Zoology · Ch 7 — Human Reproduction
The Female Reproductive System
The Female Reproductive System
The female reproductive system is designed to carry out several functions: produce the female gamete (the ovum), receive the male gamete (the sperm), provide a suitable environment for fertilisation and the development of the foetus, and deliver the baby at the end of pregnancy. Every part of this system has a specific role in this sequence.
The system consists of a pair of ovaries, a pair of oviducts (also called fallopian tubes), the uterus, the cervix, the vagina, and the external genitalia. A pair of mammary glands (breasts) are also functionally part of the system.
Ovaries are the primary female sex organs. They are a pair of oval, almond-shaped structures located one on each side of the uterus, inside the pelvic cavity. Each ovary is about 2–4 cm long. The ovary produces the female gamete (ovum) and also secretes the female sex hormones — oestrogen and progesterone.
Oviducts (Fallopian tubes) are a pair of narrow, muscular tubes that run from the ovary to the uterus. The part of the oviduct closest to the ovary is funnel-shaped and is called the infundibulum. The infundibulum has finger-like projections called fimbriae that help collect the ovum released from the ovary. The infundibulum leads into the wider part of the tube called the ampulla, and the ampulla then joins the isthmus, which is the narrower part that connects to the uterus. Fertilisation of the ovum by a sperm typically occurs in the ampulla of the oviduct.
Uterus is a single, hollow, pear-shaped, muscular organ. It is also called the womb. The uterus is located in the pelvic cavity between the urinary bladder and the rectum. Its wall has three layers:
- Perimetrium — the thin outer covering.
- Myometrium — the thick middle layer made of smooth muscle. This layer contracts strongly during childbirth to push the baby out.
- Endometrium — the inner glandular lining. This layer undergoes cyclic changes during the menstrual cycle and is the site where the embryo implants and develops. If implantation does not occur, the endometrium is shed during menstruation.
The uterus opens into the vagina through a narrow canal called the cervix. The cervix has a small opening called the cervical os.
Vagina is a muscular, elastic, tubular structure that extends from the cervix to the outside of the body. It serves as the birth canal (the passage through which the baby is delivered), as the receptacle for the penis during coitus, and as the passage for the outflow of menstrual blood.
External genitalia include the following structures:
- Mons pubis — a cushion of fatty tissue covered by skin and pubic hair, located over the pubic symphysis.
- Labia majora — two large, fleshy folds of skin that enclose and protect the other external structures.
- Labia minora — two smaller, hairless folds of skin located inside the labia majora.
- Clitoris — a small, erectile, finger-like structure located at the upper junction of the labia minora. It is homologous to the penis in males and is highly sensitive.
- Vestibule — the space enclosed by the labia minora. The openings of the vagina and the urethra lie in the vestibule.
- Hymen — a thin membrane that partially covers the opening of the vagina in some females. It is often torn during the first sexual intercourse, but it can also be torn by other physical activities such as sports or cycling. Its presence or absence is not a reliable indicator of virginity. …
Drawn by us to help you understand the concept clearly, and verified to make sure it's accurate. For exams, practice from your textbook's own diagram.
Figure 2.3 is a two-panel diagram that gives you two complementary views of the female reproductive system — one from the side (sagittal) and one from the front (frontal). Together, they build a complete mental picture of how these organs sit inside the pelvis and how they connect.
Panel (a) is a mid-sagittal section of the female pelvis. Imagine cutting the body exactly down the midline, from front to back, and looking at the cut surface. This view shows the reproductive organs in relation to the bladder (anterior) and the rectum (posterior). The uterus is shown in its normal position — tilted forward (anteverted) over the bladder. The vagina runs downward and forward, opening to the exterior. You can see the cervix projecting into the vagina. This panel is crucial for understanding the spatial relationships: the uterus sits between the bladder and rectum, and the vagina lies behind the urethra.
Panel (b) is a frontal (coronal) sectional view — as if you sliced the body from side to side and looked from the front. This is the view that shows the paired nature of the system. You see:
- Ovaries — one on each side, almond-shaped, the sites of egg production.
- Fallopian tubes (oviducts) — each tube has three distinct parts: the infundibulum (the funnel-shaped end near the ovary, fringed with fimbriae that sweep the egg in), the ampulla (the wider middle section where fertilisation usually occurs), and the isthmus (the narrow part that joins the uterus).
- Uterus — a pear-shaped, thick-walled muscular organ. The wall is shown with its three layers: the outer perimetrium, the middle myometrium (the thick muscle layer responsible for contractions during labour), and the inner endometrium (the lining that builds up and sheds during menstruation).
- Cervix — the lower, narrow part of the uterus that opens into the vagina.
- Vagina — the muscular canal leading from the cervix to the outside.
Arrows or labels in the figure typically trace the path of the egg: from the ovary, into the infundibulum, through the ampulla and isthmus, and into the uterine cavity. The figure also makes clear that the two ovaries and tubes are mirror images on the left and right sides. …
Drawn by us to help you understand the concept clearly, and verified to make sure it's accurate. For exams, practice from your textbook's own diagram.
The figure is a vertical cross-section through the mammary gland, showing its internal structure from the chest wall to the nipple. The gland is embedded in a thick layer of adipose tissue (fat), which gives the breast its shape and cushions the functional parts.
The glandular tissue is organised into mammary lobes — these are the major subdivisions visible in the section. Within each lobe, the actual milk-producing units are clusters of alveoli. Each alveolus is a tiny, sac-like structure lined with milk-secreting cells. The alveoli in a cluster drain into small mammary tubules. These tubules from within a lobe converge to form a larger mammary duct.
As the mammary ducts approach the nipple, each one widens into a mammary ampulla — a temporary storage chamber for milk. From the ampulla, a lactiferous duct continues and opens directly at the tip of the nipple. The nipple itself is the external projection through which milk is released.
The figure also shows the areola, the pigmented circular area surrounding the nipple. The overall layout is radial: the lobes are arranged like spokes around the nipple, and the duct system funnels milk from the deep alveoli outward to the surface. …