8 - Hematology and Special Environment Physiology 2025

Plasma

55% of blood whole blood

44% Erythrocytes

What is the fluid medium of the blood and is also the non-cellular part?

Platelets and Lymphocytes (Buffy Coat)

What cellular components are found in <1% of the whole blood?

Bone marrow of CENTRALLY-LOCATED bones

1st Trimester: Yolk Sac / Aortic Gonad Mesonephros

2nd and 3rd Trimester: Liver

After birth to puberty: Bone Marrow of all Bones

What organ is responsible for blood cell formation at age 20 and above?

Serum

What refers to the plasma minus clotting proteins with higher serotonin content?

Albumin

What is the major contributor to the oncotic pressure of the plasma?

Hematocrit

This refers to the percentage of cells in the whole blood:

Males: 46 (40-54)

Females: 42 (37-47)

What is the normal hematocrit value among males and females?

Proerythroblast

At what RBC stage does the synthesis of hemoglobin start?

Polychromatic erythroblast

At what RBC stage does the hemoglobin appear?

α2 - γ 2

What is the component of Hemoglobin F?

Hemoglobin A (α2 - β2)

HbF: binds less

What type of hemoglobin binds more with 2,3-BPG?

Immunity

This refers to the ability of the human body to resist almost all types of organisms/toxins that tend to damage the tissues and organ:

Innate Immunity

What branch of the immune system is present at birth, and does not change over time?

Innate Immunity

What branch of the immune system is triggered by structures shared by a group of microbes?

Adaptive Immunity

What branch of the immune system improves after each repeated exposure?

Adaptive Immunity

What branch of the immune system uses lymphocytes and antigen-presenting cells as cellular components?

Innate Immunity

What branch of the immune system uses complements as blood proteins?

Origin: Bone Marrow

Mature: Thymus

Where do the T-lymphocytes originate and mature?

Extracellular Microbes

Toxin induced diseases

Infections (virulence-related to polysaccharide capsule)

The humoral immunity offers protection against what type of microbes?

Humoral: Superficial Cortex

Cell-Mediated: Paracortical Areas

Where in the lymph nodes are the humoral and cell-mediated immunity located?

Type IV

Types I, II, and III are Humoral

What type of hypersensitivity is associated with cell-mediated immunity?

T lymphocytes

B lymphocytes

Macrophage

What are the three cells required for antibody synthesis?

Neutrophils

What cells utilize oxidants or ROS to kill bacteria during acute inflammation?

Eosinophils

What cells are highly phagocytic for antigen-antibody (immune) complexes?

Histamine, heparin, bradykinin, serotonin

What are some of the secretions from basophils?

Monocytes

What cell is known for its "frosted-glass" or ground-glass cytoplasm?

Monocytes

What cells are known as the largest WBC?

7-10 days

What is the lifespan of the platelets?

Tissue Macrophages

2nd line: Neutrophils

What immune cells act as the 1st line of defense and are present within minutes?

TNF, IL-1, GM-CSF, M-CSF

4th line: ↑ Monocytes & Granulocyte production by Bone marrow

What are the 4 mediators of the 4th line of immune defense?

Variable Portion

Which part of the antibodies determine specificity to antigen?

FAB region

Which region of the immunoglobulins is the antigen-binding site found?

FC region

Which region of the immunoglobulins is the site of complement and macrophage binding?

IgG

Contains two identical gamma heavy chains and two identical light chains

Which immunoglobulin is tetrameric in structure?

IgG

The most abundant Ig in the serum?

IgA

The most produced antibody overall?

IgG

The smallest Ig?

IgM

The Ig for primary immune response?

IgE

The Ig associated with Type I hypersensitivity?

IgA

The Ig available as a monomer and dimer?

Opsonization

This refers to the process that makes it easier to phagocytize foreign bodies:

Classic Pathway

Mannose-binding lectin pathway: triggered by lectin binding with mannose groups in bacteria

Alternative/properdin pathway: triggered by contact with various viruses, bacteria, fungi, and tumor cells

Complement pathway triggered by immune complexes:

C3a, C4a, C5a

Complement proteins that induce inflammation and are anaphylatoxins:

C5a

Complement protein that causes WBC chemotaxis:

Cytokines

What are these hormone-like molecules that act on nearby cells (paracrine) to regulate immune responses?

IL2

Interferon-γ

What are the cytokines secreted by TH-1?

IL4

IL5

What are the cytokines secreted by TH-2?

IL3

What interleukin is also called multi-CSF and promotes proliferation of all types of blood cell?

IL-8

What cytokine is responsible for the chemotaxis of neutrophils, basophils, and T cells?

IL-5

What cytokine is responsible for the differentiation of eosinophils?

IL-4

What cytokine is responsible for the IgE class switching?

Interferon-γ

What cytokine enhances the killing of phagocytosed bacteria in chronic granulomatous disease?

Interferon-β

What cytokine is used to reduce the frequency and severity of relapses in multiple sclerosis?

CD8 – cytotoxic T cells

MHC-II: CD4, Helper T cells

What immune cell is associated with the MHC-I?

Vascular Constriction

What is the first step in hemostasis?

vWF and Gp1b

mediated by vWF of ruptured blood vessel walls and Gp1b of platelets

In the formation of a loose platelet plug, what mediates platelet adhesion?

Gp2b-3a and fibrinogen

mediated by fibrinogen and Gp2b-3a of platelets (also by PAF)

In the primary hemostasis, what mediates platelet aggregation?

Blood Coagulation

Primary: formation of a loose plug

What is the end goal of the secondary hemostasis?

Factors IX, X, XI and XII

What are the clotting factors inhibited by Antithrombin III?

VII and III

Common pathway: XIII, X, V, II, I

What are the clotting factors involved in the extrinsic pathway?

XII, XI, IX, VIII

Common pathway: XIII, X, V, II, I

What are the clotting factors involved in the intrinsic pathway?

Thrombomodulin

What anticlotting substance is expressed in all endothelial cells except in the cerebral microcirculation?

Plasmin

What anticlotting substance lyses fibrin?

12 weeks

gain 20% of ultimate strength in 3 weeks, maximum tensile strength in 12 weeks but never 70% of the strength of normal skin

During wound healing, when is the maximum tensile strength gained?

IL-6

What is the major inducer of the acute phase reactants?

Albumin

Transferrin

Transthyretin

Retinol-Binding Protein

Adiponectin

What are the 5 known negative acute phase reactants?

C-reactive protein

What ARP is used as the biomarker for ongoing inflammation

Hepcidin

↓ iron intestinal absorption (degrades ferroportin) and ↓ iron release (from macrophages)

What ARP plays a key role in the anemia of chronic disease?

Muscle strength, power, and endurance

What are the factors involved in muscle performance?

Muscle Size

What is the greatest determinant of muscle strength?

Oxidative metabolism

What is the source of most energy used for long-term muscle contraction?

18,000 feet

12,000 feet – Acute effects felt

23,000 feet - death

In an unacclimatized person, at what feet/level does a seizure occur?

200 feet below sea level

What is the maximum safe depth during diving?

Nitrogen bubble formation

During rapid ascent

What causes decompression sickness?