What is the purpose of leukocytes?
A To transport fluid from interstitial spaces in tissues and return to the blood.
B To transport food and oxygen interstitial spaces in tissues and return to the blood
C To transport air from interstitial spaces in tissues and return to the blood
D To defend the body against foreign invaders and
The correct answer and explanation is:
The correct answer is D) To defend the body against foreign invaders.
Leukocytes, commonly known as white blood cells, are essential components of the immune system. Their primary function is to protect the body against infections, foreign substances, and abnormal cells. These cells circulate in the bloodstream and are able to move to areas of the body where they are needed, such as sites of infection or injury, through a process known as chemotaxis.
Leukocytes come in several different types, each with a specific role in immune defense. For example, neutrophils are the first responders to bacterial infections, engulfing and digesting pathogens through a process called phagocytosis. Lymphocytes, including T-cells and B-cells, are involved in recognizing and attacking infected cells, as well as producing antibodies to neutralize pathogens. Monocytes, which mature into macrophages, are crucial for removing dead cells and pathogens. Eosinophils and basophils play roles in defending against parasitic infections and mediating allergic reactions.
Leukocytes can differentiate between normal body cells and foreign invaders such as bacteria, viruses, and fungi. They have receptors that allow them to detect pathogens or signals from infected cells, initiating an immune response. Once activated, they work together to neutralize or destroy the invaders. Some types of leukocytes also help the body “remember” previous infections, which enables a quicker response if the same pathogen enters the body again, a process known as immunity.
In summary, leukocytes are critical in defending the body from a wide range of threats, including pathogens, toxins, and abnormal cells. Their ability to recognize, attack, and neutralize these threats helps maintain health and prevent disease.