chapter 4 human reproduction/fetal dev ppt Flashcards
external organs
mons pubis
labia majora
labia minora
clitoris
vestibule of the vagina
bartholin glands
perineum
mons pubis
pad of fat that lies over the symphysis pubis
labia majora
two folds of tissue that ext4end from the mons pubis to the sides of the vulva
labia minora
two smaller folds of tissue forming the prepuce, which surrounds the clitoris
clitoris
small sensitive organ with erectile tissue
vestibule of the vagina
the area where the urethra and vagina open
bartholin glands
secrete lubricating fluids
perineum
the skin from vaginal opening to the anus
internal organs
ovaries
fallopian tubes
uterus
vagina
ovaries
two small glands about the size and shape of almonds that are on either side of the uterus slightly behind and below the fallopian tubes
- store approximately one half million eggs and secrete estrogen and progesterone
fallopian tubes
provide a channel for the sperm to travel to the egg and to transport the fertilized egg into the uterus
uterus
a muscular triangle shaped organ that provides the environment for fetal growth
top portion of uterus
fundus
bottom portion of uterus
cervix
- provides a protective entrance to the uterus
- very elastic and has the ability to stretch to allow for childbirth
2 coats of uterus
muscular coat
inner mucous membrane (rugae)
3 layers of uterus
endometrium
myometrium
epimetrium
endometrium
a mucous membrane that lines the cavity of the uterus and is the site where the embryo implants after arriving in the uterus
myometrium
the middle layer of smooth muscle that contracts and expel the feteus and placenta during childbirth
epimetrium
a smooth, transparent membrane that lines most of the external surface
ligaments
provide support and stabilize the reproductive organs
- includes the broad ligaments, the round ligaments, the cardinal ligaments and the uterosacral ligaments
vagina
- a 4 to 6 in elastic muscular tube that extends from the cervix to the external vaginal opening
- tissue is composed of smooth muscle and elastic connective tissue, and lined with stratified squamous epithelium
- two main functions are for sexual intercourse and childbirth
female pelvis
- former posteriorly by the sacrum and coccyx
- sides and front formed by the hip bones (ilium, ischium, pubis)
- shorter, wider, and more circular than the male pelvis, making it ideal for childbearing
breasts
- two glands that secrete milk
- begin to develop during puberty and further develop during pregnancy due to pituitary and ovarian hormones
- nipple becomes darker in pregnancy
colostrum
a fluid rich with antibodies; first form of milk that extremely benefits the newborn
- milk production typically begins 2-3 days after childbirth
female reproductive cycle
- begins on the first day of menstrual bleeding and ends on the first day of the next menstrual bleeding
- hormones involved include the follicle stimulating hormone, luteinizing hormone, estrogen, and progesterone
follicular phase
- anterior lobe of pituitary secretes follicle stimulating hormone which stimulates the development of a follicle in the ovary- maturing egg follicle secretes estrogen, which thickens the endometrium to prepare for the implanting of the fertilized egg
- elevated estrogen levels cause FSH to stop and luteinizing hormone is released by the pituitary gland
luteal phase
- begins on the day the egg is released
- LH peaks on approx day 14 of the cycle, causing ovulation or the release of the egg from the follicle
- LH converts the ruptured follicle into the corpus luteum, which secretes progesterone
- progesterone completes the development of the uterine lining in preparation for a fertilized egg
- if egg is not fertilized, the corpus luteum degenerates dropping levels of progesterone and estrogen
- uterine lining sheds and menstrual cycle begins again
male reproductive system: external organs
scrotum
penis
scrotum
made of two sacs that hold the testicles, the epididymis, and the beginning of a spermatic cord
penis
made f cavernous tissue that allows erection, and expels semen upon sexual climax
male reproductive system: internal organs
testicles
testes
seminiferous tubules
epididymis
vas deferens
prostate gland
seminal vesicles
ejaculatory ducts
urethra
testicles
the reproductive glands of the male
testes
have cells that produce testoerone, which promotes the development of male reproductive organs and the secondary male characteristics
seminiferous tubules
the site of germination and maturation of cells into spermatozoa
epididymis
facilitates sperm motility
vas deferens
ducts that transport mature sperm from the epididymis to the ejaculatory ducts
prostate gland
provides additional fluid to the sperm
seminal vesicles
two pouch like sacs that create sugar rich fluid to provide energy to the sperm
ejaculatory ducts
formed by the fusion of vas deferens and the seminal vesicles, and empty into the urethra
urethra
carries urine and semen out of the body
male reproductive cycle
fsh
lh
testosterone
fsh
stimulates sperm production in the testes
lh
stimulates testerone production
testosterone
allows development of spermatozoa to mature sperm cells during a 72 day process
both FSH and LH are released from
the anterior pituitary gland
fertilization
- occurs when the sperm and the egg (gametes) meet in the same place at the same time after intercourse
- occurs in the outer third portion of the fallopian tube
- only one sperm will penetrate the egg’s outer layer and fertilize the ovum
each gamete typically has…
one set of 23 single chromosomes; when fused, a total of 46 chromosomes produce the zygote
embryo sex is determined at…
fertilization by the male gamete; xx chromosome for genetically female, xy chromosome for genetically male
upon fertilization, the zygote…
divides during mitosis and travels down the fallopian tube to implant in the uterine lining
- estrogen and progesterone levels remain high
- human chorionic gonadotropin is produced to support the development of the embryo
- elevated levels of hCG can be detected by a blood test 1 days after conception and in urine tests 12-14 days after conception
embryo
the stage of development between the fertilized ovum and the fetus
blastocyst
a maturing embryo in which some cell differentiation has occurred
- in blastocyst stage, embryo implants 7-10 days after fertilization into the uterine endometrium
placenta
