The Reproductive System

Female

Reproductive role

• Produce the female gamete (ova)• Nurture and protect a developing fetus during

9 months of pregnancy• Primary reproductive organ: Ovaries- Produce exocrine product: Ova- Produce endocrine product: estrogen and

progesterone

Ovaries• The paired ovaries are the size and shape of almonds• Ovarian follicles: tiny saclike structures within the ovaries- Each follicle consists of an immature egg called an oocyte- Oocyte is surrounded by one or more layers of very

different cells called follicle cells

Ovulation• As a developing egg within a

follicle begins to mature:- The follicle enlarges and develops

a fluid-filled central region called an antrum

- At this stage, ovulation happens: the follicle is mature and the developing egg is ready to be ejected from the ovary

• After ovulation, the ruptured follicle is transformed into a very different looking structure called a corpus luteum, which eventually degenerates

Ovulation Video

• https://www.youtube.com/watch?v=nLmg4wSHdxQ

Duct System

• duct system:- The uterine (fallopian)tubes- Uterus - Cervix- Vagina

Fallopian tubes• Form the initial part of the

duct system• Receive the ovulated oocyte

and provide a site where fertilization can occur

• Each of the fallopian tubes is about 10 cm long

• There is little or no actual contact between the fallopian tubes and the ovaries

Fallopian tubes• The distal end of each fallopian

tube is expanded and has fingerlike projections called fimbriae:

- As an oocyte is expelled from an ovary during ovulation, the waving fimbriae create fluid currents that carries oocyte into the uterus

- The oocyte is carried toward the uterus by a combination of peristalsis and rhythmic beating of cilia

Fertilization • The usual site of

fertilization is the fallopian tube

• To reach the oocyte, sperm must swim upward through the vagina and uterus to reach the fallopian tube

Uterus• It is located in the

pelvis between the urinary bladder and rectum

• Function: to receive, retain, and nourish a fertilized egg

• No pregnancy: It is about the size and shape of a pear

Uterus

• The major portion of the uterus is referred to as the body

• Its superior rounded region above the entrance of the fallopian tube is the fundus

• Its narrow outlet which protrudes into the vagina below is the cervix

Uterus• The wall of the uterus is thick and composed of 3

layers:- endometrium: inner layer- Myometrium: bulky middle muscle layer- Epimetrium: outermost layer

Endometrium

• If fertilization occurs:- The fertilized egg implant itself

into the endometrium of the uterus and resides there for the rest of its development

• When a woman is not pregnant:- The endometrial lining is brushed

off periodically, usually about every 28 days, in response to changes in the levels of ovarian hormones in the blood (menses)

Ovulation 2 Video

• https://www.youtube.com/watch?v=NkLUA05ExHA

Myometrium

• Myometrium: - It is composed of

interlacing bundles of smooth muscle

- The myometrium plays an active role during the delivery of a baby

Vagina• It is a thin-walled tube 8 to 10

cm long• It lies between the bladder

and rectum and extends from the cervix to the body exterior

• The distal end of the vagina is partially closed by a thin fold of the mucosa called the hymen:

- The hymen is very vascular and tends to bleed when it is ruptured

External Genitalia

• Includes:- Mons pubis- Labia- Clitoris- Urethra- Vaginal orifice- Greater vestibular glands

Vestibular glands

• A pair of mucus-producing glands• Their secretion lubricates the distal end of the

vagina

Clitoris

• A small protruding structure that corresponds to the male penis

• Like the penis, it is hooded by a prepuce and is composed of sensitive erectile tissue

• The clitoris differs from the penis in that it lacks reproductive duct

Perineum• The diamond shaped region between the

posterior end of the labial folds and the anterior end of the anus is the perineum