and Answers
what are male gametes? - answerSperm
What are female gametes? - answerSecondary oocytes
Embryonic period? - answerFrom fertilization through the eighth week of development
Fetal period? - answerBegins at week 9 and continues on until birth
Describe the first trimester? - answerThe first trimester is from conception to 13 weeks. This period
is very critical to babies health due to the extensive oran-system development, and baby is most
vulnerable to teratogens.
Describe the second trimester? - answer14 weeks to 27 weeks. Baby begins to develop human like
features
Describe the third trimester? - answer28 weeks to 40 weeks. Rapid fetal growth, fetus doubles in
weight.
Cleavage of zygote - answerMitotic division after fertilization
Day 1: two-cell stage
Day 2: four-cell stage
Day 3: eight-cell stage
Day 4: morula
Day 5: blastocyst
Day 6: Implantation in uterine wall
, FIGURE 29.5
What factors stimulate the thirst center in the hypothalamus? - answerIncreased blood
osmolarity(more solutes)
Decreased blood volume
Decreased blood pressure
Dry mouth
What does a decreased blood pressure stimulate in the kidneys? - answerStimulates the release of
renin, which increases angiotensin II formation, leading to increased thirst, increased water
intake, and increased blood volume, and increased blood pressure
What are the two main solutes in extracellular fluid and in urine? - answerNa+ and Cl-
ADH function - answerADH responds to increased osmolarity, by inserting aquaporins in late DCT
and collecting ducts, which increases the permeability to water and allows for more water to be
reabsorbed, decreasing blood osmolarity, increasing blood volume, increasing blood pressure
What are the two most important hormones in renal reabsorption and urine regulation? -
answerAldosterone and ANP
When is RAAS activated? - answerDecreased blood pressure or Na+ deficiency in plasma, this
causes an increase in renin release which activates the RAAS system. This increases Na+
reabsorption and water reabsorption in the late DCT and collecting ducts
Functions of ANP - answerANP responds to increased blood volume and increased stretch of atria
of the heart, promoting natriuresis (elevated excretion of Na+ into urine). Where sodium goes,
water follows, therefore there is also a loss of water, and a decrease in blood volume.
What are the most abundant cation and anion of ECF? - answerNa+ and Cl-
What are the most abundant cation and anion of the ICF? - answerK+, proteins, and phosphates