Weegy: Alveoli are the small sacs that are the site of gas exchange in the lungs. User: In addition to being an airway, the _______ is the location of the human vocal cords. Weegy: In addition to being an airway, the "Larynx" is the location of the human vocal cords. User: Cilia in cells along the trachea and nasal passages secrete _______ which traps dirt and particles from the air. Weegy: Cilia in cells along the trachea and nasal passages secrete Mucus which traps dirt and particles from the air. User: ______ are chemical messengers secreted by glands. Weegy: Hormones are chemical messengers that are secreted by glands User: Exocrine glands, such as sweat glands, secrete fluids through ducts. _______ glands secrete hormones directly into the bloodstream. Weegy: Glands which secrete hormones through ducts are called the exocrine glands. User: The _______ gland plays an important role in puberty and growth. (More)

Weegy: The testes are male reproductive organs that produce and store sperm, which is the male gamete containing half of the DNA in somatic cells. User: Lymph ______ are found throughout the body and are a signal of a disease, infection, or problem if they become and remain swollen for long periods of time. Weegy: Lymph nodes are found throughout the body and are a signal of a disease, infection, or problem if they become and remain swollen for long periods of time. User: ______ are pathogens that cannot be killed with antibiotics because they are non-living. They take over cellular organelles to replicate and spread. Weegy: Viruses are pathogens that cannot be killed with antibiotics because they are non-living. They take over cellular organelles to replicate and spread. User: Killing pathogens and then using them to provide the body with active immunity is called ______. This is often done in young children. Weegy: Killing pathogens and then using them to provide the body with active immunity is called IMMUNIZATION . This is often done in young children. User: When the immune system treats otherwise harmless substances, such as pollen, as if they were invaders, a/n ______ can occur. Weegy: When the immune system treats otherwise harmless substances, such as pollen, as if they were invaders, an ALLERGY can occur. User: HIV is a virus that attacks ______ in the body, weakening the immune system. (More)