Title: Anatomy / 6 Blood

Q: origin
of blood cells, general amount of blood, distribution of cells and plasma
A: - Origin: Blood cells originate from the bone marrow;
- Amount: 7-8% of total body weight ~ 5-6 litres;
- Distribution:
- 45 % blood cells;
- 55 % blood plasma;

Q: working
mechanism of immune system
A: The immune system protects the body by identifying and reacting to foreign substances;
- Antigen: A substance that cause an immune reaction in the body;
- Antibody: Specialized proteins that recognize and bind to specific antigens;

Q: characteristics
of red blood cells
A: - They have no nucleus;
- Lifespan: 120 days;
- Disassembly: broken down in the spleen and liver;
- Components: hemoglobin and hematocrit;
- Amount: 5 Mio / µl

Q: characteristics
of white blood cells
A: Amount: 4000 – 8000/µl;
Have a nucleus
Types:
- Granulocytes (Subdivided into neutrophilic, basophilic, and eosinophilic);
- Lymphocytes: Includes T-cells, B-cells, and Th-cells;
- Monocytes / Macrophages

Q: Characteristics of platelets
A: - They have no nucleus;
- Lifespan: only 5 – 10 days;
- Amount: 150000 – 350000/µl;

Q: Blood
types (incl. distribution)
A: AB0 System:
- Type A: 44%.
- Type 0: 42%.
- Type B: 10%.
- Type AB: 4%.
Rhesus Factor:
- Rh-positive: 85%.
- Rh-negative: 15%.

Q: differentiation
of primary and secondary lymphatic organs
A: - Primary: Where lymphocytes are produced/mature (e.g. bone marrow);
- Secondary: Where immune responses are initiated (e.g. lymph nodes, spleen)

Q: characteristics
of lymphatic drainage
A: - Blind Beginning: Unlike the closed cardiovascular circuit, lymph drainage begins "blindly" with capillaries in the extracellular space;
- Filtration: The fluid passes through lymph nodes, which act as filters and are rich in lymphocytes;
- Fat Transportation: The system plays a key role in transporting fats from the digestive tract;
- Sequence of Flow: Extracellular fluid → Lymph capillaries → Lymph vessels → Lymph nodes → Thoracic duct or right lymphatic duct → Superior vena cava (venous system);