Podcast
Questions and Answers
Where does hematopoiesis occur in the body?
Where does hematopoiesis occur in the body?
Which cells are involved in the immune system?
Which cells are involved in the immune system?
Which organ is considered part of the lymphoid system?
Which organ is considered part of the lymphoid system?
Where does hematopoiesis begin in humans?
Where does hematopoiesis begin in humans?
Signup and view all the answers
What is the origin of all blood cells?
What is the origin of all blood cells?
Signup and view all the answers
What is the defining characteristic of stem cells?
What is the defining characteristic of stem cells?
Signup and view all the answers
Which type of cell does a stem cell differentiate into early in hematopoiesis?
Which type of cell does a stem cell differentiate into early in hematopoiesis?
Signup and view all the answers
What is the defining characteristic of progenitor cells during hematopoiesis?
What is the defining characteristic of progenitor cells during hematopoiesis?
Signup and view all the answers
What happens to stem cells during the development of the lymphoid and myeloid lineages?
What happens to stem cells during the development of the lymphoid and myeloid lineages?
Signup and view all the answers
Which cells give rise to lymphoid and myeloid progenitors?
Which cells give rise to lymphoid and myeloid progenitors?
Signup and view all the answers
From where do all lymphoid cells descend?
From where do all lymphoid cells descend?
Signup and view all the answers
Where do some dendritic cells come from during hematopoiesis?
Where do some dendritic cells come from during hematopoiesis?
Signup and view all the answers
What is the average lifespan of a RBC (Erythrocyte)?
What is the average lifespan of a RBC (Erythrocyte)?
Signup and view all the answers
How long can WBCs (Leukocytes) live?
How long can WBCs (Leukocytes) live?
Signup and view all the answers
What is hematopoietic homeostasis?
What is hematopoietic homeostasis?
Signup and view all the answers
What is one way in which steady-state regulation of hematopoiesis is accomplished?
What is one way in which steady-state regulation of hematopoiesis is accomplished?
Signup and view all the answers
Which cell types produce cytokines with hematopoietic activity?
Which cell types produce cytokines with hematopoietic activity?
Signup and view all the answers
What is regulated in stem cells and progenitor cells to influence hematopoiesis?
What is regulated in stem cells and progenitor cells to influence hematopoiesis?
Signup and view all the answers
Which morphologic changes are associated with cells undergoing programmed cell death?
Which morphologic changes are associated with cells undergoing programmed cell death?
Signup and view all the answers
Which process leads to the release of cell contents and may induce a local inflammatory response?
Which process leads to the release of cell contents and may induce a local inflammatory response?
Signup and view all the answers
Which type of cell death does not induce a local inflammatory response?
Which type of cell death does not induce a local inflammatory response?
Signup and view all the answers
What percentage of the body’s white blood cells do lymphocytes constitute?
What percentage of the body’s white blood cells do lymphocytes constitute?
Signup and view all the answers
Which cells are responsible for adaptive immunity and immunologic diversity?
Which cells are responsible for adaptive immunity and immunologic diversity?
Signup and view all the answers
What is the predominant cell type in the lymph?
What is the predominant cell type in the lymph?
Signup and view all the answers
What is the defining characteristic of naïve lymphocytes?
What is the defining characteristic of naïve lymphocytes?
Signup and view all the answers
How are different lineages or maturational stages of lymphocytes distinguished?
How are different lineages or maturational stages of lymphocytes distinguished?
Signup and view all the answers
What are blast cells called when they interact with antigen and proliferate?
What are blast cells called when they interact with antigen and proliferate?
Signup and view all the answers
Naïve lymphocytes have not interacted with antigen.
Naïve lymphocytes have not interacted with antigen.
Signup and view all the answers
Lymphoblasts are 15μm-diameter blast cells.
Lymphoblasts are 15μm-diameter blast cells.
Signup and view all the answers
All monoclonal antibodies that react with a particular membrane molecule are grouped together as a cluster of differentiation (CD).
All monoclonal antibodies that react with a particular membrane molecule are grouped together as a cluster of differentiation (CD).
Signup and view all the answers
What is the phase of the cell cycle in which resting (naive or unprimed) lymphocytes reside?
What is the phase of the cell cycle in which resting (naive or unprimed) lymphocytes reside?
Signup and view all the answers
What do B and T lymphocytes enlarge into after antigen activation?
What do B and T lymphocytes enlarge into after antigen activation?
