PHS 203 Blood Physiology Flashcards
1
Q
Blood is made up of
A
Plasma
Formed Elements
•Erythrocytes (red blood cell)
•Leukocytes (white blood cell)
•Thrombocytes (platelets)
2
Q
PCV/ Haematocrit for males
A
40-46%
3
Q
PCV/ Haematocrit for females
A
38-42%
4
Q
Low PCV is an indication of
A
Anaemia
5
Q
High PCV is called
A
Polycythemia
6
Q
Normal blood pH
A
7.35-7.45
7
Q
Normal body temp
A
36.5-37.5
8
Q
What color is arterial blood and why?
A
Scarlet red because it contains more oxygen
9
Q
What color is venous blood and why?
A
Purple red because it contains more carbon dioxide
10
Q
Volume of blood in males, females and babies
A
Males 5-6L
Females 4-5L
Babies 450ml
11
Q
In a normal healthy 70kg human being, blood is _% of body weight
A
8%
12
Q
pH of blood
A
7.35-7.45
13
Q
Viscosity/density of blood and why?
A
Blood is denser than water and 5 times more viscous than water
Due to red blood cells and plasma proteins
14
Q
Th pigment that makes blood red is_
A
Hemoglobin
15
Q
the average rbc count ranges from_
A
5 million/cmm3
16
Q
the average rbc count in males is
A
5.1-5.8 million/cmm3
17
Q
the average rbc count in females is
A
4.3-5.2 million/cmm3
18
Q
Average lifespan of RBC is about _
A
120 days
19
Q
Old rbc’s are destroyed in the_
A
In the spleen by macrophages
20
Q
How can we determine the lifespan of rbc’s?
A
Lifespan of the RBC is determined by radioisotope
method. RBCs are tagged with radioactive substances
like radioactive iron or radioactive chromium.
21
Q
What is the diameter of an erythrocyte?
A
7.5 micron(10-6m)
22
Q
What is the thickness of an erythrocyte?
A
2 micron at the periphery
1 micron at the center
23
Q
Why do rbc carry out anaerobic respiration?
A
because they lack mitochondria
24
Q
What is haemoglobin made of?
A
Haem and globin
Haem: pigment, Fe attaches to haem group
globin: polypeptide, it has 4 polypedtides (2 alpha and 2 beta)
Each polypeptidehas one haem group and each ahem group carries one oxygen molecule, which also attaches the the Fe
25
Normal haemoglobin level in infants_
14-20 g/dl
26
Normal haemoglobin level in females_
12-16 g/dl
27
Normal haemoglobin level in males_
13-18 g/dl
28
PCV value depends on_ and _
age and gender
29
What are the states of Hemoglobin?
1. oxyhemoglobin - When oxygen is bound to iron
2. deoxyhemoglobin - When no oxygen is bound to iron
3. carbaminoglobin - when carbon dioxide is bound to the polypeptide chain
4. Methaemoglobin (MetHb)
30
What is haematopoesis?
the maturation, development and formation of blood cells
31
What is erythropoesis?
the maturation, development and formation of rbc's
32
What is the normal shape of a rbc?
Biconcave and diskshape
33
Stages of erythropoesis
Haemocytoblast
proerythroblast
early (basophile) erythroblast
late erythroblast
(hemoglobin) nomoblast
(nucleus ejected when there's enough hemoglobin) recticulocyte
retaining some ER
ERYTHROCYTE
34
How long does it take a hemocytoblast to become a reticulocyte?
3-5 days
35
Which stage of erythropoesis consists of a nucleus?
nomoblast
36
Why shouldn't you give iron to an SS patient?
Because the breaking down of red blood cells results in the its constituent parts which includes a large amount of iron
37
How is erythropoesis regulated?
1. Hormonal controls - erythropoietin is the hormone that stimulates rbc production in the bone marrow
2.Low oxygen levels in the blood causes kidneys to increase release of erythropoietin
38
Which hormone stimulates rbc production in the bone marrow?
erythropoietin
39
Where is erythropoietin (EPO) produced and by which cells?
In the kidney by interstitial cells
40
What is hemolysis?
