Type of muscle that pumps blood to the heart

As you sit in the library with your friend studying for your weekly quiz on the integumentary system, you come upon an article about the hazards of prolonged exposure to the sun's rays. your curious nature leads you to research the subject further. you're fascinated to learn that minimal exposure to the sun allows you skin to manufacture vitamin d, which is important to maintain homeostasis. you also read that although sunscreen can protect you from the ultraviolet (uv) rays of the sun, some medications can actually increase a person's sensitivity to the sunlight.

Protein deficiency can result in a malfunctioning metabolism, a weak or irregular immune system, and possible blindness and deafness a rapid period of weight loss a significant and rapid weight gain damage to connective tissue and bones

Some bacteria injure cells by giving off poisons called pathogens antibodies phagocytes toxins