I1: I Flashcards by S F

MCQ: During an acute infection, approximately what percentage of the body’s total energy is consumed by the immune system?
A. 5–10%
B. 10–15%
C. 20–30%
D. 40–50%

C. 20–30%

How well did you know this?

Not at all

Perfectly

Fill in the blank: The two primary immune organs where immune cells are born or mature are the ______ and the ______.

Bone marrow; Thymus

How well did you know this?

Not at all

Perfectly

MRQ: Which of the following are classified as secondary immune organs?
A. Spleen
B. Bone marrow
C. Lymph nodes
D. Peyer’s patches

A, C, D

How well did you know this?

Not at all

Perfectly

FFQ: Explain why fever and fatigue are considered energy‑relocation strategies.

During infection the immune system consumes ~20–30% of body energy. Fever and fatigue redirect energy away from activity toward immune defense.

How well did you know this?

Not at all

Perfectly

MCQ: All immune cells originate from which cell?
A. Myeloid progenitor
B. Haematopoietic stem cell
C. Lymphoid progenitor
D. Naive T cell

B. Haematopoietic stem cell

How well did you know this?

Not at all

Perfectly

Fill in the blank: The immune system consists of approximately ______ immune cells.

102 trillion

How well did you know this?

Not at all

Perfectly

MRQ: Myeloid lineage cells include:
A. Neutrophils
B. NK cells
C. Monocytes
D. Eosinophils

A, C, D

How well did you know this?

Not at all

Perfectly

MCQ: Which lymphoid cell functions in innate immunity?
A. B lymphocyte
B. Plasma cell
C. NK cell
D. CD4 T cell

C. Natural Killer (NK) cell

How well did you know this?

Not at all

Perfectly

FFQ: Contrast innate vs adaptive immunity.

Innate cells respond rapidly and non‑specifically without memory. Adaptive cells respond specifically and develop long‑term memory.

How well did you know this?

Not at all

Perfectly

MCQ: Most potent professional APC?
A. Macrophage
B. B lymphocyte
C. Dendritic cell
D. Neutrophil

C. Dendritic cell

How well did you know this?

Not at all

Perfectly

Fill in the blank: The most abundant white blood cell is the ______.

Neutrophil

How well did you know this?

Not at all

Perfectly

MRQ: Professional APCs expressing MHC II include:
A. Dendritic cells
B. Neutrophils
C. Macrophages
D. B lymphocytes

A, C, D

How well did you know this?

Not at all

Perfectly

MCQ: APCs present antigen on MHC II to:
A. CD8 T cells
B. NK cells
C. CD4 T cells
D. Plasma cells

C. CD4+ Helper T cells

How well did you know this?

Not at all

Perfectly

FFQ: Explain the Rule of 8 for MHC.

MHC I presents endogenous peptides to CD8 cells (1×8). MHC II presents exogenous peptides to CD4 cells (2×4).

How well did you know this?

Not at all

Perfectly

Fill in the blank: Signaling to nearby cells is ______ signaling; signaling to the same cell is ______.

Paracrine; Autocrine

How well did you know this?

Not at all

Perfectly

MRQ: Immune signaling pathways include:
A. JAK‑STAT
B. NF‑κB
C. Krebs Cycle
D. MAPK

A, B, D

How well did you know this?

Not at all

Perfectly

MCQ: Function of chemokines?
A. Kill bacteria
B. Guide cell migration
C. Cause fever
D. Neutralize toxins

B. Guide cell migration

How well did you know this?

Not at all

Perfectly

Fill in the blank: Short‑range immune signaling proteins are ______.

Cytokines

How well did you know this?

Not at all

Perfectly

FFQ: Components of an immunologic synapse.

Interaction between APC and T cell including TCR–MHC binding, B7–CD28 co‑stimulation and adhesion molecules.

How well did you know this?

