Blood Flashcards
What is happening in systemic circulation?
Pulmonary?
Blood is pumped from left chambers of heart to perfuse entire body with oxygenated blood
Blood is being pumped back to the lungs to be reoxygenated
Circulatory system is mostly closed (meaning blood remains inside) exception?
Circulatory system can sometimes be where immature forms reach maturity and then leave the system to enter other tissues (or if they are immune cells fighting infection)
What is microcirculation?
Only place where this happens?
Phase of circulation where exchange of O2, CO2, glucose, nutrients, waste take place
This exchange only happens in capillaries
Difference in composition between arteries and veins
Arteries: more smooth muscle and elastic fibers
Veins: thicker tunica adventitia and are typically larger than arteries
~arteries tend to be stiffer, veins tend to be softer
3 different structural types of capillaries?
Continuous (non-fenestrated), fenestrated, and sinusoids
- Fenestrated capillaries structure and function
2. Sinusoids structure and function
- Looks like tiny holes are poked into the endothelial cells; allows direct passage between blood and tissue external to capillary (most common)
- Very large gaps (almost looks ripped); gaps lead to large blood filled spaces in certain tissues where there is a lot of filtration of blood (liver, spleen, bone marrow, erectile tissue)
What kind of endothelial cells are present in CNS capillaries?
What is it called?
What cannot enter the CNS?
Not fenestrated; they have tight junctions (zona occludens)
Blood brain barrier; lipids diffuse, hydrophilic substances via transmembrane protein transporters
Immune cells (aka CNS is immune privileged)
What is contained in lymph fluid?
Difference between course of lymphatic vessels and circulatory vessels?
Some types of blood cells (mostly lymphocytes), and different types of macromolecules/debris that was removed from tissue
They run in parallel with each other, but lymph is uni-directional
What happens at lymph nodes?
Lymph fluid is filtered by WBCs and WBCs related to the immune system can be activated
Name 5 lymphatic organs
Bone marrow, thymus, spleen, lymph nodes and lymphatic nodules
What happens at the following lymphatic organs:
- Spleen?
- Thymus?
- Nodules?
- Blood is filtered by WBCs and can respond to pathogens in blood
- Where T-lymphocytes matures
- Clusters of lymphocytes throughout the body where immune response to local tissue occurs
What is the buffy coat?
The very thin layer between plasma and RBCs after centrifuge that contains WBCs
Plasma vs. serum?
Plasma contains fibrinogen (clotting factors); serum is what you get if blood was allowed to clot before centrifuging
Normal RBC is 44%; if it is less than 44%, what does that indicate?
either RBCs are not being produced, there is a hemorrhage, or something is breaking RBCs down that should not be
- Shape of RBCs
- Size of RBCs?
- Normal hematocrit % range
- Why was nucleus removed during cell formation of RBC?
- Life span?
- B concave shape
- ~7-8 um (slightly narrower than capillary diameter)
- ~42-47%
- Once RBCs mature, they dont need a nucleus because they are just transporting oxygen
- ~120 days (made by stem cells because they do not undergo mitosis)