Fundamentals of Blood and Red Blood Cells Flashcards
1
Q
What is the circulatory system?
A
The circulatory system is a network of vessels through which blood moves around the body.
2
Q
What are the two main components of blood?
A
Blood has a cellular component and an extracellular matrix liquid component known as blood plasma.
3
Q
What is the color of blood plasma?
A
Blood plasma is yellow in color.
4
Q
What are the main constituents of blood plasma?
A
The main constituents of blood plasma are water (92%), biomolecules (proteins, hormones, carbohydrates), and inorganic compounds such as salts (8%).
5
Q
What is the function of blood plasma?
A
Blood plasma transports various substances, including metabolites (products of cellular metabolism).
6
Q
What percentage of water is found in blood plasma?
A
Approximately 92% of blood plasma consists of water.
7
Q
What are some examples of biomolecules found in blood plasma?
A
Biomolecules found in blood plasma include proteins, hormones, and carbohydrates.
8
Q
Apart from cells and plasma, what other substances are transported by blood?
A
Blood also transports metabolites, which are the byproducts of cellular metabolism.
9
Q
What is the role of inorganic salts in blood plasma?
A
Inorganic salts help buffer the pH of blood, contribute to osmotic balance, and regulate the cell membrane potential.
10
Q
What is the function of blood plasma in transporting nutrients?
A
Blood plasma transports nutrients such as glucose and vitamins throughout the body.
11
Q
What substances are transported by blood plasma?
A
Blood plasma transports proteins, hormones, and antibodies throughout the body.
12
Q
What is the role of blood plasma in removing waste compounds?
A
Blood plasma helps remove metabolic waste compounds from the body.
13
Q
How do inorganic salts contribute to osmotic balance?
A
Inorganic salts in blood plasma help maintain the proper concentration of solutes inside and outside of cells, ensuring osmotic balance.
14
Q
Why is pH regulation important in blood plasma?
A
pH regulation is essential for maintaining the proper functioning of enzymes and overall cellular processes.
15
Q
Which component of blood plasma is responsible for transporting antibodies?
A
Blood plasma transports antibodies, which are crucial for the immune response.
16
Q
Besides nutrients, what other substances does blood plasma transport?
A
In addition to nutrients, blood plasma transports various biomolecules, gases, waste products, and regulatory substances throughout the body.
17
Q
What is the main function of red blood cells (erythrocytes)?
A
The main function of red blood cells is to transport oxygen (O2) and carbon dioxide (CO2) throughout the body.
18
Q
What is the term used to describe the percentage of red blood cells in the total blood volume?
A
The percentage of red blood cells relative to the total blood volume is called the “hematocrit.”
19
Q
What are the different types of white blood cells (leukocytes)?
A
the different types of white blood cells are basophils, eosinophils, neutrophils, lymphocytes, and monocytes.
20
Q
What is the function of white blood cells?
A
White blood cells are part of the immune system and play a role in defending the body against infections and foreign substances.
21
Q
What is the role of platelets in blood?
A
Platelets are essential for blood clotting, preventing excessive bleeding.
22
Q
Are platelets considered cells?
A
No, platelets are not cells but rather cytoplasmic cell fragments derived from cellular precursors.
23
Q
How would you describe the shape of red blood cells?
A
Red blood cells have a characteristic “flexible disc” or “doughnut” shape that is biconcave.
24
Q
What is the advantage of the biconcave shape of red blood cells?
A
The biconcave shape of red blood cells allows them to travel through blood vessels, including narrow capillaries. It also provides a large surface area for efficient gas exchange.
25
Do human red blood cells have a nucleus?
No, human red blood cells do not have a nucleus.
26
Are there any exceptions to the lack of nucleus in red blood cells?
Yes, there are exceptions in some mammals and all other vertebrate species where red blood cells do have a nucleus.
27
How do human red blood cells differ in terms of organelles and cellular membrane structures?
Human red blood cells have a reduced number of organelles and cellular membrane structures compared to other cells.
28
What happens to older red blood cells?
Older red blood cells rupture easily, and the debris left behind is degraded by macrophages, which are immune system cells.
29
How is the composition of the red blood cell plasma membrane asymmetrical?
The red blood cell plasma membrane is asymmetrical, with mainly negatively charged phospholipids located on the inner part of the lipid bilayer.
