The cervix (from Latin "neck") is actually the lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall. Approximately half its length is visible with appropriate medical equipment; the remainder lies above the vagina beyond view. It is occasionally called "cervix uteri", or "neck of the uterus".
The portion projecting into the vagina is referred to as the portio vaginalis or ectocervix. On average, the ectocervix is 3 cm long and 2.5 cm wide. It has a convex, elliptical surface and is divided into anterior and posterior lips.
The ectocervix opening is called the external os. The size and shape of the external os and the ectocervix varies widely with age, hormonal state, and whether the woman has had a vaginal birth. In women who have not had a vaginal birth the external os appears as a small, circular opening. In women who have had a vaginal birth, the ectocervix appears bulkier and the external os appears wider, more slit-like and gaping.
The passageway between the external os and the uterine cavity is referred to as the endocervical canal. It varies widely in length and width, along with the cervix overall. Flattened anterior to posterior, the endocervical canal measures 7 to 8 mm at its widest in reproductive-aged women.
The endocervical canal terminates at the internal os which is the opening of the cervix inside the uterine cavity.
Normally the external os is blocked by a thick mucus that prevents infection, however the mucus thins when ovum are ready to be fertilized, allowing spermatozoa to pass through the cervix. Most oral contraceptives increase their effectiveness by not allowing this mucus to thin, therefore blocking spermatozoa from passing even when ovum are ready to be fertilized. During pregnancy the cervix is completely blocked by a special antibacterial mucosal plug which prevents infection as before. The mucous plug comes out as the cervix dilates in labor or shortly before.
In humans the cervix is associated with cervical cancer, a particular form of cancer which is detectable by cytological study of epidermal cells removed from the cervix in a process known as the Pap smear. Evidence now shows that those with exposure to HPV or Human Papilloma Virus are at increased risk for cervical cancer. This virus is related to the virus that causes warts.
Cervical cancer is a malignancy of the cervix. Worldwide, it is the second most common cancer of women. It may present with vaginal bleeding but symptoms may be absent until the cancer is in advanced stages, which has made cervical cancer the focus of intense screening efforts utilizing the Pap smear. Most scientific studies point to human papillomavirus (HPV) infection as a necessary pre-requisite for development of cervical cancer. Treatment is with surgery (including cryosurgery) in early stages and chemotherapy and radiotherapy in advanced stages of the disease.
Diagnosis is made by doing a biopsy of the cervix, which often involves colposcopy, or a magnified visual inspection of the cervix aided by using an acetic acid solution to produce color changes in precancerous or cancerous areas. A Pap smear is insufficient for the diagnosis. Many researchers recommend that since more than 99% of invasive cervical cancers worldwide contain human papillomavirus, HPV testing should be carried out together with routine cervical screening. Further diagnostic procedures are loop electrical excision procedure (LEEP) and conization, in which the inner lining of the cervix is removed to be examined pathologically. These are carried out if the biopsy confirms severe dysplasia.
Cervical cancer is staged by the FIGO staging system, which is based on clinical examination, rather than surgical findings. It allows only the following diagnostic tests to be used in determining the stage: palpation, inspection, colposcopy, endocervical curettage, hysteroscopy, cystoscopy, proctoscopy, intravenous urography, and X-ray examination of the lungs and skeleton, and cervical conization.
The TNM staging system for cervical cancer is analogous to the FIGO stage.