Destruction of rbc's
41
_% of iron in the body is in_
65, hemoglobin
42
What is Kernicterus?
Kernicterus is a type of brain damage that can result from high levels of bilirubin in a baby's blood. It can cause athetoid cerebral palsy and hearing loss. Kernicterus also causes problems with vision and teeth and sometimes can cause intellectual disabilities.
43
What is the ratio of rbc's to wbc's in the body?
800:1
44
Difference between plasma and serum
plasma – liquid portion of blood
serum – remaining fluid when blood clots and the solids are removed
(Fibrinogen is absent)
45
What are the 3 main categories of plasma proteins
Albumin
Fibrinogen
Glubulins
46
Role of albumin
contributes to viscosity and osmolarity, influences blood pressure, flow and fluid balance
(Smallest and most abundant)
47
Role of globulins
provide immune system functions
alpha, beta and gamma globulins
48
Role of fibrinogen
precursor of fibrin threads that help form blood clots
49
What percentage of blood components are in blood (plasma, buffer sol and rbc)
Plasma 55%
Buffer sol 1%
Red blood cell 45%
50
What part of the rbc determines blood type?
Surface glycoprotein and glycolipids
51
What is the role of the cytoskeletal proteins (spectrin and actin)
It gives the membrane durability and resilience
52
A rbc larger than 100fl is known as a
Macrocyte
53
A rbc smaller than 100fl is known as a
Microcyte
54
Normal volume of rbc's
100fl
55
What do morphological classifications of anemia depend on
Morphological classification depends upon the size and
color of RBC
56
Types of anemia based on size
Macrocytic
Microcytic
Normocytic
57
Macrocytic anemia/ pernicious anemia
This occurs when cells fail to complete their cycle of division resulting in large immature RBC's
1. Caused by folate and B-12 deficiency
2. It is an auto-immune condition
3. Parietal cells in the stomach secrete glycoproteins called intrinsic factors which B-12 binds to
4. the body produces antibodies that bind to parietal cells preventing the binding of B-12
5. B-12 cannot be absorbed and it is needed for the maturation of RBC's
6. Results in large immature RBC's, macrocytic
7. Large rbc can get stck in capillaries and undergo hemolysis
Symptoms same as microcytic
Treatment: Intramuscular injection of B-12
Common with old age and in females
58
Microcytic anemia and examples
Also known as iron deficiency anemia
Hemoglobin deficiency due to iron deficiency
Symptoms
1. shortness of breath (dyspnea)
2. fatigue
3. tachycardia (rapid heartbeat over 100 times a minute)
Causes
1. Hemorrhage
2. Heavy menstruation
3. Low iron diet
Treatment:
Iron intake
59
Normocytic
Anemia in which size of rbc's do not change
60
What are the 3 categories of the causes of anemia?
1. inadequate erythropoiesis or hemoglobin synthesis
kidney failure and insufficient erythropoietin
iron-deficiency anemia
inadequate vitamin B12 from poor nutrition or lack of intrinsic factor (pernicious anemia)
hypoplastic anemia – slowing of erythropoiesis
aplastic anemia - complete cessation of erythropoiesis
2. hemorrhagic anemias from bleeding
3. hemolytic anemias from RBC destruction
61
Causes of anemia
Toxins and drugs
Trauma
Hemolysis
Hemorrhage
Hemopoietic disorder
Infection
Inflammation
Irradiation
Neoplasia (cancer)
Nutritional deficiency
Sepsis
Systemic disease
62
Aplastic anemia
Caused by the inability of the bone marrow to produce red blood cells
63
What PCV indicates anemia?
a PCV less than 30%
64
What PCV indicates polycythemia?
PCV greater than 60%
65
Define anemia
Anemia is reduced blood cell count, reduced PCV, or reduced hemoglobin concentration below levels that are considered normal for age and sex significant enough to bring about a reduction in oxygen-carrying capacity
66
Megaloblastic anemia
deficiency of folic acid.
Results in immature RBCs
DNA synthesis is also defective, so the nucleus remains immature.
The RBCs are megaloblastic
and hypochromic.