30
What is the significance of the asymmetrical composition of the red blood cell plasma membrane?
The asymmetrical composition is important for cell signaling and communication.
31
How is the biconcave shape of red blood cells achieved?
The biconcave shape of red blood cells is achieved through a mesh-like network formed by the protein spectrin.
32
What is the role of spectrin in red blood cells?
Spectrin, a filamentous protein (~100 nm), is the primary component of the red blood cell cytoskeleton. It interacts with cell membrane proteins and helps maintain the biconcave shape of red blood cells.
33
What happens when there are abnormalities in the spectrin gene?
Abnormalities in the spectrin gene can lead to the production of spherical and fragile red blood cells.
34
How are platelets released?
Platelets are released by megakaryocytes, which are large cells found in the bone marrow.
35
What role do enzymes in platelets play?
Enzymes in platelets help initiate the process of blood clotting.
36
What happens when circulating platelets come in contact with collagen fibers in damaged blood vessels?
When platelets come in contact with collagen fibers, they undergo swelling and form a "sticky patch," initiating the blood clotting cascade.
37
What is the role of inactivated precursor proteins in blood clotting?
Blood clotting relies on inactivated precursor proteins, such as prothrombin and fibrinogen, which are produced in the liver and circulate in the blood.
38
How are inactivated precursor proteins involved in clotting?
Inactivated precursor proteins are cleaved into active forms, thrombin and fibrin, respectively, which are essential for the formation of blood clots.
39
What occurs after the formation of a blood clot during wound healing?
Following the formation of a blood clot, wound healing progresses with the formation of scar tissue.
40
Where does hematopoiesis occur in humans?
Hematopoiesis, the process of blood cell formation, occurs in the bone marrow throughout life.
41
What is the role of bone marrow in hematopoiesis?
Bone marrow ensures a constant supply of red blood cells (RBCs) at a rate of approximately 3.5 x 10^11 per day.
42
How much blood does the average adult have, taking into account the average hematocrit?
The average adult has approximately 5,000 ml of blood, with half or 2,250 ml consisting of red blood cells, considering the average healthy hematocrit.
43
What is the average daily blood production of red blood cells for a healthy adult?
The average daily blood production of red blood cells for a healthy adult is estimated to be 18.75 ml/day.
44
Where does erythropoiesis, the specific process of red blood cell production, take place?
Erythropoiesis occurs in the hematopoietic or red marrow, which is located within the trabecular (spongy) bone at the ends of long bones.
45
What happens after hemoglobin synthesis is completed in erythroblasts?
After hemoglobin synthesis is completed, the nucleus of the erythroblast, which has been progressively condensing, is expelled, yielding a reticulocyte.
46
What happens to reticulocytes after they are formed?
Reticulocytes enter the vascular circulation and mature into erythrocytes within a span of 1 to 3 days.
47
How many reticulocytes are typically found in the blood circulation of a healthy individual?
A healthy individual typically has approximately 25 to 125 x 10^9/L reticulocytes in their blood circulation.
48
What does an elevated number of reticulocytes indicate?
An elevated number of reticulocytes suggests an active bone marrow response to blood loss, such as trauma or anemia. It is a compensatory mechanism.
49
How can reticulocytes be visualized?
Reticulocytes can be visualized using a supravital stain. In the staining, the blue dots represent ribosomes within the reticulocytes.
50
What is the composition of adult hemoglobin (HbA)?
Adult hemoglobin (HbA) consists of four subunits: two identical α chains and two identical β chains.
51
What is the composition of fetal hemoglobin (HbF)?
Fetal hemoglobin (HbF) consists of two identical α chains and two identical γ chains.
52
What is the main secondary structure of the hemoglobin protein subunits?
The main secondary structure of the hemoglobin protein subunits is the α-helix.
53
How many heme groups are bound to each hemoglobin subunit?
Each hemoglobin subunit binds to a heme group, and there are four heme groups in total (shown in green) within the hemoglobin molecule.
54
What is the role of hemoglobin?
Hemoglobin binds to and transports oxygen (O2) throughout the body.
55
How does the oxygen binding affinity differ between HbA and HbF?
HbF (fetal hemoglobin) exhibits a stronger binding affinity for oxygen than HbA (adult hemoglobin).
56
What is responsible for the red color of hemoglobin?
The heme group within hemoglobin is responsible for its red color.
