Biology Chapter 14: Blood Components

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Questions and Answers

What is the main role of plasma in blood?

To produce hormones and growth factors

To provide structural support to cells

To engage in immune responses

To transport gases, nutrients, and waste (correct)

Which type of white blood cell is most abundant in the blood?

Neutrophils (correct)

Lymphocytes

Monocytes

Eosinophils

What is the lifespan of neutrophils?

3-4 days

1-2 days (correct)

Months to years

Several weeks

Which of the following components is involved in the body's acquired immune response?

Lymphocytes Signup and view all the answers

What is the primary function of platelets in the blood?

Prevent blood loss Signup and view all the answers

How long is the lifespan of platelets in the blood?

7-10 days Signup and view all the answers

Which white blood cell type is known for phagocytosing bacteria?

Neutrophils Signup and view all the answers

What substance do basophils primarily release?

Histamine Signup and view all the answers

Which type of white blood cell matures into macrophages?

Monocytes Signup and view all the answers

What is a primary role of blood in the body?

Regulating water balance Signup and view all the answers

What is the survival duration if Acute Leukaemia is untreated?

Weeks to months Signup and view all the answers

Which presenting feature is common in Chronic Leukaemia?

Non-specific complaints Signup and view all the answers

What characterizes the pathological biology of Acute Leukaemia?

Abundance of immature 'blastic' cells Signup and view all the answers

Pancytopaenia in a patient indicates a deficiency in which elements?

Platelets, red blood cells, and leukocytes Signup and view all the answers

What is a common symptom associated with neutropaenia?

Infection and mouth ulcers Signup and view all the answers

Which of the following conditions is characterized by high blasts and low mature cells?

Acute Myeloblastic Leukaemia Signup and view all the answers

What is the effect of excess malignant blood cells on blood viscosity?

Increased risk of stroke Signup and view all the answers

Which feature is indicative of Acute Lymphoblastic Leukaemia (ALL)?

Cervical and supraclavicular lymphadenopathy Signup and view all the answers

What does the term 'neoplastic transformation' refer to in the context of leukaemia?

Malignant changes in blood cells Signup and view all the answers

In Chronic Leukaemia, compensation for symptoms is often possible due to what factor?

Presence of more mature cells Signup and view all the answers

What is the role of CD8+ T cells in the context of organ rejection?

They recognize foreign antigens and contribute to acute rejection. Signup and view all the answers

Which of the following is NOT a signal required for T cell activation?

Cytokine stimulation such as IL-6. Signup and view all the answers

How is the diversity of alpha-beta T cell receptors primarily generated?

By the combination of different gene segments. Signup and view all the answers

What percentage of human peripheral blood T cells express the alpha-beta TCR complex?

Over 95% Signup and view all the answers

What elements contribute to TCR diversity during the gene rearrangement process?

V, D, and J gene segments. Signup and view all the answers

What is the significance of N-region diversity in TCRs?

It increases the diversity by adding non-templated nucleotides. Signup and view all the answers

What characterizes the third signal in T cell activation?

It involves cytokine stimulation such as IFN-gamma. Signup and view all the answers

Which molecules are primarily involved in the co-stimulatory signals necessary for T cell activation?

CD28 and B7. Signup and view all the answers

What distinguishes between indolent and aggressive lymphomas based on histopathology?

Indolent lymphomas have mostly small cells while aggressive lymphomas have mostly large cells. Signup and view all the answers

Which stage of lymphoma is characterized by cancer spread beyond lymph nodes and involvement of one or more organs?

Stage 4 Signup and view all the answers

What is the primary method used for the diagnosis of lymphoma?

Large tissue biopsy for histological assessment Signup and view all the answers

What does the presence of abnormal blood findings generally indicate in comparison to lymphoma?

It is more common in patients with leukemia. Signup and view all the answers

Which treatment strategy is typically appropriate for indolent lymphomas?

Watch and wait approach Signup and view all the answers

What is a common feature of cutaneous T cell lymphoma expressed in mycosis fungoides?

Presence of a rash with brown spots. Signup and view all the answers

Which marker is used for identifying B cells in lymphoma diagnosis?

CD20 Signup and view all the answers

What is indicated by a predominance of either kappa or lambda light chains in B cell malignancies?

Monoclonality of the malignant cell type. Signup and view all the answers

Which of the following drugs is NOT commonly used in lymphoma treatment?

Amoxicillin Signup and view all the answers

Which imaging study is utilized for lymphoma staging?

PET scan Signup and view all the answers

What type of lymphoma is characterized by a 'nodular' histological appearance and is generally classified as indolent?

Follicular lymphoma Signup and view all the answers

Which of the following statements about lymphoma is correct?

Aggressive lymphomas may have a 30-40% cure rate. Signup and view all the answers

What is the most common type of lymphoma that can be classified as diffuse?

Diffuse large B cell lymphoma Signup and view all the answers

What is the primary location of malignant cells in leukemias?

Bone marrow Signup and view all the answers

Which cell type is most commonly associated with lymphomas?

B cells Signup and view all the answers

What differentiates lymphoma from leukemia?

Lymphomas primarily affect lymphatic tissues. Signup and view all the answers

Which type of lymphocyte is primarily responsible for humoral immunity?

B cells Signup and view all the answers

Where do T cells mature in the body?

Thymus Signup and view all the answers

What type of leukemia is characterized by an overproduction of abnormal lymphocytes?

Chronic lymphocytic leukaemia Signup and view all the answers

Which statement is NOT true regarding lymphomas?