Stage 0 - full-thickness involvement of the epithelium without invasion into the stroma (carcinoma in situ)
Stage I - limited to the uterus
IA - diagnosed only by microscopy; no visible lesions
IA1 - stromal invasion less than 3 mm in depth and 7 mm or less in horizontal spread
IA2 - stromal invasion between 3 and 5 mm with horizontal spread of 7 mm or less
IB - visible lesion or a microscopic lesion with more than 5 mm of depth or horizontal spread of more than 7 mm
IB1 - visible lesion 4 cm or less in greatest dimension
IB2 - visible lesion more than 4 cm
Stage II - invades beyond uterus
IIA - without parametrial invasion
IIB - with parametrial invasion
Stage III - extends to pelvic wall or lower 1/3 of the vagina
IIIA - involves lower 1/3 of vagina
IIIB - extends to pelvic wall and/or causes hydronephrosis or non-functioning kidney
IVA - invades mucosa of bladder or rectum and/or extends beyond true pelvis
IVB - distant metastasis
Note that the FIGO stage does not incorporate lymph node involvement in contrast to the TNM staging for most other cancers.
Microinvasive cancer (stage IA) is usually treated by hysterectomy (removal of the whole uterus including part of the vagina). For stage IA2, the lymph nodes are removed as well. An alternative for patients who desire to maintain fertility is a local surgical procedure such as a LEEP or cone biopsy.
Early stages (IB1 and IIA less than 4cm) can be treated with radical hysterectomy with removal of the lymph nodes or radiation therapy. Radiation therapy is given as external beam radiotherapy to the pelvis and brachytherapy (internal radiation). For patients treated with surgery who have high-risk features found on pathologic examination, radiation therapy with or without chemotherapy is given in order to reduce the risk of relapse.
Larger early stage tumors (IB2 and IIA more than 4cm) may be treated with radiation therapy and cisplatin-based chemotherapy, hysterectomy (which then usually requires adjuvant radiation therapy), or cisplatin chemotherapy followed by hysterectomy.
Advanced stage tumors (IIB-IVA) are treated with radiation therapy and cisplatin-based chemotherapy.
The clitoris (plural: clitorides) is a sexual organ in the body of female mammals. The visible knob-like portion is located near the anterior junction of the labia minora, above the opening of the vagina. The clitoris has no urethra and functions solely to induce sexual pleasure. The only known exception to this is in the Spotted Hyena, where the urogenital system is modified so that the female urinates, mates and gives birth via an enlarged, erectile clitoris.
In female human anatomy, the clitoral hood, (also called prepuce), is a fold of skin that surrounds and protects the clitoral glans. It develops as part of the labia minora and is homologous with the foreskin (equally called prepuce) in male genitals.
This is a protective hood of skin that covers the clitoris. There is no standard size or shape for the hood. Some women have large clitoral hoods that completely cover the tip of the clitoris.
The uterus or womb is the major female reproductive organ of most mammals, including humans. One end, the cervix, opens into the vagina; the other is connected on both sides to the fallopian tubes. In mammals, the four main forms in which it is found are: bipartite, as in cows; bicornuate, as in pigs; simplex, as with the pear-shaped one found in humans and horses; and duplex, found in rabbits.
The uterus is located in the pelvis immediately dorsal (and usually somewhat rostral) to the urinary bladder and ventral to the rectum. It is held in place by eight ligaments (one anterior; one posterior; two lateral or broad; two uterosacrals; and two round ligaments). It is usually slightly anteverted (tipped forward) but is sometimes retroverted (tipped backwards). Outside of pregnancy, its size is several centimeters in diameter.
The uterus mostly consists of muscle, known as myometrium. The innermost layer of myometrium is known as the junctional zone, which becomes thickened in adenomyosis. The lining of the uterine cavity is called the endometrium. In most mammals, including humans, the endometrium builds a lining periodically which, if no pregnancy occurs, is shed or reabsorbed. Shedding of the endometrial lining in humans is responsible for menstrual bleeding (known colloquially as a woman's "period") throughout the fertile years of a female and for some time beyond. In other mammals there may be cycles set as widely apart as six months or as frequently as a few days.
The loose surrounding tissue is called the parametrium.
