BLOOD

FUNCTION: • Blood transports substances

(hormones, oxygen, glucose etc.)• Average adult has 5 liters in body • Maintains homeostasis in the

body• Regulation of pH (7.4) and

water levels• Maintenance of body

temperature• Maintenance of blood sugar

levels Hematophobia

= fear of blood

Blood and Blood Cells Composition1. Red blood cells = 45%2. White blood cells + platelets (“Buffy Coat”) = <1%3. Plasma (water, proteins, amino acids, etc.) = 55%

Hematocrit – dense, bottom layer of cells in a blood sample (around 45%) when placed in a centrifuge machine that rapidly spins test tubes around in circle

Three Types of Blood Cells

1. red blood cells (erythrocytes)2. white blood cells (leukocytes)3. platelets (thrombocytes)

1. Red Blood Cells (erythrocytes) • Biconcave discs

• 5 million per cubic millimeter

• 120 day life span

HEMATOPOEISIS – formation of blood cells in spongy red bone marrow PHAGOCYTOSIS – destruction of dead and damaged RBCs in liver & spleen

Main Functions of RBCs• Transports oxygen throughout

the body and picks up carbon dioxide waste to deliver to the lungs

• HEMOGLOBIN - molecule found in RBC that binds with O2

• IRON (“heme”) is critical to synthesize hemoglobin recycled in liver after RBC death

• Each hemoglobin molecule consists of 4 heme groups (tetramer) that allows four oxygen molecules to bind to hemoglobin

• Competitive inhibitors like carbon monoxide easily bind to hemoglobin (250x greater affinity than oxygen) and can lead to dramatic reduction in oxygen levels (“poisoning”)

• No nucleus & no organelles no cell division

• No mitochondria means RBCs generate ATP anaerobically or without oxygen (O2) this prevents consumption of the O2 being transported

• Oxygen helps make more ATP = ENERGY!!

Endocrine System: EPO, or erythropoietin, is a hormone produced by the liver and kidneys to increase production of red blood cells under conditions of hypoxia (low oxygen levels)Disgraced cyclist Lance Armstrong admitted to Oprah Winfrey that he took banned substances, including EPO, during all seven of his Tour de France victories.

What is EPO? (Gizmodo Article)

WHITE BLOOD CELLS (Leukocytes) Immune System: protect the body against foreign

invaders (bacteria, viruses, fungi etc.) Contain nucleus + organelles

WHITE BLOOD CELLS (Leukocytes) Immune System: protect the body against foreign

invaders (bacteria, viruses, fungi etc.) Contain nucleus + organelles

WHITE BLOOD CELLS (Leukocytes) Neutrophils – phagocytes (to swallow) of

bacterial and fungal cells

WHITE BLOOD CELLS (Leukocytes) Basophils – regulate inflammatory immune

responses using histamine

WHITE BLOOD CELLS (Leukocytes) Lymphocytes – produce immune responses to

foreign pathogens; memory of previous infections

LYMPHOCYTES

1. B cells – produce antibodies to tag and bind to specific antigens (what antibodies bind to, ex: bacterial protein), and then attract T cells

2. T cells – attack and destroy viral-infected and tumor cells

Platelets (thrombocytes) Allow blood to clot and aid in

blood vessel repair when damaged

No nucleus

RBC PLATELET WBC

PLASMA (55%)• The liquid portion of blood is

92% water• Organic nutrients – glucose,

amino acids, lipids (cholesterol, fatty acids)

• Electrolytes – sodium, potassium, calcium chloride, bicarbonate etc.

• Respiratory gases – oxygen & carbon dioxide

Plasma Proteins (7%)• Albumins – regulate osmotic pressure so cells don’t

burst from water flowing in

• Globulins (alpha, beta, gamma) – form antibodies for immune responses

• Fibrinogen – important for blood clotting

Definition and Functions: Facts:

BLOOD

A type of connective tissue whose cells are suspended in a liquid matrix.

1. Maintain stability of interstitial fluid2. Distributes heat3. Transports nutrients, oxygen, wastes

and hormones

Red blood cells• Erythrocytes• Transports gases

White blood cells• Leukocytes• Protect against disease

Blood platelets• Thrombocytes• Close breaks in damaged blood

vessels• Initiate formation of blood clots

Hematocrit (HCT) • Red blood cells• 45%

Buffy coat• White blood cells and platelets• >1%

Plasma• mixture of water, amino acids, proteins,

carbs, lipids, vitamins, hormones, electrolytes, and cellular wastes

• 55%

*Men have more blood than women• 1.5 gallons versus .875

gallons*Blood is 3-4x more viscous than water*Average adult has 5.3 quarts (5 liters)*the pH of the blood = 7.4