Ch. 19-21 Worksheets Flashcards
Describe the general composition of blood
Whole blood is made up of fluid plasma and formed elements. The plasma is 92% water and the formed elements are 99% RBCs and 1% WBCs and platelets.
Describe the composition of blood plasma
Plasma is made up of plasma proteins, other solutes (nutrients, electrolytes, wastes), and water
What are the 3 types of plasma proteins?
Albumins
Globulins
Fibrinogen
Function of albumins
Contributes to plasma osmolarity and osmotic pressure. Important for transporting fatty acids, thyroid hormones, and steroid hormones
Function of globulins
Play an important role in liver function, blood clotting, and fighting infection
Function of fibrinogen
The formation of fibrin that binds together platelets and some plasma proteins in a hemostatic plug
Where are the 3 plasma proteins produced?
The liver
What are the formed elements?
RBCs
WBCs
Platelets
Structure of a RBC
Biconcave disc with a thin central region and a thicker outer margin
Structure of a WBC
Has a nucleus, which is often large and lobed. Each WBC structure consists of a nucleus, cytoplasm and cell wall
Structure of a platelet
They contain proteins on their surface that allow them to stick to breaks in the blood vessel wall and also to stick to each other. They contain granules that can secrete other proteins required for creating a firm plug to seal blood vessel breaks. Look like disc-shaped cell fragments in a blood smear.
Function of RBCs
Bring oxygen to the tissues in your body and release carbon dioxide to your lungs for you to exhale
Function of WBCs
Responsible for protecting your body from infection. As part of your immune system, white blood cells circulate in your blood and respond to injury or illness.
Function of platelets
Release chemicals important in the clotting process and forms a temporary patch in the walls of damaged blood vessels
Another name for RBCs
Erythrocytes
Another name for WBCs
Leukocytes
List the 5 types of leukocytes in order of abundance
Neutrophils Lymphocytes Monocytes Eosinophils Basophils
Function of neutrophils
Specializes in attacking and digesting bacteria that have been marked with antibodies or complement proteins
Function of lymphocytes
Defend against invading foreign cells; produce antibodies; detect and destroy abnormal cells; help to prevent cancer
Function of monocytes
Engulf items as large/larger than themselves; release chemicals that attract neutrophils, monocytes, and other phagocytic cells; secrete substances that draw fibroblasts to the region
Function of eosinophils
Attack objects coated with antibodies; engulf antibody-marked bacteria, protozoa, or cellular debris
Function of basophils
Migrate to injury sites and cross the capillary endothelium to accumulate in the damaged tissues; they discharge their granules in the interstitial fluids; release chemicals that attract eosinophils and other basophils to the area
Describe the structure and function of hemoglobin
4 polypeptide subunits (2 alpha and 2 beta chains). Each polypeptide is bound to iron-containing compound called a heme group. Iron in each heme group binds to oxygen in places where oxygen levels are high (lungs) to form oxyhemoglobin.
What is hematocrit?
The ratio of the volume of RBCs to the total volume of blood
Locations of hematopoiesis
Organs and tissues such as the bone marrow, liver, and spleen
What is the significance of the hematopoietic stem cell?
In red bone marrow, hematopoietic stem cells divide to produce myeloid stem cells (which provide RBCs and several WBCs) and lymphoid stem cells (which produce lymphocytes)
What is erythropoiesis?
The formation of RBCs in red bone marrow
What is the process of erythropoiesis?
Erythropoiesis is regulated through a negative feedback loop. Blood oxygen levels may begin to decrease and kidney cells will detect this drop. The kidney cells will signal the kidney to produce more EPO and release into the blood. Production of erythrocytes increases.
What is the reticulocyte count used for?
To estimate the degree of effective erythropoiesis and can help in the diagnosis of different types of anemia
Describe the vascular phase of hemostasis
The endothelial cells contract and expose the underlying basement membrane to the bloodstream. The endothelial cells begin releasing chemical factors and local hormones. The endothelial plasma membranes become sticky. The stickiness helps platelets to attach.
Describe the platelet phase of hemostasis
The process of platelet aggregation forms a platelet plug that may close the break in the vessel wall if the damage is not severe or the vessel is small
Describe the steps involved in the formation of a platelet plug
As platelets arrive at the injury site, they become activated and release ADP, thromboxane, and calcium ions to further aggregation, which produces a platelet plug
Describe the basic steps of coagulation resulting in the formation of the insoluble fibrin clot.
