Blood Flashcards
White Blood Cells (General Info)
- WBC = leukocytes
- have nuclei
- colourless
White Blood Cells (Function)
- Protects body from pathogens (disease-causing agents)
* WBC count increases when fighting an infection
Components of WBC
• 2 major cell types:
1) macrophages
2) lymphocytes
Macrophages
- part of body’s innate immune response (every healthy person has this automatically)
- phagocytic cells
- pass directly through capillaries
- engulfs pathogens
Lymphocytes
- part of body’s acquired immune response (created response to a virus)
- 2 types of lymphocytes: T cells (thymus gland - kill) and B cells (bone marrow - memory)
B Cells
- causes production of antibodies
* guides the attack on infected cells
T Cells
- cytotoxic T cells: directly attack infected cells
* Helper T cells: activate Cytotoxic T cells, B cells, or macrophages
Platelets
General Info:
• fragments of cells broken off from larger cells in the bone marrow
Function:
• play important role in blood clotting
• helps prevent excessive blood loss after injury
Blood Clotting (Vascular & Platelet Phases)
- Vascular Phase
• broken blood vessels trigger clotting
• clotting does not occur otherwise - Platelet Phase
• platelets gather at site of damage
• they stick to damaged tissues
Blood Clotting (Coagulation Phase)
• platelets rupture and release chemical agents • chemical agents lead to the following: -thromboplastin -prothrombin (inactive enzyme) -thrombin (active enzyme) -fibrinogen (soluble) -fibrin (non-soluble)
What is blood?
- collection of cells that perform vatiety of specialized tasks
- considered a tissue even though it appears fluid
- circulation of blood transports/distributes materials
Components of Blood
• Plasma 55% • red blood cells 44% • white blood cells 1% • Blood is separated into: 1) Fluid components 2) Cellular components
Fluid Portion of Blood
- fluid portion: Plasma
* made up of water, dissolved gases, proteins, sugars, vitamins, minerals, and waste product
Blood Plasma
- the medium ehich carries RBC
- Contains protein components involved in immune defense, clotting, and maintaining blood volume and pressure
- transports O2, CO2, H2O, and HCO3
Cellular Components of Blood
• The solid portions of blood:
1) RBC (red blood cells)
2) WBC (white blood cells)
3) Platelets
Red Blood Cells: General Info
• RBC = Erythrocytes • Discoid shape - Increases surface area for gas exchange - 20-30% more SA than a sphere • no nuclei - Increases space for more Hb • ~4.5-5.5 million RBCs/mL of blood
Hemoglobin (Hb)
• 1 Hb contains 4 heme groups - each heme group can bind with one O2 molecule - O2 binds to the iron on each group • 1 Hb can carry 4 O2 molecules • 98% of O2 via Hb • 2% of O2 molecules
Hb + O2 -> HbO2
Hemoglobin + Oxygen -> Oxyhemoglobin
Red Blood Cell: Function
- cells specialized for O2 transport
- 1 RBC contains 280 million Hb
• Remember:
- Hb allows easy transport of O2
- 98% of O2 transportee via Hb
