Cardiovascular Physiology - Lecture 7 Flashcards
What makes up the blood?
Plasma and cells
What is blood plasma?
Water Ions Nutrients Hormones Wastes Proteins
What proteins are in blood plasma?
Albumins
Globulins
Fibrinogen
What makes up blood serum?
RBCs
WBCs
Platelets
Hematocrit
The percent of the blood’s volume that is comprised of RBCs
How many erythrocytes are in a mm3 of blood?
5,000,000
How many leukocytes are in a mm3 of blood?
7,000
What percent of leukocytes do Neutrophils make up?
50-70%
What percent of leukocytes do Eosinophils make up?
1-4%
What percent of leukocytes do Basophils make up?
0.1-0.3%
What percent of leukocytes do Monocytes make up?
2-8%
What percent of leukocytes do Lymphocytes make up?
20-40%
How many platelets are in a mm3 of blood?
250,000
Which cells in the blood are the only true cells with nuclei?
Leukocytes
Erythrocytes
Biconcave disc shape High surface-volume ratio Better diffusion of oxygen and carbon dioxide Contain large amounts of Hemoglobin Binds oxygen via Fe atoms
Why are storage and recycling mechanisms of Fe highly developed in humans?
Because the availability of dietary iron can be a limiting factor in erythropoesis
Ferritin
Serves as a storage budder for iron
What is the lifespan of an erythrocyte?
~120 days
1% of RBCs are replaced daily
Bilirubin
Major breakdown product of hemoglobin
What happens to iron released form destroyed RBCs?
Bound by transferrin, and delivered to the bone marrow
How is erythropoiesis regulated?
Hormonally
Decreased oxygen delivered to the kidney causes the secretion of erythropoietin, which activates receptors in the bone marrow, leading to an increase in the rate of erythropoeisis
What is a limiting factor for erythropoeisis?
The avaliability of dietary iron
What things are important for RBC function
Iron
Folic acid
B12
Why is folic acid important for RBCs?
It is needed for thymine
If someone is folic acid deficient, it can lead to impaired cell division
Why is B12 important for RBCs?
Required for action of folic acid
B12 absorption requires an intrinsic factor, and if there is no intrinsic factor, it can lead to pernicious anemia
What are the major causes of anemia?
1) Dietary deficiencies of iron, B12, or folic acid
2) Bone marrow failure due to toxic drugs or cancer
3) Blood loss form the body (hemorrhage) leading to iron deficiency
4) Inadequate secretion of erythropoietin in kidney disease
5) Excessive destruction of erythrocytes (ie sickle-cell anomia)
What is anemia?
Decrease in the ability of the blood to carry oxygen due to:
- decrease in the total number of erythrocytes
- diminished concentration of hemoglobin
- a combination of the both of those
In what people(s) does anemia manifest in?
People who are homozygous for the mutated gene
Colony-stimulating factor stimulate progenitor cells leading to what?
Granulocytes and monocytes
Interleukins stimulate progenitor cells leading to what?
Various leukocytes
Thrombopoeitin stimulates progenitor cells leading to what?
Platelets
Stem cell factor stimulates progenitor cells leading to what?
Many types of blood cells
What is hematostasis?
The stoppage of bleeding
What are the 2 process that accomplish hemostasis?
Formation of a platelet plug
Blood coagulation (clotting)
These occur in rapid succession, and platelets are critical to both
