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A&P final
| Question | Answer |
|---|---|
| Chapter 15 the male reproductive system | |
| Word roots and combining forms | |
| Andr/o - male | |
| Crypt/o - hidden | |
| Epididym/o - epididymis | |
| Orch/o, orchi/o, and orchid/o - testes testicles | |
| Pen/o - penis | |
| Prostat/o - prostate | |
| Semin/i - semen | |
| Sperm/o, and Supermat/o - sperm | |
| Test/o - testis testicle | |
| Vas/o - duct vas deferens | |
| Overview | |
| All humans start from a zygote | |
| Gender is determined by the 23rd pair of chromosomes which are the sex chromosomes | |
| All eggs are an X chromosome the sperm can be x or y so the sex of the child is determined by the sperm of the father | |
| The sry gene on the Y chromosome codes for a protein so that androgen receptors are produced in a male fetus | |
| Testosterone and androgen receptors are needed in the fetus for male anatomy to develop | |
| Male reproductive system | |
| Major organs | |
| Testes | |
| Accessory structures | |
| Scrotum | |
| Spermatic ducts | |
| Epididymis | |
| Ductus deferens | |
| Accessory glands | |
| Seminal vesicles | |
| Prostate gland | |
| Bulbourethral glands | |
| Penis | |
| Functions | |
| Production and delivery of sperm | |
| Secretion of sex hormones | |
| Male reproductive anatomy | |
| Testes | |
| Testes belong to the endocrine and reproductive systems because they produce testosterone and sperm | |
| Testes descend from the abdomen to the scrotum because of the gubernaculum | |
| The testes descend through an opening in the abdominal wall called the inguinal canal | |
| For the testes to produce viable sperm the temperature of each testis must be approximately 2 degrees celsius cooler than the core body temperature which is the reason for they descend into the scrotum | |
| Each testis has an outer fibrous capsule called the tunica albuginea | |
| Sperm are produced in the seminiferous tubules | |
| Interstitial cells located between seminiferous tubules produce testosterone | |
| Secondary sex organs and structures | |
| Scrotum | |
| Spermatic cord | |
| Spermatic duct | |
| Accessory glands | |
| Penis | |
| Secondary sex organs and structures | |
| Scrotum | |
| The testes are housed in the scrotum | |
| Dartos muscle - smooth muscle wall of the scrotum that reacts to temperature changes by contracting and relaxing | |
| If it’s warm it relaxes maximizing the space for the testes to keep them cool | |
| If it’s cool it contracts reducing the space in the scrotum to keep them warm | |
| Spermatic cord | |
| Suspends each testis and contains | |
| Cremaster muscle - outer layer of the spermatic cord that completely covers the testis regulates the temperature for the testes | |
| Ductus deferens - tube that carries sperm | |
| Testicular artery - carries warm blood to the testes | |
| Pampiniform plexus - cools the warm blood from the testicular artery | |
| Spermatic ducts | |
| Efferent ductules - carries sperm from the testes to the epididymis | |
| Epididymis - location of sperm maturation and storage | |
| Ductus deferens - merges with the seminal vesicle to form the ejaculatory duct | |
| Ejaculatory ducts - carries sperm from the ductus deferens to the urethra | |
| The 5 accessory glands in the male are | |
| 2 seminal vesicles - secretes a thick yellowish fluid mixture of sugar and protein that makes up 60% semen | |
| 1 prostate gland - surrounds the urethra inferior to the bladder that produces a thin whitish alkaline mixture containing prostaglandins that makes up 30% semen | |
| 2 bulburethral glands - produce a small amount of slightly alkaline lubricant that makes intercourse easier and neutralizes the ph of the male urethra | |
| Penis | |
| Penis has an internal root and an external shaft and glans | |
| Glands contain many nerve endings for sexual stimulation it’s covered by prepuce (foreskin) | |
| Prepuce is surgically removed during a circumcision | |
| Penis is composed of 3 columns of erectile tissue | |
| 2 columns of corpora cavernosa that have large spaces | |
| 1 column of corpus spongiosum that has smaller spaces | |