Not at all

Perfectly

MCQ: Cytotoxic pathway used by NK and CD8 cells:
A. Phagocytosis
B. Perforin‑granzyme
C. Histamine release
D. Opsonization

B. Perforin‑granzyme pathway

How well did you know this?

Not at all

Perfectly

MRQ: Antibody effector outcomes include:
A. Neutralization
B. Phagocytosis of antibody
C. Opsonization
D. Complement activation

A, C, D

How well did you know this?

Not at all

Perfectly

Fill in the blank: IgE‑mediated hypersensitivity cells are ______.

Mast cells

How well did you know this?

Not at all

Perfectly

FFQ: Role of co‑stimulation in T‑cell activation.

B7 on APC binding CD28 on T cells provides the second signal required for full activation.

How well did you know this?

Not at all

Perfectly

MCQ: Cell defending against helminths:
A. Neutrophil
B. CD8 T cell
C. Eosinophil
D. M1 macrophage

C. Eosinophil

How well did you know this?

Not at all

Perfectly

MRQ: CD4 T helper subsets include: A. Th1 B. Th17 C. Plasma cells D. Tfh

A, B, D

Fill in the blank: B cells differentiate into ______ cells.

Plasma

FFQ: Role of CD4 helper T cells.

They coordinate immune responses via cytokine signaling to other immune cells.

MCQ: Cell preventing autoimmunity: A. Memory B cell B. Regulatory T cell C. CD8 T cell D. Dendritic cell

B. Regulatory T cell

MRQ: Sentinel cells include: A. Epithelial cells B. Dendritic cells C. Plasma cells D. Macrophages

A, B, D

Fill in the blank: Barrier epithelial cells release alarmins such as ______ and ______.

IL‑25; IL‑33

FFQ: Importance of memory cells.

They enable rapid antigen‑specific responses upon re‑exposure and underpin vaccination.

MCQ: Clinical immunology bridges: A. Biochemistry and physiology B. Laboratory bench and bedside C. Surgery and medicine D. Pharmacology and radiology

B. The laboratory bench and the patient's bedside

MRQ: Categories of immune‑mediated disease: A. IEI B. Autoimmune C. Autoinflammatory D. Allergic

A, B, C, D

Fill in the blank: There are approximately ______ inborn errors of immunity.

570–600

FFQ: Autoimmunity vs autoinflammation.

Autoimmunity involves adaptive immunity against self antigens. Autoinflammation involves dysregulated innate immunity.

MCQ: Example of secondary immune deficiency: A. Type 1 diabetes B. SCID C. HIV infection D. Asthma

C. HIV infection

MRQ: Effector mechanisms include: A. Phagocytosis B. Cytotoxic killing C. Degranulation D. Antigen creation

A, B, C

Fill in the blank: The immune system can recognize about ______ antigens.

100000000

FFQ: NK vs CD8 recognition.

CD8 T cells recognize antigen on MHC I; NK cells kill cells lacking normal MHC I.

MCQ: MALT is located: A. Primary organs B. Tissues/mucosa C. Bone marrow only D. Spleen only

B. Outside the bloodstream in tissues/mucosa

MRQ: Main immune functions: A. Defense B. Tolerance C. Repair D. Memory

A, B, C, D

Fill in the blank: Innate immune cells detect pathogens using ______ recognition receptors.

Pattern

FFQ: What occurs when receptor signals reach the nucleus?

Signaling cascades activate transcription factors leading to gene expression.

MCQ: NK killing of antibody‑coated cells is: A. Opsonization B. Complement activation C. ADCC D. Degranulation

C. Antibody‑dependent cellular cytotoxicity

MRQ: Why immunology is difficult: A. High detail B. Cross‑talk C. Exceptions D. Irrelevant

A, B, C

Fill in the blank: Myeloid lineage mainly produces ______ immunity cells; lymphoid lineage produces ______ immunity cells.

Innate; Adaptive

FFQ: Importance of cross‑talk.

Immune cells communicate via cytokines and feedback loops to regulate responses.

