The Blood

Characteristics  Part of cardiovascular system  Functions Transportation (plasma & RBCs) Transportation (plasma & RBCs) Protection (WBCs) Protection (WBCs) Prevent blood loss & infectionPrevent blood loss & infection Regulation of pH & temperature Regulation of pH & temperature

General Properties of Blood  Color (hemoglobin or Hb) Arterial – high oxygen – bright red Arterial – high oxygen – bright red Venous – low oxygen – dark red Venous – low oxygen – dark red  Volume Men – 5 to 6 L Men – 5 to 6 L Women – 4 to 5 L Women – 4 to 5 L Caused by size, not gender Caused by size, not gender

Arterial vs Venous Blood

General Properties of Blood  Viscosity Resistance to flow / thickness Resistance to flow / thickness Blood is actually thicker than water Blood is actually thicker than water  pH (7.35 – 7.45) Acidosis – pH drops too low Acidosis – pH drops too low Alkalosis – pH too high Alkalosis – pH too high

Plasma  The liquid portion of the blood  90% water, 10% dissolved stuff 8% Plasma proteins – thickeners, antibodies, & clotting factors 8% Plasma proteins – thickeners, antibodies, & clotting factors 2% Other – gases, nutrients, ions, wastes, hormones 2% Other – gases, nutrients, ions, wastes, hormones  Function – transportation

Blood Serum  Plasma with clotting factors removed  For storage, testing, & testing, & blood typing blood typing

Formed Elements  Cells found in the plasma Red blood cells (Erythrocytes) Red blood cells (Erythrocytes) White blood cells (Leukocytes) White blood cells (Leukocytes) Platelets (Thrombocytes) Platelets (Thrombocytes)

Formed Elements

Hematocrit  Determining % of formed elements in a sample

Red Blood Cells (RBCs)  95% formed elements, 40% total blood volume  Structure Biconcave for more surface area Biconcave for more surface area No nucleus for more volume No nucleus for more volume

Red Blood Cells (RBCs)

 Function – transport O 2 & CO 2  Iron within Hb that attracts & binds to O 2

Red Blood Cells (RBCs)  Short life span - ~120 days  Anemia – decrease in the number of healthy RBCs – over 400 types Iron-deficiency Iron-deficiency Sickle cell Sickle cell Aplastic Aplastic

Iron deficiency anemia  Not enough iron means the body cannot produce enough hemoglobin  Diet, blood loss, endurance training, medications, etc.

Sickle Cell Anemia  Genetic & more prevalent in African-Americans

Aplastic anemia  Red bone marrow damaged so not producing enough RBCs  LOTS of causes

White Blood Cells (WBCs)  Many different types  Less than 1% total blood volume  Function – protect from disease  Talents Diapedesis – squeeze between cells of vessel wall Diapedesis – squeeze between cells of vessel wall Phagocytosis – engulf invader or damaged cells with pseudopods Phagocytosis – engulf invader or damaged cells with pseudopods

Diapedesis & Phagocytosis

White Blood Cells (WBCs)  We’ll learn more about WBS types when we discuss immunity!  Some produce… Antibodies – proteins to fight specific invaders Antibodies – proteins to fight specific invaders Histamine – SOS signal Histamine – SOS signal

Hives caused by histamine

How do we counteract histamine?

UNDERSTANDING CHECK

Leukemia  Overproduction of immature WBCs

Platelets  Initiate formation of a blood clot

Hemostasis  Stoppage of bleeding  Blood vessel spasm - <30 mins  Platelet plug formation Platelets change shape and cling to fibers from torn wall Platelets change shape and cling to fibers from torn wall  Coagulation Fibrin netting formed to trap RBCs Fibrin netting formed to trap RBCs

Animation

Bruising  Black & blue – oxygen poor blood in tissues

Bruising  Green/yellow/brown – body breaks down RBCs & Hb, releasing iron & pigments

Hemostasis  Blood may clot when you don’t want it to!  Often from poor blood flow  pools  Thrombus – fixed in place  Embolus – free floating

UNDERSTANDING CHECK

Blood Groups  Antigens on RBCs  Antibodies in plasma  Mix the wrong ones & blood clumps

ABO System  2 co-dominant antigens – A & B  4 blood types – A, B, AB, O  You have antibodies for antigens not present  Genetically acquired

ABO System

Rules of DONATIONS  Best to use the same type  CANNOT mix A with anti-A, etc.  BUT antibodies only work in YOUR body

Rh system  Rh + or Rh –  + is dominant over –  Antibodies only formed by sensitization (exposure)  Sensitization is often from pregnancy (- mom with + child)

Rules of DONATION  Same as ABO  CANNOT mix Rh+ with anti-Rh  BUT antibodies only work in YOUR body

Blood Donations  Who’s the universal recipient?  Who’s the universal donor?