Chapter 19 The Blood Flashcards
How does blood contribute to homestasis?
transportation of gases, regulation of pH and temperature and protection through clotting and immune defenses
What is the total blood volume by weight?
8% of total body weight
What is the pH of blood?
7.35-7.45
What is the extracellular matrix of blood?
blood plasma
What are the formed elements?
RBC’s, WBC’s and platelets
What % of blood makes up the formed elements?
45%
What % of the blood is plasma?
55%
What % of the formed elements are RBC’s?
about 99%
What is plasma?
Fluid component of the blood and contains everything in blood except the formed elements
What is the major protein in plasma?
albumin
What are the functions of albumin?
to increase viscosity of the blood, therefore increase the blood pressure; carrier molecule
Describe what alpha globulin does
carries bilirubin and sterioids
describe what beta globulin does
carries copper and iron
describe what gamma globulin does
antibodies
What is hydrostatic pressure?
pressure that is exerted when blood enters the arterioles. It pushes fluid out into the interstitial space
What is osmotic pressure?
Pressure that is exerted when blood enters the venules. It pulls water into the circulatory system due to large plasma proteins.
What is colloid osmotic pressure?
Osmotic pressure due to colloids.
How do the plasma proteins contribute to colloid osmotic pressure?
Plasma proteins can not pass through the capillary walls. When water is pushed into the interstitial space by hydrostatic pressure some of what remains are the colloids. Due to the imbalance of water to solute ratio, water is pulled back into the circulatory system.
How does hydrostatic pressure contribute to getting nutrients into the interstitial space?
It pushes the nutrients into the space.
How does osmotic pressure contribute to keeping the vessels from collapsing?
It pulls water back into the circulatory system, keeping blood pressure intact.
Where do blood cells come from?
red bone marrow
What is a stem cell?
A blank cell that can turn into anything the body needs
What is the term used to describe blood cell production?
hematopoiesis
What is meant by hematocrit and what is its percentage?
Hematocrit is the RBC count. It’s percentage is 40-45%
What is the normal RBC count?
4.8 million-5.4 million
What is the function of red blood cells?
To carry hemoglobin that carry oxygen to the tissues
How does the shape of RBC’s aid in its function?
It increases the cell surface area and gives them a high oxygen carrying capacity. It also allows them to deform and fit in small capillary beds.
What is erythropoiesis?
making of RBC’s
What is the function of EPO?
Speeds up the maturation and release of immature blood cells, increases overall RBC count
What are reticulocytes?
immature RBC’s
Describe the formation of a RBC.
stem cell -> myeloid stem cell -> proerythroblast -> reticulocyte-> erythrocyte
What is hemoglobin?
oxygen carrying protein molecule found in RBC’s
What is the function of hemoglobin?
transport oxygen to the tissues
What is the color oxyhemoglobin and deoxyhemoglobin?
red and blue
How does B12 affect RBC production?
It is required for DNA synthesis which is used for RBC production. A lack of B12 will cause a decrease in RBC’s.
How does intrinsic factor affect RBC production?
Intrinsic factor is needed to absorb B12
How does folic acid affect RBC production?
It is required for DNA synthesis. It is especially needed during pregnancy due to increased fluid retention.
How does iron affect RBC production?
It is required for hemoglobin synthesis. Irons is part of the hemoglobin molecule.
What is anemia?
Low RBC or hemoglobin
What is polycythemia? What causes this?
Too many RBC’s. Caused by COPD, doping, hypoxia or dehydration