Natural Killer Cells Function and Characteristics

Play an AI-generated podcast conversation about this lesson

Which of the following statements about natural killer (NK) cells is correct?

They cannot lyse target cells that have undergone malignant transformation.

They do not play a role in antibody-dependent cellular cytotoxicity (ADCC).

They have an 'activating receptor' that recognizes carbohydrate ligands. (correct)

They express antigen-specific receptors.

Which of the following statements about the complement system is correct?

The term 'complement' refers to its ability to complement the effects of other immune system components. (correct)

Complement proteins are synthesized solely by the liver.

Complement proteins do not interact via proteolytic cascades.

The complement system functions only in the innate host defense system.

Which of the following statements about NK cell receptors is correct?

The 'activating receptor' on NK cells recognizes MHC class I molecules.

NK cells have only one type of surface receptor.

The 'inhibitory receptor' on NK cells recognizes MHC class II molecules.

NK cells have an 'inhibitory receptor' that recognizes MHC class I molecules. (correct)

Which of the following best describes the role of antibodies in the immune system?

Antibodies enhance the ability of other immune components to eliminate pathogens and infected cells. Signup and view all the answers

Which of the following statements about the complement system is incorrect?

Complement proteins are synthesized only by phagocytic cells. Signup and view all the answers

Which of the following statements about antibodies is incorrect?

Antibodies directly lyse target cells through their own cytotoxic mechanisms. Signup and view all the answers

Which of the following statements about type I interferons (IFNs) is correct?

They are highly effective inhibitors of viral replication. Signup and view all the answers

Which of the following is NOT a main function of phagocytic cells during infections?

Antibody production Signup and view all the answers

Which of the following statements about phagocytosis is correct?

It is the process by which pathogens are ingested and killed by phagocytic cells. Signup and view all the answers

Which of the following cells are considered mononuclear phagocytic cells?

Macrophages and Kupffer cells Signup and view all the answers

What is the primary function of the spleen in the context of immune defense?

Filtering microorganisms from the bloodstream Signup and view all the answers

Patients with a non-functional or removed spleen are at increased risk of which type of infection?

Bacterial sepsis, particularly with pneumococci and salmonellae Signup and view all the answers

What is the primary mechanism by which the organism can overcome antibody-mediated resistance?

Breaking down the antibody with a protease Signup and view all the answers

Which of the following is a key function of phagocytes in the body's defense against pathogens?

Preventing the further spread of large numbers of bacteria Signup and view all the answers

Which of the following is a mechanism by which the mucociliary apparatus aids in the removal of bacteria in the respiratory tract?

Stimulating the cough reflex to expel bacteria Signup and view all the answers

What is the primary function of the acidity of the stomach in inactivating ingested bacteria?

Killing many ingested bacteria, such as Vibrio cholerae Signup and view all the answers

Which of the following is a way in which the normal microbial flora of the body's mucous membranes can help defend against pathogenic microorganisms?

Competing with pathogens for resources and attachment sites Signup and view all the answers