Hematologic System

• Blood is a liquid connective tissue composed of cells suspended in an extracellular matrix
• Blood


  Closely related to other body fluids like lymphatic fluid, cerebrospinal fluid, and interstitial fluid
• Functions of blood


  • Transports oxygen, carbon dioxide, nutrients, hormones
  • Regulates homeostasis, pH, temperature
  • Protects against disease, clots to prevent blood loss
• Physical characteristics of blood

  • Denser and more viscous than water
  • Temperature of 38°C
  • Slightly alkaline pH of 7.35-7.45
• Blood makes up about 8% of total body weight, with volumes of 5.6L in adult males and 4.5L in adult females</b>
• Exercise increases blood plasma volume initially, then increases red blood cell production
• Oral health


  Can affect cardiovascular system and lead to conditions like endocarditis
• Plasma


  The fluid component of blood, making up 55% of total blood volume
• Plasma composition


  • 91.5% water
  • 7% proteins
  • 1.5% solutes (electrolytes, nutrients, gases, hormones, waste)
• Plasma proteins


  Include albumin, globulins, fibrinogen
• Formed elements


  The cellular component of blood, making up 45% of total blood volume
• Formed elements


  • Red blood cells
  • White blood cells
  • Platelets
• Red blood cells


  • Lack nucleus and mitochondria
  • Contain hemoglobin to carry oxygen
  • Shaped as biconcave discs for efficient gas exchange
• Red bone marrow produces over 2 million red blood cells per second
• Hemoglobin


  Oxygen-carrying protein in red blood cells
• Each red blood cell contains 280 million hemoglobin molecules, each able to carry 4 oxygen molecules
• Anemia


  Reduced number of red blood cells or decreased hemoglobin
• Types of anemia


  • Iron deficiency
  • Vitamin B12 or folate deficiency
  • Hemorrhagic (in females)
• White blood cells


  Protect against infections and foreign invaders
• Platelets


  Cell fragments that play a role in blood clotting and wound repair
• Blood clots consist of fibrin threads and trapped blood cells