Mons Pubis Anatomy

Chapter 2 Human Reproductive Anatomy and Physiology This chapter addresses the male and female reproductive systems Puberty A period of rapid change in the lives of boys and girls during which the reproductive systems mature and become capable of reproduction. Secondary sexual characteristics appear (pubic hair). Ends when mature sperm are formed or when regular menstrual cycles occur. Male Male hormonal changes normally begin between 10 and 16 years of age. Outward changes become apparent when the size of the penis and testes increases and there is a general growth spurt. Testosterone, the primary male sex hormone, causes the boy to grow taller, become more muscular, and develop secondary sex characteristics such as public hair, facial hair, and a deeper voice. The voice deepens but is often characterized by squeaks or cracks before reaching its final pitch. Testosterone levels are constant, not cyclical as are female hormones, although levels may decrease with age to 50% of peak levels by age 80. Nocturnal emissions (wet dreams) may occur without sexual stimulation, however these emissions do not contain sperm. Female The first outward change of puberty in females is development of the breasts. The first menstrual period (menarche) occurs 2 to 2 years later (age 11 to 15). Female reproductive organs mature to prepare for sexual activity and childbearing. The female experiences a growth spurt, but her growth spurt ends earlier than the male's. Here hips broaden as her pelvis assumes the wide basin shape needed for birth. Pubic and axillary hair appear. The quantity varies, as it does in males. Reproductive Systems Male Consists of external and internal organs (figure 2-1, page 21) External Genitalia Penis and the scrotum, which contains the testes. Penis Consists of the glans and the body. The glans is the rounded, distal end of The penis. It is visible on a circumcised penis but is hidden by the foreskin on An uncircumcised one. Smegma is a cheese like sebaceous substance that Collects under the foreskin and is easily removed with basic hygiene. At the Tip of thee glans is an opening called the urethral meatus. Th body of the Penis contains the urethra (the passageway for sperm and urine) and Erectile tissue (the corpus spongiosum and the corpora cavernosa). The Usually flaccid penis becomes erect during sexual stimulation when blood Is trapped within the spongy erectile tissues. The erection allows the male to Penetrate the female's vagina during sexual intercourse. The penis has two Functions: 1). Provides a duct to expel urine from the bladder 2). Deposits Sperm in the female's vagina to fertilize an ovum. Scrotum A sac that contains the testes. It is suspended from the perineum, keeping The testes away from the body and thereby lowering their temperature, Which is necessary for normal sperm production (spermatogenesis). Internal Genitalia Includes the testes, vas deferents, prostate, seminal vesicles, ejaculatory ducts, Urethra, and accessory glands Testes (testicles) A pair of oval glands housed in the scrotum. They have two functions: 1. Manufacture male germ cells (spermatozoa or sperm) 2. Secrete male hormones (androgens) Sperm are made in the convoluted seminiferous tubules that are contained Within the testes. Sperm production begins at puberty and continues Throughout the life span of the male. The production of testosterone begins with the anterior pituitary gland. Under the direction of the hypothalamus, the anterior pituitary gland Secretes follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Both initiate the production of testosterone in the Leydig cells of the testes. Testosterone has the following effects not directly related to sexual Reproduction: 1. Increases muscle mass and strength 2. Promotes growth of long bones 3. Increases basal metabolic rate (BMR) 4. Enhances production of red blood cells 5. Produces enlargement of vocal cords 6. Affects the distribution of body hair These effects result in the greater strength and stature and a higher Hematocrit level in males than in females. Testosterone also increases The production of sebum, a fatty secretion of the sebaceous glands of the Skin, and it may contribute to the development of acne during early Adolescence. As the skin adapts to the higher levels of testosterone, acne Generally recedes. Ducts Each epididymis, one from each testicle, stores and carries the sperm to the Penis. The sperm may remain in the epididymis for 2 to 10 days, during Which time they mature and then move on to the vas deferents. Each vas Deferents passes upward into the body, goes around the symphysis pubis, Circles the bladder, and passes downward to form (with the ducts from the Seminal vesicles) the ejaculatory ducts. The ejaculatory ducts then enter the Back of the prostate gland and connect to the upper part of the urethra, Which is in the penis. The urethra transports both urine from the bladder And semen from the prostate gland to the outside of the body, although Not at the same time. Accessory Glands Seminal vesicles, the prostate gland, and the bulbourethral glands, also Called Cowper's glands. The accessory glands produce secretions (seminal plasma). The secretions of These glands have three functions: 1. Nourish the sperm 2. Protect the sperm from the acidic environment of the woman's vagina 3. Enhance the motility (movement) of the sperm The combined seminal plasma and sperm are called semen. Semen may be Secreted during sexual intercourse before ejaculation. Therefore pregnancy May occur even if ejaculation occurs outside the vagina. Increased heat in the environment around the sperm(testes) increases the motility but shortens the lifespan of the sperm. A constant increase in temperature around the testes can prevent spermatogenesis and lead to permanent sterility. Female Female reproductive system consists of external genitalia, internal genitalia, And accessory structures such as the mammary glands (breasts). External Genitalia External genitalia are collectively called the vulva. They include the mons pubis, Labia Majorca, labia minor a, four heat, clitoris, vaginal vestibule, and Perineum. Mons Pubis (mons Veneris) is a pad or fatty tissue covered by coarse hair and Skin.It protects the symphysis pubis and contributes to the rounded contour Of the female body. Labia Majora are two folds of fatty tissue on each side of the vaginal vestibule. Many small glands are located on the moist interior surface. Labia Minora are two thin, soft folds of tissue that are seen when the labia Majora are separated. Secretions from sebaceous glands in the labia are Bactericidal to reduce infection and also lubricate and protect the skin of the Vulva. Fourchette is a fold of tissues just below the vagina, where the labia Majora And the labia minora meet. It is also known as the obstetrical perineum. Lacerations in this area often occur during childbirth. Clitoric is a a small, erectile body in the most anterior portion of the labia Minora. It is similar in structure to the penis. Functionally, it is the most erotic Sensitive part of the female genitalia, and it produces smegma. Smegma is a Cheese like secretion of the sebaceous glands. Vaginal Vestibule is the area seen when the labia minora are separated and Includes five structures: 1. Urethral meatus- lies approximately 2 cm below the clitoris. It has a Foldlike appearance with a slit type opening, and it serves as the exit for urine. 2. Skene's ducts-(paraurethral ducts) are located on each side of the urethra and provide lubrication for the urethra and the vaginal orifice. 3. The vaginal introitus is the division between the external and internal female genitalia. 4. The hymen is a thin elastic membrane that closes the vagina from the Vestibule to various degrees. 5. The ducts of the Bartholin glands provide lubrication for the vaginal introitus during sexual arousal and are normall not visible. Perineum is a strong, muscular are between the vaginal opening and the anus. The elastic fibers and connective tissue of the perineum allow stretching to permit the birth of a full-term infant. The perineum is the site of the episiotomy (incision) if performed or potential tears during childbirth. Pelvic weakness or painful intercourse (dyspareunia) may result if the tissue does not heal properly. Internal Genitalia Are the vagina, uterus fallopian tubes, and ovaries.