They primarily affect the bone marrow. Signup and view all the answers

Which immunological function is NOT associated with T cells?

Antibody production Signup and view all the answers

Which of the following is a subtype of leukemia?

Acute myeloid leukaemia Signup and view all the answers

What role do dendritic cells play in the immune response?

They present antigens to T cells. Signup and view all the answers

What characterizes non-Hodgkin lymphoma?

Can arise from both B and T cell neoplasms Signup and view all the answers

Which of the following structures primarily contains B cells?

Follicle centres of lymph nodes Signup and view all the answers

What is the differentiation path of a long-term haematopoietic stem cell (LTHSC)?

It can become either short-term HSC or common lymphoid progenitor. Signup and view all the answers

Study Notes

Blood Components and Haematopoiesis

Blood is a connective tissue consisting of 2L cells and 3L plasma, totaling 5L of blood.
Plasma acts as a buffer, making up approximately ¼ of the extracellular fluid (ECF).

Functions of Blood

Transport: Carries gases, nutrients, waste, hormones, and growth factors.
Regulation: Maintains body temperature, pH levels, and fluid balance.
Protection: Aids in blood loss prevention and infection control.

Composition of Blood

Key cell types include lymphocytes (20-35% of WBC), monocytes, neutrophils (50-70% of WBC), eosinophils, and basophils.
Lymphocytes: Include T-cell, B-cell, and NK-cell subtypes, responsible for the acquired immune response.
Monocytes: Mature into macrophages, capable of phagocytosis, with a lifespan of months to years.
Neutrophils: Short lifespan (1-2 days) and primarily involved in phagocytosis of bacteria.
Eosinophils: Combat allergic reactions and parasitic diseases; contain pink-stained granules.
Basophils: Release inflammatory mediators like histamine and heparin.

Platelets

Small, round, colorless cell fragments involved in clotting; life span of 7-10 days.

Lymphomas and Leukaemias

Lymphomas: Predominantly affect lymph nodes; most common is B-cell lymphoma (80%).
Leukaemias: Involve abnormal blood cell production in bone marrow, equally derived from B-cell and T-cell lineages.

Haematopoiesis

Initiates from long-term haematopoietic stem cells (LTHSC), differentiating into short-term haematopoietic stem cells (STHSC).
Common progenitors: Differentiate into lymphoid (T-cells, B-cells, NK-cells) and myeloid lineages (erythrocytes, granulocytes).

Types of Lymphocytes

B-cells: Responsible for humoral immunity and antibody production.
T-cells: Involved in cellular immunity, providing help to B-cells and cytotoxicity against pathogens.

Lymph Node Anatomy

Follicle centers: Contain predominantly B-cells.
Cortical regions: Mainly composed of T-cells.

Clinical Features of Lymphoma

Symptoms include lymphadenopathy, potentially identified incidentally during exams.
Abnormal blood findings are less common compared to leukaemia.
Mycosis fungoides presents as a skin rash progressing to Sezary syndrome in blood.

Diagnosis of Lymphoma

Requires a large tissue biopsy for histological assessment; flow cytometry assesses surface protein expression.

Histopathology of Lymphoma

Classifies lymphomas as nodular (indolent) or diffuse (aggressive).
80% of lymphomas are classified into follicular (40% of HL) and diffuse large B-cell lymphoma (aggressive).

Gene Translocation in Lymphoma

Changes in gene structure can lead to different types of lymphoma, requiring further investigation for diagnosis and treatment planning.

Staging of Lymphoma

Stage I: Cancer in a single lymph node region or organ.
Stage II: Cancer in multiple lymph nodes on one side of the diaphragm.
Stage III: Lymph nodes above and below the diaphragm are affected.
Stage IV: Widespread disease has spread beyond lymph nodes to organs like the liver or bone.

Treatment Strategies for Lymphoma

Indolent lymphomas: Watchful waiting and local radiation, progressing to chemotherapy as needed.
Aggressive lymphomas: Fast-track treatment with multi-agent chemotherapy and possibly stem cell transplantation.

Common Anti-Lymphoma Drugs

Include Chlorambucil and combinations like CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone).

Outcomes of Therapy

Indolent lymphoma: Median survival of 8 years; 25% alive after 10 years.
Aggressive lymphoma: Cure rate of 30-40%; 50% mortality within 2 years.

Acute vs. Chronic Leukaemia

Acute Leukaemia: Rapidly progressive; characterized by high blast count and primarily affects bone marrow.
Chronic Leukaemia: Slower progression with more mature cells present.

Presenting Features of Leukaemia

Acute Leukaemia: Bone marrow failure presents with severe symptoms, typically requiring treatment within weeks.
Chronic Leukaemia: Often discovered during routine blood tests, symptoms related to splenomegaly and lymphadenopathy.

Pathobiology

Acute Leukaemia: Characterized by abundance of immature 'blastic' cells.
Chronic Leukaemia: Arises from a more mature haematopoietic stem cell.

T-Cell Activation Signals

T-cell receptors recognize specific antigen-MHC complexes and require co-stimulatory signals for activation.

TCR Diversity

Generated through genetic mechanisms during T-cell development, essential for effectively responding to various antigens, estimated to have around 25 million unique TCRs in humans.

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Description

Explore Chapter 14 on blood components and hematopoiesis. This chapter delves into the composition of blood, focusing on the balance between cellular elements and plasma. Understand the significance of blood as a connective tissue crucial for physiological functions.