Health & Living
Female Reproductive System
Whether you’re 12 and starting your first period or 30 and expecting your first child, the female reproductive system plays a constant role in your life. It controls physical and emotional changes in life and even produces new life.
Anatomy
The primary reproductive organ in a female is the ovary, however the system is also comprised of secondary organs such as the uterus, vagina, clitoris, and labias minora and majora. The ovary produces eggs and hormones and is the site of ovulation in the body. The uterus is a thick-walled, pear-shaped muscular pouch that opens into the vagina over the bladder. It is made up of three layers; necrosis of the innermost layer, the endometrium, causes menstrual flow. The vagina allows for discharge of menstrual fluid and semen, receipt of penis, and birth of baby.
Puberty and Periods
Puberty begins around ages nine to ten and is triggered by the release of Gonadotropin Releasing Hormone (GnRH), which stimulates the anterior pituitary to produce Follicle Stimulating Hormone (FSH and Luteinizing Hormone (LH). Follicles develop and being to secrete estrogen and progesterone. This causes the development of breasts, growth of pubic and auxiliary hair, and periods. As you age, your body goes through menopause, which is the cessation of menstrual cycles. Oogenesis is the monthly event that produces a haploid egg by meiosis. This sexual cycle averages 28 days. The follicular phase lasts about two weeks and is when menstruation occurs during the first three to five days of the cycle. The uterus replaces lost endometrium and follicles grow. The next stage is the luteal phase, which also lasts two weeks and is when the corpus luteum stimulate endometrial thickening.
Breast Cancer
Breasts are comprised of the nipple, areola, and suspensory ligaments. 1 out of 8 American woman will develop breast cancer in heir lifetime. Symptoms of this cancer include: palpable lumps, skin puckering, skin texture, and drainage from nipple. Most breast cancer is nonhereditary and may be stimulated by estrogen. Risk factors include: aging, ionizing radiation, carcinogenic chemicals, alcohol, and fat intake. However, 70% of women lack these risk factors. It is important to get breasts exams regularly from your doctor.
Pregnancy
Gestation or pregnancy averages 266 days, however birth is predicted 280 days from LMP. It is timed by trimesters comprising of three three-month intervals. During pregnancy, certain hormones are secreted, such as progesterone, which prevents mensuration, and estrogens that cause breast enlargement. Pregnancy affects almost all of the other systems in the body, producing side effects such as nausea, constipation, heartburn, weight gain, increased respiration and cardiac output, and stretch marks. During labor, the cervix starts to dilation until they reach ten centimeters, the diameter of the baby’s head. Next comes expulsion where the baby’s head enters the vagina until delivery, and finally placental where the uterine contracts to continue to causing placental separation. When born, the fetus is then called a neonate until it reaches 6 weeks old.
Male Reproductive System
Reproduction cannot take place without the male reproductive system. The male and female reproductive system work together to ensure that fertilization can occur. The male counterpart contributes sperm that is present in the semen. Read on to find out how the male body ensures that reproduction can occur…
The Awkward Years
Puberty is known to be an awkward period of time in a person’s life due to the “hormones.” It is defined as first few years of adolescence until the first ejaculation of viable sperm. During this time, the body is going through some changes. The growth of sex organs, the first visible sign of puberty, involves the enlargement of the testes and scrotum. The body also experiences a growth spurt due to the presences of testosterone which stimulates elongation of long bones. It also causes the skin to become darker and deeper, and produce sebum which can lead to acne. Testosterone causes the larynx, also known as the voice box, to increase in size, deepening the voice. At this point in life, hair begins to grow on the face, armpit, and the pubic area. Testosterone awakens libido, or sex drive, causing ejaculations or erections occur during sleep.
Anatomy of the Male Reproductive System
The male reproductive system is composed of primary sex organs and secondary sex organs. Primary sex organs produce gametes, or sex cells. An example of a primary sex organ would be the testes. Within the testes are the seminiferous tubules which produces sperm. Interstitial cells secrete testosterone while sustentacular cells secrete androgen binding proteins needed to regulate sperm production. Sustentacular cells also protect germ cells and promote their development. The blood testes barrier are tight junctions between the adjacent sustentacular cells that prevents antibodies and large molecules in the blood from getting to the germ cells. The testes is enclosed in a pouch of skin called the scrotum. The scrotum is divided by the median septum. The scrotum helps keep the body warm through the cremaster muscle, dartos muscle, and pampiniform plexus. The cremaster muscles draws the tested closer to keep the body warmer. The dartos muscle helps retain body heat by making it taut and wrinkled. Increasing the surface area. The pampiniform plexus removes heat from descending arterial blood.
The testes achieves the function of reproduction along with the secondary sex organs, such as the ducts, glands, and penis. The spermatic duct consists of the duct of epididymis and the ejaculatory duct. The duct of epididymis is the site of sperm maturation and storage. The ejaculatory duct passes through the prostate and empties into the urethra. The seminal vesicles empties into the ejaculatory duct. The prostate gland surrounds the urethra and ejaculatory duct and empty through pores in urethral wall. The bulbourethral glands produce a clear slippery fluid that lubricates the head of the penis.
The penis serves to deposit semen into the vagina. The root is internal and the shaft and glans are visible. The skin around the penis is known as prepuce. The prepuce is attached through the frenulum. The glans is located at the head and distal end of the penis. The penis is composed by three erectile tissues, the copus spongiosum, corpus carvernosum, and the tunica albuginea. These tissues contains lacunae and trabeculae within the lacunae. The corpora cavernosa diverge to attach the penis to the pubic arch. Each divergence is called the crus.
How Sperm is made
Spermatogenesis is the process of sperm production, dividing and remodeling the large germ cells into flagella. Meiosis is the process of cell division that allows different genes to be exchanged, reduce the chromosome number by half, and produce 4 daughter cells. The first stem cell destined to become sperm is known as primordial germ cells. The primordial germ cell becomes spermatogonia when the primordial germ cell crawls into the embryo. The spermatogonia divides and the type b spermatocyte migrates into the blood testes barrier until it goes through meiosis to to produce secondary spermatocytes. Spermatids transform into a single spermatozoon. The spermatozoon contains nucleus that had chromosomes, an acrosome that contains enzymes, and the basal body. The tail is divided into three regions, the midpiece, principal piece, and the endpiece. Semen is fluid expelled during orgasm and has a sperm count of 50 to 120 sperm per mL.
