Lecture Exam 3 BLOOD

• Blood is a specialized connective tissue. Blood cells are suspended in a
• fluid matrix.

• 1.
• Transport dissolved gases,
• nutrients, hormones and metabolic wastes.

• 2.
• The restriction of fluid losses at
• injury sites.

• 3.
• Defense against toxins and
• pathogens.

• 4.
• The stabilization of body
• temperature.

The yellow-colored liquid component of blood, in which blood cells are suspended.

90% water, molectules including Na+ and CI-, hormones, vitamins, and three types of proteins.

• Difference between plasma and interstitial fluids are:
• 1. Different levels of oxygen and carbon dioxide
• 2. Different amounts and types of dissolved proteins (plasma proteins do not pass through capillary walls).

Like interstitial fluid, plasma is an extracellular fluid. Water, ions and small solutes are continually exchanged between the plasma and interstitial fluid across the walls of capillaries.

• Three main classes of plasma proteins:
• 1. Albumins 60% transport substances such as fatty acids, thryoid hormones and steroid hormones.
• 2. Globulins 35% Antibodies, transport globulins
• 3. Fibrinogen 4% Form clots by producing long insoluble strands of fibrin.

• Hematocrit is the percentage of red blood cells in a whole blood sample.
• These three things equal a hematocrit percentage. About 48% for men and 38% for women.

The process of blood cell production. Occurs in Red Marrow.

Myeloid Stem Cell and Lymphoid Stem Cell.

• Carry oxygen from the lungs to the tissues around your body.
• Getting waste carbon dioxide from your tissues to your lungs, where it can be breathed out.

• Male - 5 million / mm3
• Females are slightly lower.

• 1. Concave disc shape gives each RBC a high surface to volume ratio, to quickly absorb and release oxygen.
• 2. Enables RBC's to form stacks, which smoothes the flow through narrow blood vessels.
• 3. Enables RBC's to bend and flex when enetering small capillaries and branches.

• 1. Hemocytoblasts, stem cells in bone marrow divide to produce myeloid stem cells (to become RBC's) and lymphoid stem cells. (to become lymphocytes).
• 2. Myeloid stem cells differentiate into proerythroblasts.
• 3. Proerythroblasts mature in several stages, losing organelles and reducing in size to become a reticulocyte.
• 4. Reticulocytes are released into the blood stream and complete maturation.
• Hemocytoblasts ->Myeloid / Lymphoid Stem Cells ->Proerythroblasts -> Reticulocytes ->

• 120 Days for the life of a RBC
• 2 million are replaced per second.

The Spleen and liver.

5,000 to 10,000 per mm3 of blood.

• 1. Neutrophils
• 2. Eosinophils
• 3. Basophils
• 4. Monocytes
• 5. Lymphocytes

• 1. All can migrate out of the bloodstream
• 2. All are capable of amoeboid movement
• 3. All are attracted to specific chemical stimuli
• 4. Some are capable of phagocytosis (neutrophils, eosinophils and monocytes).

• 50-70% of all WBC's
• Their cytoplasm is packed with pale granules containing lysosomal enzymes and bacteria killing compounds. The breakdown of used neutrophils in an infected wound forms pus.

• 2-4% of all WBC's
• Their mode of attack is the excrete toxic compounds such as nitric oxide and cytotoxic enzymes, which are effective against parasites that are too large to engulf. Also Eosinophils are sensitive to allergenad and increase during allergic reactions. They release enzymes that counteract the inflammatory effects of neutrophils and mast cells.

• <1% of WBC's
• Small; accumulate in damaged tissue and release histamine, which dialates blood vessels and heparins, which prevents blood clotting.

• 2-8% of WBC's
• Large; they become macrophages to engulf large particles and pathogens.

• 20-30% of WBC's
• Migrate in and out of the blood. Spend most of their time in connective tissues and lymphatic organs.
• T-Cells - attack foreign cells directly.
• B-Cells differentiate into plasma cells which synthesize antibodies
• NK natural killer cells - detect and destroy abnormal tissue cells, such as cancer.

• All WBC's except monocutes develop fully in the bone marrow. (Monocytes develop into macrophages in peripheral tissues).
• All WBC's originate from hemoblasts:
• Hemoblasts -> Myeloid Stem Cells -> Progenitor Cells -> All other WBC's
• Hemoblasts -> Lymphoid Stem Cells -> Lymphocytes

• Platelets are cell fragments involved in the clotting system.
• 1. Release of chemicals inportant to the clotting process
• 2. Formation of a temporary patch in the walls of damaged blood vessels
• 3. Active tissue contraction after clot formation has occurred.

Thrombocytopoiesis occurs in bone marrow. Giant cells called megakaryocytes manufacture platelets by shedding cytoplasm packets until they are used up. The process is controlled by thrombopoietin (TPO).