57
What does the heme group consist of?
The heme group consists of four pyrrole rings that form a tetrapyrrole ring called protoporphyrin.
58
What is the role of the heme group in oxygen binding?
Each of the nitrogen atoms in the pyrrole rings of the heme group participates in the binding of a Fe atom (Fe2+), which is responsible for binding oxygen.
59
What happens when oxygen binds to the heme group?
When oxygen binds to the heme group, there is a partial transfer of an electron from Fe to O2, resulting in the formation of Fe3+ and a superoxide ion (O2-), which is a reactive oxygen species.
60
How does hemoglobin ensure the release of O2 rather than O2- in tissues?
The haemoglobin protein subunits are structured in a way that favors the release of O2 rather than O2- in tissues, preventing the buildup of reactive oxygen species.
61
What does the S-like shape of the hemoglobin binding curve indicate?
The S-like shape of the hemoglobin binding curve indicates cooperative binding behavior, where the binding of oxygen to one heme group increases the likelihood of oxygen binding to the other three heme groups.
62
How does cooperative binding assist in the unloading of oxygen?
Cooperative binding behavior ensures that when one heme group releases oxygen, it assists in the unloading of oxygen from the other three heme groups, promoting efficient oxygen release.
63
Where does strong oxygen binding occur in hemoglobin?
Strong oxygen binding occurs in the lungs, where the partial pressure of oxygen is approximately 100 torr.
64
Where is oxygen easily released from hemoglobin?
Oxygen is easily released from hemoglobin in the tissues, where the partial pressure of oxygen is much lower, approximately 20 torr.
65
Why is cooperative binding behavior important for hemoglobin's function?
Cooperative binding behavior allows hemoglobin to efficiently bind oxygen in the lungs and readily release it in the oxygen-depleted tissues, ensuring effective oxygen transport.
66
How does 2,3-BPG affect the affinity of hemoglobin for oxygen?
2,3-BPG lowers the affinity of hemoglobin for oxygen, ensuring the release of oxygen in tissues.
67
How does 2,3-BPG function as an allosteric regulator of hemoglobin?
2,3-BPG binds to a specific site in the center of the hemoglobin tetramer, which is different from the oxygen-binding sites. This binding causes a conformational change in hemoglobin, resulting in a lower oxygen-binding affinity
68
What is the consequence of 2,3-BPG binding to hemoglobin?
When 2,3-BPG binds to hemoglobin, it promotes a conformation that has a lower affinity for oxygen, leading to the occupancy of more oxygen binding sites. This lower oxygen binding affinity ensures easier release of oxygen in the tissues.
69
How does 2,3-BPG contribute to efficient oxygen delivery?
By lowering the oxygen affinity of hemoglobin, 2,3-BPG facilitates the release of oxygen from hemoglobin in the tissues, enabling efficient oxygen delivery to the cells.
70
What is the nucleotide sequence similarity between the genes for the β chain (HbA) and the γ chain (HbF)?
The genes for the β chain (HbA) and the γ chain (HbF) share 72% nucleotide sequence similarity.
71
How does the binding of 2,3-BPG differ between HbF and HbA?
Due to their nucleotide sequence differences, 2,3-BPG does not bind as efficiently to HbF as it binds to HbA. Therefore, HbF has a lower affinity for 2,3-BPG compared to HbA.
72
Do fetal red blood cells (RBCs) have a higher affinity for oxygen than maternal RBCs?
Yes, fetal RBCs have a higher affinity for oxygen than maternal RBCs due to the presence of HbF, which exhibits stronger oxygen binding.
73
How is oxygen efficiently transferred from maternal RBCs to fetal RBCs?
During embryonic development, oxygen can be efficiently transferred from maternal RBCs to fetal RBCs due to the higher affinity of fetal HbF for oxygen. This allows for optimal oxygen exchange between the maternal and fetal circulatory systems.
74
What is the purpose of cellular respiration?
The purpose of cellular respiration is to generate energy in the form of ATP by breaking down glucose and utilizing oxygen.
75
What is fermentation?
Fermentation is an alternative metabolic pathway that occurs in the absence of oxygen. It involves the breakdown of glucose into lactic acid (lactate) and a small amount of ATP.
76
Where does fermentation take place and when does it occur?
Fermentation takes place in muscle cells, especially during intense exercise when the demand for ATP is higher than the rate at which oxygen can be transported. It serves as a rapid source of ATP production.