| Anatomy of a sperm | |
| Spermatozoon is a single cell with 2 principal parts - head and tail | |
| Head contains 23 chromosomes and use an enzyme-filled acrosome cap used to penetrate an egg | |
| Tail contains a midpiece (with large mitochondria) to supply ATP to energize the tail the function of the tail is to propel the sperm | |
| Physiology | |
| Testosterone production ceases a few months after birth and doesn’t resume until puberty | |
| Puberty begins with the production of FSH and LH at approximately 10-12 in body and it ends usually 2-4 years after puberty starts | |
| Hormone control at puberty | |
| FSH stimulates sustentacular cells in the seminiferous tubules to produce androgen-binding protein (ABP) | |
| ABP and testosterone are needed for testosterone to have an effect on sperm production | |
| LH stimulates interstitial cells to produce testosterone | |
| Male secondary sex characteristics | |
| Skeletal and muscle development | |
| Changes in the larynx that cause a deeper voice | |
| Development of axillary and pubic hair with activation of associated apocrine glands | |
| Development of facial hair and possible thickening of hair on the torso and limbs | |
| Aggression | |
| Development of the libido (sex drive) | |
| Sperm production | |
| Mitosis is a one-division process that forms all body cells | |
| Parent cell of 46 chromosomes replicates and divide to produce 2 daughter cells | |
| Each daughter cell has a set of 46 chromosomes that is identical to the other daughter cell set | |
| Meiosis is a two-division process that starts with a parent cell of 46 chromosomes | |
| Meiosis 1 - forms daughter cells with an independent assortment of chromosomes through crossing-over | |
| Meiosis 2 - 4 cells are produced each having half the number of chromosomes (haploid) as the original parent cell | |
| Sperm production involves 2 processes - spermatogenesis and sperminogenesis | |
| Spermatogenesis | |
| Produces 4 cells (each with 23 chromosomes) from a specialized stem cell with 46 chromosomes | |
| Male germ cell is known as spermatogonia | |
| Steps | |
| Spermatogonium near the basement membrane of the seminiferous tubule divides by mitosis producing 2 identical spermatogonia | |
| 1 remains (A) near the basement membrane to serve as a spermatogonium later | |
| The other spermatogonium (B) migrates slightly away from the wall toward the lumen of the seminiferous tubule it will continue on in the production process | |
| Spermatogonium B enlarges to become a primary spermatocyte | |
| Once protected by the blood-testis barrier the primary spermatocyte goes through meiosis 1 | |
| This produces two equal-size genetically unique secondary spermatocytes each having 23 chromosomes | |
| Each secondary spermatocyte undergoes meiosis 2 which produces in total 4 spermatids from the 1 original spermatogonium type b | |
| Spermiogenesis | |
| Sperm production transforms soermatids to functional sperm | |
| Each spermatid forms a tail and sheds its cytoplasm to become a sperm | |
| Goes to epididymis to mature | |
| Hormone control in the adult male | |
| Testosterone has a positive effect on many tissues but it also has a negative-feedback effect on the hypothalamus (by inhibiting GnRH) and the anterior pituitary (by reducing its sensitivity to GnRH) | |
| Sustentacular cells produce the hormone inhibin when they are busy with sperm production so that FSH from the anterior pituitary is inhibited | |
| Pathway for sperm | |
| Seminiferous tubules | |
| Rete testes | |
| Efferent ductules | |
| Epididymis | |
| Ductus deferens | |
| Ejaculatory ducts | |
| Urethra | |
| Outside the body | |
| Sexual response in the male | |
| 4 stages | |
| Arousal results in an erection neural signs cause the arteries in the penis to dilate so the penile erectile tissues fill with blood bulbourethral glands secrete their fluid | |
| Emission sperm moves by peristaltic contractions through the ductus deferens to its ampulla through the ejaculatory duct to the urethra prostate and seminal vesicles secrete their fluids | |
