Flashcards in Physiology Deck (99):
What are the 2 key functions of ovary/testicles?
1. generation of gametes with full competence
2. secretion of steroid hormones required for spermatogenesis and for preparation of the female reproductive tract to allow fertilization & subsequent establishment of pregnancy
Main hormones from pituitary for reproduction?
What is testis composed of?
-seminiferous tubule & epididymis
At base: have all spermatigonia, they mature undergoing meiosis (get 4 haploid spermatozoa)
Role of LH in males?
-cause leydig cells to produce testosterone
Role of FSH in males?
-most important for sperm production
Role of LH & FSH in females?
-growth of follicle, estradiol production
How do IUDs work?
-prevent fertilization by causing premature activation of sperm, destroying it
Eggs in female?
-at birth have 1-2 million oocytes
-they begin necrotic process before birth to reduce from original 7 million number
-reduce to 400,000-500,000 eggs at puberty
-from puberty to menopause there will be 1,000 left that undergo apoptosis
For every ovulated egg, how many are apoptosed?
How many eggs are in 1 follicle?
Ovarian Follicle Development
1. Primordial Follicle (egg 40-50microns)
2. PRimary Follicle (egg gets bigger, surrounding cells are cubic in shape)
3. Secondary Follicles (egg gets bigger, multiple layers of granulosa cells)-makes fluid now & estrogen
Primary Oocytes are arrested in ? at birth
What phase does crossing over occur?
-egg with nucleus
-immature, nucleus is lost later
When does Meiosis II complete?
When sperm fertilizes it
After mature egg forms, what phase is it in?
Acrozonal part of sperm contain?
-enzymes to break down zona pellucia to break through and penetrate
What penetrates the egg?
head of sperm, never tail
-pronucleus is released inside egg
2 cell stage?
-happens at day 1
-transfer embryos at 8 cell stage (day 3)
-or blastocyst stage at day 5-6
Where does fertilization occur?
-in ampulary portion of tube
Most common site of ectopic pregnancy?
ampullary portion of tube
How does trophoblast implant?
-the inner cell mass implants on surface of uterine lining, the inner cell becomes the baby
-the outer cells make placenta and produce HcG (acts as LH-causes progesterone production)
-time since last period
-time since conception
% to get pregnant in 1 cycle?
% get pregnant in 3 months?
% to get pregnant in 1 year?
85% - considered normal fertility, subfertilie if doesn't happen
-1 year of unprotected intercourse without conception
-after 35 years, only 6 months of unprotected intercourse without conceptions
-effects 10-15% of couples in US
Human reproductive process?
1. sperm ascend through Cx, Ut, Tubes & acquire the capacity to fertilize the oocyte (male factor)
2. Cx filters and nurtures sperm into Ut and Tubes (Cervical factor)
3. ovulation of mature oocyte must occur (ovarian factor)
4. Tubes capture ovulated oocyte & transport sperm and embryo (tubal/peritoneal factor)
5. Ut is receptive to embryo implantation & support pregnancy (uterine factor)
Causes of Infertility?
-Male factor (40%)
-Combined F-M (20%)
-Female Factor (60%)
-semen analysis: vol. 1.5-5mL
conc. >20mil/ml motility>40%
morphology > 14% ph > 7.2
round cells < 1mil/ml
-low volume & other parameters
retrograde ejaculation (type 1 diabetes)
duct obstruction, hypogonadism, CBAVD
Evaluation of Male Factor Infertility
-FSH, LH, PRL, Testosterone
-Y Chromosome microdeletions
-anatomical changes (DES exposure)
-Changes in mucus characteristics
Evaluation of cervical factor
-anatomical changes (congential malformations, fibroids, adhesions)
-functional abnormalities (endometritis, dec. receptivity)
Evaluation of Uterine/Endometrial Factor
-TV ultrasound & sonohysterogryaphy
-anatomical changes (congential malformations, BTL, adhesions, endometriosis)
Evaluation of Tubal/Peritoneal Factor
-laproscopy with chromopertubation
-ovulatory dysfunction: oligo/anovulation, luteal phase deficiency
Evaluation of dysfunction?
