Module 2: Blood Chapter 10 Flashcards
What is blood composed of?
Specialized cells (such as leukocytes, erythrocytes, and platelets) suspended in plasma
What is hematocrit?
The volume of blood occupied by cells - determined through centrifugation
What is the buffy coat?
Part of blood composed of leukocytes (WBC’s) and platelets: makes up <1%
Blood plasma is composed of 90% ______ which serves as a transport medium for the cellular components of blood as well as for:
- _____
- _____
- _____
- _____
- _____
- _____
Blood plasma is composed of 90% water which serves as a transport medium for the cellular components of blood as well as for:
- electrolytes
- nutrients
- gases
- plasma proteins
- wastes
- hormones
What is the function of the following blood constituent:
- Water:
Water serves as a transport medium and also carries heat
What is the function of the following blood constituent:
Electrolytes:
- Membrane excitability
- osmotic distribution of fluid between the ECF and ICF
- buffer pH changes
What is the function of the following blood constituent:
Nutrients, wastes, gases, hormones:
Transported in the blood;
The blood gas CO2 plays a role in acid base balance
What is the function of the following blood constituent:
plasma proteins:
- In general, exert an osmotic effect important in the distribution of ECF between the vascular and interstitial compartments
- Buffers pH changes
What is the function of erythrocytes (red blood cells)?
Transport O2 in the circulatory system
How is the shape of erythrocytes (red blood cells) related to their function?
- A mature erythrocyte has a biconcave shape, which increases its surface area,
- a thin and flexible membrane, which allows for movement of the erythrocyte through vessels with small diameters, and
- no nucleus or organelles, which allows more intracellular space for hemoglobin.
There are more than 250 million molecules of haemoglobin in each erythrocyte.
Each haemoglobin molecule is composed of four ________\_(called the globin portion), each of which binds to a heme group. Each heme group contains an _____\_, which binds an O2 molecule and appears red in colour when O2 is bound (e.g., in systemic arterial blood), and appears blue in colour when O2 is not bound (e.g., in systemic venous blood)
There are more than 250 million molecules of haemoglobin in each erythrocyte.
Each haemoglobin molecule is composed of four polypeptide chains (called the globin portion), each of which binds to a heme group. Each heme group contains an iron ion, which binds an O2 molecule and appears red in colour when O2 is bound (e.g., in systemic arterial blood), and appears blue in colour when O2 is not bound (e.g., in systemic venous blood)
The majority of adult hemoglobin is composed of two ____\_and two ____\_ _____\_ ______.
The majority of adult hemoglobin is composed of two alpha and two beta polypeptide chains.
Haemoglobin also combines with
- ,
- _______, and
- _________.
Haemoglobin also combines with
- carbon dioxide (CO2),
- hydrogen ions (H+),
- carbon monoxide (CO2), and
- nitric oxide (NO).
In addition to containing haemoglobin, erythrocytes contain
- _____\_ and
- the enzyme ______\_
In addition to containing haemoglobin, erythrocytes contain
- glycolytic enzymes and
- the enzyme carbonic anhydrase.
Glycolytic enzymes are important in erythrocytes why?
Erythrocytes lack organelles = thus lack a mitochondria = depend on glycolytic enzymes for energy production
What is the purpose of Carbonic anhydrase in erythrocytes?
Carbonic anhydrase catalyzes the rxn required to convert CO2 into bicarbonate (HCO3-) which is the primary form that CO2 is carried in the blood
Define erythropoiesis
The process of erythrocyte production
Describe erythropoiesis
Erythropoiesis takes place in the RED BONE MARROW at a rate of 2-3million erythrocytes/second
- In the red bone marrow, pluripotent stem cells can be stimulated to differentiate into erythrocytes, leukocytes or platelets
Blood cells and blood cell precursors:
In the bone marrow, undifferentiated __________\_ are the precursor cells to all blood cells.
These multipotent stem cells differentiate into a _______\_line and a _________\_ line.
Myeloid stem cells will further differentiate to produce ______\_, ______\_, ______\_and ______\_.
Lymphoid stem cells will further differentiate to produce ___________.
Blood cells and blood cell precursors:
In the bone marrow, undifferentiated multipotent stem cells are the precursor cells to all blood cells.
These multipotent stem cells differentiate into a myeloid stem cell line and a lymphoid stem cell line.
