PHS 203 Blood Physiology 3 WBC and Hemostasis

Question 1

Difference between rbc and wbc

Answer 1

WBCs differ from RBCs in many aspects.
1. Larger in size.
2. Irregular in shape.
3. Nucleated.
4. Many types.
5. Granules are present in some type of WBCs.
6. Lifespan is shorter

Question 2

Types of granulocytes

Answer 2

i. Neutrophils with granules taking both acidic and
basic stains.
ii. Eosinophils with granules taking acidic stain.
iii. Basophils with granules taking basic stain

Question 3

Types of agranulocytes

Answer 3

i. Monocytes.
ii. Lymphocytes.

Question 4

Function of Monocytes

Answer 4

Monocytes: Defend against infection by cleaning up damaged cells
- precursor pf tissue macrophages

Question 5

Function of basophils (and nucleus shape)

Answer 5

Basophils:
- Produces an allergic response like coughing, sneezing or a runny nose
- secrete histamine which results in inflammation associated with asthma
- role in signalling when infectious agents invade the body

Shape of nucleus: irregular

Question 6

Function of eosinophils (and nucleus shape)

Answer 6

Eosinophils:
- Identify and destroy parasites, cancer cells and assists basophils with your allergic response

Shape of nucleus: bilobular connected by thin chromatin strand

Shape of nucleus: bilobed

Question 7

Function of lymphocytes

Answer 7

Lymphocytes:
T cells, involved in inntae immunity, they are natural killer cells which kill tumore cells

B cells to protect against viral infections and produce proteins to help you fight infection (antibodies).
They produce plasma cells and are involved in cell-mediated immunity

Shape of nucleus: round with an indentation

Question 8

Function of neutrophils (and nucleus shape)

Answer 8

Neutrophils
- Help protect your body from infections by killing bacteria, fungi and foreign debris
- the most numerous of all leukocytes in the body
- 1st line of defence for the body’s immune system
- main component of pus

Shape of nucleus: multilobular connected by chromatin strands

Question 9

What is hemostasis?

Answer 9

Hemostasis is defined as arrest or stoppage of bleeding

Question 10

What are the stages of hemostasis?

Answer 10

1. Vasoconstriction
2. Platelet plug formation
3. Coagulation of blood

Question 11

Describe vasoconstriction

Answer 11

Immediately after injury, the blood vessels (usually arterioles and small arteries) constrict and decrease the loss of blood from damaged portion.
When the blood vessels are cut, the endothelium is damaged and the collagen is exposed.
Platelets adhere to this collagen and get activated. The activated platelets secrete serotonin and other vasoconstrictor substances which cause constriction of the blood vessels. Adherence of platelets to the collagen is accelerated by von Willebrand factor. This factor acts as a bridge between a specific glycoprotein present on the surface of platelet and collagen fibrils.

Question 12

Describe the platelet plug formation

Answer 12

Platelets get adhered to the collagen of ruptured blood vessels and secret adenosine diphosphate (ADP) and thromboxane A2. These two substances attract more and more platelets and activate them. All these platelets aggregate together and form a loose temporary platelet plug or temporary hemostatic plug, which closes the ruptured vessel and prevents further blood loss. Platelet aggregation is accelerated by platelet­ activating factor (PAF).

Question 13

Describe the coagulation of blood

Answer 13

During this process, the fibrinogen is converted into fibrin. Fibrin threads get attached to the loose platelet plug, which blocks the ruptured part of blood vessels and prevents further blood loss completely.

Question 14

State Landsteiner law

Answer 14

Landsteiner law states that: 1. If a particular agglutinogen (antigen) is present in the RBCs, corresponding agglutinin (antibody) must be absent in the serum.
2. If a particular agglutinogen is absent in the RBCs, the corresponding agglutinin must be present in the serum.
Though the second part of Landsteiner law is a fact, it is not applicable to Rh factor

Question 15

What are the 2 categories of abnormal hemoglobin

Answer 15

1. Hemoglobinopathies
2. Hemoglobin in thalassemia and related disorders.

Question 16

What are hemoglobinopathies?

Answer 16

Hemoglobinopathy is a genetic disorder caused by abnormal polypeptide chains of hemoglobin.

i. Hemoglobin S: It is found in sickle cell anemia. The α-chains are normal and β-chains are abnormal.
ii. Hemoglobin C: The β-chains are abnormal. It is found in people with hemoglobin C disease, which is characterized by mild hemolytic anemia and splenomegaly.
iii. Hemoglobin E: Here also the β-chains are abnormal. It is present in people with haemoglobin E disease which is also characterized by mild hemolytic
anemia and splenomegaly.
iv. Hemoglobin M: It is the abnormal haemoglobin present in the form of methemoglobin. It occurs
due to mutation of genes of both in α and β chains, resulting in abnormal replacement of amino acids. It is present in babies affected by hemoglobin M disease or blue baby syndrome. It is an inherited disease, characterized by methemoglobinemia.

