(A) $(1)$ $\text{Neural system}$: Uses neurotransmitters for rapid,short-lived responses.
$\text{Endocrine system}$: Uses hormones for slower,long-lasting physiological effects.
$(2)$ $\text{Oxytocin}$: Stimulates uterine contractions during childbirth and milk ejection.
$\text{Vasopressin}$: Also known as $\text{ADH}$,it stimulates the reabsorption of $H_2O$ and electrolytes by the distal tubules of the kidney.
$(3)$ $\text{Dwarfism}$: Caused by the hyposecretion of growth hormone $(GH)$ during childhood,leading to stunted growth.
$\text{Gigantism}$: Caused by the hypersecretion of growth hormone $(GH)$ during childhood,leading to abnormal overgrowth of the body.
$(4)$ $FSH$ $(\text{Follicle Stimulating Hormone})$: Stimulates the growth and development of ovarian follicles in females and spermatogenesis in males.
$LH$ $(\text{Luteinizing Hormone})$: Induces ovulation of fully mature follicles and maintains the corpus luteum in females; stimulates the synthesis and secretion of androgens in males.