an organ that develops at the site of implantation to sustain the fetus during intrauterine life or the gestation period
the embryo changes through the processes of…
morphogenesis and cell differentiation
fetal circulation
- in the uterus, the mother’s body provides oxygenation, filtration, and nutrition to the fetus
- oxygenated blood from the mother enters the fetus’s blood through the umbilical vein
- the ductus venosus allows oxygenated blood to bypass the liver and combined with deoxygenated blood i the inferior vena cava
- blood rejoins deoxygenated blood from the superior vena cava and goes to the right atrium
- the foramen ovale (a small hole between the atria) allows blood to move to and from the right atrium to the left atrium
- small amount of blood moves from right atrium to right ventricle into pulmonary system
- most blood bypasses pulmonary arteries and moves directly into aorta through ductus arteriosus and out to the rest of the body
- deoxygenated blood returns to placenta through umbilical arteries
first trimester (week 1-12)
- a critical time of rapid changes to the fertilized cell; development of major organs and structures
- 3 germ layers are created within 2 weeks after fertilization as foundation for the body tissues and organs
- ectoderm: outer layer; nervous system, skin epidermis, glands, tooth enamel, and lens and cornea of the eye
- 3 germ layers are created within 2 weeks after fertilization as foundation for the body tisues and organs
mesoderm
middle layer; connective tissue, musculoskeletal, circulatory system, and the dermis of the skin
endoderm
inner layer; digestive tract, accessory organs, respiratory tract, kidney nephrons, bladder, and endocrine glands
second trimester (weeks 13-28)
- organs and structures develop
- the woman becomes more aware of growing fetus
third trimester (weeks 29-40)
- the fetus gains weight, matures, and prepares for life outside the uterus
reducing the risk of birth defects include
- avoiding all medications unless directed by the provider
- avoiding alcohol
- avoiding tobacco
- avoiding street drugs
- having a healthy diet
- avoiding harmful substances and cat feces
placenta
- provides oxygen and nourishment
- fetal cells (trophoblasts) attach to the uterus wall and grow into uterine tissue
- connect indirectly with mother’s blood vessels
- fetal blood vessels form in the placental villi and the vessels connect back to the fetus through the umbilical cord, which attaches the fetus to the placenta
- measures 15-20cm and weighs about lb
- also functions as an endocrine organ by producing progesterone, estrogen, hcg, human placental lactogen, relaxin
villi form
these are finger like projections that are responsible for gas, nutrient, and antibody exchange as well as waste removal
progesterone
supports the endometrium; calms and quiets the uterine muscle
estrogen
stimulates breast development for breastfeeding and the growth of the myometrium; improves blood flow between placenta and fetus
hCG
stimulates the corpus luteum for estrogen and progesterone production; used to determine pregnancy
human placental lactogen
assists with milk preparation and increases the mother’s metabolism during pregnancy
relaxin
maintains pregnancy together with progesterone; causes relaxation of pelvic ligaments
umbilical cord
- joins the fetus to the placenta
- composed of 2 arteries and one vein
- vessels are surrounded by wharton’s jelly, a gelatinous substance that provides support and protection inside the cord
- the site where the umbilical cord was attached to the fetus is known as the umbilicus, navel/bellybutton
chorion
a thick membrane that develops from trophoblast and becomes part of the placenta villi to support the growing embryo
amniotic membrane
a thin membrane from the ectoderm that contains amniotic fluid and the growing fetus
amniotic fluid
functions as cushion to the fetus, allows fetal movement, and can be used for fetal health and maturity analysis; average volume is 700-800mL. Variations can indicate potential health problems.
multiple pregnancy occurs when…
the woman has 2 or more embryos in the uterus
- identical: embryos from the same egg
- fraternal: embryos from 2 or more eggs
monozygotic twins
form when a single fertilized egg splits; separate amniotic sacs but share a placenta; always the same sex
dizygotic twins
two eggs fertilized by two separate sperm; each embryo has its own amniotic sac and placenta; with similarities but will not have the exact same genetic material
contributing factors for multiple pregnancy
older than age 35
African American descent
family history of twins
undergone fertility treatment
previous multiple births
teratogen
- any substance that may cause a birth defect
- most substances can cross the placenta from the mother and the fetus and cause abnormalities
- susceptibility depends on period of fetal development
- fetus is very vulnerable to the effects of medications during the first trimester so it is crucial to verify the date of the woman’s last menstrual period. Any concern of pregnancy must be reported.
medications
- summary describing potential risks of drug use during pregnancy and lactation
- information also included for women and men in need of contraceptives, pregnancy testing, and infertility related to drug use
tobacco
- important modifiable cause of poor pregnancy outcomes
- ecigs,vaping including exposure to secondhand smoking are unsafe practices
- causes a small baby with delayed development
- other adverse effects include low birth weight, premature rupture of membranes, placenta previa, placenta abruption, preterm labor, ectopic pregnancy, and increased risk of cleft lip or palate
- use the 5 A’s model to address smoking
alcohol
avoid throughout pregnancy
causes fetal alcohol spectrum disorders
caffeine
- linked with miscarriage and preterm birth
- light and moderate intake (less than 200mg per day) is acceptable
marijuana
- most widely used by pregnant women
- affects neurological development of the newborn
cocaine
- leads to microencephaly: a small brain and head
- fetus’s genital, kidneys, or brain may have abnormalities
- may cause placental abruption and neurobehavioral abnormalities
opioids
- can lead to neonatal abstinence syndrome, premature birth, low birth weight, hypoglycemia, intracranial hemorrhage in uterus
methamphetamines
- associated with fetal and maternal heart rate elevation, preterm labor, and placental abruption
