Posterior Pituitary Flashcards
1
Q
The posterior pituitary develops from the floor of which ventricle
A
3rd ventricle
2
Q
Axons from which hypothalamic nuclei terminate in the posterior pituitary
A
Supraoptic and Paraventricular nuclei
3
Q
What are the three receptors for ADH and what are they responsible for
A
V1- vasoconstriction
V2- water reabsorption in the kidneys
V1b- increased ACTH secretion from the anterior pituitary
4
Q
What is the precursor molecule that oxytocin is synthesized as
A
preoxyphysin
5
Q
Two stimuli for oxytocin
A
- pressure on cervix during contraction
- sucking on nipples
6
Q
Actions of oxytocin
A
- contraction of uterus
- milk ejection
- ejaculation by contraction of vas deferens smooth muscle
7
Q
Where are the hypothalamic osmoreceptors located
A
- organum vasculosum lamina terminalis (OVLT)
- subfornical organ (SFO)
8
Q
Which hormones are released from the posterior pituitary
A
ADH and oxytocin
9
Q
Stimuli for ADH secretion
A
- Large decreases in blood volume
- Decreases in arterial blood pressure
- High osmolarity of the extracellular fluid
10
Q
For SIADH describe: Serum Na+ Urine output Urine Na+ Plasma volume ADH levels
A
Serum Na+ - low Urine output - low Urine Na+ - high Plasma volume - normal/high ADH levels - high
11
Q
For central diabetes insipidus describe: Serum Na+ Urine output Urine Na+ Plasma volume ADH levels
A
Serum Na+ - high Urine output - high Urine Na+ - low Plasma volume - low ADH levels - low
