Blood Lecture #1 Flashcards
List the organs of the cardiovascular system and their general function:
- Heart
- Vessels: Arteries, Arterioles, Capillaries and Veins
Function: Tubes for transport - Blood
Function: Transport vehicle for everything. Transport, regulate and protect.
How does blood fulfill its function of “transport”?
- RBCs move oxygen from lungs to cells that make up tissues.
- RBSc and plasma transport CO2 from the cells that make up tissues to the lungs.
- Plasma transports minerals and nutrients to and from cells.
- Plasma transports metabolic wastes tot he kidney and liver for removal.
- Plasma transports chemical messengers, such as hormones, from glands to target tissues.
How does blood fulfill its function of “regulation”?
Major role in regulating body temp. Buffering systems play a role in regulating pH.
How does blood fulfill its function of “protection”?
Clotting pathways protect blood vessels if damages to maintain fluid balance. WBCs mediate immune responses.
Is blood homogeneous or heterogenous?
Heterogeneous as its components have different densities.
Plasma accounts for what percentage of whole blood?
55%
What is dissolved in plasma?
Nutrients and vitamins
The Buffy coat accounts for what percentage of whole blood?
< 1%.
What two things make up the Buffy coat?
Leukocytes and platelets
Erythrocytes account for what percentage of whole blood?
45% (hematocrit)
What are erythrocytes fill with and what do they do?
They are filled with Iron and transport oxygen around the body.
When taking a blood draw from a vein, you would expect the oxygen poor venous blood to appear ______.
What would the pH be?
Darker
7.35-7.45
What is the general functional role of an RBC?
Transport oxygen from the lungs to the cells of your tissues.
How do you calculate hematocrit?
Hematocrit = Height of RBC Column/Height of Whole Column. (Measure from bottom of blood column to the tope of blood column.)
Unit: %
Define Anemia
Hematocrit is below the reference range
List some causes of Anemia
Excessive bleeding, menstrual bleeding, iron deficiency, cancer, genetic factors, impaired metabolism of spleen.
Define polycythemia
Hematocrit above the reference range
List some causes of Polycythemia
Dehydration, changes in O2 sat., smoking, splenectomy, blood doping, testosterone replacement therapy, and altitude training.
Outline how blood moves from the heart to the capillaries -
- Heart moves blood into arteries
- Arteries move blood away from the heart
- Arteries branch into arterioles
- Arterioles feed into capillaries
The exchange of what substances takes place in capillaries?
Nutrient, waste and gas exchange.
When plasma crosses the wall of a capillary, what does it become?
Interstitial fluid.
What creates interstitial fluid?
Filtration
What is reabsorption?
The movement of interstitial fluid back into a capillary.
Name the 3 plasma proteins
Albumins, fibrinogens and globulins
What is the most abundant plasma protein?
Albumin
What percentage of plasma proteins does Albumin make up?
60%
Where is albumin produced?
Liver
What is albumin the main contributor for?
Blood Colloid Osmotic Pressure
What is the job of albumin?
To suck fluid back into capillaries
What is Blood Colloid Osmotic Pressure (B Cop)?
What prevents fluid from leaking out of capillaries uncontrollably to eventually lead to edema
What are the primary functions of albumin?
- Maintain B Cop
2. Transport lipid soluble substances
If a patient was suffering from protein starvation, what may begin to happen to the blood plasma? How would this begin to manifest physically?
Liver stops producing albumins. BCop decreases. Tissues become full of fluid. This would appear as belly edema.
Can lipid-substances move around in blood plasma?
No
In regard to lipid substances, what does Albumin allow?
Albumin creates a transport vehicle to move lipid substances around since albumin are proteins and proteins are water soluble.
What are the 2 types of globulins?
Alpha and Beta
Where are globulins synthesized?
Exclusively in the liver.
Globulins are the transport vehicles for what specifically?
Fat-soluble substances (steroid hormones)
What does the depression in the middle of an RBC allow it to do?
Fold in 1/2
What does the biconcave nature of an RBC help maximize?
The surface area available for gas exchange
If a pulse oximeter reads a patient’s O2 Sat as 75%, how many O2 molecules are bound to each hemoglobin molecule?
3.
Define erythropoiesis
Formation of red blood cells
Where does erythropoiesis take place?
Within red bone marrow in spongy bone
Walk through the secretion of erythropoietin starting with the stimulus -
STIMULUS - Hypoxia due to: - decreased RBC - decreased amount fo hemoglobin - decreased availability of O2 RECEPTOR - Kidney (and liver to a smaller extent) CONTROL CENTER - Kidney/Liver EFFECTOR - Erythropoietin TARGET - Enhanced Erythropoiesis increases RBC count
How would training at a higher altitude help someone during an upcoming endurance event?
- Training at higher altitude levels will increase erythropoiesis occurring
- Increased erythropoiesis increases hematocrit
- Increased hematocrit increases oxygen carrying capabilities of your blood
- Muscles are less likely to fatigue with high oxygen concentration
Explain the Erythropoietin (EPO) mechanism for regulating erythropoiesis
- Low O2 levels in blood stimulate kidneys to produce erythropoietin
- Erythropoietin levels rise in blood
- Erythropoietin and necessary raw materials in blood promote erythropoiesis in red bone marrow
- New erythrocytes (RBC) enter bloodstream; function for about 120 days
- Aged and damaged red blood cells are engulfed by macrophages of spleen, liver and bone marrow; the hemoglobin is broken down
- Raw materials are made available in blood for erythrocyte synthesis
How long do new RBCs last for?
About 120 days
What happens to RBCs when they get too old?
They get stiff and can no longer fold in half.
When RBCs get stiff, where do they get caught?
What begins to happen?
In filtration networks of the spleen and liver
The cells in the liver begin to eat the RBCs.
What is the base color of bilirubin?
Yellow
What is the base color of urobillinogen?
Yellow
What is the base color of stercobilin?
Brown
When stored iron is needed, what happens to it?
It is shuffled over into the red bone marrow for cells to use in the synthesis of RBCs.
What converts bilirubin to urobillinogen?
Bacteria
What gives urine its yellow color?
Urobillinogen
What causes Jaundice?
If the liver is not getting rid of bilirubin appropriately, it will start to build up in the body. Because it is fat soluble, it can embed itself into the skin and turn it and the eyes yellow.
Why is Jaundice dangerous?
Because bilirubin is a neurotoxin
Why do infants tend to suffer from Jaundice?
Because their liver is not functioning at full capacity yet.
How should bilirubin be eliminated if everything is functioning fully?
Almost 100% by the liver