MCQ: Short‑lived NET‑forming cell: A. Macrophage B. Monocyte C. Neutrophil D. Mast cell

C. Neutrophil

MRQ: Barrier sites include: A. Skin B. Airway mucosa C. Gut mucosa D. Liver parenchyma

A, B, C

Fill in the blank: Advanced treatments include ______, biologics and gene editing.

Immunotherapies

Match the cell type to its surface marker: B-cell: CD19 All mature T-cells: CD3 Helper T-cells: CD4 Cytotoxic T-cells: CD8

Match the cell to its lineage/stage in the bone marrow diagram: A: Common lymphoid progenitor B: Common myeloid progenitor C: Plasma cell D: Macrophage

Which type of immunity involves phagocytes and the complement system?

Innate immunity

Which immune cells are the first responders in an innate immune response to a virus?

NK cells

What is the main function of HLA molecules?

To distinguish self from non-self

Which cell is considered the most potent professional antigen-presenting cell?

Dendritic cell

Which antibody is the first class produced during a primary infection?

IgM

The innate immune system is more specific than the adaptive immune system.

False (Adaptive is highly specific).

T-cells and B-cells are primary role players in the innate immune system.

False (They are adaptive).

List the three steps of phagocytosis:

Opsonisation, immune adherence, and internalisation

HLA Class I is presented on which cells?

All nucleated cells

Where do B-cells and T-cells mature?

B-cells in Bone marrow; T-cells in Thymus/GALT

A patient is found to have a genetic defect in the common lymphoid progenitor. Which of the following effector functions would be most severely impaired? A. Phagocytosis of bacteria by neutrophils B. Histamine release from mast cells C. Production of high-affinity antibodies D. Immediate detection of PAMPs by macrophages

C. Production of high-affinity antibodies (B-cells are lymphoid lineage).

According to the "Team Sport" analogy of the immune system, which cells would be classified as "The Backs"? A. Neutrophils and Macrophages B. Mast cells and Basophils C. B-lymphocytes and T-lymphocytes D. Dendritic cells and NK cells

C. B-lymphocytes and T-lymphocytes.

The immune system consumes approximately 5% of total body energy during an acute infection.

False (It consumes 20–30% of total energy).

Innate lymphoid cells (ILCs) possess specific antigen receptors like TCRs.

False (They have no antigen receptors).

The immune system’s ability to recognize "danger" rather than a specific antigen is mediated by ________ receptors.

Pattern recognition (PRR).

The main function of the immune system associated with healing is ________.

Repair.

Column A (Function) | Column B (Cell/Molecule) 1. Guidance of cell movement | Chemokines 2. Elimination of "sick" (viral) cells | CD8+ Cytotoxic T-cells 3. Coordination via "cytokine showers" | CD4+ Helper T-cells 4. Rapid microbial killing in acute infection | Neutrophils

Explain the role of MHC II molecules in cell-cell communication.

MHC II molecules are expressed by professional APCs to present processed antigen peptides to CD4+ helper T-cells, effectively "talking" to the adaptive system to initiate a response.

What are the five main functions of the immune system?

Defense (attack), Remember (memory), Tolerate (tolerance), Regulate (control), and Repair (healing).

From which cell do all immune cells originate?

A single hematopoietic stem cell.

Which cells belong to the myeloid lineage?

Neutrophils, Eosinophils, Basophils, Monocytes/Macrophages, Dendritic cells, and Mast cells.

Which cells belong to the lymphoid lineage?

B-lymphocytes, T-lymphocytes, and Natural Killer (NK) cells.

What are PRRs and which system uses them?

Pattern Recognition Receptors; used by the innate immune system to respond non-specifically to any invader.

Contrast the memory of the innate and adaptive systems.

Innate has no memory; Adaptive has long-lasting memory that improves with every exposure.

What is the primary function of a Dendritic cell?

Antigen capture, internalisation, and presentation to initiate the immune response (most potent professional APC).

