What happens when there is contraction of the dartos muscle?

Contraction of the dartos muscle, also known as the dartos reflex, causes wrinkling and puckering of the skin of the scrotum in males and the labia minora in females. This reflex is an involuntary response to cold temperatures or sexual arousal. It serves to protect the reproductive organs from cold and enhance sexual pleasure. Additionally, contraction of the dartos muscle can lead to erection of the penis and engorgement of the clitoris.