77
What are the consequences of lactate buildup during fermentation?
Lactate buildup leads to a lowering of pH, causing muscle fatigue and discomfort.
78
What is the structure of myoglobin?
Myoglobin has the same structure as one hemoglobin subunit and contains one heme group.
79
Where is myoglobin present?
Myoglobin is present in skeletal muscle cells.
80
What is the role of myoglobin?
Myoglobin ensures oxygen diffusion within skeletal muscle cells, serving as a storage and transport molecule for oxygen.
81
How does myoglobin's affinity for oxygen compare to that of hemoglobin?
Myoglobin has a higher affinity for oxygen compared to hemoglobin. It binds oxygen more tightly.
82
What is the consequence of myoglobin's high oxygen affinity?
The high oxygen affinity of myoglobin results in inefficient or low oxygen release to the tissues.
83
How does the oxygen-carrying capacity of myoglobin compare to hemoglobin?
Hemoglobin can deliver approximately 10 times more oxygen to tissues compared to myoglobin due to its cooperative binding behavior and ability to release oxygen more readily.
84
What happens when carbon monoxide (CO) binds to hemoglobin?
Carbon monoxide binds to hemoglobin at the oxygen binding site, forming carboxyhemoglobin.
85
How does carbon monoxide binding differ from oxygen binding to hemoglobin?
Carbon monoxide binds very tightly to hemoglobin, approximately 200 times stronger than oxygen, which leads to the displacement of bound oxygen molecules.
86
What is the consequence of carbon monoxide binding to hemoglobin?
When carbon monoxide binds to hemoglobin, it increases hemoglobin's affinity for oxygen, resulting in the reduced release of oxygen in the tissues.
87
What are the symptoms of carbon monoxide poisoning?
Carbon monoxide poisoning can cause symptoms such as disorientation, nausea, lethargy, and weakness.
88
How is carbon monoxide poisoning treated?
Hyperbaric oxygen therapy is a treatment option for carbon monoxide poisoning. It involves administering 100% oxygen at a higher atmospheric pressure to enhance oxygenation and promote the removal of carbon monoxide from hemoglobin.
89
What is hypovolemia?
Hypovolemia refers to a condition characterized by a loss of extracellular fluid, specifically a decrease in blood volume.
90
What are the causes of hypovolemia?
Hypovolemia can be caused by various factors, including excess bleeding due to trauma, diarrhea or vomiting, renal failure, and the use of diuretics.
91
What are the symptoms of hypovolemia?
Symptoms of hypovolemia include fatigue, headaches, cyanosis (bluish discoloration of the skin), and tachycardia (rapid heart rate).
92
What percentage of blood volume loss is indicated by the symptoms mentioned?
The symptoms mentioned are consistent with more than a 10% loss of blood volume.
93
What can happen if hypovolemia is left untreated?
If left untreated, hypovolemia can lead to hypovolemic shock, organ failure, and even death.
94
What is anemia?
Anemia is a condition characterized by a reduced concentration of hemoglobin, leading to a decreased ability of the blood to transport oxygen.
95
What are the clinical symptoms of anemia?
Clinical symptoms of anemia include tachycardia (rapid heart rate), breathlessness, pallor (pale skin), and lethargy (fatigue and weakness).
96
What are the causes of anemia?
Anemia can be caused by various factors, including iron deficiency (common in pregnancy and childbirth), bone marrow suppression (e.g., myelodysplastic syndrome, aplastic anemia), blood loss, folate deficiency, vitamin B12 deficiency (pernicious anemia), hemolysis (hemolytic anemia), inherited problems in hemoglobin synthesis (e.g., β-thalassemia), and autoimmune disorders.
97
What are some examples of inherited problems in hemoglobin synthesis?
One example of an inherited problem in hemoglobin synthesis is β-thalassemia, which affects the production of the β chain of hemoglobin.
98
How can autoimmune disorders contribute to anemia?
Autoimmune disorders can cause anemia by triggering the immune system to attack and destroy red blood cells.
99
What causes sickle cell anemia?
Sickle cell anemia is caused by a single mutation in the β-globin gene, where the amino acid glutamate at position 6 is replaced with valine. This mutation leads to the production of abnormal hemoglobin called HbS.
100
What happens to hemoglobin in sickle cell anemia?
