Ch 14 Lab

What is a thrombocyte?

A platelet

Platelets cling to exposed collagen at the site of injury of a blood vessel. What is the result of this process called?

Platelet plug

Chemicals released by damaged cells, white blood cells, and platelets act to attract white blood cells to the area. What is this attraction called?

Positive chemotaxis

Define hemostasis.

Process that stops bleeding

The stem cells that give rise to all of the formed elements are called __________ stem cells.

hematopoietic

What is the typical life span of a red blood cell?

120 days

Complete the sentences describing hemostasis.

Damage to a blood vessel results in contraction of smooth muscle cells in the vessel wall. This may be due to direct stimulation, a reflex response to pain, and/or the presence of serotonin released by platelets. The collagen in the vessel wall that is exposed when damage occurs allows adhesion of platelets. Accummulation of these formed elements can plug a small break in a vessel. Formation of a blood clot, called coagulation, results from a series of reactions occurring in cascade. The result is a meshwork of a protein called fibrin. For a small break in a blood vessel, the sequence of vascular spasm, platelet plug formation, and coagulation results in the break being sealed off. Blood loss is reduced and healing can begin.

What is a result of reduced red blood cell count and/or reduced hemoglobin content of the blood?

Diminished oxygen-carrying capacity of the blood

Complete the following sentences about the process of red blood cell production.

Having an adequate RBC count ensures that tissues will receive enough oxygen to function. If oxygen delivery to tissues is reduced, the homeostatic response is to produce more red blood cells. Specifically, if the tissues of the kidney sense a drop in oxygen delivery, the hormone erythropoietin is released into the bloodstream. This hormone stimulates production of more RBCs in the red bone marrow. As more RBCs enter the blood, increasing the RBC count, the oxygen delivery will improve. This mechanism of control of RBC count is an example of negative feedback control.

What component of blood accounts for the largest proportion of the blood volume?

Plasma

Name the formed element that is a cell fragment.

Platelet

Describe the function of platelets.

Reduces blood loss from damaged blood vessels

Complete the following sentences describing blood plasma.

The average human has approximately five liters of blood in their circulation. The fluid portion of the blood, called plasma, accounts for about 55% of the blood volume. Plasma is approximately 92% water, 7% protein, and 1% other solutes. Most of the plasma proteins are produced by the liver, except for the gamma globulins, which are produced by immune cells.

What is the role of hematopoietic growth factors?

To influence hemocytoblasts to give rise to specific formed elements

Complete the sentences about the WBC life cycle.

White blood cells are responsible for the defense system in the body. Like red blood cells, these cells are formed from the stem cells of the bone marrow. The different types of these cells have life spans from hours to years. Approximately 5 to 10 thousand of these cells are found per microliter of blood. Their function includes defense of the body against infection. These cells use the process of diapedesis to leave the circulation and move toward areas of infection or inflammation. They move about within the interstitial fluid by the process of ameboid motion.

What stage in the process of hemostasis is illustrated in this image?

Platelet plug formation

This figure shows the result of interaction of RBC antigens (A antigens) with the antibody against the RBC antigen (anti-A antibodies). What is this result called?

Agglutination

The kidney hormone that stimulates red blood cell production is called __________.

erythropoietin

The value of 45% is a normal value for The value of 5,200,000 per microliter is a normal value for The value of 300,000 per microliter is a normal value for The value of 6,000 per microliter is a normal value for

hematocrit red blood cell count platelet count white blood cell count

An excessive number of white blood cells is classified as A deficiency in white blood cells is classified as

leukocytosis leukopenia

Complete these sentences describing blood.

Blood contains numerous biconcave cells called red blood cells, contained in a featureless matrix called plasma. These numerous cells, also called erythrocytes, are unique in that they lack nuclei. Fewer in number are the white blood cells, also called leukocytes. They are large and have multi-lobed nuclei. Blood is located within the cardiovascular system where it functions to transport nutrients, gases, wastes, and other biologically relevant molecules.

Complete the sentences describing the components of plasma and their functions.

Plasma is 92 percent water. Water serves as the solvent in which a variety of organic and inorganic substances are dissolved. Blood gases, including oxygen and carbon dioxide, are transported between the lungs and the cells of the body via the blood. These gases are involved in cellular metabolism. The plasma transports nutrients from the digestive system to the cells of the body to be used as fuel or as raw material to produce needed compounds. Nonprotein nitrogenous substances are waste molecules, such as urea and uric acid, produced during metabolism. They are carried by the plasma to be excreted. Also present in plasma are the electrolytes, including sodium, potassium, calcium, bicarbonate, and others. They have a variety of functions, including maintenance of blood osmotic pressure and pH.

Complete the sentences describing ABO blood groups.

The ABO blood type of an individual depends upon the type of surface molecules, called antigens, that they have on their red blood cells. These molecules are classified as A or B. Depending on a person's ABO blood type, they may also have in their blood one or more antibodies, molecules which are "against" specific antigens. List the antigens and antibodies associated with each blood type:Type A: only A antigens and only anti-B antibodies.Type B: only B antigens and only anti-A antibodies. Type AB: both A and B antigens and neither anti-A or anti-B antibodies.Type O: neither A or B antigens and both anti-A and anti-B antibodies.

Complete the sentences describing the breakdown of red blood cells.

As red blood cells wear out, they typically rupture as they pass through the spleen or liver. Phagocytic cells called macrophages then phagocytize and breakdown the cells. As hemoglobin is released from the ruptured cells, each molecule is broken down into its component parts: four proteins chains, called globin, and the iron-containing group, called heme. The globin is broken down into individual amino acids which can be reused or released into the blood. The heme group is broken down into its components: iron which served to bind oxygen, and biliverdin which is a green pigment. The iron is either stored in the liver as the storage molecule ferritin or enters the blood and is transported to the red bone marrow bound to transferrin. The biliverdin is converted to bilirubin, an orange pigment that is excreted by the liver in bile.

Complete these sentences describing the components of plasma. Some labels are used more than once.

The proteins in plasma are of three types: albumins, globulins, and fibrinogen. The albumins, being the most abundant, are important in determining the osmotic pressure of the plasma. Both albumin and some of the globulins function as transporter molecules in the plasma, carrying substances such as lipids, hormones, and certain drugs. Fibrinogen is important in coagulation of the blood. It is the largest of the plasma protein molecules. A class of plasma proteins called gamma globulins are produced by lymphocytes. The other types of plasma proteins are synthesized by the liver. In order, the albumins are most abundant; the globulins account for about 36% of the plasma proteins; and fibrinogen is least abundant.