The main function of the uterus is to accept a fertilized ovum, which becomes implanted into the endometrium, and derives nourishment from blood vessels, which develop exclusively for this purpose. The fertilized ovum becomes an embryo, develops into a fetus and gestates until childbirth. Due to anatomical barriers such as the pelvis, the uterus is pushed partially into the abdomen due to its expansion during pregnancy. Even in pregnancy the mass of a human uterus amounts to only about a kilogram (2.2 pounds).
Some pathological states include:
· Prolapse of the uterus
· Carcinoma of the cervix - malignant neoplasm
· Carcinoma of the uterus - malignant neoplasm
· Ectopic pregnancy-an ectopic pregnancy is one in which the fertilized ovum is implanted in any tissue other than the uterine wall. Most ectopic pregnancies occur in the fallopian tube (so-called tubal pregnancies), but implantation can also occur in the cervix, ovaries, and abdomen.
· Fibroids - benign neoplasms
· Adenomyosis - ectopic growth of endometrial tissue within the myometrium
Uterine fibroids (leiomyomata, singular leiomyoma) are the most common neoplasm in females, and may affect about of 25 % of white and 50% of black women during the reproductive years. Fibroids can be removed simply by means of a hysterectomy, but much more favorably by a uterine artery embolization, as it preserves the uterus.
Leiomyomas grossly appear as round, well circumscribed (but not encapsulated), solid nodules that are white, or tan whorled. The size varies, from microscopic to lesions of considerable size. Leiomyomas are estrogen sensitive and have estrogen receptors. They may enlarge rapidly during pregnancy due to increased estrogen levels. As estrogen levels decline with menopause, fibroids tend to regress after menopause. Hormonal therapy is based on these facts.
Fibroids, particularly when small, may be entirely asymptomatic. Generally, symptoms relate to the location of the lesion and its size. Important symptoms include abnormal gynecologic hemorrhage, pain, infertility, dysuria and urinary frequency. During pregnancy they may be the cause of miscarriage, bleeding, premature labor, or interference with the position of the fetus.
Fibroids may be single or multiple. Most fibroids start in an intramural location,- that is the layer of the muscle of the uterus. With further growth, some lesion may develop towards the outside of the uterus (subserosal or pedunculated), some towards the cavity (submucosal or intracavitary). Lesions affecting the cavity tend to bleed more and interfere with pregnancy. Secondary changes that may develop within fibroids are hemorrhage, necrosis, calcification, and cystic changes. Less frequently, leiomyomas may occur at the lower uterine segment, cervix, or uterine ligaments.
Diagnosis is usually accomplished by bimanual examination, better yet by gynecologic ultrasonography. Sonography will depict the fibroids as focal masses with a heterogeneous texture, which usually cause shadowing of the ultrasound beam. In cases where a more precise assay of the fibroid burden of the uterus is needed, also magnetic resonance imaging (MRI) can be used to generate a depiction of the size and location of the fibroids within the uterus.
The presence of a fibroid does not mean that it needs to be treated, many lesions are followed expectantly. Treatment of uterine fibroids that cause problems can be accomplished by:
· Surgery: Hysterectomy or myomectomy can be performed. Based on the size and location of the lesion different approaches can be considered: laparotomy, laparoscopy, or hysteroscopy.
· Uterine artery embolization (UAE): Using interventional radiology techniques, the Interventional physician occludes both uterine arteries and reducing blood supply to the fibroid(s).
· Medical therapy: This involves the use of medication to reduce estrogens in an attempt to create a medical menopause-like situation. Gonadotropin-releasing hormone analogs are used for this. Selective progesterone receptor modulators, such as Progenta, are under investigation as therapeutic agents. (2005)
· HIFU (High frequency focused ultrasound), also called MRgFUS (Magnetic Resonance guided Focused Ultrasound), is a non-invasive intervention (requiring no incision) that uses high intensity focused ultrasound waves to ablate (destroy) tissue in combination with Magnetic Resonance Imaging (MRI), which guides and monitors the treatment.
All text of this article available under the terms of the GNU Free Documentation License (see Copyrights for details).