Blood Notes Red blood cells & White blood cells

Interesting Blood Facts How long does it take a drop of blood to travel away from the heart and back again? Roughly 20 to 60 seconds.

NOTES - BLOOD Blood components only fluid tissue – has both solid & liquid elements living blood cells suspended in a non living matrix called PLASMA Formed Elements elements include: red blood cells (rbc), white blood cells (wbc) – many different forms, and platelets

RED BLOOD CELLS aka: ERYTHROCYTES Function: carry oxygen to other cells – doesn’t use the O2, just carries it (rbc has no mitochondria)

RBC count: approximately 4-6 million/mm3 Total: 30 trillion in an adult RBC production aka: HEMATOPOIESIS produced by red marrow in bones rate of RBC production controlled by hormone called ERYTHROPOIETIN erythropoietin is produced by the kidneys and stimulated by blood level of oxygen low 02 = more erythropoietin high O2 = less erythropoietin

Hemoglobin (symbol “Hb”) functions to carry O2 inside RBC contains iron - low iron decreases ability to transport O2 one RBC contains 280 million Hb molecules – 4 oxygen molecules per Hb group

Iron Iron deficiency: ANEMIA ability to transport O2 impaired – symptom easily fatigued sources of iron: liver, red meats, kidney beans, egg yolks, spinach

WHITE BLOOD CELLS – aka: Leukocytes Function: fight disease 5,000 – 9,000/mm3 RBC to WBC ratio 700 : 1 WBC can squeeze through capillaries – RBC’s cannot - DIAPEDESIS

Granulocytes granule containing WBC’s (3 types)

1. Neutrophils 50 – 70% most mobile – first to arrive phagocytes - BACTERIA life span: 12 hours or 2 dozen bacteria

2. Eosinophils 2 –4 % attacks parasites releases chemicals that reduce inflammation

3. Basophils less than 1% - rare discharge granules at injury sites histamine – causes inflammation – prevents clots

Agranulocytes WBC’s lacking visible cytoplasmic granules – 2 types 1. Monocytes 2 – 8% phagocyte – bacteria, dead cells, debris within tissues

2. Lymphocytes 20 – 30% 2 kinds: B – cells and T - cells control of IMMUNE SYSTEM responsible for allergies, graft rejection, tumor control