| Ejaculation orgasm occurs (increased heart rate and blood pressure) and sperm are forcefully expelled from the urethra | |
| Resolution excess blood is forced from the penis thus causing it to become flaccid arteries that bring blood to the penis are constricted | |
| Effects of aging | |
| Testosterone production peaks at 20 and decline from there so at 80 a male may make only 20% of the testosterone he produced at his prime | |
| Sperm production continues into old age | |
| Increased FSH and LH levels rise significantly after 50 producing andropause in which men can experience hot flashes and mood swings | |
| Erectile dysfunction occurs in about 20% of men in their 60s and increases to 50% of men in their 80s | |
| 80% of men have benign prostatic hyperplasia by 80 | |
| Enlargement of the prostate (grows toward the middle) that compresses the urethra and makes micturition difficult | |
| Common diagnostic tests | |
| Digital rectal exam - procedure in which the doctor inserts fingers into the rectum to detect any abnormalities | |
| Lab test/microscopic exam of samples - procedures that involve collecting urine or specimen samples from the urinary tract to determine the presence of viruses or bacteria that may cause infection | |
| PSA test - test the measures the presence of prostate-specific antigens in the blood increased levels may indicate prostate cancer | |
| Transrectal ultrasound and biopsy of the prostate - procedure in which ultrasound tech is used to assess the prostate for evidence of cancer if a mass is detected a sample is collected and examined by a lab for the presence of cancerous cells | |
| Ultrasound - cause of hydrocele examine a mass in the testis and diagnose epididymitis and cryptorchidism | |
| Male reproductive system disorders | |
| Prostate cancer | |
| 90% of men over 50 will develop prostate cancer | |
| Can be detected by a digital rectal exam and a blood test that measures PSA levels | |
| Testicular cancer | |
| Most common in white males between 15-34 | |
| Routine testicular self-exams are recommended for early detection | |
| Hypospadias is a congenital defect in which the urethra opens on the ventral side or base of the penis instead of on the tip of the glans | |
| Epididymitis - inflammation of the epididymis usually caused by a bacterial infection | |
| Phimosis - tight foreskin that can’t be pulled back over the glans penis | |
| Hydrocele - fluid has accumulated and causes swelling in the scrotum | |
| Male reproductive disorders | |
| Cryptorchidism - condition of undescended testes in male infants | |
| Chlamydia - std caused by the chlamydia trachomatis bacteria | |
| Gonorrhea - std caused by the neisseria gonorrhea bacteria | |
| Syphilis - std caused by the treponema pallium bacteria | |
| Infertility - inability to fertilize an egg | |
| Chapter 16 female reproductive system | |
| Word roots and combining forms | |
| amni/o - amnion | |
| cervic/o - cervix neck | |
| chorion/o - chorion | |
| episi/o - vulva | |
| gynec/o - female | |
| hyster/o - uterus | |
| lact/o - milk | |
| mamm/o - breast | |
| mast/o - breast | |
| men/o - menses menstruation | |
| metr/o, metri/o - uterus | |
| o/o and ov/o - egg | |
| oophor/o - ovary | |
| ovari/o - ovary | |
| ovul/o - egg | |
| salping/o - uterine tube | |
| uter/o - uterus | |
| vagin/o - vagina | |
| vulv/o - vulva | |
| Overview | |
| Female zygote has xx as the sex chromosome | |
| Without the SRY gene on the Y chromosome and therefore the lack of androgen receptors and testosterone a zygote develops female reproductive anatomy | |
| Ovaries produce ova and are therefore the primary sex organs of the female reproductive system | |
| Ovaries are enclosed in a capsule called the tunica albuginea | |
| Anatomy | |
| Ovaries | |
| Belong to the reproductive and endocrine systems | |
| Ovary has 2 layers - cortex containing follicles and a medulla containing blood vessels | |
| Ligaments suspend the ovaries in the pelvic cavity and anchor them to the uterus | |
| Broad ligament - extension of the peritoneum | |
| Ovarian ligaments- attaches the medial edge of the ovary to the uterus | |
