Biology 212 Anatomy & Physiology I Dr. Thompson Blood

Biology 212 Anatomy & Physiology I Dr. Thompson Blood

Blood: Volume: Components: Formed Elements: Plasma: pH: Buffered to remain stable

Erythrocytes Primary Function – Biconcave disks No nucleus million per microliter (cubic millimeter) billion per milliliter (cubic centimeter) Slightly higher in men

Hemoglobin Each molecule: 4 large Globin proteins Each surrounding an iron- containing Heme Group Oxygen

Erythrocyte formation = Occurs Developing erythrocytes =

Erythropoiesis regulated

Erythrocytes also carry specific glycoproteins, or antigens, on their surfaces which are responsible for blood types If transfused into person with incompatible blood type,

Erythrocytes normally survive Trapped and destroyed Iron

Leukocytes (White blood cells) Five different types of cells All formed 4,000 to 10,000 per cubic millimeter or 4,000,000 to 10,000,000 per milliliter (cubic centimeter)

Each type has specific functions, but in general: Leukocytes function in body defenses by: Engulfing Directly Producing Secreting

Leukocytes Grouped into two categories Abundant, distinct granules = Few, small granules =

Granular Leukocytes Named according to how these granules react to routine lab stains ("Wright's Stain" is most common) The nucleus of each type also has a characteristic shape and/or density Three types:

Neutrophils. Granules present in cytoplasm but stain weakly with both acidic and basic stains Nucleus Also called

Eosinophils Granules attract acidic stain eosin, therefore stain red or orange Nucleus

Basophils Granules attract the basic stain hematoxylin, therefore stain blue or purple Nucleus Outside of circulation:

Agranular Leukocytes Two unrelated types of leukocytes, neither of which has abundant granules: The nucleus of each type also has a characteristic shape and density

Monocytes Nucleus Stains Cytoplasm Outside of circulation:

Lymphocytes Nucleus Varying amounts of cytoplasm

Lymphocytes Two types of lymphocytes with different functions in immune system, but they appear identical in blood:

All leukocytes formed in bone marrow, then enter blood But: Not particularly active when in the blood. Most leukocytes are using the blood to get to other tissues and organs, where they differentiate and become active

Since they generally function outside of the circulatory system, primarily in the connective tissues of other organs, All leukocytes can leave (and most can also reenter) the blood vessels by a process called Therefore: All of the leukocytes, and the cells which they mature into, are normally found in connective tissues throughout the body

Platelets Function 250,000 to 500,000 per cubic millimeter or 250,000,000 to 500,000,000 per milliliter (cubic centimeter)

Platelets Fragments of much larger cells, which remain in

When blood vessels are damaged, the flow of blood through them must be stopped until the body can repair the injury. This is called It involves three processes in rapid sequence: Vasospasm

When blood vessels are damaged, the flow of blood through them must be stopped until the body can repair the injury. This is called It involves three processes in rapid sequence:

Formation of a Platelet Plug - Under normal conditions, platelets do not stick to each other or to the walls of blood vessels - As new platelets attach, they also - When a blood vessel is injured, it releases chemicals which cause platelets to attach to each other and to the injured part of the vessel. This is

When blood vessels are damaged, the flow of blood through them must be stopped until the body can repair the injury. This is called It involves three processes in rapid sequence:

Formation of a Fibrin Blood Clot - This involves a series of sequential chemical reactions in which the products of the first reaction serve as the catalysts of the second reaction, whose products are the catalysts of the third reaction, whose products are the catalysts of the fourth reaction, etc. - This allows for a very rapid increase in the rate at which the clot forms. - It also allows many chances to stop the process if it began by mistake or gets too far away from where the vessel was injured.

Formation of a fibrin blood clot involves 13 "clotting factors". Each of these is the reactant for the next of these sequential reactions FactorSynonyms Factor IFibrinogen Factor IIProthrombin Factor IIITissue Thromboplastin Factor IVCalcium Factor VProaccelerin Factor VILabile Factor Factor VIIProthrombin accelerator Factor VIIIAntihemophilic Factor A Factor IXAntihemophilic Factor B Factor XStuart Factor Factor XIThromboplastin Antecedent Factor XIIHageman Factor Factor XIIIFibrin Stabilizing Factor

Formation of a fibrin blood clot involves 13 "clotting factors". Each of these is the reactant for the next of these sequential reactions Last reaction:

Once the fibrin clot has formed, Over the next 30 to 60 minutes, End result: Dense network of interconnected strands of fibrin with platelets, erythrocytes, and leukocytes trapped within it.

Over next few days, after vessel has time to repair itself: Clot is dissolved and removed by process called Plasma protein converted to active enzyme which dissolves fibrin.