Final answer:
Oxytocin is synthesized in the hypothalamus and released by the posterior pituitary gland to stimulate uterine contractions during labor and milk ejection during breastfeeding. It does not have a primary diuretic effect and is not significantly metabolized in the liver. A bolus dose of oxytocin can increase central venous pressure.
Step-by-step explanation:
The student's question relates to the properties and effects of the hormone oxytocin. Oxytocin is a peptide hormone known for its roles in facilitating childbirth and lactation. It's synthesized in the hypothalamus and released by the posterior pituitary gland. Its primary function is to stimulate uterine contractions during labor and to promote milk ejection during breastfeeding.
Looking at the options provided:
- Oxytocin is synthesized in the hypothalamus, not the posterior pituitary, hence option A is incorrect.
- Oxytocin does not have a diuretic effect; in contrast, it may have slight antidiuretic effects, thus option B is incorrect.
- Oxytocin is metabolized by oxytocinases, but primarily in the placenta and not significantly in the liver, so option C is incorrect.
- A bolus dose of oxytocin can indeed increase central venous pressure as a result of increased intravascular volume from uterine contractions and fluid shifts, which makes option D correct.
- Systemic vascular resistance may not significantly increase and is not the primary effect of oxytocin; instead, oxytocin's main cardiovascular effect is to increase uterine blood flow, so option E is incorrect.