PATHO / CHAP 19 [Structure and Function of the Hematologic System]

Leukocytes act primarily in the tissues but are transported in the?

Circulation

What do COLONY-STIMULATING factors trigger?

Colony-stimulating factors trigger STEM CELLS

What granulocytes are segmented, constitute only 1% to 4% of leukocyte differential, and have the unique property of ingesting ANTIGEN-ANTIBODY complexes induced by IgE-mediated hypersensitivities?

EOSINOPHILS

Before becoming erythrocytes, what are the precursor cells?

ERYTHROBLAST aka NORMOBLAST and then RETICULOCYTE

Which cells are the most abundant blood cells (48% in men) and lack a nucleus, so they can reproduce (mitose)?

ERYTHROCYTES or RBC

Erythrocyte formation is stimulated by?

ERYTHROPOIETIN

Each factor is converted to its active form by?

Each factor is converted to its active form by the preceding factor until fibrin is produced

In which type of infections are Eosinophils especially efficient?

Eosinophils increase in PARASITIC infections (parasites)

What is ERYTHROPOIESIS?

Erythropoiesis is the development of red blood cells

Where is ERYTHROPOITIN produced? and what is it stimulated by?

Erythropoietin comes from the kidneys / Hypoxia stimulates the production & release or Erythropoietin / Erythropoietin causes an increase in red cell production and release from bone marrow

What is the main clotting factor protein in plasma?

FIBRINOGEN: precursor of the fibrin clot.

What do lymph nodes do?

Facilitate maturation of lymphocytes, monocytes & macrophages / Transport lymphatic fluid back to the circulation / Cleanses lymphatic fluid of microorganisms and foreign particles by monocytes & macrophages

What is FIBRONOLYSIS?

Fibronolysis is clot retraction and clot dissolution which is also initiated by platelets

Each hemoglobin molecule is composed of 2 pairs of polypeptide chains also called the?

GLOBINS

Globulins are other plasma proteins. What are their functions?

Globulins are carrier proteins and immunoglobulins (antibodies)

What is the word that means "arrest of bleeding"?

HEMOSTASIS

What is HEMOGLOBIN?

Hemoglobin is the oxygen carring portein on erythrocytes

Where does Hematopoiesis occurs after birth?

In the BONE MARROW

In the Plasma we have 6-7% of plasma proteins, where are the majority of the plasma proteins synthesized?

In the LIVER

Which blood cells are nucleated, defend ag infection & remove debris, and have varied lifespans depending on their types?

LEUKOCYTES or WBC

Found all throughout the body, linked by lymphatic vessels, they enlarge during infection due to accumulation of macrophages, what are they?

LYMPH NODES: part of the immune and hematologic systems

Blood tests for bone marrow function?

Large variety of tests

What kind of immunity are lymphocytes involved in?

Lymphocytes are involved in humoral and cell-mediated immunity

LYMPHOCYTES constitute what % of leukocyte count?

Lymphocytes constitute 36% of the total leukocyte count

What kind of life span do lymphocytes have?

Lymphocytes have variable life span

Adults have 2 kind of bone marrow, red or active (hematopoietic) marrow, and yellow, or inactive marrow. What is the other name for the red, active bone marrow?

MYELOID TISSUE

The bone marrow is used for storage and also for?

Making blood cells. The bone marrow contains a population of hematopoietic stem cells that have partially differentiated.

Leukocytes are the primary cells of the immune response. Leukocytes circulate the blood and eventually reside in lymphoid tissues as?

Mature T cells, B cells, or plasma cells

What do granulocytes contain?

Membrane bound granules in their cytoplasm

Which cells make up the mononuclear phagocyte system (MPS)?

Monocytes and Macrophages

What are Monocytes?

Monocytes are immature macrophages, formed and released in the bone marrow into the bloodstream, and fully mature into tissue macrophages. Monocytes consist of 3-7% of leukocyte differential, and migrate to infammatory site

What do the Agranulocytes cells consist of?

Monocytes, Macrophages, and Lymphocytes

These cells develop in the bone marrow and circulate in the blood, they resemble lymphocytes, represent 5-10% of circulating lymphoid pool, and kill some types of virus and tumor cells without prior exposure, what are they?

NATURAL KILLER (NK) cells

Which granulocytes are segmented, are the most numerous granulocytes and are about 55% of leukocyte count?

NEUTROPHILS or POLYMORPHONUCLEAR NEUTROPHIL (PMN)

What is the main function of Neutrophils?

Neutrophils are the chief phagocytes of early inflammation.

Where do we have MYELOID TISSUE or active (red) bone marrow?

PELVIS / VERTEBRAE / CRANIUM / MANDIBLE / STERNUM / and RIBS

Not truly cells, but disk-shaped cytoplasmic fragments that are essential for blood coagulation and control of bleeding, what are they?

PLATELETS

What is the PRIMARY (CENTRAL) lymphoid organs, and what is the function?

Primary lymphoid organs are the THYMUS and BONE MARROW and they are the site where B and T cells are made

Numbers of RBC tend to?

