role of the placenta Flashcards
what does the foetus need from the mothers blood?
glucose
amino acids
fatty acids
water
oxygen
mineral ions
vitamins
how does the foetus blood connect to and from the placenta?
by the umbilical cord
what hormone does the placenta secrete?
progesterone
what does the progesterone do?
ensures the uterus lining remains thick and prevents the embryo from aborting
what does the amnion do?
encloses the developing embryo
what fluid does the ambion secrete?
a fluid called amniotic fluid
what does amniotic fluid do?
protects the developing embryo against jolts and bumps, drying out and temperature fluctuations due to waters high specific heat capacity
when do we call it a foetus?
when it looks human
what happens at the end of nine months of development?
there isn’t any room left for the foetus to grow and it sends a hormonal signal to the mother to initiate birth- going into labour
when do we call it a baby?
when the foetus is born
what does the placenta develop from?
the embryo
what does the placenta do to the embryo in the uterus?
anchors the embryo in the uterus
what does the mothers blood also do?
absorbs the waste products from the foetus blood in the placenta
what waste products are removed from the foetus blood?
carbon dioxide and urea
how does the movement of most molecules across the placenta occur by?
diffusion due to difference in concentration gradients
how is the placenta adapted by diffusion?
by having a large surface area and a thing wall for efficient diffusion
what does the placenta act as?
a barrier to prevent toxins and pathogens getting into the foetus blood
why does the blood between the embryo and the mother not mix?
the mothers blood is much higher pressure than the feral blood
the mothers blood has white blood cells and other chemicals that would see the fetal blood as foreign and attack it
why are pregnant women advised not to smoke during pregnancy?
not all toxin molecules or pathogenic organisms are stopped from passing through the placenta- nicotine can pass across the placenta
why does the umbilical cord being cut not hurt?
there are no nerves in it, just 2 blood vessels
what type of nutrients are moved from the mother to the embryo?
glucose, amino acids and salts
what metabolic waste is moved from the embryo to the mother?
carbon dioxide and urea
