Caroline G. Mendez
Fetal Pig Dissection Lab Analysis Questions
1. The word "gestation" comes from the Latin "gestare" meaning "to carry or to bear."
Gestation period means fetal development period from the time of conception until birth. For
humans, the full gestation period is normally 9 months.
2. The approximate age of my pig Porkers measured with the yarn is 41 days.
3. There are 15 digits visible.
4. The walls of both veins and arteries have three layers of tissues, but veins are much thinner
and less elastic than arteries. Veins also have valves that help in the process of returning
blood to the heart by preventing blood from flowing reverse. Arteries transport oxygenated
blood away from the heart and veins transport de-oxygenated blood back towards the heart.
-thick muscular wall
-much elastic tissue
-small lumen relative to diameter
-valves in pulmonary artery and Aorta only
-blood under high pressure (10-16kPa)
-blood moves in pulses
-blood flows rapidly
-thin muscular wall
-little elastic tissue
-large lumen relative to diameter
-not capable of constriction
-valves throughout all veins
-blood under low pressure (1kPa)
-blood flows slowly
5. A fetus, especially a fetal pig, gets rid of its waste products through the umbilical cord. The
waste products in the blood stream of the fetus is passed into the blood stream of the mother.
Then the mother gets rid of the waste herself for the both of them. Fetal pigs, like all
mammals, filter waste through the placenta. Fetuses develop with an amniotic sac, placenta
and an umbilical cord. These three components serve the same function across mammalian
development. The amniotic sac houses the embryo and the placenta, which are attached via
the umbilical cord. The mother's blood passes through the placenta and cord carrying
nutrients, and then the waste product is carried back out through the cord to be filtered by the
placenta. The filtered blood is then returned to the mother. The fetus doesn't produce urine or
fecal matter, even after the development of the digestive and urinary tract, because it doesn't
yet digest food. Instead, all nutrients are received and expelled via the bloodstream. The
placenta serves as a filter between the mother and fetal pig's blood streams so that the two are
never in direct contact. However, the placenta cannot filter out all undesirables, such as some
drugs, or in the case of people, alcohol. After the baby is born, the umbilical cord attached to
the placenta is cut, and the piglet begins typical digestive processes to ingest nutrients and
expel waste. The placenta is also birthed by the mother following the piglet, as it is no longer
6. External features mammals are classified into are listed in the following sentences.
Mammals are a class of vertebrate, air-breathing animals whose females are characterized