The Blood Flashcards
The average adult has 4-6 liters of blood circulating through the body. What are the components of blood?
Blood is a connective tissue composed of plasma and formed elements. Formed elements are erythrocytes, leukocytes, and platelets.
How does viscosity of blood effect blood pressure?
Viscosity is a measure of “thickness” of a fluid. Regarding the blood, a high viscosity (thicker) blood raises blood pressure because the heart has to pump harder (more force) to move the components through the vessels. Blood with high viscosity has more formed elements and less water. Polycythemia is an excess in erythrocytes.
Low viscosity blood has high water content compared to formed elements. Blood pressure drops when viscosity is low because the heart does not need to pump with as much force to circulate the blood.
Describe what hematocrit is and how it can be measured?
Hematocrit is the percent (%) of blood that is cells. Blood is a suspension and when allowed to sit in a test tube for a period of time (or centrifuged), heavier components settle to the bottom and lighter components rise to the top. The percent of erythrocytes is added to the percent of leukocytes to determine the hematocrit level. Plasma is not considered part of the hematocrit measure.
What is a function of the blood?
The blood has many functions; some include nutrient transport (supply and removal), temperature regulation, and immune functions.
Describe hemopoiesis and where this occurs occurs in a middle aged person.
Hemopoiesis is the production of blood cells. The production takes place primarily in the bone marrow of long bones; most notably the femur.
Provide 3-4 ways erythropoiesis can occur.
Erythropoiesis can occur as a result of blood loss (hemorrhaging), traveling to high altitude, and through exercise. All of these factors are a result of the demand for more oxygen to be delivered to the system.
When traveling to high altitude (from Pittsburgh to Denver), when would you suggest an athlete arrive in order to acclimate to the environment and why?
Acclimation to high altitude training takes approximately 3-4 days because of the low concentration of oxygen in the atmosphere. By arriving 3-4 days early, athletes can produce more erythrocytes to help transport more oxygen to supply the body’s tissues.
What element is responsible for erythropoiesis and what chemical is responsible for transporting oxygen on an erythrocyte?
Iron is required for erythropoiesis. Hemoglobin is needed for attaching oxygen to an erythrocyte for transport.
Describe what thrombopoiesis is and how the process occurs.
Thrombopoiesis is the production of platelets. This occurs when fragments of the plasma membrane of leukocytes split off. They can circulate in the blood for approximately 10 days. The spleen can store thrombocytes for future use.
What two factors determine how much oxygen a can be carried in the blood?
The amount of erythrocytes in the blood and concentration of hemoglobin on the erythrocytes determine how much oxygen can be carried in the blood.
Why is sickle cell disease potentially lethal at high altitudes?
Sickle cell disease occurs as a result of hemoglobin structure modification. Hemoglobin becomes gel-like in low oxygen concentrated environments and loses its ability to attach oxygen to an erythrocyte. Further, the modification of hemoglobin causes an erythrocyte to elongate, fold on top of itself, and form a cycle shape. Due to the lack of oxygen, tissue becomes hypoxic; due to the gel-like hemoglobin, erythrocytes agglutinate and block vessel, which can lead to a stroke, heart failure, kidney failure, paralysis and/or death.
