Care of Mother, Child, Adolescent (Well Clients) PDF

CARE OF MOTHER,CHILD, ADOLESCENT (WELL CLIENTS) The Reproductive System Female Reproduction Unlike males, who are able to produce sperm cells throughout their reproductive lives, females produce a finite number of egg cells. During early fetal development germ cells migrate into the ovaries and...

CARE OF MOTHER,CHILD, ADOLESCENT (WELL CLIENTS) The Reproductive System Female Reproduction Unlike males, who are able to produce sperm cells throughout their reproductive lives, females produce a finite number of egg cells. During early fetal development germ cells migrate into the ovaries and differentiate into oogonia Reproductive System The ovaries The ovaries are solid, ovoid structures, about 2 cm in length and 1 cm in width. Like the testes, they develop from embryonic tissue along the posterior abdominal wall, near the kidneys. Accessory organs include the uterine tubes, uterus, and vagina Reproductive System Oogonia The oogonia divide by mitosis for the next few months and some differentiate into primary oocytes. By fifth month there are about 7 million primary oocytes, but most will degenerate during the next 2 months Reproductive System Oogonia Those that remain will be surrounded by a single layer of squamous epithelial cells (follicle cells) called a primordial follicle. Degeneration of primary oocytes continues. At birth =1million primordial follicles At puberty 400,000 remain Only 400-500 will reach maturity Reproductive System Oogonia Each follicle consists of an immature egg called an oocyte  Cells around the oocyte are called: Follicle cells (one cell layer thick) Stimulated to mature by FSH from the pituitary gland Granulosa cells (when more than one layer is present) Thecal cells: Cells in the ovarian stroma Thecal & granulosa cells work together to produce estrogen A protective layer of glycoprotein forms around the egg called the zona pellucida Reproductive System Follicle development Primordial follicle: one layer of squamous-like follicle cells surrounds the oocyte Primary follicle: two or more layers of cuboidal granulosa cells enclose the oocyte Secondary follicle: has a fluid-filled space between granulosa cells that coalesces to form a central antrum Graafian follicle: secondary follicle at its most mature stage that bulges from the surface of the ovary Corpus luteum : ruptured follicle after ovulation The Breasts The breast is the tissue overlying the chest (pectoral) muscles. Breasts are made of specialized tissue that produces milk (glandular tissue) as well as fatty tissue. The amount of fat determines the size of the breast. The milk-producing part of the breast is organized into 15 to 20 sections, called lobes. Within each lobe are smaller structures, called lobules, where milk is produced. The milk travels through a network of tiny tubes called ducts. The ducts connect and come together into larger ducts, which eventually exit the skin in the nipple. The dark area of skin surrounding the nipple is called the areola. The Breasts Mammary glands Modified sweat glands that produce milk (lactation) Milk-secreting glands open by lactiferous ducts at the nipple Mammary line is a thickened ridge of embryonic tissue that extends from the axilla to the groin. Hormones of the breasts Prolactin from the pituitary gland stimulates the synthesis of milk Oxytocin from the posterior pituitary gland stimulates milk ejection Lymph glands - Lymph nodes draining the breast are located in the axilla. Hormones of the breasts Prolactin from the pituitary gland stimulates the synthesis of milk Oxytocin from the posterior pituitary gland stimulates milk ejection Lymph glands - Lymph nodes draining the breast are located in the axilla. IMPORTANT TERMS Menarche – first menstruation Puberty – transitional stage between childhood and sexual maturity. At around age 13. - age at which reproductive organs become functionally active Menopause – the cessation of menstrual cycle Post menopausal period – it is the time of life ff. menopause Perimenopausal – period during which menopausal change are occurring between 44 – 50 years old Menopause – the cessation of menstrual cycle Post menopausal period – it is the time of life ff. menopause Perimenopausal – period during which menopausal change are occurring between 44 – 50 years old Functions of the Male Reproductive System The two main functions of the male reproductive system are the production and storage of sperm and the transfer of sperm to the female’s body during sexual intercourse. Hormones produced in the pituitary gland stimulate the production of testosterone Testosterone initiates physical changes that signal maturity, including broadening of the shoulders, development of muscles and facial and other body hair, and deepening of the voice. Structure of the Male Reproductive System External structure: 1. Scrotum - a skin-covered, highly pigmented, muscular sack that extends from the body behind the penis; site of sperm production; protects the sperm by keeping the temperature in the testes slightly below normal 2. Penis - the male organ of copulation (sexual intercourse); penetrates into the vagina and deposit semen into the female reproductive tract. 