Biology | first term | transport in human 3 | blood | دكتور مصطفى خضر

Key Concepts:

• Blood Composition:
  • Blood consists of plasma (54%), Red Blood Cells, White Blood Cells, and Platelets.
  • Plasma is primarily composed of:
    • 90% water
    • 7% proteins (albumin, globulin, fibrinogen)
    • 1% organic salts
    • 2% other substances including enzymes and hormones.
• Blood Characteristics:
  • Normal pH of blood: 7.4
  • Normal temperature of blood: 37°C
  • Volume of blood in the human body: approximately 5 to 6 liters.
  • Blood color varies based on oxygen content:
    • Bright red when oxygenated.
    • Dark red when deoxygenated.
• Types of Blood Cells:
  • Red Blood Cells (RBCs):
    • Produced in the bone marrow.
    • Approximately 4.5 million cells per cubic millimeter in males and slightly less in females.
    • Lifespan of about 120 days; die in the spleen, liver, or bone marrow.
    • Function: Transport oxygen (via hemoglobin) and carbon dioxide.
  • White Blood Cells (WBCs):
    • Approximately 7,000 cells per cubic millimeter.
    • Lifespan of 13 to 20 days; also die in the spleen.
    • Function: Immune defense against pathogens.
  • Platelets:
    • Approximately 250,000 cells per cubic millimeter.
    • Lifespan of about 10 days.
    • Function: Blood clotting.

Blood Clotting Process:

Blood clotting is crucial for preventing blood loss from injuries. The process involves several factors:

• Thromboplastin: Activates clotting factors.
• Prothrombin: Converts to thrombin in the presence of calcium.
• Fibrinogen: Converts to fibrin, forming a mesh that traps blood cells to create a clot.

Key factors influencing clotting include calcium levels and the presence of certain proteins.

Homeostasis:

Blood plays a role in maintaining homeostasis, regulating body temperature, pH, and nutrient levels.

Measurement of Blood Pressure:

Blood pressure is measured using a sphygmomanometer, indicating systolic (120) and diastolic (80) pressures.

Researchers/Sources Featured:

• Dr. Mustafa Khodr (دكتور مصطفى خضر)

This summary encapsulates the essential scientific information regarding blood transport and its functions as presented in the video.