Unit II Review Flashcards
(Chapter 19)
What are the 5 functions of blood?
- Transport gases, nutrients, hormones and waste
- Regulate pH and ion composition of ISF
- Restrict fluid loss at injury sites
- Defend against toxins and pathogens
- Stabilize body temperature
How does blood temperature compare to body temperature?
Blood temperature is slightly higher (100.4F or 38C)
What is the pH of blood?
7.35 - 7.45
What is the viscosity of blood vs water?
Blood is 5x more viscous than water
What is whole blood?
Plasma + formed elements
What is plasma?
92% water, 7% plasma proteins, 1% other solutes
What is the composition of formed elements?
99.9% RBCs, <0.1% WBC, <0.1% platelets
What is hematocrit?
The percentage of formed elements (or RBCs) in whole blood
List the different plasma proteins and their functions
Albumins - 60% - major contributor to osmotic pressure, transport fatty acids, some thyroid/steroid hormones
Globulins - 35% - antibodies and transport globulins
Fibrinogen - 4% - Important in the clotting process
List the different solutes that are found in blood
Nutrients, electrolytes, waste
What is the ratio between RBCs and WBCs
1000:1
What is oxyhemoglobin?
Hemoglobin (Hb) whose iron ion holds O2 –> HbO2
What is deoxyhemoglobin?
Hb molecule whose iron ion does not hold O2 –> Hb
What is carbaminohemoglobin?
Hb bound to CO2
What is the average life span of a red blood cell?
120 days
What type of white blood cell recycles red blood cell components?
Phagocytic macrophage
What is hemoglobinuria?
Abnormally large numbers of RBCs break down in the bloodstream, and may cause urine to turn red or brown
What is hematuria?
The presence of intact RBCs in urine
What is biliverdin?
After RBC breakdown, when a heme is stripped of its iron by a phagocytic cell
Note: Bruises commonly developed a greenish tint when biliverdin forms in the blood-filled tissues
What is bilirubin?
Biliverdin is converted to bilirubin, an orange-yellow pigment, and released into the bloodstream. There, the bilirubin binds to albumin and is transported to the liver for excretion in bile.
What causes jaundice?
Yellowing of the skin and eyes caused by a backup of bilirubin. This may happen if bile ducts are blocked or the liver cannot absorb or excrete bilirubin.
What are urobilins and stercobilins?
Created from bilirubin in the large intestine.
What is transferrin?
A plasma protein which binds and transfers iron ions. (Large quantities of iron by itself are toxic). Absorbed by RBCs in red bone marrow.
What are ferritin and hemosiderin?
Excess transferrin is removed in the liver and spleen and the iron is stored in ferritin and hemosiderin.
Where are RBCs produced in adults?
Red bone marrow exclusively
What are hemocytoblasts?
Produce myeloid and lymphoid stem cells
What nutrients are needed by the red bone marrow for proper erythropoiesis?
Amino acids, iron, and vitamins B6/B12/Folic Acid
What factor in females accounts for the lower hematocrit values when compared to males?
Estrogens do not stimulate erythropoiesis
What is erythropoietin (EPO)?
Formed by kidneys and liver. Released when O2 levels are low, especially at kidneys. Stimulates RBC development.
What determines your blood type?
Surface antigens
What are the three surface antigens of importance when addressing blood types?
A, B, Rh
If a person has type A- blood, what type of antibody would be in their plasma?
Anti-B antibodies (does NOT have Rh antibodies - this occurs only after sensitization)
What are agglutinogens and agglutinins?
Surface antigens
What is sensitization? (In reference to Rh)
Previous exposure to Rh+ RBCs, causing the formation of anti-Rh antibodies.
How are WBCs different from RBCs
Have nuclei and organelles. Lack hemoglobin.
List the four characteristics of WBCs
- Can migrate out of the bloodstream
- Capable of amoeboid movement
- Attracted to specific chemical stimuli
- Neutrophils, Eosinophils, and Monocytes are capable of phagocytosis
How do neutrophils protect the body from bacteria?
Attack and digest bacteria that have been marked with antibodies.
What types of pathogens are the main focus of eosinophils?
Attack objects coated with antibodies.
What is the role of basophils in the inflammatory response?
Release histamine (dilates blood vessels) and heparin (prevent clotting) at injury sites to enhance inflammation (similar to mast cells)
What are the three classes of lymphocytes?
T cells, B cells, NK cells
What is a differential count?
Shows the number of each type of WBC in a sample of 100
What is leukopenia?
Inadequate number of WBCs
What is leukocytosis?
Excessive number of WBCs
Which WBCs are derived from myeloid stem cells?
Neutrophils
Basophils
Eosinophils
Monocytes
What are platelets?
Thrombocytes. Clump together when they recognize blood vessel damage.
What is thrombocytopenia?
Excessive platelet destruction or inadequate platelet production
What is thrombocytosis?
High platelet counts. Usually results in response to infection, inflammation, or cancer.
What is hemostasis?
The stopping of bleeding.
What are the phases of hemostasis?
- Vascular phase
- Platelet phase
- Coagulation phase
What is coagulation time?
The time it takes blood to clot in a fine glass tube (8-18 minutes)
What is bleeding time?
The time it takes a small puncture wound to stop bleeding (1-4 minutes)
What are the naturally occurring anticoagulants found in the body?
Antithrombin-III, Heparin, Thrombomodulin, Protein C
What is the role of calcium ions and vitamin K in the blood clotting
Ca+2 is required for all pathways - intrinsic, extrinsic and common
Vitamin K is required for the liver to synthesize four of the clotting factors, including prothrombin
What is clot retraction?
Pulls the torn edges of the vessel closer together
What is fibrinolysis?
Gradual dissolving of a clot
What is plasmin?
Digests fibrin strands to erode a clot
(Chapter 20)
What are the two types of cardiac muscle cells?
Myocardial contractile and myocardial conducting cells
What causes the SA node to spontaneously depolarize?
Slow inflow of Na+ without a compensating outflow of K+
Before atrial systole begins, how much blood is in each ventricle as a result of passive filling?
70% of 130 mL = 91 mL
What occurs during the 0.1 second delay in action potential propagation at the AV node?
Atrial systole
What is the volume of blood that is in the ventricles at the end of atrial systole called?
End diastolic volume
The fully filled ventricles place a stretch on the walls of the ventricles. What is this called?
Preload
What is the pressure in the wall of the left ventricle during ejection called?
Afterload
What is ejection fraction?
SV divided by EDV = EF %
What is the formula for cardiac output?
Heart rate x SV
(Chapter 21)
Which layer of the blood vessel contains smooth muscle?
Tunica media
What are the main differences between arteries and veins?
- Artery walls are thicker
- Arteries hold their shape better
- Arteries are more resilient
- Veins contain valves
What are elastic arteries?
aka Conducting arteries, they carry large volumes of blood away from the heart. Diameter up to 2.5 cm. Examples are the pulmonary trunk and aorta, as well as their major branches.
What are muscular arteries?
Aka distribution arteries, most vessels of the arterial system are muscular arteries. Some muscular arteries are important pressure points.
What is another name for arterioles and why?
Resistance vessels, because their changing diameter can introduce resistance to the circulatory system.
What are the main characteristics of continuous capillaries?
Permit water, small solutes, and lipid-soluble material to diffuse into the interstitial fluid, but prevent the loss of blood cells and plasma proteins.