Blood By the end of the lesson you should be able to:  State the composition of Blood  State the function of red blood cells and plasma  Explain the function of hemoglobin in the transport of oxygen  State the function of white blood cells

 the average human has 5 litres of blood  it is a transporting fluid  it carries vital substances to all parts of the body Blood

Human blood smear X 500

 plasma (~55%)  red blood cells (5-6 million /ml)  white blood cells (5000/ml)  platelets skool blood plasma

x 1000

Plasma -liquid part of blood -transports:  food (glucose & amino acids)  waste products  heat  carbon dioxide  hormones  antibodies

Red blood cells (Erythrocytes)  transport oxygen specialized to do this Also carry some CO 2

Red blood cells specializations 2) no nucleus  extra space inside 3) contain hemoglobin  the oxygen carrying molecule  250 million molecules / cell Quirky Almost Unnecessary Cartoon 1) biconcave shape increases the surface area so more oxygen can be carried

Hemoglobin  gives red blood cells their color  can carry up to 4 molecules of O 2  associates and dissociates with O 2  contains iron Quick clip Quick clip

Platelets if you get cut:-  platelets produce tiny fibrin threads  these form a web-like mesh that traps blood cells.  these harden forming a clot, or "scab."  150,000 to 400,000 per mm 3

Platelets  SEM of a clot with platelet, fibrin mesh, rbc’s

White blood cells (Leukocytes)  the bodies “defense”  part of the immune system  much larger than RBCs  far fewer  have a nucleus  per mm 3

Neutrophils  ~60% of WBCs  Function Phagocytize & destroy bacteria  First cells to respond to infection  Secrete antibacterial chemicals

Phagocytosis

Lymphocytes 20-40% of WBCs  Produces anti-bodies  recognizes and acts against a specific antigen (foreigner)  There are 2 types: T-cells B-cells

Lymphocytes  T lymphocytes can attack foreign cells directly (17.6) (17.6a)

Lymphocytes  B lymphocytes transform into plasma cells and secrete antibodies (17.6b)

Monocytes  Up to 10% of WBCs  Become wandering macrophages after DIAPEDESIS Diapedesis is the process of white blood cells migrating outside of blood vessels

Diapedesis

Eosinophils  1-7% of WBCs  Phagocytize  Secrete antihistamine (allergic reactions)  Attack parasites

Basophils  <3% of WBCs Histamine – creates inflammation in allergic reaction Increases circulation to allow for other WBC’s to arrive and help out (counteracted later by Eosinophils) Neutrophils

Robin, Suzanne. “5 types of White Blood Cells,” 2011 Basophils < 3% Eosinophils ~7% Monocytes up to 10% Lymphocytes 20-40% Neutrophils 45-75% Frequency of white blood cells (on average)

Blood Can you?  State the composition of Blood  State the function of red blood cells and plasma  Explain the function of hemoglobin in the transport of oxygen  State the function of 5 white blood cells

Quick test… 1.Which is more abundant? White blood cells Red blood cells

Quick test… 2. What is the advantage of red blood cells NOT having a nucleus?

Quick test… 3. Which white blood cell is most abundant? Eosinophils Neutrophils

Quick test… 4. Which important oxygen-carrying molecule is found in abundance WITHIN red blood cells?

Quick test… 5. Which cellular component found in blood plays a role in blood-clotting?

Quick test… 6. Which white blood cell contains both T and B cells? Lymphocytes Monocytes

Quick test… 7. Which white blood cell is considered the “wanderer” after Diapedesis? Basophils Monocytes

Quick test… 8. Which white blood cell secretes histamine, a chemical causing inflammation to increase blood flow? Basophils Eosinophils

Quick test… 9. Which white blood cell secretes anti- histamine, a chemical working OPPOSITE of histamine to reduce swelling form allergic reactions? Basophils Eosinophils

Quick test… 10. Which white blood cell ALSO attacks parasites that enter the body? Basophils Eosinophils

Quick test… 11. Which Lymphocytes attack cells directly? T cells B cells