The cervix or cervix uteri is the lower part of the uterus (womb) in the human female reproductive system. The cervix is usually 2 to 3 cm long and roughly cylindrical in shape, which changes during pregnancy. The narrow, central cervical canal runs along its entire length, connecting the uterine cavity and the lumen of the vagina. The opening into the uterus is called the internal os, and the opening into the vagina is called the external os. The lower part of the cervix, known as the vaginal portion of the cervix, bulges into the top of the vagina. The cervix has been documented anatomically since at least the time of Hippocrates, over 2,000 years ago.
The uterus or womb is the main hormone-responsive, secondary sex organ of the female reproductive system in humans, and most other mammals. Events occurring within the uterus are described with the term in utero. In the human, the lower end of the uterus, the cervix, opens into the vagina, while the upper end, the fundus, is connected to the fallopian tubes. It is within the uterus that the embryo and later fetus develops during gestation. In the human embryo, the uterus develops from the paramesonephric ducts which fuse into the single organ known as a simplex uterus. The uterus has different forms in many other animals and in some it exists as two separate uteri known as a duplex uterus.
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen. At the deep end, the cervix bulges into the vagina. The vagina allows for sexual intercourse and birth. It also channels menstrual flow, which occurs in humans and closely related primates as part of the menstrual cycle.
The internal pudendal artery is one of the three pudendal arteries. It branches off the internal iliac artery, and provides blood to the external genitalia.
The internal iliac artery is the main artery of the pelvis.
The femoral nerve is a nerve in the thigh that supplies skin on the upper thigh and inner leg, and the muscles that extend the knee.
The uterine artery is an artery that supplies blood to the uterus in females.
The superior gluteal artery is the largest and final branch of the internal iliac artery. It is the continuation of the posterior division of that vessel. It is a short artery which runs backward between the lumbosacral trunk and the first sacral nerve. It divides into a superficial and a deep branch after passing out of the pelvis above the upper border of the piriformis muscle.
The lateral sacral arteries is an artery in the pelvis that arises from the posterior division of the internal iliac artery. It later splits into two smaller branches, a superior and an inferior.
The middle rectal artery is an artery in the pelvis that supplies blood to the rectum.
The inferior vesical artery or inferior vesicle artery is an artery in the pelvis that supplies the lower part of the bladder.
The inferior rectal artery is an artery that supplies blood to the lower third of the anal canal below the pectinate line.
The ovarian artery is an artery that supplies oxygenated blood to the ovary in females. It arises from the abdominal aorta below the renal artery. It can be found in the suspensory ligament of the ovary, anterior to the ovarian vein and ureter.
The posterior ethmoidal nerve is a nerve of the orbit around the eye. It is a branch of the nasociliary nerve from the ophthalmic nerve (CN V1). It supplies sensation to the sphenoid sinus, the ethmoid sinus, and part of the dura mater in the anterior cranial fossa.
The uterine artery supplies branches to the cervix uteri and others which descend on the vagina; the latter anastomose with branches of the vaginal arteries and form with them two median longitudinal vessels—the vaginal branches of uterine artery —one of which runs down in front of and the other behind the vagina.
The dorsal artery of the penis is an artery on the top surface of the penis. It is a branch of the internal pudendal artery. It runs forward on the dorsum of the penis to the glans, where it divides into two branches to the glans penis and the foreskin (prepuce).
The vaginal venous plexus is a group of veins draining blood from the vagina. It lies around the sides of the vagina. Its blood is eventually into the internal iliac veins.
Vesical arteries are variable in number. They supply the bladder and terminal ureter. The two most prominent are the superior vesical artery and the inferior vesical artery. The superior vesical artery comes off of the internal iliac artery and sometimes the umbilical artery. The inferior vesical artery comes off of the internal iliac artery. The inferior vesical artery is a pelvic branch of the internal iliac artery in men; and in women it branches from the vaginal artery. This literature has been reviewed recently with observations of variation in pelvic vascularization and the close relationship between vaginal and bladder vascularization in women.
The uterine vein is a vein of the uterus in women. It is found in the cardinal ligament. It drains into the internal iliac vein. It follows a similar course to the uterine artery. It helps to drain blood from the uterus, and removes waste from blood in the placenta during pregnancy.
This glossary of medical terms is a list of definitions about medicine, its sub-disciplines, and related fields.
