblast cells are in contact with the endometrium. The blastocyst is implanted into the endometrium after three stages of positioning, adhesion and penetration, and becomes the implantation. The uterus allows implantation of blastocysts only during a very short critical period, which is the sensitive or receptive period of the uterus. About 9 to 10 days after fertilization, the inner cell mass quickly proliferates and differentiates, dividing into two layers, namely the ectoderm and the endoderm. Both layers of cells divide quickly, and each forms a cavity, namely the amnion cavity and the yolk sac. The tissue between the two is called the blastoderm, which will differentiate into parts of the fetal body in the future. Beginning in the third week after fertilization, the blastoderm gradually differentiates into inner, outer, and middle germ layers, and embryos form.

Vaginal microecological environment of female reproductive system

In the female vulva area, the labia majora on both sides are naturally closed, covering the vaginal opening and urethral opening; the vaginal opening is closed and the front and back walls of the vagina are tightly attached. The female vaginal wall is composed of intact stratified squamous epithelial cells, which can continuously proliferate and thicken with the increase of estrogen levels in the body, and fall off periodically with the change of the endocrine cycle. No secretory glands were found in the vagina, but the secretions could come from the vestibular glands, paraurethral glands, cervical mucus, endometrium, and fallopian tubes. The vaginal secretion layer of healthy women is acidic and the cervical mucus plugs are alkaline. These anatomical and physiological characteristics form a natural defense function.

Among normal vaginal flora, Lactobacillus predominates. Lactobacillus is a Gram-positive bacterium, which is slightly aerobic, but grows better in an anaerobic environment, and the optimal growth temperature is 35 ° C to 38 ° C. More than 20 types of Lactobacillus can be isolated from the vagina of healthy women. Lactobacilli normally present in the vagina play a key role in maintaining the normal vaginal flora. Glycogen in vaginal squamous epithelial cells is decomposed into lactic acid by the action of Lactobacillus, which causes a weakly acidic environment (pH 4.5, mostly between 3.8 and 4.4) in the vagina, which can inhibit the excessive growth of other parasitic bacteria. Therefore, under normal circumstances, women's vulva care immediately cleans the vulva, and intravaginal washing should not be performed to prevent damage to the vaginal microecological environment. Once the vaginal acid-base balance is disrupted, vaginitis or vaginosis may be induced ^{[1] [2]} .

Adjacent organs of female reproductive system

Female reproductive organs and other organs of the pelvic cavity are not only adjacent to each other in position, but also blood vessels, lymph and nerves are closely related to each other. When a certain organ has lesions, such as trauma, infection, tumor, etc., it is easy to affect neighboring organs.

Urethra

Between the pubic symphysis and the anterior wall of the vagina. The internal urethral sphincter is an involuntary muscle, the external urethral sphincter is an arbitrary muscle, and is closely associated with the deep perineal transverse muscle. Because women's urethra is short and straight, and close to the vagina, it is easy to cause urinary system infection.

Bladder

It is a cystic muscular organ, and the empty bladder is cone-shaped, located after the pubic symphysis and before the uterus. Its size and shape can change due to its excess and deficiency and the condition of adjacent organs. The bladder can be divided into 4 parts: top, bottom, body and neck. A triangular area is formed in the mucosa at the bottom of the bladder, which is called the bladder triangle. The tip of the triangle is the inner urethral opening, and the sides of the triangular base are the ureteral openings. The two mouths are about 2.5 cm apart. This part is adjacent to the cervix and anterior wall of the vagina, but under normal circumstances, the tissue is relatively loose. Because the bladder can affect the uterus and vagina, the bladder must be emptied before gynecological examination and surgery. When the bladder is full, it can protrude toward the pelvic cavity or even the abdominal cavity. If large uterine fibroids or ovarian tumors are combined, filling the bladder can squeeze the uterus or ovaries behind it, and can even restore the viscera to the pelvis after emptying the bladder. Unreachable.

3. The ureter

It is a pair of muscular circular cord-shaped long tubes, starting from the renal pelvis and finally the bladder, each about 30cm in length and varying in thickness. The inner diameter of the thinnest part is only 3 to 4mm, and the thickest can reach 7 to 8mm. During gynecological surgery, care should be taken to avoid damage to the ureter.

4. Rectum

Located at the back of the pelvic cavity, its upper end meets the sigmoid colon at the level of the 3rd sacral vertebra, passes down through the pelvic ridge, and its lower end is connected to the anal canal. Adults are 15-20cm in length from the left sacroiliac joint to the anus. The anal canal is 2 to 3 cm in length, with anal and external anal sphincter and levator anal muscles around it, while the external anal sphincter is a part of the superficial muscles of the pelvic floor. Therefore, care should be taken to avoid damage to the anal canal and rectum during gynecological surgery and childbirth.

5.Appendix

The root of the appendix is connected to the posteromedial wall of the cecum, and the distal end is free. It is 7-9 cm long and is usually located in the right popliteal fossa. However, its position, length, and thickness vary considerably. Some lower ends can reach the right fallopian tube and ovary, and the position of the appendix during pregnancy can gradually shift upwards and outwards with the increase of the month of pregnancy. Therefore, women with appendicitis may involve uterine appendages and should pay attention to differential diagnosis.

References:

1. Feng Youji and other editors. Obstetrics and Gynecology: People's Medical Publishing House, 2005: 6-16.

Edited by 2.F.GARYCUNNINGHAM, etc., and translated by Duan Tao. Williams Obstetrics: Shandong Science and Technology Press 2001: 27-47.