Features of pernicious anemia appear in megaloblastic
anemia also. However, neurological disorders may not
develop
67
Types of anemia based on color of RBC's
Normochromic
Hypochromic
Hyperchromic
68
Types of anemia due to etiology
1. Hemorrhagic anemia
2. Hemolytic anemia
3. Nutrition deficiency anemia (B-12 and folic acid)
4. Aplastic anemia
5. Anemia of chronic diseases
69
Hemorrhagic anemia
Anemia due to excessive loss of blood
Types:
Acute: Acute hemorrhage refers to the sudden loss of a large quantity of blood as in the case of an accident.
Chronic hemorrhage
It refers to loss of blood by internal or external bleeding,
over a long period of time. It occurs in conditions like
peptic ulcer, purpura, hemophilia, and menorrhagia.
70
Aplastic anemia (pancytopenia)
Aplastic anemia is due to the disorder of the red bone
marrow. Red bone marrow is reduced and replaced
by fatty tissues. Bone marrow disorder occurs in the
following conditions:
i. Repeated exposure to Xray or gamma ray
radiation.
ii. Presence of bacterial toxins, quinine, gold salts,
benzene, radium, etc.
iii. Tuberculosis.
iv. Viral infections like hepatitis and HIV infections.
In aplastic anemia, the RBCs are normocytic and
normochromic.
71
Thalassemia
In thalassemia, the production of these chains becomes imbalanced because of defective synthesis of globin genes. This causes the precipitation of the polypeptide chains in the immature RBCs, leading
to a disturbance in erythropoiesis. The precipitation also occurs in mature red cells, resulting in hemolysis.
an inherited disorder, characterized by abnormal hemoglobin.
Aka Cooley’s anemia or Mediterranean anemia.
Common in Thailand and Mediterranean countries
Types:
thalassemia is of two types:
i. α thalassemia (loss of an α)
ii. β thalassemia(more common) loss of a β
72
Sickle cell anemia
Sickle cell anemia is an inherited blood disorder,
characterized by sickleshaped red blood cells. It is also
called hemoglobin SS disease or sickle cell disease. It
is common in people of African origin.
Sickle cell anemia is due to abnormal hemoglobin
called hemoglobin S (sickle cell hemoglobin). In this,
α chains are normal and βchains are abnormal. The
molecules of hemoglobin S polymerize into long chains
and precipitate inside the cells. Because of this, the
RBCs attain a sickle (crescent) shape and become more
fragile leading to hemolysis
73
What mutation occurs in sickle cell anemia
missense point mutation where valine is produced instead of glutamic acid
73
What mutation occurs in sickle cell anemia
missense point mutation where valine is produced instead of glutamic acid
74
Necessary hormones for erythropoesis
i. Erythropoietin
ii. Thyroxine (and some testosterone)
74
Necessary hormones for erythropoesis
i. Erythropoietin
ii. Thyroxine (and some testosterone)
75
Action of erythropoietin for erythropoesis
1. Increases rate of RBC maturation
2. released in response to tissue hypoxia
3. Development of proerythroblasts into matured RBCs through several stages – early normoblast, intermediate normoblast, late normoblast, and reticulocyte
4. Production of proerythroblasts from CFU-E of the bone marrow
5. Release of matured erythrocytes into the blood. Even some reticulocytes (immature erythrocytes) are released along with matured RBCs.
76
Role of thyroxine in erythropesis
Being a general metabolic hormone, thyroxine accelerates the process of erythropoiesis at many levels
77
Vitamins necessary for erythropoesis
Vitamins necessary for erythropoiesis:
a. Vitamin B: Its deficiency causes anemia and pellagra (disease characterized by skin lesions, diarrhea, weakness, nervousness and dementia).
b. Vitamin C: Its deficiency causes anemia and scurvy (ancient disease characterized by impaired collagen synthesis resulting in rough skin, bleeding gum, loosening of teeth, poor wound healing, bone pain, lethargy and emotional changes).
c. Vitamin D: Its deficiency causes anemia and rickets (bone disease – Chapter 68).
d. Vitamin E: Its deficiency leads to anemia and malnutrition
e. Vitamin B-12 and folate
78
Nutrients required for erythropoesis
1. Folate: Folic acid is also essential for maturation. It is required for the synthesis of DNA. In the absence of folic acid,
the synthesis of DNA decreases causing the failure of maturation. Folate deficiency results in megaloblastic anemia
3. Iron: Necessary for the formation of heme part of the hemoglobin.
79
What are the plasma proteins in the blood
1. Serum albumin
2. Serum globulin
3. Fibrinogen
80
Why doesn’t serum contain fibrinogen?