Signup and view all the answers
At what stage can B and T lymphocytes not be distinguished morphologically?
At what stage can B and T lymphocytes not be distinguished morphologically?
Signup and view all the answers
Where do B cells mature in birds?
Where do B cells mature in birds?
Signup and view all the answers
What distinguishes mature B cells from other lymphocytes?
What distinguishes mature B cells from other lymphocytes?
Signup and view all the answers
What is the fate of memory B cells?
What is the fate of memory B cells?
Signup and view all the answers
Where do T lymphocytes (T cells) mature?
Where do T lymphocytes (T cells) mature?
Signup and view all the answers
What is the main site of antigen recognition for T cells?
What is the main site of antigen recognition for T cells?
Signup and view all the answers
Which subpopulation of T cells generally functions as T cytotoxic (Tc) cells?
Which subpopulation of T cells generally functions as T cytotoxic (Tc) cells?
Signup and view all the answers
Which receptor do Natural Killer (NK) cells express that allows them to attach to antibodies and subsequently destroy targeted cells?
Which receptor do Natural Killer (NK) cells express that allows them to attach to antibodies and subsequently destroy targeted cells?
Signup and view all the answers
What is the primary function of Natural Killer (NK) cells in the innate immune response?
What is the primary function of Natural Killer (NK) cells in the innate immune response?
Signup and view all the answers
Which type of lymphocyte is large, granular, and involved in the innate immune response?
Which type of lymphocyte is large, granular, and involved in the innate immune response?
Signup and view all the answers
Which cells do not express clonally distributed receptors for antigens but participate in initiating lymphocyte responses to antigens?
Which cells do not express clonally distributed receptors for antigens but participate in initiating lymphocyte responses to antigens?
Signup and view all the answers
Which cells originate in the bone marrow, circulate in the blood, and mature into macrophages in various tissues?
Which cells originate in the bone marrow, circulate in the blood, and mature into macrophages in various tissues?
Signup and view all the answers
What are the cells that settle in tissues, mature, and become macrophages?
What are the cells that settle in tissues, mature, and become macrophages?
Signup and view all the answers
What is the fate of the digested antigen after phagocytosis?
What is the fate of the digested antigen after phagocytosis?
Signup and view all the answers
What enhances phagocytosis?
What enhances phagocytosis?
Signup and view all the answers
What happens to some of the digested antigen after phagocytosis?
What happens to some of the digested antigen after phagocytosis?
Signup and view all the answers
Where are follicular dendritic cells (FDCs) primarily found?
Where are follicular dendritic cells (FDCs) primarily found?
Signup and view all the answers
Which type of dendritic cells has long membranous extensions resembling dendrites on nerve cells?
Which type of dendritic cells has long membranous extensions resembling dendrites on nerve cells?
Signup and view all the answers
What is the primary role of dendritic cells in the immune system?
What is the primary role of dendritic cells in the immune system?
Signup and view all the answers
Which leukocyte is the first to arrive at the site of inflammation?
Which leukocyte is the first to arrive at the site of inflammation?
Signup and view all the answers
Which leukocyte plays a role in parasitic organism defense?
Which leukocyte plays a role in parasitic organism defense?
Signup and view all the answers
Which leukocyte plays a role in allergic reactions?
Which leukocyte plays a role in allergic reactions?
Signup and view all the answers
Where do mature lymphocytes interact with antigens in the immune system?
Where do mature lymphocytes interact with antigens in the immune system?
Signup and view all the answers
Which organs are considered primary lymphoid organs responsible for the maturation of lymphocytes?
Which organs are considered primary lymphoid organs responsible for the maturation of lymphocytes?
Signup and view all the answers
What is the function of gut-associated lymphoid tissues (GALT) in the immune system?
What is the function of gut-associated lymphoid tissues (GALT) in the immune system?
Signup and view all the answers
Primary organs of the immune system are thymus and bone marrow.
Primary organs of the immune system are thymus and bone marrow.
Signup and view all the answers
Once mature lymphocytes have been generated in the primary lymphoid organs, they circulate in the blood and lymphatic system.
Once mature lymphocytes have been generated in the primary lymphoid organs, they circulate in the blood and lymphatic system.
Signup and view all the answers
Lymph nodes, spleen, and mucosa-associated lymphoid tissues are examples of secondary organs of the immune system.
Lymph nodes, spleen, and mucosa-associated lymphoid tissues are examples of secondary organs of the immune system.