| Suspensory ligament - attaches the lateral edge of the ovary to the posterior wall of the pelvic cavity | |
| Round ligament | |
| Secondary female reproductive organs and structures | |
| Ovaries uterus and vagina are internal | |
| Vulva and breasts are external | |
| Uterus is held in place by the broad and round ligaments and expands with pregnancy | |
| Thick wall has 3 layers | |
| Perimetrium - outer layer known as the visceral peritoneum | |
| Myometrium - thick layer of smooth muscle that contracts to expel uterine contractions | |
| Endometrium - inner lining made up of 2 sublayers | |
| Stratum basalis - deep ⅓ | |
| Stratum functionalis - superficial ⅔ | |
| Uterus has 3 regions | |
| Fundus - broad superior curve | |
| Body - wide mid portion | |
| Cervix - inferior (neck) region | |
| Uterine tubes transport eggs to the uterus | |
| Also called fallopian tube or oviduct | |
| Ends called infundibulum has fimbriae which coax the eggs into the uterine tube | |
| Lined by ciliated cells | |
| Vagina allows for the flow of the menses is a receptacle for sperm and serves as the birth canal | |
| External vaginal opening is covered by the hymen | |
| Lining is stratified squamous epithelial tissue | |
| Vulva includes the following | |
| Mons pubis - pubic hair cover mound of adipose tissue superficial to the pubic symphysis | |
| Labia - includes labia major and minora | |
| Frames the vestibule | |
| Clitoris | |
| Erectile tissue - external portion is glans | |
| Vestibular bulbs - erectile tissue in labia majora | |
| Vestibular glands - lubricating glands in posterior vestibule similar to the bulbourethral glands in the male | |
| Breasts contain mammary glands that don’t fully develop until the 1st pregnancy | |
| Process of producing milk called lactation | |
| Breast tissue supported by suspensory ligaments | |
| Dark skin around nipple called areola | |
| Small bumps in the areola are called areolar glands they secrete a substance to prevent chafing and cracking of the nipple during nursing | |
| Laciteferous ducts drain the milk from the breast | |
| Hormonal control of puberty | |
| Puberty begins between 8-10 for most girls | |
| Puberty begins when the GnRH from the hypothalamus stimulates the anterior pituitary to secrete FSH & LH | |
| FSH stimulates follicles in the ovaries to produce estrogen | |
| Estrogen is responsible for the development of female sex characteristics | |
| Female secondary sex characteristics | |
| Breast development | |
| Development of axillary (armpit) and pubic hair | |
| Widening of the pelvis | |
| Fat deposition | |
| Menstruation | |
| Physiology of the female reproductive system | |
| Oogenesis - egg production | |
| 1 haploid gamete is formed from each oogonium | |
| Follicle is responsible for carrying for an oocyte and producing hormones | |
| All oocytes have been produced from oogonia by birth | |
| Many oogonia and oocytes are lost by atresia | |
| Oogenesis is halted mid-meiosis 1 until puberty which means the primary oocyte remains dormant until adolescence | |
| Primary oocyte is diploid which means it has 46 chromosomes | |
| Secondary oocytes are formed each month | |
| Meiosis 1 also produces a polar body | |
| Meiosis 2 isn’t completed until an egg is fertilized | |
| Follicles develop along an oocyte | |
| Some primordial follicles develop each month after puberty | |
| Mature graafian follicles rupture to release an egg during ovulation | |
| After ovulation the follicle becomes a corpus luteum which secretes hormones to support the pregnancy if the egg is fertilized | |
| If the egg doesn’t become fertilized the corpus luteum stops secreting hormones within 2 weeks and becomes a corpus albicans | |
| Hormone control in the adult female | |
| Female reproductive cycle is typically 28 days and begins on the 1st day of a women’s period | |
| Composed of 2 parts | |
| Ovarian cycle - affects the oocytes in the ovary | |
| Menstrual cycle - affects the endometrial ring of the uterus | |
| Ovarian cycle has 2 phases | |
| Follicular phase days 1-14 | |