In sickle cell anemia, oxyhemoglobin (oxygenated form of hemoglobin) is not affected, but deoxyhemoglobin (deoxygenated form) forms fibrous aggregates, resulting in the characteristic sickle-like shape of red blood cells.
101
How does the sickle-like shape of red blood cells affect blood flow?
The sickle-like shape of red blood cells in sickle cell anemia can cause clogging of capillaries and hinder smooth blood flow. These abnormal red blood cells also stick frequently to vessel walls, leading to further complications.
102
What is the result of reduced circulation time for sickle cell anemia?
Due to their abnormal shape and reduced lifespan, red blood cells in sickle cell anemia have a shorter circulation time, leading to a decreased oxygen-carrying capacity and other complications.
103
What are some symptoms and complications of sickle cell anemia?
Symptoms and complications of sickle cell anemia include severe pain crises, organ damage, increased susceptibility to infections, anemia-related fatigue, and various other health issues.
104
What causes α-thalassemia?
α-thalassemia is caused by the deletion or inactivation of three or four of the α-globin genes. The deletion or inactivation of one or two genes typically does not cause symptoms.
105
What is the result of the deletion or inactivation of all four α-globin genes?
Deletion or inactivation of all four α-globin genes leads to a condition called Hb Bart's syndrome, which is usually lethal in the embryonic stage.
106
What is HbH disease?
HbH disease is a form of α-thalassemia resulting from the deletion or inactivation of three α-globin genes. It is characterized by symptoms such as enlarged spleen and liver, anemia (sometimes requiring blood transfusions), and hemolysis (premature destruction of red blood cells).
107
What causes β-thalassemia?
β-thalassemia is caused by mutations or deletions of the β-globin gene, which affects the production of β-globin chains.
108
What are the symptoms and complications of β-thalassemia?
β-thalassemia is characterized by symptoms such as anemia, hemolysis, erythroid hyperplasia (overproduction of red blood cells), bone marrow expansion, and extramedullary hematopoiesis (production of blood cells outside the bone marrow).
109
What is aplastic anemia?
Aplastic anemia is a condition characterized by bone marrow failure, resulting in impaired hematopoiesis (formation of blood cells). It leads to pancytopenia, which is a reduction in the number of red blood cells, white blood cells, and platelets.
110
What are the symptoms of aplastic anemia?
Symptoms of aplastic anemia include fatigue, weakness, shortness of breath, pale skin, frequent infections, and easy bruising or bleeding.
111
What is Fanconi anemia?
Fanconi anemia is a rare genetic disorder characterized by bone marrow failure, congenital abnormalities, and an increased risk of developing certain cancers.
112
What are the symptoms of Fanconi anemia?
Symptoms of Fanconi anemia can vary but often include bone marrow failure, physical abnormalities (such as skeletal, kidney, and heart defects), growth problems, and an increased susceptibility to cancers (such as leukemia).
113
How is aplastic anemia and Fanconi anemia managed?
The management of aplastic anemia and Fanconi anemia is complex and may involve treatments such as blood transfusions, medications to suppress the immune system, and, in some cases, bone marrow transplantation. Regular medical monitoring and support are necessary for individuals with these conditions.
114
What is polycythemia?
Polycythemia is a condition characterized by an elevated hematocrit, which refers to an increased percentage of red blood cells in the blood.
115
What are the possible causes of polycythemia?
Polycythemia can be caused by a decrease in blood volume or an increased production of red blood cells entering circulation, known as erythrocytosis. It can also be associated with gene mutations affecting the JAK-STAT signaling pathway or malfunction of erythropoietin (EPO) and its receptor.
116
What are the symptoms of polycythemia?
Symptoms of polycythemia may include fatigue, dizziness, headaches, gum bleeding, and nosebleeds. In more severe cases, it can affect heart, spleen, and blood clotting.
117
What is myeloproliferative neoplasm?
Myeloproliferative neoplasms are a group of disorders characterized by the overproduction of blood cells in the bone marrow. Polycythemia is an example of a myeloproliferative neoplasm, while thrombocythemia refers to an increased number of platelets.
118
How is polycythemia managed?
The management of polycythemia aims to reduce blood volume and control the production of red blood cells. This may involve therapeutic phlebotomy (removal of blood), medications to suppress bone marrow activity, and addressing the condition's underlying causes.
