OB CH 3

Human chorionic gonadotropin (hCG)

A hormone produced by the chorionic villi and found in the urine of pregnant women. Also called prolan.

Progesterone

A hormone produced by the corpus luteum, adrenal cortex, and placenta whose function is to stimulate proliferation of the endometrium to facilitate growth of the embryo.

Gonatotropin-releasing hormone

A hormone secreted by the hypothalamus that stimulates the anterior pituitary to secrete FSH and LH.

Broad ligament

A ligament that keeps the uterus centrally placed and provides stability within the pelvic cavity. It is a double layer that is continuous with the abdominal peritoneum. The broad ligament covers the uterus anteriorly and posteriorly and extends outward from the uterus to enfold the fallopian tubes.

Sacral promontory

A projection into the pelvic cavity on the anterior upper portion of the sacrum; serves as an obstetric guide in determining pelvic measurements.

Corpus luteum

A small yellow body that develops within a ruptured ovarian follicle; it secretes progesterone in the second half of the menstrual cycle and atrophies about 3 days before the beginning of menstrual flow. If pregnancy occurs, the corpus luteum continues to produce progesterone until the placenta takes over this function.

Alveoli

Alveoli Small units of the breast tissue in which milk is synthesized by the alveolar secretory epithelium.

Ampulla

Ampulla The outer two-thirds of the fallopian tube; fertilization of the ovum by a spermatozoon usually occurs here.

LH

Anterior pituitary hormone responsible for stimulating ovulation and for development of the corpus luteum.

Cardinal ligaments

Cardinal ligaments The chief uterine supports, the cardinal ligaments suspend the uterus from the side walls of the true pelvis. Also known as Mackenrodt's or transverse cervical ligaments, they arise from the sides of the pelvic walls and attach to the cervix in the upper vagina. They prevent uterine prolapse and support the upper vagina.

Diagonal conjugate

Diagonal conjugate An anteroposterior diameter that extends from the subpubic angle to the middle of the sacral promontory and is typically 12.5 cm. One of three diameters that are used to assess the size and shape of the pelvic inlet.

Obstetric conjugate

Distance from the middle of the sacral promontory to an area approximately 1 cm below the pubic crest.

FSH

Hormone produced by the anterior pituitary during the first half of the menstrual cycle, stimulating development of the graafian follicle.

Nidation

Implantation of a fertilized ovum in the endometrium.

Conjugate

Important diameter of the pelvis, measured from the center of the promontory of the sacrum to the back of the symphysis pubis. The diagonal conjugate is measured and the true conjugate is estimated.

Ovarian ligaments

Ligaments that anchor the lower pole of the ovary to the cornua of the uterus. They are surrounded by muscle fibers that allow the ligaments to contract.

Round ligaments

Ligaments that arise from the sides of the uterus near the fallopian tube insertions. They extend outward between the folds of the broad ligament, passing through the inguinal ring and canals and eventually fusing with the connective tissue of the labia majora.

Uterosacral ligaments

Ligaments that provide support for the uterus and cervix at the level of the ischial spines. They arise on each side of the pelvis from the posterior wall of the uterus and sweep back around the rectum to insert on the sides of the first and second sacral vertebrae.

Spermatazoa

Mature sperm cells of the male animal, produced by the testes.

Fimbria

The funnel-like structure at the abdominal opening of the uterine tube that has many fingerlike projections (fimbriae) reaching out to the ovary.

Transverse diameter

The largest diameter of the pelvic inlet; helps determine the shape of the inlet.

Infundibulopelvic ligament

The ligament that suspends and supports the ovaries. It arises from the outer third of the broad ligament and contains the ovarian vessels and nerves.

Graafian follicles

The ovarian cyst containing the ripe ovum; it secretes estrogens.

False pelvis

The portion above the pelvic brim, or linea terminalis, that serves to support the weight of the enlarged pregnant uterus and direct the presenting fetal part into the true pelvis below.

True pelvis

The portion that lies below the linea terminalis, made up of the inlet, cavity, and outlet

Spermatogenesis

The process by which mature spermatozoa are formed, during which the number of chromosomes is halved.

Labor

The process by which the fetus is expelled from the maternal uterus. Also called childbirth, confinement, or parturition.

Isthmus

The straight, narrow part of the fallopian tube with a thick muscular wall and an opening (lumen) 2 to 3 mm in diameter; the site of tubal ligation. Also, a constriction in the uterus that is located above the cervix and below the corpus.

Conjugate vera

The true conjugate, which extends from the middle of the sacral promontory to the middle of the pubic crest.

Rugae

Transverse ridges of mucous membranes lining the vagina that allow the vagina to stretch during the descent of the fetal head.

Fallopian tubes

Tubes that extend from the lateral angle of the uterus and terminate near the ovary; they serve as a passageway for the ovum from the ovary to the uterus and for the spermatozoa from the uterus toward the ovary. Also called oviducts and uterine tubes.

Cornua

the enlogated portion of the uterus where the fallopian tubes enter

External os

the opening between the cerxic and the vagina

Corpus

upper two thirds of the uterus

Ischial spines

Prominences that arise near the junction of the ilium and ischium and jut into the pelvic cavity; used as a reference point during labor to evaluate the descent of the fetal head into the birth canal.

Internal os

an inside mouth or opening; the opening between the cervix and uterus