Because fibrinogen is converted into fibrin during blood clotting
81
Normal values of plasma protein
Total protein: 7.3g/dl (6.4 to 8.3 g/dl)
Serum albumin: 4.7 g/dl
Serum globulin: 2.3 g/dl
Fibrinogen: 0.3 g/dl
82
Molecular weight of plasma proteins
Albumin: 69,000
Globulin: 156,000
Fibrinogen: 400,000
83
Which plasma protein plays a major role in oncotic pressure
Albumin
84
Specific gravity of plasma protein
1.026
85
Origin of plasma proteins in the embryo
In embryonic stage the plasma proteins are synthesized by the mesenchyme cells. The albumin is synthesized first and other proteins are synthesized later
86
Origin of plasma proteins in adults
Synthesized from reticuloendothelial cells of liver
Also spleen, bone marrow, disintegrating blood cells and general tissue cellls
87
B lymphocytes synthesize
Gamma globulin
88
Functions of plasma proteins
1. Role coagulation of blood (fibrinogen)
2. Role in defense mechanism of body (gamma globulin)
3. Role in transport mechanism
4. Role in maintaining of osmotic pressure in blood
5. Role in regulation of acid base balance 6. Role in production of chief and substances role in viscosity of blood
7. Role in erythrocyte sedimentation rate 8. role in suspension stability of red blood cells
9. Role as reserve proteins
89
Advantages of Biconcave Shape of RBCs
1. Biconcave shape helps in equal and rapid diffusion of oxygen and other substances into the interior of the cell.
2. Large surface area is provided for absorption or removal of different substances.
3. Minimal tension is offered on the membrane when the volume of cell alters.
4. Because of biconcave shape, while passing through minute capillaries, RBCs squeeze through the capillaries very easily without getting damaged.
90
Which mammal has a nucleated rbc
Camel
91
Due to the absence of mitochondria the energy in a red blood cell is produced…
In the glycolytic process
92
What causes hereditary sperocytosis? What is it’s impact?
The absence of spectrin in the rbc cytoskeleton (in which actin is also present). Spectrin is anchored to transmembrane proteins by the protein ankyrin.
In this condition the cell is deformed , loses its biconcave shape and becomes globular (spherocytic). The spherocyte is very fragile and easily ruptured (hemolyzed) in hypotonic solutions
93
Discuss the rouleaux formation
The piling up of rbc’s (like a pile of coins) when blood is taken oit of the blood vessels.
Accelerates by globulin and albumin
(Plural rouleau)
94
Specific gravity of rbc
1.092-1.101
95
Function of rbc's
1. Transport of Oxygen from the Lungs to the Tissues Hemoglobin in RBC combines with oxygen to form oxyhemoglobin.
2. Transport of Carbon Dioxide from the Tissues to the Lungs Hemoglobin combines with carbon dioxide and form
carbhemoglobin.
3. Buffering Action in Blood
Hemoglobin functions as a good buffer. By this action, it regulates the hydrogen ion concentration
4. In Blood Group Determination
RBCs carry the blood group antigens like A antigen, B antigen and Rh factor. This helps in determination of blood group and enables to prevent reactions due to
incompatible blood transfusion
96
Physiological variations in the no. of rbc (increase)
age
gender (after menopause, and before puberty)
high altitude (hypoxia)
muscular exercise ( because of mild hypoxia and contraction of spleen)
emotional conditions (anxiety)
increase in temp (increases all body activities including erythropoesis)
after meals (oxygen needed for metabolic activity)
97
Physiological variations in the no. of rbc (decrease)
1. High barometric pressures
At high barometric pressures as in deep sea, oxygen tension of blood is higher, the RBC count
decreases.