-basal body temperature
-urinary LH excretion (ov. predictor kits)
-basal FSH/Clomiphene challenge test
1. layer of mononucleated cells
2. forms new cells that migrate into the syncytiotrophoblast
1. Multinucleated, no cell boundaries
2. Invades the endometrium
-basic placental structure
3. Major source of hormone production, particularly hCG
Primary chorionic villi
-by end of 2nd week, proliferation of cytotrophoblastic cells produces cellular extensions that grow into the syncytiotrophoblast
-The blastocyst is inner cell mass and placental stem cell
-Stimulatory Factors: IGF-1, SCF-1, fibronectin, etc.
Attachment of blastocyst trophoblast to uterine endometrial epithelium?
-initiates decidualisation in uterine stroma underneath conceptus (increase in vascular permeability & secretary activity of stromal cells)
-decidua allows efficient placenta (access to maternal blood), restricts trophoblast invasion, provides nutrients
-seen as early as day 23 (10 days after peak of luteinizing hormone surge) of the normal menstrual cycle, when the spiral arteries of the endometrium
-over next few days, stromal cells surrounding spiral arteries become increasingly eosinophilic and enlarged as the differentiating effect of progesterone transforms these cells into predecidual cells
-progressive decidualization of endomerial stroma in later part of menstrual cycle prepares the uterine lining for the presence of invasion trophoblasts, but simultaneously closes the door to implantation
-within hours of attachment trophoblast destroys epithelial cells
-some trophoblast cells fuse (syncytiotrophoblasts) others retain cellularity (cytotrophoblast)
-finger-like outgrowths 'villi' invade decidua (release nutrients), attack blood vessel walls
-occurs 2-3 weeks gestation. Spaces enlarge to form intervillous space
-villi invaded by embryonic blood vessels
9 day implantation site
-embryo surrounded by 2 layers of trophoblsts & outermultinucleated syncytiotrophoblast layer
Development of Placenta
-by end of third week, anatomical arrangements necessary for physiological exchanges b/w the mother and her embryo are established
-complex vascular network is established in the placenta by the end of the 4th week, which facilitates maternal-embryonic exchanges of gases, nutrients, & metabolic waste products
Secondary Chorionic Villi
-shortly after primary chorionic villi appear at the end of the 2nd week, they begin to branch
-early in 3rd week, mesenchyme grows into primary villi, forming a core of mesenchymal tissue
-villa at that this stage -secondary chorionic villi- cover the entire surface of the chorionic sac
Beginning of 8th Week
-chorionic villi cover entire sac until this
-as sac grows, the villi associated with the decidua capsularis are compressed, reducing the blood supply to them
-these villi soon degenerated, producing a relativley avascular bare area, the smooth chorion
-as villi disappear, those associated with the decidua basalis rapidly increase in number, branch profusely, and enlarge
-this bushy part of chorionic sac is villous chorion
Placental Functional Units
-# approximately 40-60 in the term placenta
-composed of villi arranged with the larger fetal stem villi at the periphery (like staves of a barrel)
-chorionic villi branch towards the center of the barrel, with most of the nutrients and oxygen exchange areas located more centrally in terminal chorionic villi
-placenta attached to the myometrium
-absence of the fibrinoid layer b/w the villi and decidua (nitabuch's layer)
-placenta invades the myometrium
-placenta invades to or through the uterine serosa
-implantation of the placenta in the lower uterine segment
Complete: placenta covers entire cervical os
Partial: placenta covers a portion of the os
Marginal: placenta immediately adjacent to internal os
Low-Lying: placenta in the lower uterine segment
Incidence of Placenta Previa
-up to 25% found in screening second-trimester ultrasound
-1/200-250 deliveries at term
-as the lower uterine segment develops, placental "migration" occures
-separation of a normally-implanted placenta before the birth of the fetus
-occurs in 0.8% if dekuverues
Abruption Placenta Risk Factors
-sudden uterine decompression
-maternal cocaine use
-maternal cigarette smoking
Abruption Placenta Presentation
-vaginal bleeding with abdominal pain
-tender, sometimes rigid abdomen
-hypercontractile uterine contraction pattern
How long should you Breastfeed?
-exclusive breastfeeding for the first 6 months of life
-AAP recommends continuing for first year of life (and as long as mutually desired after ~2 years)
Lowest Breastfeeding rates?
-women in WIC
-comen with highschool or less
-lowest in southeastern United State
Benefits of Breastfeeding to Infants?
-Colostrum: high level of immune protection (IgA)
milk composition changes to match infant needs (Protein & Na+ decrease as fat & lactose increase in first 4-7 days)
Antimicrobial properties protect against infection
Breastfeeding Risk Reductions for Mothers?
