An is an egg-producing reproductive organ found in
Female organisms. It is often found in pairs as part of the
Vertebrate female
Reproductive System . Ovaries in females are
Homologous to
Testes in males. The term
Gonad s refers to the ovaries in females and testes in males.
As female mammals develop within the womb, each ovary develops a number of immature eggs associated with groups of other cells called
Follicles . While mammals were thought to develop their entire supply of eggs prenatally and soon after birth, new evidence from laboratory mice has called this into question, showing that female mice in fact produce new eggs throughout their reproductive lifetime
1, However, there is no direct evidence showing that human females produce new eggs after birth. As the animal becomes reproductively mature (the process called
Puberty in humans), eggs will periodically mature and be released from the ovary (a process called
Ovulation ) so that they will be available for
Fertilization by
Sperm . A fertilized egg resulting from union with a sperm becomes a
Zygote and then an
Embryo as it develops.
In humans, an egg launched from an ovary has to traverse a slight space before entering the
Fallopian Tube and moving gradually down to the
Uterus . If fertilized, it performs
Implantation into the lining of the uterus and develops as the pregnancy continues. If the fertilized egg settles into the fallopian tube instead of the uterus an
Ectopic Pregnancy will result. Ectopic pregnancy can also happen if a fertilized egg settles onto the
Cervix or onto the ovary itself, or if a fertilized egg passes through the gap between the ovary and the fallopian tube into the abdomen.
Animal and human ovaries also produce various
Steroid and peptide
Hormone s.
Estrogen and
Progesterone are the most important of these in mammals.
These hormones serve many functions:
Ovaries are oval shaped and, in the human, measure approximately 3 cm x 1.5 cm x 1.5 cm. The ovary (for a given side) is located in the lateral wall of the pelvis in a region called the
Ovarian Fossa . The fossa usually lies beneath the
External Iliac Artery and in front of the
Ureter and the
Internal Iliac Artery .
In the human the paired ovaries lie within the pelvic cavity, on either side of the
Uterus , to which they are attached via a fibrous cord called the
Ovarian Ligament . The ovaries are uncovered in the
Peritoneal Cavity but are tethered to the body wall via the
Suspensory Ligament Of The Ovary . The part of the
Broad Ligament Of The Uterus that covers the ovary is known as the
Mesovarium .
There are two extremities to the ovary:
- The end to which the Uterine Tube attach is called the ''tubal extremity''.
- The other extremity is called the ''uterine extremity''. It points downward, and it is attached to the Uterus via the ovarian ligament.
Each ovary receives blood from the
Ovarian Artery , which arises directly from the anterior
Abdominal Aorta and the ovarian branch of the
Uterine Artery that enters the ovary by way of the broad ligament and thus the mesovarium. The right ovarian vein drains to the inferior vena cava and the left ovarian vein drains to the left renal vein. The ovarian artery and vein are within the suspensory ligament of the ovary (infundibulopelvic ligament). Sources of innervation include the
Ovarian Plexus .
s. The ''Genital cord'' or
Genital Ridge is still discernable in this young child. A blood vessel and an
Ovarian Follicle is also seen]]
| |
"http://wwwinformationdelightinfo/information/entry/uterine_artery" class="copylinks">Uterine Artery , Ovarian Artery and Vaginal Arteries
|