Which cells are responsible for "Type 2" effectors (parasite and allergy)?

Eosinophils, Mast cells, and Basophils.

What is the role of the J chain in an antibody?

It joins the five immunoglobulin molecules together to form an IgM pentamer.

Define Chemokines.

Signaling proteins that guide cell movement, directing them toward lymphoid organs or inflamed tissue.

What is the CD4 count threshold for an AIDS diagnosis?

Below 200 cells/μL.

Which MHC molecule presents endogenous (internal) peptides to CD8+ cells?

MHC Class I.

Which MHC molecule presents exogenous (processed) peptides to CD4+ cells?

MHC Class II.

What are the two main domains of an antibody?

One for antigen binding (Fab) and one for specific effector functions (Fc).

Why is immunology described as a "team sport"?

Because it relies on multiple pathways, cross-talk, and feedback loops involving both "forwards" (innate) and "backs" (adaptive) to function effectively.

The immune system consumes ________ of the body’s energy during an acute infection.

20–30%

Fever and fatigue are not side effects but ________ strategies during an infection.

energy-relocation

The body has the potential for specific immunity against ________ different antigens.

100 million

Immune memory is remarkably long-lived, often lasting for ________.

decades

The two primary immune organs where cells are born and trained are the ________ and the ________.

bone marrow; thymus

The "commuter system" used to transport immune cells consists of the ________ and ________.

blood; lymphatic vessels

Secondary immune organs, where immune responses are often initiated, include the lymph nodes, spleen, ________, and tonsils.

Peyer’s patches

The majority of immunity happens outside the bloodstream in the ________.

tissues (such as MALT)

All immune cells originate from a single ________.

haematopoietic stem cell

The two main lineages of immune cells are the ________ lineage and the ________ lineage.

myeloid; lymphoid

________ are the most abundant white blood cells and act as rapid, short-lived microbial killers.

Neutrophils

________ are considered the most potent "professional" antigen-presenting cells.

Dendritic cells

________ belong to the lymphoid lineage but provide innate cytotoxicity that is ________.

Natural killer (NK) cells; MHC-independent

The innate immune system uses ________ to respond non-specifically to any invader.

pattern-recognition receptors (PRRs)

Unlike the innate system, the ________ immune response improves with every subsequent exposure to an antigen.

adaptive

Sentinels of the innate system detect danger by sensing ________ and ________.

PAMPs; DAMPs

CD4+ T helper cells coordinate the immune response by "showering" the system with ________.

cytokines

CD8+ cytotoxic T cells eliminate "sick cells" (viruses and tumours) using the ________ pathway.

perforin-granzyme

B-lymphocytes differentiate into ________ to execute antibody-mediated (humoral) immunity.

plasma cells

The "Type 2 effectors" involved in parasite defence and allergic inflammation are eosinophils, mast cells, and ________.

basophils

Cell-to-cell communication that acts on distant sites in an endocrine-like fashion is called ________ signaling.

systemic

________ are a specific type of cytokine that guide immune cell movement toward inflamed tissue.

Chemokines

MHC Class II molecules are used by professional APCs to "talk" specifically to ________.

CD4+ helper T cells

MHC Class I molecules show what is happening ________ a cell to CD8+ cytotoxic T cells.

inside

Intracellular signaling cascades transmit messages from receptors to the ________ to trigger gene transcription.

nucleus

The ________ and ________ pathways are critical cascades for intracellular signaling and cell activation.

JAK-STAT; NF-ĸβ

The five main functions of the immune system are Defense, Remember, Tolerate, Regulate, and ________.

Repair (healing)

________ diseases occur when the immune system mistakenly targets self-antigens.

Autoimmune

________ diseases are characterized by the uncontrolled activation of the innate immune system.

Autoinflammatory

There are approximately ________ recognized inborn errors of immunity caused by genetic defects.

600

Secondary immune disorders are caused by ________, such as HIV infection or chemotherapy.

external factors

I1: I Flashcards

(116 cards)