Circulating fibrinogen is converted into fibrin. As the fibrin network grows, blood cells and additional platelets are trapped in the fibrous tangle, forming a blood clot that seals off the damaged portion of the vessel.
The main difference between intrinsic and extrinsic pathways
The intrinsic pathway is activated by a trauma inside the vascular system whereas the extrinsic pathway is activated by external trauma.
What does the intrinsic pathway begin with?
The activation of factor XII exposed to collagen fibers at the injury site
When does the extrinsic pathway begin?
When damaged endothelial cells or peripheral tissues release factor III
When does the common pathway begin?
The common pathway may result after the activation of factor X at the end of the intrinsic OR extrinsic pathway
Explain how the positive feedback loops in the platelet and coagulation phases promote hemostasis.
As the platelets continue to amass, more of the chemicals are released and more platelets are attracted to the site of the clot. The positive feedback accelerates the process of clotting until the clot is large enough to stop the bleeding
Explain the role of vitamin K in blood clotting.
Vitamin K must be present for the liver to synthesize four of the clotting factors. Vitamin K deficiency can deactivate the entire clotting system
Describe the process of fibrinolysis
Fibrinolysis begins when two enzymes activate plasminogen, which produces the enzyme plasmin that begins digesting the fibrin strands and eroding the blood clot.
Explain the role of surface antigens on erythrocytes in determining blood groups.
Blood type is determined by the presence or absence of specific surface antigens in RBC plasma membranes. Your immune system ignores surface antigens on your own RBCs. Your plasma contains antibodies that will attack antigens on foreign RBCs.
List the type of antigen and the type of antibodies present in type A blood
Anti-B antibodies
A antigens
List the type of antigen and the type of antibodies present in type B blood
Anti-A antibodies
B antigens
List the type of antigen and the type of antibodies present in type AB blood
No antibodies
A & B antigens
List the type of antigen and the type of antibodies present in type O blood
Anti-A & anti-B antibodies
No antigens
Describe how the presence or absence of Rh antigen results in blood being classified as positive or negative.
The Rh blood group is based on the presence or absence of the Rh surface antigen. Rh+ indicates the presence of the Rh surface antigen. Rh- does not have the Rh factor.
Describe the development and clinical significance of anti-Rh antibodies.
If an Rh- mother has an Rh+ fetus the first time, it is not a big deal. If this happens during the second pregnancy, the mother’s blood will abort the fetus.
Predict which blood types are compatible
A blood is compatible with A and O. B blood is compatible with B and O. AB is compatible with A, B, AB, and O. O blood is compatible with O.
What happens when the incorrect ABO or Rh blood type is transfused?
Transfusion with the wrong blood type can cause a severe reaction that may be life-threatening.
What is MCV?
Mean cell volume
How to calculate MCV
Hematocrit x 10 divided by the RBC count
Why is the mean cell volume important?
Describes the average size of RBCs in a blood sample and can help diagnose health conditions and anemia.
What is MCHC?
Mean corpuscular hemoglobin concentration
Why is the MCHC important?
If MCHC is too low, you’re not carrying the right amount of oxygen and could have anemia. If it’s excessive, you could be hyperchromic
List the parts of the electrical conduction system of the heart in the correct sequence for one contraction
The sinoatrial node starts the sequence by causing the atrial muscles to contract. Next, the signal travels to the atrioventrical node, through the bundle of HIS, down the bundle branches, and through the Purkinje fibers, causing the ventricles to contract.
Explain how the electrical conduction system functions.
The heart conduction system is the network of nodes, cells and signals that controls your heartbeat. Each time your heart beats, electrical signals travel through your heart. These signals cause different parts of your heart to expand and contract. The expansion and contraction control blood flow through your heart and body.
Explain why the SA node normally paces the heart.
Because the SA node reaches threshold first, it establishes the basic heart rhythm. The impulse generated by the SA node brings the AV pacemaker cells to threshold faster than the pacemaker potential of the AV pacemaker cells
Explain how the cardiac conduction system produces coordinated heart chamber contractions.
The SA node sends out an electrical impulse. The atria contract. The AV node sends an impulse into the ventricles.
Explain what happens during a QRS wave
Impulses travel through ventricles, causing ventricles to contract
Explain what happens during a P wave
The depolarization of the atrial contractile cells causes the atria to contract
Explain what happens during a QRS wave
1 The depolarization of the ventricular contractile cells causes the ventricles to contract. During this time, atrial repolarization is taking place.
Explain what happens during a T wave
Ventricles return to resting state, indicating repolarization of the ventricular contractile cells.