| Anterior pituitary secretes FSH which targets the primordial follicles to secrete estrogen | |
| Estrogen levels peak just before day 14 | |
| Luteal phase days 14-28 | |
| Ruptured follicle remains in the ovary and becomes a corpus luteum | |
| Corpus luteum secretes estrogen and progesterone which causes FSH & LH production to be inhibited (called negative feedback) | |
| Menstrual cycle has the following phases | |
| Menstrual day 1-5 | |
| Proliferative day 5-14 | |
| Estrogen is secreted by the follicle which targets the uterine lining to thicken | |
| Secretory days 14-26 | |
| High levels of estrogen and progesterone cause the lining of the uterus to thicken | |
| Endometrial glands secrete glycogen a nutritional source for the fertilized egg | |
| Premenstrual day 26-28 | |
| Estrogen and progesterone levels decrease causing PMS | |
| Ovulation typically occurs on day 14 | |
| So your cycles are determined by whether the egg is fertilized or not | |
| If the egg is fertilized it happens in the uterine tubes and the corpus luteum continues to secrete hormones | |
| If the egg isn’t fertilized the corpus luteum shrinks stops secreting hormones and turns into a corpus albicans | |
| Corpus luteum knows what to do because the fertilized egg secretes HCG this is the hormone that’s detected in a home pregnancy test | |
| Female sexual response | |
| 4 stages | |
| Arousal - innermost part of the vagina dilates and the vaginal lining and vestibular glands secrete fluid that lubricates the vestibule and vagina to make intercourse easier | |
| Plateau - lower ⅓ of the vagina constricts around the penis due to the engorgement of the vestibular bulbs clitoris becomes engorged with blood | |
| Orgasm - uterus undergoes peristaltic contractions that cause the cervix to dip down into the possible pool of semen which helps facilitate the journey for the sperm | |
| Resolution - reproductive anatomy returns to pre-arousal stage | |
| Unlike the male a women doesn’t have a refractory period in her sexual response | |
| Aging effects | |
| Woman’s body goes through a climacteric in midlife due to the decreased production of estrogen and progesterone | |
| Menstruation ceases during menopause | |
| Hot flashes are common caused by lower levels of estrogen and progesterone | |
| Tissues of the vagina labia minora clitoris uterus uterine tubes and breasts atrophy the thinning of the vagina and decreased secretions may cause dryness and make intercourse painful | |
| Yeast infections become more common | |
| Bone mass declines | |
| Muscle and connective tissue decrease can cause sagging breasts prolapse of bladder (which causes incontinence) and difficult bowel movements | |
| Skin becomes thinner | |
| Cholesterol levels rise | |
| Diagnostic tests | |
| Biopsy - procedure in which tissue is collected and examined for the presence of abnormal cells | |
| Blood test - reveal hormone levels pregnancy and presence of infection | |
| Colposcopy - procedure in which a lighted colposcope is used to visualize the vagina and cervix | |
| Hysteroscopy - procedure in which a lighted hysteroscope is used to visualize the uterus | |
| Lab tests - procedure that involves collecting urine or specimen samples from the female reproductive tract to determine the presence of viruses or bacteria that may cause infection | |
| Laparoscopy - procedure in which a lighted laparoscope is used to visualize collect biopsies from or perform surgical procedures in the abdomen or pelvic regions | |
| Mammogram - x ray of the breast that’s used in screening for breast cancer or disease | |
| Pap smear - part of the gynecological exam that helps detect abnormal cells in the lining of the cervix | |
| Pregnancy test - test that detects hCG hormone in pregnant woman | |
| Ultrasound - determine whether a woman is pregnant or detect any structural abnormalities of the reproductive organs and the developing fetus | |
| Disorders | |
| Breast cancer | |
| Abnormal growth of breast tissue usually occurring in the lactiferous ducts and lobules of the breast | |
| Age family history genetic mutations personal history and lifestyle choices affect breast cancer risk | |