Question 17

What is Methemoglobinemia

Answer 17

Methemoglobinemia (MetHb) is a blood disorder in which an abnormal amount of methemoglobin (oxidized hemoglobin) is produced.

Question 18

What is Cyanocobalamin?

Answer 18

Vitamin B12 (Cyanocobalamin)
Vitamin B12 is the maturation factor necessary for erythropoiesis.
Source
Vitamin B12 is called an extrinsic factor since it is obtained mostly from the diet. Its absorption from the intestine requires the presence of the intrinsic factor of Castle.
When necessary, it is transported to the bone marrow to promote the maturation of RBCs. It is also produced in the large intestine by the intestinal flora.

Question 19

Where is Vitamin B12 stored

Answer 19

In the liver and small quantities in the muscle

Question 20

Action of vitamin B12

Answer 20

Vitamin B12 is essential for the synthesis of DNA in RBCs.
Its deficiency leads to failure in the maturation of the cell
and reduction in cell division. Also, the cells are
larger with fragile and weak cell membranes resulting in
macrocytic anemia.

Question 21

Why is vitamin B12 called anti pernicious factor?

Answer 21

A deficiency of vitamin B12 causes pernicious anemia.
So, vitamin B12 is called anti pernicious factor.

Question 22

What is a normal Mean Corpuscular Volume (MCV)?

Answer 22

90 cu µ (78 to 90 cu µ).

Question 23

How does MCV change the name of a rbc

Answer 23

When MCV is normal, the RBC is called normocyte.
When MCV increases, the cell is known as a macrocyte
and when it decreases, the cell is called a microcyte

Question 24

What is MCV

Answer 24

MeanCorpuscular volume
MCV is the average volume of a single RBC and it is expressed in cubic microns (cu µ)

Question 25

What is MCH?

Answer 25

MCH is the quantity or amount of hemoglobin present in one RBC C. It is expressed in micro­microgram or picogram (pg)

Question 26

What is the normal value for Mean Corpuscular Hemoglobin (MCH)

Answer 26

Normal value of MCH is 30 pg (27 to 32 pg).

Question 27

What is MCHC?

Answer 27

Mean Corpuscular Hemoglobin Concentration (MCHC) is the concentration of hemoglobin in one RBC

Question 28

Normal value of MCHC?

Answer 28

Normal value of MCHC is 30% (30% to 38%).

Question 29

Which is the most important absolute value in the diagnosis of anemia?

Answer 29

MCHC

Question 30

How does MCHC affect change the name of rbc?

Answer 30

When the MCHC(Mean corpuscular hemoglobin concentration) decreases, the RBC is known hypochromic.

Question 31

What is CI?

Answer 31

Color index is the ratio between the percentage of hemoglobin and the percentage of RBCs in the blood. Actually, it is the average hemoglobin content in one cell of a patient compared to the average hemoglobin content in one cell of a normal person

Question 32

Normal value for CI

Answer 32

Normal color index is 1.0 (0.8 to 1.2). However, it is useful in determining the type of anemia. It increases in macrocytic (pernicious) anemia and megaloblastic anemia. It is reduced in iron deficiency anemia. And, it is normal in normocytic normochromic anemia

Question 33

5 Characteristics of adaptive immunity

Answer 33

1. Timing of response: this develops over a long period of time (time of response is slow) 2. Immune response is highly specific: This refers to the ability of the immune system to recognize non-self-antigens and respond in a specific manner to them, rather than responding in a random manner. 3. Memory response: the initial contact with a molecule eliciting an immune response(antigen) leaves an imprint of information. 4. Recognition of pathogens: it recognizes pathogens using memory cells (T and B cells) and activated B cells. B cells are lymphoid cells concerned with humeral immunity (short lived), T cells are the type of white blood cells, can also be called T lymphocyte and thymocyte. 5. Self-limitation: The adaptive immune response wanes with time after antigenic stimulation, returning the immune system to its resting basal state, a process called homeostasis.

Question 34

What is Adaptive immunity?

Answer 34

Adaptive immunity involves specialized immune cells and anti-bodies that attack and destroy foreign invaders and are able to prevent diseases in the future by remembering what those substances look like and mounting a new immune response. It may last for a few weeks or months or even a lifetime.

Question 35

Secondary causes of polycythemia vera

Answer 35

1) Dehydration 2) Pulmonary Fibrosis 3) Living at a high altitude 4) Carbon monoxide exposure 5) Kidney cancer

Question 36

Vasoconstriction is purely a local phenomenon T/F

Answer 36

TRUE

Question 37

Adherence of platelets to the collagen is accelerated by what?

Answer 37

von Willebrand factor

Question 38

What is Hypercoagulability/Thrombophilia and what does it cause?

Answer 38

This is when the blood clots too much or too easily. This is dangerous because those clots can develop or get stuck in different places in the body and cause severe, life-threatening problems. Examples of these problems include: * Stroke. * Deep vein thrombosis (DVT) which can then cause a pulmonary embolism. * Heart attack.

