Thymus Gland Structure and Function

Play an AI-generated podcast conversation about this lesson

Where do immature lymphocytes differentiate into T lymphocytes?

Thymus gland (correct)

Spleen

Bone marrow

Lymph nodes

Which organ collects antigens from the bloodstream?

Thymus gland

Spleen (correct)

Lymph nodes

MALT

Where do mature T lymphocytes primarily locate in the spleen?

Medulla

Cortex

Red pulp

White pulp (correct)

During which developmental stage does the thymus gland increase in size?

Infancy Signup and view all the answers

What is the primary function of the medulla in the thymus gland?

Migrate T lymphocytes to secondary lymphoid organs Signup and view all the answers

Where do mature B cells primarily locate in the spleen?

White pulp Signup and view all the answers

Which cells express MHC molecules on their surface?

Healthy cells Signup and view all the answers

What is the role of MHC molecules in the activation of T cells?

Presenting foreign antigens to T cells Signup and view all the answers

Why do mature red blood cells not express MHC molecules on their surface?

Due to lack of nucleus Signup and view all the answers

What is the function of the deep groove in the outer region of MHC molecules?

Peptide-binding site Signup and view all the answers

Why do key amino acid sequences in MHC proteins vary widely from person to person?

As identity markers on cell surfaces Signup and view all the answers

Which diseases are mentioned as potentially involving overabundance of cytokines causing tissue damage?

COVID-19, influenza and Ebola virus disease Signup and view all the answers

What is the main immunological function of the spleen?

Breaking down defective red blood cells and pathogens Signup and view all the answers

Where are lymph nodes located in the body?

Groin, armpits, neck, and along the small intestine Signup and view all the answers

Which layer of a lymph node contains mainly B cells?

Cortex Signup and view all the answers

What type of tissues contain non-encapsulated small aggregations of lymphocytes?

Mucosa of the digestive, respiratory, and urinary tracts Signup and view all the answers

What is the role of MALT in the body?

Neutralizing pathogens before they enter the body Signup and view all the answers

Which immune cells are mainly responsible for mounting immune responses in lymph nodes?

T and B lymphocytes Signup and view all the answers

What is the purpose of fusing lysosomes with the phagosome?

Antigen processing Signup and view all the answers

How do superantigens differ from protein antigens in terms of presentation to T cells?

Activate a large fraction of T cells directly Signup and view all the answers

What is the consequence of activating large numbers of Th-lymphocytes by superantigens?

Excessive cytokine secretion Signup and view all the answers

Which pathogen toxin is responsible for toxic shock syndrome?

Staphylococcal toxic shock toxin Signup and view all the answers

What happens when cells become infected by intracellular pathogens like viruses?

MHC-I molecules collect peptides Signup and view all the answers

Which type of T cells are recognized by MHC class I molecules presenting viral peptides?

CD8+ T cells Signup and view all the answers

What is the term used to describe the second signal a T cell receives from an antigen-presenting cell to become activated?

Costimulation Signup and view all the answers

Which molecules on the antigen-presenting cell (APC) bind with CD28 on the T cell to provide the second signal for T cell activation?

B7.1 and B7.2 Signup and view all the answers

In the humoral immune response, what are the main targets of antibody production?

Extracellular organisms Signup and view all the answers

What is the main function of plasma cells in the immune response?

Secrete antibodies Signup and view all the answers

Which type of cells costimulate B cells in the humoral immune response?

T helper cells Signup and view all the answers

What is the observed physical sign of lymph node swelling usually indicative of?

Efficient immune response to infection Signup and view all the answers