FETAL DEVELOPMENT (exam 1) Flashcards
from notes in class ati called fetal lifespan
when does fertilization occur
week 3 of an average 28 day cycle
when an egg and a sperm form a zygote
zygote
A single cell that is formed by the joining of two parental cells. This is the first stage of gestation.
gestation
Time frame from egg fertilization until birth.
after egg and sperm meet to make a zygote
what happens during week 1-2 of gestation
fertilization has not yet taken place. During that time, the egg follicle matures within the ovary as the result of follicle-stimulating hormone
week 5 gestation
marks the beginning of the embryonic period which continues until week 9 gestation when the fetal period beings
week 9 gestation
fetal period begins
embryogenesis
from fertilization of egg through week 9 of gestation
yolk sac
provides nutrition and gas exchange until the placenta is formed
amnion
creates amniotic fluid
allantois
removes waste products
chorion
aids in placental formation
blastocyst stage
reached 5 days after fertilization
four distinct membranes that result in development of the blastocyst
amnion
chorion
allantois
yolk sac
what happens after fertilization occurs
hCG is present in client’s blood and urine
first signs of pregnancy occur (swollen breasts and fatigue)
implatation
occurs during week 4 of gestation
At this point in the menstrual cycle, the lining of the uterine wall is thick and can support the growing blastocyst with a rich blood supply.
ends the pre-embryonic period at the end of week 4
embryonic period
week 5-10 gestation
until the embryo’s tail is gone and is now called a fetus at the end of week 10
what happens during embryonic period
cells multiply
growth is rapid (blood, kidneys, nerve cells)
birth defects can happen at this time (exposed to teratogens)
teratogens
Anything that negatively affects normal embryonic or fetal development, including medications, illicit drugs, radiation, chemicals, and infections.
during embryonic period
week 5 embryonic development
musculoskeletal: bone formation, limb buds, muscles begin to develop
cardio: heart begins to develop, blood cells develop
respiratory: trachea and bronchi are formed
GI: GI tract begins to develop
GU: bladder and kidneys begin to develop, females: ovaries develop
neurological: nerve cells develop, brain and spinal cord begin to develop
skin/sensory: inner and middle ear begin to develop
week 6-7 embryonic development
musculoskeletal: arms/legs/feet begin to form, movement occurs
cardio: heart begins to beat (around 110-120 bpm)
respiratory: lung development occurs
GI: mouth begins to form, bowel moves outside the abd to develop
neuro: brain development continues, parasympathic nerve can be detected, tissue develops that will form spinal cord
skin/sensory: eyes/nostrils/ears begin to develop
week 8 embryonic development
musculoskeletal: limbs grow longer, hands/feet form, finger and toes begin to develop
neuro: brain development continues
week 9 embryonic development
musculosketal: elbows form, toes and fingers are visible
respiratory: breathing movements are seen
GU: males: Testosterone production begins, Male genitalia development begins.
skin/sensory: nipples and hair follicles develop
week 10 embryonic development
musculoskeletal: cartilage is replaced with bone cells
GI: Developed bowel migrates back into the abdomen.
GU: kidneys function, urine production, females: Uterus and fallopian tubes form.
skin/sensory: Facial features become more distinct, eye lids are more developed and begin to not close, and outer ear begins to develop, Fingerprints are developing
when does fetus start producing urine
week 10
adds to the amniotic fluid content
when does placenta develop
during first trimester and continues to grow
Oxygen and nutrients are provided to the fetus via
maternal blood flow through embryonic capillaries.
what does placenta produce
glycogen
provides the fetus with a source of energy and cholesterol that is instrumental in fetal hormone production
where is placenta normally located
upper portion of uterus
purpose of placenta
The placenta sustains the pregnancy with endocrine, immunological, and physiological factors. It aids in transfer of gases, oxygen, hormones, antibodies, nutrition, and waste between the maternal client and the fetus.