2. During sleep: RBC count decreases slightly and immediately after getting up . Generally all the activities of the body are decreased during sleep including production of RBCs.
3. Pregnancy
In pregnancy, the RBC count decreases because
of increase in ECF volume. Increase in ECF volume,
increases the plasma volume also resulting in hemodilution. So, there is a relative reduction in the RBC count.
98
Pathological l variations in the no. of rbc
Primary polycythemia - Polycythemia Vera
2.secondary polycythemia
3. anemia
99
Microcytes are present in...
i. Iron-deficiency anemia
ii. Prolonged forced breathing
iii. Increased osmotic pressure in blood.
100
Macrocytes are present in...
i. Megaloblastic anemia
ii. Decreased osmotic pressure in blood
101
Anisocytes occurs in
pernicious anemia.
102
Variations in the shape of rbc's
1. Crenation: Shrinkage as in hypertonic conditions.
2. Spherocytosis: Globular form as in hypotonic conditions.
3. Elliptocytosis: Elliptical shape as in certain types of anemia.
4. Sickle cell: Crescentic shape as in sickle cell anemia.
5. Poikilocytosis: Unusual shapes due to deformed
cell membrane. The shape will be of flask, hammer or any other unusual shape.
103
Variations in the structure of rbc's
PUNCTATE BASOPHILISM
Striated appearance of RBCs by the presence of dots of basophilic materials (porphyrin) is called punctate
basophilism. It occurs in conditions like lead poisoning.
RING IN RED BLOOD CELLS
Ring or twisted strands of basophilic material appear
in the periphery of the RBCs. This is also called the
Goblet ring. This appears in the RBCs in certain types
of anemia.
HOWELL-JOLLY BODIES
In certain types of anemia, some nuclear fragments are present in the ectoplasm of the RBCs. These nuclear fragments are called Howell Jolly bodies.
104
Use of gamma globulins
Also known as immunoglobulin
Used in the bodies defense mechanism (act as antibodies)
105
Define erythropoiesis
Erythropoiesis is the process of the origin development and maturation of erythrocytes
106
Intrauterine stages of erythropoiesis
1.Mesoblastic stage (first trimester)
During the first two/three
months of intrauterine life the rbc’s are produced from mesenchyme of yolk sac (wall)
2. Hepatic stage (2nd trimester) the liver spleen and lymphoid organs are responsible for the production of red blood cells
3. Myeloid stage (third trimester) bone marrow (and liver) is responsible for my blood cell production
107
What type of bones produce red blood cells up to the age of 20
Red bone marrow of all long bones and flat bones
108
What type of bones produce red blood cells after the age of 20
Membranous bones like, vertebra, sternum, ribs, scapula, iliac bones and skull bones and from the ends of long bones. After 20 years of age the shaft of a long bones becomes yellow bone marrow because of fat deposition and loses the Erythropoietic function
109
In what circumstances can the liver and spleen produce red blood cells
In emergency situations if the bone marrow is destroyed or fibrosed
110
What is a uncommitted Pluripotent
hemopoietic stem cell
A cell that can give rise to all types of blood cells
111
What is a committed Pluripotent
hemopoietic stem cell
A cell which is restricted to give rise to one group of blood cells
112
Types of committed PHSC’s
1. Lymphoid stem cells which give rise to lymphocytes and natural killer cells
2. colony forming blastocysts which give rise to myeloid cells. Myeloid cells are the blood cells other than lymphocytes and grown in culture these that these cells form colonies hence the name colony forming processes sites
113
Hemopoietic stem cells in the bone marrow are called
Uncommitted pluripotent hemopoietic stem cells
114
Best source of UPHSC
Umbilical cord blood
115
Changes in the development of red blood cells
Reduction in size (25u -7.2u in diameter)
disappearance of nuclei and nucleus appearance of hemoglobin
change in the staining properties of the cytoplasm
increase in number of the developing red blood cell
116
STAGES OF ERYTHROPOIESIS
1. Proerythroblast
2. Early normoblast
3. Intermediate normoblast
4. Late normoblast
5. Reticulocyte
6. Matured erythrocyte.
117
Actions of erythropoietin
a. Production of proerythroblasts from CFU-E of the bone marrow
b. Development of proerythroblasts into matured RBCs through the several stages
c. Release of matured erythrocytes into blood. Even some reticulocytes (immature erythrocytes) are released along with matured RBCs.