Signup and view all the answers
Bone marrow is the site of generation of all circulating blood cells.
Bone marrow is the site of generation of all circulating blood cells.
Signup and view all the answers
T cells mature in the thymus.
T cells mature in the thymus.
Signup and view all the answers
The function of the thymus includes generating and selecting a repertoire of T cells to protect the body from infection.
The function of the thymus includes generating and selecting a repertoire of T cells to protect the body from infection.
Signup and view all the answers
Where does hematopoiesis occur mostly?
Where does hematopoiesis occur mostly?
Signup and view all the answers
What is the primary function of the thymus?
What is the primary function of the thymus?
Signup and view all the answers
Where do immature B cells proliferate and differentiate?
Where do immature B cells proliferate and differentiate?
Signup and view all the answers
What is the primary function of the thymus?
What is the primary function of the thymus?
Signup and view all the answers
Where do T cells mature?
Where do T cells mature?
Signup and view all the answers
What decreases with age?
What decreases with age?
Signup and view all the answers
Where is interstitial tissue fluid carried into progressively larger lymphatic vessels?
Where is interstitial tissue fluid carried into progressively larger lymphatic vessels?
Signup and view all the answers
What is the fluid called after it leaves the lymph nodes?
What is the fluid called after it leaves the lymph nodes?
Signup and view all the answers
Where does the lymph finally drain into the circulatory system?
Where does the lymph finally drain into the circulatory system?
Signup and view all the answers
Where are immune responses initiated?
Where are immune responses initiated?
Signup and view all the answers
Which region of the lymph node contains T helper cells and dendritic cells?
Which region of the lymph node contains T helper cells and dendritic cells?
Signup and view all the answers
What is the primary cell type found in the medulla of the lymph node?
What is the primary cell type found in the medulla of the lymph node?
Signup and view all the answers
Where are old and defective red blood cells destroyed and removed?
Where are old and defective red blood cells destroyed and removed?
Signup and view all the answers
Which type of lymphocytes are mainly populated in the PALS (periarteriolar lymphoid sheath) of the white pulp in the spleen?
Which type of lymphocytes are mainly populated in the PALS (periarteriolar lymphoid sheath) of the white pulp in the spleen?
Signup and view all the answers
Through which vessel are blood-borne antigens and lymphocytes carried into the spleen?
Through which vessel are blood-borne antigens and lymphocytes carried into the spleen?
Signup and view all the answers
Where are Peyer’s patches found?
Where are Peyer’s patches found?
Signup and view all the answers
Which organ defends against antigens entering through nasal and oral epithelial routes?
Which organ defends against antigens entering through nasal and oral epithelial routes?
Signup and view all the answers
Where are the adenoids located?
Where are the adenoids located?
Signup and view all the answers
Where are M cells located?
Where are M cells located?
Signup and view all the answers
What is the main function of Peyer's patches in the intestine?
What is the main function of Peyer's patches in the intestine?
Signup and view all the answers
Where is the antigen released after being transported across M cells?
Where is the antigen released after being transported across M cells?
Signup and view all the answers
Where does antigen transportation across the epithelial layer by M cells take place?
Where does antigen transportation across the epithelial layer by M cells take place?
Signup and view all the answers
What do activated B cells differentiate into after being activated in the underlying lymphoid follicles?
What do activated B cells differentiate into after being activated in the underlying lymphoid follicles?
Signup and view all the answers
What is the primary characteristic of intraepithelial lymphocytes in the outer mucosal epithelial layer?
What is the primary characteristic of intraepithelial lymphocytes in the outer mucosal epithelial layer?
Signup and view all the answers
Which cells are primarily responsible for inducing a local inflammatory reaction in the skin?
Which cells are primarily responsible for inducing a local inflammatory reaction in the skin?
Signup and view all the answers
What type of cells in the skin can express class II MHC molecules and function as antigen-presenting cells?
What type of cells in the skin can express class II MHC molecules and function as antigen-presenting cells?
Signup and view all the answers
What is the main function of the epidermal layer of the skin in nonspecific (innate) defenses?
What is the main function of the epidermal layer of the skin in nonspecific (innate) defenses?
Signup and view all the answers
What is the defining characteristic of a secondary follicle?
What is the defining characteristic of a secondary follicle?
Signup and view all the answers
What comprises a primary follicle?
What comprises a primary follicle?
Signup and view all the answers
What happens to a primary follicle after antigenic activation?
