The Blood Characteristics Part of cardiovascular system Functions

The Blood

Characteristics Ø Part of cardiovascular system Ø Functions Transportation (plasma & RBCs) l Protection (WBCs) l • Prevent blood loss & infection l Regulation of p. H & temperature

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

Arterial vs Venous Blood

General Properties of Blood Ø Viscosity Resistance to flow / thickness l Blood is actually thicker than water Ø p. H (7. 35 – 7. 45) l Acidosis – p. H drops too low l Alkalosis – p. H too high l

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

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

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

Formed Elements

Hematocrit Ø Determining % of formed elements in a sample

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

Red Blood Cells (RBCs)

Red Blood Cells (RBCs)

Red Blood Cells (RBCs) Ø Function – transport O 2 & CO 2 Ø Iron within Hb that attracts & binds to O 2

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

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

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

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

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

Diapedesis & Phagocytosis

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

Hives caused by histamine

How do we counteract histamine?

UNDERSTANDING CHECK

Leukemia Ø Overproduction of immature WBCs

Platelets Ø Initiate formation of a blood clot

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

Animation

Bruising Ø Black & blue – oxygen poor blood in tissues

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

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

UNDERSTANDING CHECK

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

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

ABO System

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

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

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

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