NCMA217 WEEK 2-PART2 - Copy.docx

***Part two*** **MALE EXTERNAL STRUCTURES** **Scrotum** - - - **Testes** - - - - **Penis** - - - - - The circumcised penis' prepuce is retrated, while in uncircumcised, it is still covered. **MALE INTERNAL STRUCTURES** **Epididymis** - - Sperm are immobile...

***Part two*** **MALE EXTERNAL STRUCTURES** **Scrotum** - - - **Testes** - - - - **Penis** - - - - - The circumcised penis' prepuce is retrated, while in uncircumcised, it is still covered. **MALE INTERNAL STRUCTURES** **Epididymis** - - Sperm are immobile and incapable of fertilization as they pass through or are stored at the epididymis level. **[12 to 20 days] sperm travels** **[65 to 75 days] to reach full maturity.** **The Vas Deferens (Ductus Deferens)** - - **The Seminal Vesicles** - - - **Ejaculatory Ducts** - **The Prostate Gland** - The prostate is a **chestnut-sized gland** that lies just below the bladder and **allows the urethra to pass through the center of it,** like the hole in a **doughnut**. - **PURPOSE** is **to secrete a thin, alkaline fluid**, which, when added to the secretion from the seminal vesicles, further **protects sperm by increasing the naturally low pH level of the urethra.** **The Bulbourethral Glands** - Two bulbourethral, or **Cowper\'s, glands** lie beside the prostate gland and empty by short ducts into the urethra. - They **supply one more source of alkaline fluid** to help ensure the safe passage of spermatozoa. **Semen** - prostate gland (60%), - the seminal vesicles (30%), - the epididymis (5%), - and the bulbourethral glands (5%). **Urethra** - A **hollow tube** leading from the **base of the bladder,** which, after passing through the prostate gland, continues to the outside through the shaft and glans of the penis. - It is about **8 in. (18 to 20 cm) long.** **FEMALE REPRODUCTIVE SYSTEM** **Mons Veneris** - A pad of adipose tissue located over the symphysis pubis, the pubic bone joint. - Covered by a **triangle of coarse, curly hairs** - purpose **protect the junction of the pubic bone from trauma.** **Labia Minora** - Two hairless folds of connective tissue, - **Before menarche,** these folds are **fairly thin;** - **by childbearing age,** they have become **firm and full;** - after **menopause**, **they atrophy and again become much smaller.** Normally, the folds of the labia minora are **pink in color**; the internal surface is covered with mucous membrane, and the external surface is covered with skin.  **Labia Majora** - **two folds of tissue,** positioned lateral to the labia minora and composed of loose connective tissue **covered by epithelium and pubic hair.** - It serves as **protection** for the external genitalia; - they **shield** the outlets to the urethra and vagina. **OTHER EXTERNAL ORGANS** The **vestibule** is the flattened, smooth surface inside the labia. **The clitoris** is a small (**approximately 1 to 2 cm**), rounded organ of erectile tissue at the forward junction o of the labia minora. It\'s covered by a fold of skin, the prepuce; is sensitive to touch and temperature; and is the **center of sexual arousal and orgasm in a woman.** In nations which allow it, young girls approaching puberty may be **circumcised** or have their clitoris removed with the labia minora excised as well. Aside from being a very painful procedure, **female circumcision** can lead to contractions and scarring of the vulva that make vaginal childbirth difficult because the vagina is unable to expand with birth **Two Skene glands (paraurethral glands)** are located on each side of the **urinary meatus**; their ducts open into the urethra. **Bartholin glands (vulvovaginal glands)** are located on each side of the **vaginal opening** with ducts that open into the proximal vagina near the labia minora and hymen. The **fourchette** is the ridge of tissue formed by the posterior joining of the labia minora and the labia majora. This is the structure that sometimes **tears (laceration) or is cut (episiotomy) during childbirth to enlarge the vaginal opening.**  **Hymen** - a tough but elastic semicircle of tissue that covers the opening to the vagina during childhood. It is often torn during the time of first sexual intercourse. However, because of the use of tampons and active sports participation, many girls who have not had sexual relations can also have torn hymens at the time of their **first pelvic examination.** Occasionally, a girl has an **imperforate hymen**, or a hymen so complete that it does not allow for the passage of menstrual blood from the vagina (hematocolpometra) or for sexual relations until it is surgically incised. **Vulvar Blood Supply** - disadvantage of this rich blood supply is that trauma to the area, such as occurs from pressure during childbirth or a bicycle seat injury, can cause large hematomas. - advantage is that it contributes to the rapid healing of any tears in the area after childbirth or other injury **Vulvar Nerve Supply** - rich nerve supply makes the area extremely sensitive to touch, pressure, pain, and temperature. Luckily, at the time of birth**, normal stretching of the perineum causes a temporary loss of sensation to the area**, limiting the amount of local pain felt during childbirth. **INTERNAL STRUCTURE** **Ovaries** - Function of the two ovaries is to **produce, mature, and discharge ova (the egg cells).