Correct Answer: B

Rationale: Albuterol, also known as salbutamol, is a beta-adrenergic agonist medication commonly used for the treatment of conditions such as asthma and COPD. As a beta-adrenergic agonist, albuterol binds to beta-2 adrenergic receptors in the lungs, causing bronchodilation, which helps to relieve bronchospasms and improve airflow to the lungs. This action leads to the relaxation of smooth muscle in the airways, thus making breathing easier for patients with COPD or asthma. Anticholinergics, corticosteroids, and methylxanthines have different mechanisms of action and are not directly related to the pharmacological action of albuterol in COPD treatment.

Correct Answer: C

Rationale: Feces, urine, blood, and other body fluids are considered as vehicles of transmission in the context of communicable diseases. These substances can carry and transmit disease-causing microorganisms such as bacteria, viruses, and parasites from infected individuals to others. Through close contact or exposure to these contaminated body fluids, the pathogens can enter the body of another person and cause infection. Nurses like Nurse Keena must exercise caution and use appropriate infection control measures to prevent transmission of communicable diseases through these vehicles.

Correct Answer: D

Rationale: Complete abortion is the most likely cause of the symptoms described. In a complete abortion, all products of conception are expelled from the uterus. Symptoms include vaginal bleeding, passage of tissue, and dilation of the cervix. In this scenario, the presentation of a dilated cervix with visualized products of conception is classic for a complete abortion at 10 weeks gestation.

Correct Answer: C

Rationale: Humoral immunity is primarily responsible for protecting against infections by pathogens like viruses. In the case of the hepatitis B virus (HBV), the individual is exposed to the virus and develops immunity, which is typically mediated by antibodies produced by B cells. These antibodies circulate in the blood and can neutralize the virus, preventing future infections. This type of immunity is known as humoral immunity, as it involves the production of antibodies that target specific antigens, such as those present on the surface of the hepatitis B virus. In contrast, passive immunity is when antibodies are transferred from an external source, innate immunity provides immediate, non-specific defenses against pathogens, and cell-mediated immunity involves the activation of T cells to combat intracellular pathogens.

Correct Answer: B

Rationale: Radiologic procedures are typically not used as the least screening assessment by nurses in a perinatal unit. The nurse's initial screening assessments usually focus on gathering information through techniques such as physical examination, interviews, and reviewing laboratory results. Radiologic procedures, such as X-rays or CT scans, are usually ordered by physicians once a more specific diagnostic need has been identified, based on the initial screening assessments performed by the nurse. Therefore, in this scenario, the least screening assessment to be used by the nurse would be radiologic procedures.