Transport Systems in the Body

Red Blood Cells (RBCs) AKA erythrocytes Functions in respiratory gas transportation (with hemoglobin) Flexible biconcave shape Mature cells lack nucleus Formed in the red bone marrow Confined to blood stream due to size In the adult male, normal RBC count is 4.5 to 6.3 million Makes up around 40-50% of blood

Leukocytes AKA white blood cells Functions in immunity/protection for the body through phagocytosis “phago-” to eat “-cyto-” cells “-osis” process Made in bone marow Have cell nucleus Not confined to blood stream Makes up about 1% of blood Numbers increase when fighting pathogens

Platelets Functions in blood clotting Contain blood clotting chemicals Are cell fragments Produced in bone marrow Forms a temporary patch in the walls of damaged blood vessels. Active tissue contraction occurs after clot formation has initiated

Is that all??? Plasma – Contains dissolved materials and wastes Straw colored Plasma makes up about 50 to 60 percent of blood volume, and is more than 90 percent water.

Functions of Blood Distribution of oxygen, nutrients, metabolic wastes, and hormones Regulation of body temperature, pH, circulatory fluid volume Protection against blood loss and infection Average volume ~ 5L Approximately 8% of body weight 95% of blood components are made in the bone marrow

What Is A Blood Type? four blood groups: O, A, B and AB Based on antigens on the blood cell Rh factor (antigen) will make each group either positive or negative

Antigens and Antibodies Antigens are cell’s ID tags Proteins located on cell membrane Blood contains antibodies for unlike blood groups Antibodies are large proteins produced by white blood cells Causes agglutination (clumping) of blood cells when different antigens are present

Type A Blood antigens antibodies

Type A Has A antigens Has B antibodies (Anti B) 42% of Canadians share this blood type

Type B Blood antigens antibodies

Type B Has B antigens Has A antibodies (Anti-A) 9% of Canadians share this blood type

Type AB Blood antigens

Type AB Has A and B antigens Has no antibodies Universal Recipient!!! 3% of Canadians share this blood type

Type O Blood antibodies antibodies

Type O Has no antigens Has A and B antibodies (Anti-A and Anti- B) Universal Donor!!! 46% of Canadians share this blood type

Blood Transfusions History: English physician during the mid-17th century who infused a wounded soldier with sheep blood 19th century, European and American doctors used transfusions in a last ditch attempt to save soldiers and other patients with severe wounds Doctors in the 19th century also experimented with a variety of blood substitutes, including milk, water, and even oils. ABO blood types discovered in 1900

So what does that mean today?? Canadian Blood Services maintains bank Shelf life is ~35 days Tests blood from donor Recipient's blood tested for compatibility with donor to prevent hemolysis Whole Blood Donations: every 56 days, 450 ml given Autologous Donations: own patient’s blood Aphaeresis Donations: parts of blood are taken, some is returned Plasma Donation Platelet Donations Stem Cell Donations

Who Gets What? Blood Group Antigen Present Antibodies Present Blood That Can Be Received A Anti-B A and O B Anti-A B and O AB A and B None A, B, AB, and O Universal Recipient O Anti-A and Anti B Universal Donor

Blood Vessels In closed circulatory systems, blood is confined to vessels Blood exchanges materials with the interstitial fluid bathing the cells Arteries lead blood to capillaries from heart Veins return blood from the capillaries Action occurs in capillaries

Arteries: carry blood away from the heart to organs throughout the body Arteries are thicker than veins…why?? Thick layer of smooth muscle (nonstriated; involuntary)= middle layer Inside layer=endothelium Outside layer = thick elastic connective tissue

Capillaries are microscopic vessels with very thin, porous walls Are a single of flattened cells Site of gas exchange Occurs due to pressure Water, sugars, salts, oxygen and waste products pass through the capillary walls

Veins return blood to the heart Categorized by direction of flow, NOT whether or not they contain oxygen Thinner layer of smooth muscle = middle layer Endothelium = inside layer Thin connective tissue, not very elastic = outside layer VALVES to prevent back flow of blood Blood flows mainly due to muscle action