Pregnancy Flashcards
what is fecundity
biological capacity to bear children
what is fertility
the actual production of children
what are the 5 stages of human conception
ovulation
fertilization
cleavage
blastocyst
implantation
when is the zygote formed
fertilisation
what happens during cleavage
the cell divides for 12-48 until it reaches 26 cells
name of 16-cell
morula
when does a morula become a balstocyst
more than 100 cells it fills with fluid and becomes 2 groups
what are the two groups of a blastocyst
embryoblast
trophoblast
what part of the blastocyst becomes:
the fetus
the placenta
trophoblast is placenta
embryoblast is the fetus
describe conception
-when a sperm penetrates an egg, the genetic makeup is complete
-the zygote rapidly divides as it travels down the fallopian tube and attaches to the uterine wall
describe fetal deveopment at 4 weeks
face and neck structures become evident
-heart and blood vessel development continues
-lungs, stomach and liver development starts
-at home pregnancy test will show
describe fetal development at 8 weeks
-Grape size, now a fetus
-eyelids and ears forming
-arms and legs are well-formed
-fingers and toes become more distinct
descirbe fetal developemnt at 12 weeks
-starts own movement
-can hear the heartbeat
-can tell the gender
-top of the uterus above the pelvic bone
describe fetal development at 16 weeks
-baby can blink
-heart and blood vessels fully formed
-has fingerprints
describe fetal development at 20 weeks
-yawn, stretch, thumb suck
-quickening(mum feeling baby movement)
describe fetal developemnt at 24 weeks
-responds to sound
-inner ear developed so may sense being upside down
describe fetal development at 28 weeks
-good chance for premature birth survival
-frequent position changes
describe fetal development at 32 weeks
-less wrinkles
-layer of fat forms
-gains half of its birth weight
describe fetal development at 32 weeks
-fewer wrinkles
-a layer of fat forms
-gains half of its birth weight
describe fetal development at 32 weeks
-head positioned near pelvis
-lungs almost developed
what is the amniotic sac
amnion membrane formed around the embryo
when does the amniotic membrane form
around 2 wks post conception
what happens to the water in the amniotic sac by 10 wks
contains
-protein
-CHO
-lipids
-urea
-electrolytes
what is the purpose of the amniotic fluid
-allow it to move
-protection from infections, temperature change, dehydration and impact
when is the placenta fully formed
18-20 weeks
how much does the placenta weigh by the end of pregnancy
approx. 0.5 kgs
role of placent
-carries O2, nutrients and antibodies from mother to fetus and waste materials (CO2) from the fetus to the mother
-hormonal role of ovaries
what hormones does the placenta product to maintain preganancy
human chorionic gonadotropin
progesterone
relaxin
human placental lactogens
role of human chorionic gonadotropin hormone
prevents ovaries releasing another egg
-stimulates ovaries to produce estrogen and progesterone
role of progestorone
maintenance of pregnancy
-secreted by the placenta after 12 wks
role of relaxin
-synergistically with progesterone to maintain pregnancy
-relaxation of pelvic ligaments
role of human palcental lactogens
prolactin and growth hormone
-promote mammary gland growth
what does passive diffusion transport across the placenta
O2, CO2, fatty acids, steroids, nucleosides, electrolytes, fat-soluble vitamins
what does facilitated diffusion transport across placenta
sugars
what does active transport move across placenta
amino acids, cations, water soluable vitamins
what does active transport move across placenta
amino acids, cations, water soluble vitamins
What does solven drag transport across the placenta
elecrtrolytes
what is the placenta examined for
size, shape
presence of unusual bits
umbilical cord
why do maori bury placentas
to emphasize the relationship between them and the earth
what are teratogens
agent that disturbs development
classes of teratogens
radiation
maternal infections
chemcials
drugs
when will a fetus have a 50% chance of survival
24 weeks
short term complications of pre-term birth
respiratory distress (RDS)
Hear: patent ductus arteriosis (PDA)
Brain: intraventricular hemorrhage (IVH)
GI: necrotising enterocolitis (NEC)
long-term complications of pre-term birth
cognitive, vision, hearing, ADHD, anxiety, asthma, SIDS
