Lecture 23 Blood Componets Flashcards
Contrast the general roles of blood, lymph and interstitial fluid in maintaining homeostasis.
The general role of the blood is to transport oxygen, get rid of waste like carbon dioxide, fight disease and transport nutrients like sugar, fats, proteins, amino acids, and hormones. It also maintains the body’s temperature. It is the ultimate homeostatic organ.
Examples of transportation is through nutrients that we eat go to the digestive tract, followed then into the bloodstream and from the bloodstream it goes to the kidneys and back into the bloodstream and nutrients go into different cells. Oxygen goes into lungs and then into the bloodstream where it is distributed to other cells in the body.
Define the physical characteristics of blood (pH, viscosity, temperature and volume).
The physical characteristics of blood are plasma, Erythrocytes ( red blood cells) leukocytes (white blood cells,) and platelets. After the blood is broken down using special equipment - it separates from heaviest to lightest. The heaviest is red blood cells so that sinks to the bottom, wbc and platelets are made a small amount and the rest is plasma - the liquid portion of the blood. It is made up of mostly water. PH level of blood is 7.3 - 7.5, temperature is 36.5-37.2 C.
Identify plasma and describe its composition.
Plasma is made up of water. It is 90% water, salts make up .9%, proteins, nutrients and wastes
Describe and compare the origins of the formed elements.
There are several proteins making up about 9% of the total plasma. Albumin is the most abundant and acts as a buffer, transport protein and the blood colloid osmotic pressure. The globulins act as antibodies against anything foreign the the body and the clotting factors allow the blood to form a clot. The blood contains vitamins, minerals, glucose and amino acids as nutrients and urea, uric acid and creatinine as waste products. These make up the remaining 0.1%.
Describe the structure of erythrocytes and how they transport O2 and CO2.
Ethroycytes (RBC) count for 45% of the total blood volume. They’re are about 4.2 - 5.4m RBC in females and and 4.6 - 6.1m RBC’s in males. The ethroycytes also vary due to age and altitude - newborns have lower RCB’S.) Elderly tend to have a lower count too.
RBC’s are anuclear, they cannot reproduce and die in about 120 days. They are replaces in the hemopoeitc tissue located in the red bone marrow.
The main component of RCBS are hemoglobin, a red colored iron containing complex protein.
Reduced hemoglobin can combine with 02 to produce bright red oxyhemoglobin, which increases blood oxygen by 20fold. Hemoglobin can also bind to C02 and form carbaminohemoglobin (dark red) which transport c02 into the lungs and back into the veins.
List the types and functions of leukocytes.
Leukocytes are only 1% of the blood volume. But they are 5 different types of WCB’s. Which are divided into two groups called:
Agranulocytes- They are no granules and nucleus are fairly normal shape. They include monocytes (the largest of all of the leukocytes) and lymphocytes (the smallest)
Granulocytes - They have granules in their cytoplasm and are defined by these granules stain. Their nuclei arepolymorphic (weird.) These include eosinophils with red granules, basophils with blue granules and neutrophils with unstained granules.
5 Types:
- Neutrophil: 60% - 70% of WBC. Increased in # of response to bacterial infection. Their function is to destroy and engulf bacteria. Major component of pus.
- Eosinophil - 2 - 4% of WBCs. Cell count increases with allergies, parasite infection and menstruation. Act against the chemical agents of large parasites and surface allergens.
- Basophil - Less than 1% of WCBs. Not found in any large #’s. They secret histamine and heparin. Histamine attacks other Leukocytes and Herapin prevents blood clot formation, so that leukocytes gain access to the wound site again.
Monocyte - 3-8% of circulating WCBs. Increase in number of response to inflammation and viral infection. They convert themselves into macrophages, leave the bloodstream and follow histamine signals to the wound site. They destroy any foreign organisms that they can engulf.
Lymphocyte - 25-35% of circulating WBCs . They are part of the lymphoid series. Lymphocytes all look alike but they play different roles in the immune response. Both are divided into two groups B and T cells. Both will increase in the number of response to acute.
Describe the importance of a differential white count.
TBD
Discuss the role of leukocytes in phagocytosis and antibody production.
TBD
Discuss the structure of thrombocytes and explain their role in blood clotting.
They are smaller than RBCs. They look a bit square shaped and secrete several chemicals that can influence blood clotting, vasoconstriction, and inflammatory agents in response to injury. They engluf and digest bacteria and produce agents to begin clot destruction and several growth factors to stimulate cell proliferation.
How are RCB’s production controlled and how are they destroyed?
We have a feed back loop, which monitors the oxygen in our blood. When it is lower, it causes our bodies to react - live/kidneys to produce a hormone called ethryopoietin. This takes about 3-5 days.
As the RCBs get older they get more fragile and rupture (hemolysis.) There components are picked up by phagocytes or leukocytes.