What happens to a primary follicle after antigenic activation?
Signup and view all the answers
Which vertebrates lack B and T cells and cannot mount adaptive immune responses?
Which vertebrates lack B and T cells and cannot mount adaptive immune responses?
Signup and view all the answers
What do jawed vertebrates possess that jawless fishes lack?
What do jawed vertebrates possess that jawless fishes lack?
Signup and view all the answers
What is the primary characteristic of a secondary lymphoid follicle?
What is the primary characteristic of a secondary lymphoid follicle?
Signup and view all the answers
What causes phagocytes and lymphocytes to leave the blood stream and enter the affected area during an infection?
What causes phagocytes and lymphocytes to leave the blood stream and enter the affected area during an infection?
Signup and view all the answers
How do distant sites ensure activation of T cells and B cells in response to infection?
How do distant sites ensure activation of T cells and B cells in response to infection?
Signup and view all the answers
What brings lymphocytes and other leukocytes to the site of infection?
What brings lymphocytes and other leukocytes to the site of infection?
Signup and view all the answers
Chemotactic signals are generated that can cause phagocytes and lymphocytes to leave the blood stream and enter the affected area.
Chemotactic signals are generated that can cause phagocytes and lymphocytes to leave the blood stream and enter the affected area.
Signup and view all the answers
Inflammatory processes bring only lymphocytes to the site of infection.
Inflammatory processes bring only lymphocytes to the site of infection.
Signup and view all the answers
Antigen from distant sites can arrive at lymph nodes via lymph and dendritic cells, thereby assuring activation of T cells and B cells.
Antigen from distant sites can arrive at lymph nodes via lymph and dendritic cells, thereby assuring activation of T cells and B cells.
Signup and view all the answers
Study Notes
Hematopoiesis
- Occurs in the body mainly in the bone marrow
- Involves the development of all blood cells from hematopoietic stem cells
Immune System
- Involves lymphoid cells, including B cells and T cells, which originate from hematopoietic stem cells
- Key players: B cells, T cells, natural killer cells, dendritic cells, macrophages
Hematopoietic Stem Cells
- Define characteristic: ability to self-renew and differentiate into multiple cell types
- Early in hematopoiesis, differentiate into myeloid or lymphoid progenitor cells
- Give rise to lymphoid and myeloid progenitors, which develop into different blood cells
Progenitor Cells
- Defining characteristic: ability to differentiate into specific cell types
- During hematopoiesis, proliferate and differentiate into mature blood cells
Lymphoid and Myeloid Lineages
- Develop from hematopoietic stem cells
- Lymphoid lineage: gives rise to lymphoid cells (B cells, T cells, natural killer cells)
- Myeloid lineage: gives rise to myeloid cells (red blood cells, platelets, granulocytes, monocytes)
Blood Cells
- Red blood cells (erythrocytes): average lifespan of 120 days
- White blood cells (leukocytes): lifespan varies, some can live for years, others for only a few days
- Platelets: lifespan of 7-10 days
Lymphocytes
- Constitute 20-40% of white blood cells
- B cells: responsible for adaptive immunity and immunologic diversity
- T cells: mature in the thymus, involved in cell-mediated immunity
- Naïve lymphocytes: have not interacted with antigen, reside in G0 phase of the cell cycle
- Activated lymphocytes: enlarge and proliferate after antigen interaction
Dendritic Cells
- Originate from hematopoietic stem cells
- Primary role: antigen presentation to T cells
- Found in lymphoid organs, skin, and other tissues
Phagocytosis
- Process by which cells engulf and digest foreign particles and antigen
- Enhances phagocytosis: opsonins, complement system
- Fate of digested antigen: some is presented to T cells, some is destroyed
Immune Response
- Initiated in secondary lymphoid organs (lymph nodes, spleen, mucosa-associated lymphoid tissues)
- Involves interaction between antigen-presenting cells, T cells, and B cells
- Chemotactic signals attract phagocytes and lymphocytes to sites of infection
Lymphoid Organs
- Primary lymphoid organs: bone marrow, thymus
- Secondary lymphoid organs: lymph nodes, spleen, mucosa-associated lymphoid tissues
- Functions: maturation of lymphocytes, activation of immune responses
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on hematopoiesis, cells of the immune system, organs of the immune system, and evolutionary comparisons of lymphoid cells and organs. This quiz covers key concepts in immunology and hematopoiesis.