| Treatment may include chemo surgery radiation immunotherapy and hormone therapy | |
| Mastectomy - removal of the breast | |
| Lumpectomy - removal of the tumor of the breast | |
| Mammograms | |
| Detection of breast cancer usually begins with a monthly self-exam and mammography | |
| Ovarian cancer | |
| Cancer of the ovaries | |
| Often lack symptoms | |
| Difficult to diagnose | |
| Treatment options include surgery chemo and radiation | |
| Cervical cancer | |
| Slow growing cancer that has few symptoms | |
| Caused by HPV infection | |
| Usually detected with a pap smear | |
| Treatment options include removal of the uterus | |
| Hysterectomy (removal of the uterus) | |
| Fibroids | |
| Noncancerous growths composed of muscular and fibrous tissue | |
| Found in the uterus endometrium or on the outside of the uterus | |
| Usually left alone if it isn’t causing problems | |
| Usually removed if it’s causing pain or bleeding or if it grows too large can cause infertility | |
| Endometriosis | |
| Growth of endometrium in places other than the uterus | |
| Endometrium goes through the menstrual cycle no matter where it’s located | |
| Lead to infertility and dysmenorrhea (painful periods) | |
| Pregnancy | |
| 4 requirements of a pregnancy are | |
| Must be a sperm and egg | |
| Sperm must meet egg | |
| Sperm must fertilize egg | |
| Fertilized egg must implant | |
| Pathway for sperm to meet an egg | |
| Egg must be fertilized within 24 hrs of ovulation if it’s to survive | |
| Fertilization to implantation | |
| Sperm must go thru capacitation to fertilize an egg | |
| Many sperm may be needed to break through the cells surrounding the egg | |
| Only 1 sperm will be allowed to penetrate the egg - rest will be rejected | |
| Nuclei of the sperm and egg rupture the chromosomes mix and a new nucleus forms | |
| Zygote undergoes mitotic division on its way to the uterus | |
| Blastocyst implants in the lining of the uterus 6 days after fertilization | |
| Developing fertilized egg will be called | |
| Blastocyte from implantation-week 3 | |
| Embryo from weeks 3-9 | |
| Fetus from week 9-birth | |
| Gestation (time of fertilization to birth) is 266 days or 280 days from the start of last menstrual period | |
| Hormonal control | |
| Made by the fertilized egg the corpus luteum and placenta along with other endocrine glands during a pregnancy | |
| Hormone that control a pregnancy include HCG estrogen progesterone HCS thyroid hormone PTH ACTH glucocorticoids and aldosterone | |
| HCG | |
| From the developing blastocyte causes the corpus luteum to continue to secrete estrogen and progesterone | |
| Estrogen levels | |
| Rise 30x normal during a pregnancy | |
| Breasts to double in size encourages external genitalia and uterus to grow causes uterus to be more irritable (prone to contract) and causes pubic symphysis to become more elastic | |
| Progesterone | |
| Suppresses FSH and LH secretion so that no additional eggs are developed during the pregnancy | |
| Suppress uterine contractions promote a rich lining of the uterus for the developing blastocyst and embryo to feed upon and promotes the development of mammary glands and ducts | |
| Produced 1st by the corpus luteum and then by the placenta | |
| HCS | |
| Regulates carb and protein metabolism so that glucose and amino acids are available in the blood for the developing fetus | |
| Reduces mother’s sensitivity to insulin so that more glucose stays in her bloodstream for the fetus it also increases the ability to use fatty acids as a fuel substitute for glucose | |
| Thyroid hormone levels rise | |
| Increases the metabolism for both mother and fetus | |
| Parathyroid hormone | |
| Takes more calcium from blood | |
| Adrenocorticotropic hormone | |
| More glucocorticoids resulting in protein breakdown to produce more glucose for the fetus | |
| Aldosterone | |
| Fluid retention to increase blood volume | |
| Adjustment to pregnancy | |
| Many of the body systems are affected by the pregnancy hormones and the growing fetus’ pressure on the female anatomy | |
| Motility (movement) decreases in the digestive system | |