Blood level of erythropoietin increases in anemia
118
Vitamins necessary for erythropoiesis
Vitamin B: Its deficiency causes anemia and pellagra (disease characterized by skin lesions, diarrhea, weakness, nervousness and dementia).
b. Vitamin C: Its deficiency causes anemia and scurvy (ancient disease characterized by impaired collagen synthesis resulting in rough skin, bleeding gum, loosening of teeth, poor wound healing, bone pain, lethargy and emotional changes).
c. Vitamin D: Its deficiency causes anemia and rickets
d. Vitamin E: Its deficiency leads to anemia and malnutrition.
119
Maturation factors of rbc
Vitamin B12, intrinsic factor and folic acid
120
Examples of chronic hemorrhage
peptic ulcer, purpura, hemophilia and menorrhagia
121
What is purpura?
Purpura occurs when small blood vessels leak blood under the skin e.g. from bruising from trauma
122
What is hemophilia?
a medical condition in which the ability of the blood to clot is severely reduced, causing the sufferer to bleed severely from even a slight injury. The condition is typically caused by a hereditary lack of a coagulation factor, most often factor VIII
123
What is menorrhagia?
abnormally heavy bleeding at menstruation.
124
What is the number one cause of erythropoiesis?
hypoxia
125
Describe the rbc in hemorrhagic anemia
Due to continuous loss of blood, lot of iron is lost
from the body causing iron deficiency. This affects the
synthesis of hemoglobin resulting in less hemoglobin
content in the cells. The cells also become small. Hence,
the RBCs are microcytic and hypochromic
126
What is extrinsic hemolytic anemia?
. Extrinsic hemolytic anemia: It is the type of anemia
caused by destruction of RBCs by external factors.
Healthy RBCs are hemolized by factors outside the
blood cells such as antibodies, chemicals and drugs.
Extrinsic hemolytic anemia is also called autoimmune
hemolytic anemia.
Common causes of external hemolytic anemia:
i. Liver failure
ii. Renal disorder
127
What is intrinsic anemia?
Intrinsic hemolytic anemia: It is the type of anemia
caused by destruction of RBCs because of the defective
RBCs. There is production of unhealthy RBCs, which are
short lived and are destroyed soon. Intrinsic hemolytic
anemia is often inherited and it includes sickle cell
anemia and thalassemia.
Because of the abnormal shape in sickle cell anemia
and thalassemia, the RBCs become more fragile and
susceptible for hemolysis.
128
What is intrinsic anemia?
Intrinsic hemolytic anemia: It is the type of anemia
caused by destruction of RBCs because of the defective
RBCs. There is production of unhealthy RBCs, which are
short lived and are destroyed soon. Intrinsic hemolytic
anemia is often inherited and it includes sickle cell
anemia and thalassemia.
Because of the abnormal shape in sickle cell anemia
and thalassemia, the RBCs become more fragile and
susceptible for hemolysis.
128
What is intrinsic anemia?
Intrinsic hemolytic anemia: It is the type of anemia
caused by destruction of RBCs because of the defective
RBCs. There is production of unhealthy RBCs, which are
short lived and are destroyed soon. Intrinsic hemolytic
anemia is often inherited and it includes sickle cell
anemia and thalassemia.
Because of the abnormal shape in sickle cell anemia
and thalassemia, the RBCs become more fragile and
susceptible for hemolysis.
129
Most common type of anemia
anemia of chronic diseases after iron deficiency anemia)
130
Hematinic principle
It is called the antianemia principle. It is the principle thought to be produced by the action of an intrinsic factor or an extrinsic factor.
131
Plasma is made up of
7-10% dissolved substances
90-93% water
