What are the target tissues for the hormone oxytocin? What is the condition caused by thyroxine deficiency?

Oxytocin targets the cervix and aids in labor and also orgasm in females. I don't know what that other thing is.

Letdown reflex ? in lactating (breastfeeding) mothers, oxytocin acts at the mammary glands, causing milk to be 'let down' into a collecting chamber, from where it can be extracted by sucking at the nipple. Sucking by the infant at the nipple is relayed by spinal nerves to the hypothalamus.

Uterine contraction ? important for cervical dilation before birth and causes contractions during the second and third stages of labor.
Oxytocin is secreted into the blood at orgasm ? in both males and females (Carmichael et al 1987). In males, oxytocin may facilitate sperm transport in ejaculation.

Due to its similarity to vasopressin, it can reduce the excretion of urine slightly.
More important, in several species, oxytocin can stimulate sodium excretion from the kidneys (natriuresis), and in humans, high doses of oxytocin can result in hyponatremia.

2.Hypothyroidism is the case where there is a deficiency of thyroxine