Question 39

What is Hypocoagulability and what does it cause?

Answer 39

When the blood doesn’t clot well, any injury becomes a much more dangerous event. It also means a greater risk for injuries to organs and blood vessels inside the body, which can then cause internal bleeding. Certain types of cancer like leukemia can cause you to bleed too easily. Conditions that keep your blood from clotting are often genetic, also. Some examples of genetic conditions include: * Hemophilia * Von Willebrand disease * Inherited thrombocytopenia (low platelet count).

Question 40

Explain Albumin's buffer action

Answer 40

The imidazole group of histidine is an effective contributor. Albumin is the greatest protein buffer as it has 16 histidine residues. It is slightly acidic and because of its negative charge, it balances many positively charged molecules such as Hydrogen calcium potassium etc hence performing its function as a buffer

Question 41

How does plasma/ plasma proteins regulate blood acidity?

Answer 41

Plasma( proteins )functions as a ph regulator under the protein buffer system and offer 15 percent of the buffering capacity of blood. It is dependent on the pk of ionizable group of amino acids. Amino acids contain positively charged amino groups and negatively charged carboxyl groups, these charged regions bind with hydrogen and hydroxyl ions thus functioning as buffers. Because of the amphoteric nature of plasma proteins, they can combine with both acids and bases. In acidic pH, the amino group of proteins act as a base and is converted to ammonia when it accepts a proton.

Question 42

Applicability of Landsteiner’s Law

Answer 42

i. The first law holds true for all types of blood grouping ii. The second law is a fact for ABO blood groups iii. The Rh, M, N and other blood groups do not follow the second part of Landsteiner’s law.

Question 43

Describe the sickle cell disease

Answer 43

Hemoglobin consist of 4 polypeptide chains; 2 alpha chains and 2 beta chains. The Hbb gene provides instructions for making the beta globin, mutations of the Hbb gene affects the beta globin. It occurs when a person inherits two abnormal copies of the beta-globin that makes the hemoglobin, one from each parent. It is INHERITED AUTOSOMAL RECESSIVE PATTERN, causing erythrocytes to be sickled crescent shape and affect multiple organ systems. It is diagnosed with a blood test and usually manifest by 5-6 months of age Symptoms include: swelling in hands and feet, bacterial infections, attacks of pain. The complications that can occur as a result of this disorder include chronic pain, aseptic bone necrosis, kidney problems, and pulmonary hypertension.

Question 44

Role of cyanocobalamin in erythropoiesis

Answer 44

Cyanocobalamin is under the maturation factor for erythropoiesis. It is an extrinsic factor because it can only be gotten from diet. Most of it is stored in the liver, while some are stored in the muscles. When it is necessary, it is transported to the bone marrow to promote maturation of Red Blood Cells. It is essential for the synthesis of DNA in Red Blood Cells.

Question 45

Why is the spleen is called “graveyard of RBC?

Answer 45

The destruction occurs mainly in the red pulp of the spleen because the diameter of the spleen capillaries is very small.

Question 46

Describe the process of the destruction of RBC (fate of RBC’s)

Answer 46

Destroyed RBCs are fragmented and hemoglobin is released from the fragmented part. Hemoglobin is immediately phagocytized by macrophages of the body, particularly the macrophages of the liver (Kupffer cells), spleen and bone marrow. Hemoglobin degraded into iron, globin, porphyrin. Iron combines with the protein called apoferritin to form ferratin, which is stored in the body and reused later in erythropoiesis. Globin enters the protein depot for later use. Porphyrin is degraded into bilirubin, which is excreted by the liver through bile.

Question 47

What is a bleeding disorder?

Answer 47

Bleeding disorders are a group of health conditions in which there is a problem with the body’s blood clotting process. These disorders can lead to heavy prolonged bleed after an injury. Bleeding can also begin on it’s own, bleeding disorders can cause abnormal bleeding, both outside and inside the body. Some bleeding disorders can drastically increase the amount of blood leaving the body.

Question 48

Factor I

Answer 48

Fibrinogen

Question 49

Factor II

Answer 49

Prothrombin

Question 50

Factor III

Answer 50

Thromboplastin (Tissue factor)

Question 51

Factor IV

Answer 51

Calcium

Question 52

Factor V

Answer 52

Labile factor (Proaccelerin or accelerator globulin)

Question 53

Factor VII

Answer 53

Stable factor

Question 54

Factor VIII

Answer 54

Antihemophilic factor (Antihemophilic globulin)

Question 55

Factor IX

Answer 55

Christmas factor

Question 56

Factor X

Answer 56

Stuart-Prower factor

Question 57

Factor XI

Answer 57

Plasma thromboplastin antecedent

Question 58

Factor XII

Answer 58

Hageman factor (Contact factor)

Question 59

Factor XIII

Answer 59

Fibrin-stabilizing factor (Fibrinase).