Myeloid stem cells will further differentiate to produce platelets, erythrocytes, granulocytes and monocytes.
Lymphoid stem cells will further differentiate to produce lymphocytes.
What hormone stimulates erythropoiesis? Where is the hormone released from?
The kidneys respond to low O2 levels in the blood and release the hormone erythropoietin
Describe what is occurring in the image:
Describe what is occurring in the image:
- kidneys detect reduced O2 - carrying capacity of the blood
- When less O2 is delivered to the kidneys, they secrete the hormone erythropoietin into the blood
- Erythropoietin stimulates erythropoiesis (erythrocytes production) by the bone marrow
- Additional circulating erythrocytes increase the O2 carrying capacity of the blood
- Increased O2 - carrying capacity relieves the initial stimulus that triggered erythropoietin secretion
The reduction of the O2 carrying capacity is called?
Anaemia
What is anaemia characterized by?
What are six causes?
Anaemia is characterized by low hematocrit
It has many causes, six of which are:
- Nutritional anemia → results from a dietary deficiency of a factor required for erythropoesis, such as iron
- Pernicious anemia → results from insufficient folic acid or vitamin B12
- Aplastic anemia → results from failure of the bone marrow to maintain an appropriate rate of erythropoeisis
- Renal anemia → results from insufficient production of erythropoietin by the kidneys
- Hemorrhagic anemia → results from excessive blood loss
- Hemolytic anemia → results from premature rupture of erythrocytes, such as in sickle cell disease
What is polycythemia?
elevated hematocrit
What is the difference between Primary Polycythemia and Secondary Polycythemia?
Primary Polycythemia: caused by increased rates of erythropoiesis that occur in an unregulated manner
Secondary Polycythemia: increased rates of erythropoiesis that occurs as an adaptive mechanism in response to a prolonged reduction in O2 delivery to the tissues
What is relative polycythemia?
Refers to a loss of plasma, such as from severe dehydration which also increases the hematocrit
In the image, what is being depicted in each test tube:
At the end of their lifespan, the majority of erythrocytes are removed from circulation in the _____\_
At the end of their lifespan, the majority of erythrocytes are removed from circulation in the spleen
Explain the image showing the lifecycle of an erythrocyte?
- The life cycle of an erythrocyte begins in the bone marrow with ____\_, a process stimulated by ____\_.
- Erythropoietin is released by the ____\_in response to a _____ _____-_____ ____\_ of the blood.
- Upon production, erythrocytes are released into circulation. The average time for an erythrocyte to remain in circulation is 120 days.
- Old erythrocytes are primarily catabolized in the ____\_. Erythrocyte degradation produces ____\_ and ____\_.
- The globin is further degraded into ____\______\__ which are released into the blood for reuse.
- The heme is further degraded into iron and ____\_.
- Iron is released from the spleen and transported in the blood as - ____\_, bound to a protein called ____\_.
- This iron, as well as iron absorbed from the diet or released from F-iron (iron bound to the protein ferritin) stores in the liver, will be used to form new ____\_ in the bone marrow.
- Bilirubin is released from the spleen and transported in blood to the ____\_where further catabolism occurs with the degradation products being secreted in the ____\_ to the ____\_and to the ____\_.
Explain the image showing the lifecycle of an erythrocyte?
- The life cycle of an erythrocyte begins in the bone marrow with erythropoiesis, a process stimulated by erythropoietin.
- Erythropoietin is released by the kidneys in response to a reduced oxygen-carrying capacity of the blood.
- Upon production, erythrocytes are released into circulation. The average time for an erythrocyte to remain in circulation is 120 days.
- Old erythrocytes are primarily catabolized in the spleen. Erythrocyte degradation produces heme and globin.
- The globin is further degraded into amino acids which are released into the blood for reuse.
- The heme is further degraded into iron and bilirubin.
- Iron is released from the spleen and transported in the blood as T-iron, bound to a protein called transferrin.
- This iron, as well as iron absorbed from the diet or released from F-iron (iron bound to the protein ferritin) stores in the liver, will be used to form new hemoglobin in the bone marrow.
- Bilirubin is released from the spleen and transported in blood to the liver where further catabolism occurs with the degradation products being secreted in the bile to the small intestine and to the kidneys.