** - In the process of producing ova, the ovaries also produce estrogen and progesterone **and initiate and regulate menstrual cycles,** **Fallopian Tubes** - This open pathway is what makes conception possible. - It also, however, can lead **to infection of the peritoneum** (peritonitis) if germs spread from the perineum through the uterus and tubes to the pelvic cavity. - Clean technique must be used during pelvic examinations. - During labor and birth, **vaginal examinations** are done with **sterile technique to** ensure no organisms can enter by this route. **Uterus** - With maturity, a uterus is about **5 to 7 cm long**, 5 cm wide, and, in its widest upper part, 2.5 cm deep. - In a **nonpregnant state**, it weighs approximately **60 g.** - Receives the ovum from the fallopian tube; provide a place for implantation and nourishment; furnish protection to a growing fetus; and, at maturity of the fetus, expel it from a woman\'s body. **After a pregnancy,** the uterus never returns to exactly its nonpregnant size but remains approximately 9 cm long, 6 cm wide, 3 cm thick, and 80 g in weight. **THREE DIVISIONS OF THE UTERUS** **During pregnancy**, the body of the uterus is the portion of the structure that expands to contain the growing fetus.\\ 1. **Fundus** - Between the **points of attachmen**t of the fallopian tubes. 2. **Isthmus** - Short segment between the **body and the cervix** - Most commonly cut when a fetus is born by a cesarian birth - Nonpregnant uterus: 1 to 2mm in length 3. **Cervix** - The **lowest portion of the uterus** - One third of the total uterus size and is approximately 2 to 5mm long **LAYERS OF THE UTERUS** 1. **Perimetrium** - a part of visceral peritoneum 2. **Myometrium** - bulk of uterus\-- three layers of muscle that contract under influence of oxytocin during labor. 3. **Endometrium** - highly vascular mucosa - **Stratum functionalis** - shed during menstruation - **Stratum basalis** - deeper, permanent layer, gives rise to new stratum functionalis **Uterine Deviations** - A number of uterine deviations (i.e., shape and position) can interfere with fertility or pregnancy and so are helpful to recognize. \(A) **normal** uterus. \(B) **bicornuate** uterus. \(C) **septum-dividing** uterus. \(D) **double** uterus. Abnormal shapes of uterus allow less placenta implantation space. Ordinarily, the body of the uterus tips slightly forward. **Positional deviations** A. **Anteversion**: The entire uterus tips **far forward.** B. **Anteflexion:** The body of the uterus is **bent sharply forward** at the **junction with the cervix.** C. **Retroversion**: The entire uterus **tips far back.** D. **Retroflexion** The body of the uterus is **bent sharply back** just above the cervix. **Vagina** - FUNCTION : act as the **organ of intercourse** andto convey sperm to the cervix. - With childbirth, it **expands** to serve as the birth canal. - The **folds** make the vagina **very elastic and able to expand** so much that at the end of pregnancy, a full-term baby can pass through without tearing. - Vaginal tears at childbirth tend to bleed profusely because of this rich blood supply. - The same rich blood supply, however, is also the reason any vaginal trauma at birth heals rapidly. **Breasts** - The **mammary glands, or breasts**, form early in **intrauterine life.** - They then remain in **a halted stage of development** until a rise in **estrogen** at puberty causes them to **increase in size** The **glandular tissue** of the breasts, necessary for **successful breastfeedin**g, remains undeveloped until **a first pregnancy begins.** **Milk glands** of the breasts are divided by connective tissue partitions into approximately **20 lobes.** All of the glands in each lobe produce milk by **acinar cells** and deliver it to the nipple via **a lactiferous duct.** **The nipple** has approximately **20 small** openings through which milk is secreted. **An ampulla portion of the duct**, located just posterior to the nipple, serves as a reservoir for milk before breastfeeding. During this time, mitotic cell division, or cleavage, begins. The first cleavage occurs at about **24 hours**; cleavage divisions continue to occur at a rate of about one every 22 hours.  **Blastocyst** - large cells tend to collect at the periphery of the ball, leaving a fluid space surrounding an inner cell mass. **Trophoblast** - cells in the outer ring are cells. - They are the part of the structure that will later form the placenta and membranes. **Embryoblast** - the inner cell mass is the portion of the structure that will form the embryo **Implantation** usually occurs high in the uterus on the posterior surface. If the point of implantation is **low in the uterus**, the growing placenta may occlude the cervix and make birth of the child difficult (placenta previa) because the placenta can block the birth canal. Almost immediately, the blastocyst burrows deeply into the endometrium and establishes an effective communication network with the blood system of the endometrium. Once implanted, the zygote is called an **embryo**. Implantation is an important step in pregnancy because **as many as 50% of zygotes never achieve it.** In these instances, the pregnancy ends as early as **8 to 10 days** after conception, often before a woman is even aware she was pregnant. Occasionally, **a small amount of vagina**l spotting appears on the day of implantation because capillaries are ruptured by the implanting trophoblast cells. A woman who normally has a particularly scant menstrual flow **could mistake implantation bleeding for her menstrual period.**