State whether true or false :
$(1)$ Gastrointestinal tract,kidney and heart also produce hormones.
$(2)$ Pars distalis produces six trophic hormones.
$(3)$ $B$-lymphocytes provide cell-mediated immunity.
$(4)$ Insulin resistance results in a disease called diabetes mellitus.

(A) $(1)$ True. The gastrointestinal tract secretes hormones like gastrin,$CCK$,secretin,and $GIP$. The heart secretes Atrial Natriuretic Factor $(ANF)$,and the kidney secretes erythropoietin.
$(2)$ True. Pars distalis secretes six trophic hormones: $GH$,$PRL$,$TSH$,$ACTH$,$LH$,and $FSH$.
$(3)$ False. $T$-lymphocytes provide cell-mediated immunity,whereas $B$-lymphocytes are responsible for humoral immunity.
$(4)$ True. Insulin resistance or insufficient insulin production leads to diabetes mellitus.