-Type II Diabetes (dec 12%)
-Premenopausal Breast Cancer (dec. 28%)
-Ovarian Cancer (dec. 21%)
Community Benefits of Breast feeding?
-decreased annual health care costs
-decreased spending for WIC
-decreased parental employee absenteeism and loss of family income
-decreased environmental burden for disposal of formula cans and bottles and decreased environment burden for production and transport of artificial feeding products
Who should not breastfeed?
-Active maternal TB/varicella
-HTLV I or II + mothers
-receiving radioactive isotopes
-mothers on antimetabolites or chemotherapeutic agents
-mothers on "street drugs"
-mothers with herpes lesions on breast
-in US, maternal HIV
-6-10 lobes in mature mammary gland
-single opening from each lobe "galactophore" in the nipple
-epithelial-lined ductules form round alveolus
-glandular tissue to fat 2:1 in lactation vs. 1:1 in non-lactation
Innervation of Breast
-nipple & areola supplied by the anterior and lateral cutaneous branches of the 3rd - 4th intercostal nerves
-lateral supply of nipple & areola provided by the 4th intercostal nerve
-small sebaceous glands on the areola
-not visible before pregnancy
-secrete a cleansing and lubricating bacteriostatic fluid (odor to attract baby)
-initiation of capacity of the breast for milk secretion
prior to birth - despite high levels of prolactin very small amounts of milk due to antagonism of progesterone
-3 days postpartum, copious increase in milk volume (volume increases from 100mL/day to 600mL/day by day 4)
-the normal 2-3 day postpartum decrease of progesterone is a part of the process that initiates lactation
10 days postpartum - changes in milk composition to "mature milk"
baby and mom skin to skin contact
The process of childbirth is not finished until....
baby has safely transferred from placental to mammary nutrition
Who can breastfeed?
-nearly every women!
-even with multiple births, near term infants, and cesarean delivery
-toddler and newborn nurse at the same time
-can still breastfeed
-10% women have inverted or nonprotractile nipples
-direct breastfeeding (nipple may evert when baby begins to suckle
-establish milk production via hand or electrical expression
-with a nipple shield
Can you breastfeed while pregnant?
Can you breastfeed with flat nipples?
-pump 1-2 min before offering breast
Can you breast feed after augmentation mammoplasty?
Can you breast feed with pierced nipples?
yes, remove device before feeding
When is caution with breastfeeding required?
-assymetric, tubular, or hypoplastic breast
-full milk supply may not be possible
-alert pediatrician to this possibility
What are not contraindications to breastfeeding?
-hep C infection
-mothers exposed to low level environmental chemical
-seropostitive carriers of CMV
-maternal alcohol intake
Control of Milk Supple
1. Endocrine Control: Prolactin-milk production
Oxytocin: milk ejection
2. Autocrine Control: milk removed governs volume of milk produced "supply meets demand"
-if milk is not removed, a feedback inhibitor of lactation (FIL) protein will inhibit production and cause weaning
-causes milk synthesis
-prevented from exerting effect on milk excretion by elevated levels of progesterone
-plasma conc. increases rapidly during suckling
-increased secretion mediated through stimulation of nerve endings in the nipple-areolar complex
-tactile stimulation of nipple-areolar complex by suckling signals hypothalamus
-post. pit. releases oxytocin which travels to mammary gland
-reacts w/receptors of myoepithelial cells (contractions)
-forces milk into ducts from alveolar lumens then out through the niple
-may leak from other breast
-audible swallowing begins
-mothers may have "pins & needles" sensation or flush of heat
-triggers uterine contractions which decrease blood loss and promote involution of the uterus
Delivery: Immediate Postpartum
-optimal bonding with immediate physical contact
-preferably skin to skin
-separation may lead to hypothermia, hypoglycemia, and increased change of supplementation
Skin to Skin Contact
-thoroughly dry infants skin to prevent temperature loss
-place infant prone against mother's bare chest
-place a blanket across baby's back and pull bed covers over baby and mom
Breastfeeding After C-Section
At higher risk for:
1. producing insufficient milk
2. having attachment difficulty
3. earlier termination of breastfeeding
Delivery: First Feeding
-occur in first hour when baby is awake and alert
-longer interval b/w birth & feeding, more likely the use of supplementation
-newborn eye prophylaxis, weighing, measuring should be deferred until the first feeding
Baby's First Immunization
-breast milk in first few days (colostrum)
What is crying?
-a late sign of hunger