Remain constant

What is the SECONDARY (PERIPHERAL) lymphoid organs, and what is the function?

Secondary lymphoid organs are the SPLEEN, LYMPH NODES, TONSILS, PEYER PATCHES of small intestines, and the function is STORAGE of B and T cells

What is the diff between plasma and serum?

Serum is Plasma that has been allowed to clot in the lab in order to remove fibrinogen and other clotting factors that may interfere with some diagnostic tests.

Which hormone regulates the growth factor of platelets, meaning start a process to produce more when needed?

THROMBOPOIETIN (TPO)

Iron is transported in the blood by?

TRANFERRIN: Taxi cab for iron, carries extra iron back to liver

PLURIPOTENT STEM CELLS come from?

The FETUS

What is the largest secondary lymphoid organ?

The SPLEEN

What do the granules of granulocytes do?

The granules contain enzymes capable of killing microorganisms and also contain mediators that induce inflmmatory and immune response.

What is HEMATOPOIESIS?

The process of blood cell production

What is the SPLENIC PULP of the spleen?

The splnic pulp, consists of masses of lymphoid tissue containing lymphocytes and macrophages where blood-borne antigens encounter lymphocytes, initiating the immune response.

What is the main function of erythrocytes?

Tissue oxygenation: need to contain hemoglobin (Hb) to carry gases.

What is needed for hemostasis to occur?

Vasculature (endothelial cells and subendothelial matrix) / Blood proteins (clotting factors) / Platelets

What is the function of the VENOUS SINUSES of the spleen?

Venous Sinuses of the spleen are used for blood storage (up to 300 ml) and blood will be released from spleen if need be to raise BP. Other function of Venous Sinuses: Phagocytosis of old, damaged, & dead blood cells

Granulocytes are also capable of ameboid movement, by which they migrate through?

Vessel walls (diapedesis) and then to sites where their action is needed

What are some nutritional requirements for erythropoiesis?

Vitamin B12 and folate / Vitamin B2 and riboflavin / Pantothenic acid and niacin / Ascorbic acid and Vitamin E

How many hemoglobin molecules does each erythrocyte contain?

about 300

Where is the Coagulation Cascade synthesized?

in the LIVER except von Willebrand factor

67% of total body iron is bound to heme in erythrocytes and muscle cells, and 30% is stored in mononuclear phagocytes and hepatic parenchymal cells. How much iron is lost per day in urine, sweat, epithelial cells, or from the gut?

1 mg

Platelet plug formation sequence?

1. Activation 2. Adhesion (von Willebrand factor or vWF) 3. Aggregation 4. Secretion

What are 2 unique properties of erythrocytes?

1. Biconcave shape 2. Capacity to be reversibly deformed

What are the 2 stages of Hematopoiesis?

1. MITOSIS: proliferation 2. MATURATION: differentiation

Sequence for hemostasis?

1. Vasoconstriction 2. Formation of a platelet plug 3. Activation of the coagulation cascade 4. Formation of a blood clot 5. Clot retraction and clot dissolution

How long to platelets circulate in the blood before being removed by macrophages of the MPS, which happens mostly in the spleen.

10 days

What is the life span a erythrocytes?

120 days or 4 months

How many platelets are they per mm3?

140000 to 340000 platelets / mm3

What is the life span of Neutrophils?

4 days

How many leukocytes does the average adult have per mm3 of blood?

5000 to 10000 leukocytes/mm3 of blood

What percentage of blood is plasma?

55%

What is the average volume of blood in one person?

6 quarts or 5.5 liters

What is plasma made out of?

90% water, 10% dissolved substances or solutes such as proteins (albumins, globulins, fibrinogen) and solutes (ions, nutrients, waste, gases..)

What is a Coagulation Cascade?

A series of enzymatic reactions among the clotting factors

Which protein is about 60% of total plasma protein?

ALBUMINS: large protein and do not diffuse through vascular endothelium

Intrinsic pathway of clotting factors?

Activated when factor 12 contacts subendothelial substances exposed by vascular injury

Extrinsic pathway of clotting factors?

Activated when tissue factor (TF) (tissue thromboplastin) is released by damaged endothelial cells

What is the main functions of Albumins?

Albumins function as carriers and control plasma oncotic pressure

How many hemes and how many oxygen molecules does an hemoglobin carry?

An hemoglobin molecule has 4 hemes and can carry 4 oxygen molecules

Which granulocytes are structurally similar to mast cells, make up less than 1% leukocyte differential, and whose precise functions are not understood?

BASOPHILS: have some similar functions as the mast cells

What cells do the granulocytes include?

Basophils, Eosinophils, and Neutrophils / or BEN

What does BONE MARROW consist of?

Bone Marrow consists of: BLOOD VESSELS / NERVES / MONONUCLEAR PHAGOCYTES (MNP) / STEM CELLS / BLOOD CELLS / FATTY TISSUE

Tests for bone marrow function?

Bone marrow aspiration / Bone marrow biopsy / Measurement of bone marrow iron stores / Differential cell count