| Morning sickness | |
| Pressure builds on stomach from the growing fetus | |
| Reflux of stomach acid to the esophagus causes heartburn for the mother | |
| Cardiac output increases 30% due to her increased blood volume | |
| Kidney secrete EPO to boost RBC production | |
| Pressure from the weight of the uterus may cause hemorrhoids or varicose veins | |
| Kidneys produce more urine because blood volume is increased and they’re filtering more waste - from the mother and fetus | |
| More frequent micturition | |
| Respiratory ventilation increases 50% | |
| Breathing is either faster or deeper | |
| Respiratory rate increases because the depth of breaths can’t | |
| Integumentary system is affected in several ways | |
| Stretch marks may appear on abdomen and breasts | |
| Linea alba may darken and be referred to as the linea nigra and melanocytes may increase melanin production producing a mask of pregnancy that’s visible on her face | |
| Increased thyroid hormone secretion | |
| Raises basal metabolic rate by 15% | |
| May feel overheated and have an increased appetite | |
| Nutritional requirements | |
| Only an additional 300 calories are required to sustain a pregnancy | |
| Balanced diet is essential | |
| Folic acid | needed to prevent birth defects |
| Calcium | bone development |
| Protein | fecal growth especially during 2nd and 3rd trimesters |
| Iron | increased hemoglobin production to maintain increased blood volume |
| Imitating the birth process | |
| Fetus has a role in the timing of parturition | |
| Hormones involved in initiating parturition lead to a positive-feedback mechanism that ends with the birth of the baby | |
| 3 different stages to the birth process | |
| Dilation of the cervix | |
| Expulsion of the baby | |
| Delivery of the afterbirth | |
| Stage 1 | |
| Begins with regular uterine contractions | |
| Cervical canal widens (dilation) and the cervix thins (effacement) | |
| Stage 1 ends when the cervical canal reaches 10 cm (diameter of the fetal head) | |
| Amniotic sac in which the fetus floats often ruptures during this stage | |
| Event is called the breaking of the waters | |
| Stage 2 | |
| Baby is expelled | |
| Crowning of the baby’s head is usually seen first | |
| Doctor may make an incision (episotomy) in perineum to widen the vaginal opening | |
| Angled away from the anus to prevent the perineum tearing into anus as the baby is born | |
| Stage 3 | |
| Placenta detaches from the uterus and is expelled during this stage | |
| Further contractions of the uterus ensure that all of the placenta and its associated membranes (afterbirth) are expelled | |
| Contractions also help close blood vessels that had led to the placenta | |
| About 350 ml of blood is normally lost when the placenta detaches | |
| Lactation | |
| Milk production is preceded in the first few days after birth by colostrum | |
| Sucking on the breast causes oxytocin release and milk ejection reflex | |
| Prolactin levels surge with each feeding to ensure ample milk production to meet the baby’s needs | |
| Many reasons for nursing include | |
| Breast milk provides good nutrition | |
| Antibodies present provide the baby some immunity | |
| Laxative effects on the baby | |
| Colonize help bacteria in the baby’s intestine | |
| Pregnancy disorders | |
| 50% of zygotes don’t survive most are lost before they implant | |
| Of the zygotes that do implant 15% are miscarried due to fetal abnormalities improper implantation premature detachment of the placenta and other causes | |
| Ectopic pregnancy occurs if the fertilized egg implants anywhere other than the uterus | |
| Ectopic pregnancies are doomed | |
| Preeclampsia is a pregnancy induced hypertension accompanied by protein in the urine usually occurs after 20 weeks | |
| Lead to serious potentially fatal consequences for the mother and baby | |
| Placental abruption | placenta becomes prematurely detached from the uterine wall |
| Placenta previa | placenta is positioned over the cervix blocking the opening to the uterus |
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