3. Testes - the male gonads(the male reproductive organs); produce both sperm and androgens, such as testosterone, and are active throughout the reproductive lifespan of the male. A. seminiferous tubules - composed of developing sperm cells surrounding a lumen, the hollow center of the tubule, where formed sperm are released into the duct system of the testis B. Sertoli Cells – elongated branching cells that secrete signaling molecules that promote sperm production C. Germ Cells - The least mature cells, (spermatogonia), line the basement membrane inside the tubule; the stem cells of the testis, that are still able to differentiate into a variety of different cell types throughout adulthood. Structure of the Male Reproductive System Internal structure: 1. Epididymis: a coiled tube attached to the testis where newly formed sperm continue to mature Internal Structure 2. vas deferens - a thick, muscular tube that is bundled together inside the scrotum with connective tissue, blood vessels, and nerves; site where complete maturation of sperm takes place 3. Seminal vesicles - glands that contribute approximately 60 percent of the semen volume. Seminal vesicle fluid contains large amounts of fructose, which is used by the sperm mitochondria to generate ATP to allow movement through the female reproductive tract. 4. Ejaculatory duct - a short structure formed from the ampulla of the ductus deferens and the duct of the seminal vesicle; transport the seminal fluid into the prostate gland. Internal Structure 5. Prostate gland - formed of both muscular and glandular tissues; excretes an alkaline, milky fluid to the passing seminal fluid—now called semen 6. Bulbourethral glands (Cowper’s glands) - release a thick, salty fluid that lubricates the end of the urethra and the vagina, and helps to clean urine residues from the penile urethra Spermatogenesis Spermatogenesis is the process by which male primary sperm cells undergo meiosis and produce a number of cells calls spermatogonia, from which the primary spermatocytes are derived. Each primary spermatocyte divides into two secondary spermatocytes and each secondary spermatocyte into two spermatids or young spermatozoa. These develop into mature spermatozoa, also known as sperm cells. Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, which in turn produce four spermatozoa 1. Spermatocytogenesis Mitotic division of a diploid spermatogonium that resides in the basal compartment of the seminiferous tubules, resulting in two diploid intermediate cells called primary spermatocytes. Each primary spermatocyte then moves into the adluminal compartment of the seminiferous tubules, duplicates its DNA, and subsequently undergoes meiosis I to produce two haploid secondary spermatocytes. Secondary spermatocytes later divide into haploid spermatids. During this division, random inclusion of either parental chromosome and chromosomal crossover both increase the genetic variability of the gamete. Each cell division from a spermatogonium to a spermatid is incomplete; the cells remain connected to one another by bridges of cytoplasm to allow synchronous development. Not all spermatogonia divide to produce spermatocytes; otherwise, the supply would run out. Instead, certain types of spermatogonia divide to produce copies of themselves, thereby ensuring a constant supply of gametangia to fuel spermatogenesis. 2. Spermatidogenesis The creation of spermatids from secondary spermatocytes. Secondary spermatocytes produced earlier rapidly enter meiosis II and divide to produce haploid spermatids. The brevity of this stage means that secondary spermatocytes are rarely seen in histological preparations. 3. Spermiogenesis spermatid begins to grow a tail and develop a thickened midpiece where the mitochondria gather and form an axoneme. Spermatid DNA also undergoes packaging, becoming highly condensed. The DNA is packaged with specific nuclear basic proteins, which are subsequently replaced with protamines during spermatid elongation. The resultant tightly packed chromatin is transcriptionally inactive.  The Golgi apparatus surrounds the now condensed nucleus, becoming the acrosome. One of the centrioles of the cell elongates to become the tail of the sperm. The non-motile spermatozoa are transported to the epididymis in testicular fluid secreted by the Sertoli cells with the aid of peristaltic contraction. While in the epididymis, the spermatozoa gain motility and become capable of fertilization. However, transport of the mature spermatozoa through the remainder of the male reproductive system is achieved via muscle contraction rather than the spermatozoon’s recently acquired motility. Maturation takes place under the influence of testosterone, which removes the remaining unnecessary cytoplasm and organelles. The excess cytoplasm, known as residual bodies, is phagocytosed by surrounding Sertoli cells in the testes. The resulting spermatozoa are now mature but lack motility, rendering them sterile. The mature spermatozoa are released from the protective Sertoli cells into the lumen of the seminiferous tubule in a process called spermiation.