Cardiovascular system III
Thursday, 7 October 2021 10:24 AM
Functions of blood
- Transportation
- Regulation
○ Maintenance of homeostasis
§ Heat
- protection
Blood composition
- Blood plasma
○ Mostly water
§ 91-92%
○ Protein
§ Albumin
§ Globulins
§ Fibrinogen
□ Coagulation factor
® Causes blood to clot
□ In tubes, add some citrate? to avoid clotting
○ Other solutes
§ Electrolytes
§ Nutrients
§ Nonprotein nitrogen substances
§ Blood gases
§ Regulatory substances
○ Serum
§ Same as blood plasma except without clotting factors
§ For laboratory test
- Formed elements
○ Red blood cells
§ erythrocytes
§ Major component
○ White blood cell
§ Neutrophils
§ Lymphocytes
§ Eosinophils
§ Basophils
○ Platelets
, ○ White blood cell
§ Neutrophils
§ Lymphocytes
§ Eosinophils
§ Basophils
○ Platelets
Haematopoiesis
- Blood formation
- Starts during embryonic development throughout childhood / adulthood
- Embryo
○ Mesenchymal cells in yolk sac form blood island
○ Migrate to liver / spleen in between 6 weeks - 7 months
§ Serve as primary site for Haematopoiesis
- 3 months before birth
○ Red Bone marrow becomes major location for Haematopoiesis
○ Mostly the only site for Haematopoiesis
○ Every single bone filled with red bone marrow as they have the
ability to form blood cells
○ After red bone marrow replaced so less ability to form blood cells
- Adult
○ Red bone marrow found in axial skeleton and proximal ends of long
bones
- Originate from pluripotent stem cell in red bone marrow
○ Differentiate into
§ Myeloid stem cell
□ Further differentiate into stem cells
§ Lymphoid stem cells
§ Both lineages experience numerous differentiate to reach
final cells
Erythrocytes
- Histological ruler
○ Use to identify size of surrounding tissues
- Most abundant formed element of blood
- Biconcaved shaped
- Non-nucleated / devoid of other organelles
- Transports O2 and CO2
- Cytoplasm contains haemoglobin
○ Makes blood red
○ O2 binds to haeme group
○ More haemoglobin in peripheral
§ More red stain in red blood cells on peripheral
- Regulation
○ Short life cycle
§ 120 days
§ Bone marrow keeps producing new erythrocytes
Thursday, 7 October 2021 10:24 AM
Functions of blood
- Transportation
- Regulation
○ Maintenance of homeostasis
§ Heat
- protection
Blood composition
- Blood plasma
○ Mostly water
§ 91-92%
○ Protein
§ Albumin
§ Globulins
§ Fibrinogen
□ Coagulation factor
® Causes blood to clot
□ In tubes, add some citrate? to avoid clotting
○ Other solutes
§ Electrolytes
§ Nutrients
§ Nonprotein nitrogen substances
§ Blood gases
§ Regulatory substances
○ Serum
§ Same as blood plasma except without clotting factors
§ For laboratory test
- Formed elements
○ Red blood cells
§ erythrocytes
§ Major component
○ White blood cell
§ Neutrophils
§ Lymphocytes
§ Eosinophils
§ Basophils
○ Platelets
, ○ White blood cell
§ Neutrophils
§ Lymphocytes
§ Eosinophils
§ Basophils
○ Platelets
Haematopoiesis
- Blood formation
- Starts during embryonic development throughout childhood / adulthood
- Embryo
○ Mesenchymal cells in yolk sac form blood island
○ Migrate to liver / spleen in between 6 weeks - 7 months
§ Serve as primary site for Haematopoiesis
- 3 months before birth
○ Red Bone marrow becomes major location for Haematopoiesis
○ Mostly the only site for Haematopoiesis
○ Every single bone filled with red bone marrow as they have the
ability to form blood cells
○ After red bone marrow replaced so less ability to form blood cells
- Adult
○ Red bone marrow found in axial skeleton and proximal ends of long
bones
- Originate from pluripotent stem cell in red bone marrow
○ Differentiate into
§ Myeloid stem cell
□ Further differentiate into stem cells
§ Lymphoid stem cells
§ Both lineages experience numerous differentiate to reach
final cells
Erythrocytes
- Histological ruler
○ Use to identify size of surrounding tissues
- Most abundant formed element of blood
- Biconcaved shaped
- Non-nucleated / devoid of other organelles
- Transports O2 and CO2
- Cytoplasm contains haemoglobin
○ Makes blood red
○ O2 binds to haeme group
○ More haemoglobin in peripheral
§ More red stain in red blood cells on peripheral
- Regulation
○ Short life cycle
§ 120 days
§ Bone marrow keeps producing new erythrocytes
