WEEK 5 - BLOOD Flashcards
What are the three functions of blood?
- transport
- immune response
- coagulation
what does the blood transport?
O2, water, nutrients Co2, waste products Ions associated with pH levels and homeostasis heat hormones immune cells and coagulants
what does blood do in immune repsonse?
fights infection and produces immune response largely via white blood cells.
What is coagulation?
- prevents bleeding
- via platelets and coagulation factors found in the plasma
what is the breakdown of blood?
50% plasma, 50% formed elements
what is plasma and what does it do?
Mostly water
proteins and solutes are dissolved into the water
there proteins keep osmotic pressure equal
what three things makes up the formed elements part of blood?
- platelets
- white blood cells
- red blood cells
what are platelets and what do they do?
cell fragments made from exploded huge cells
they participate in clotting to stop bleeding.
what do white blood cells do?
identitfy pathogens and destroy them.
what are red blood cells called and what is their primary function?
erythrocytes
99% of formed elements
transport oxygen
what is hematopoeisis?
formation of blood cells from hemocytoblasts
what are hemocytoblasts?
the progenitors for all blood cells
- located in red marrow of bones
- makes red, white blood cells and platelets
- when exposed to erythropoietin it makes red blood cells
what is erythropoiesis?
the process of RBCs being made from hemocytoblasts because of exposure to erythropoietin.
what is erythropoietion?
the thing that triggers hemocytoblasts to make erythrocytes/RBCs.
what is the shape RBCs?
biconcave disc shape for maximal surface area for gas exchange
flexible for movement through capillaries
no nuclei as they don’t need to reproduce as hemocytoblasts make them.
how do RBCs do their job?
they contain a large amount of hemoglobin with 4 heme units to bind 4 oxygen molecules each.
- uses iron to bins oxygen (iron is required to make hemoglobin)
what is the fraction of the blood that is RBCs called?
hematocrit or packed cell volume
what happens to your hematocrit levels when you exercise?
you have a higher level and therefore more O2 capacity.
what are the levels of hematocrit in men and women?
men 0.4 - 0.5
women 0.37 - 0.47
what happens if you have low hematocrit?
you are anemic which means you will have low iron and low oxygen levels
what happens if you have high hematocrit?
you are polycythemic - thick blood. This will strain your heart and blood vessels.
what enhances erythropoeitin?
testostorone
what is the path of erythropoeitin?
it is put into the blood from the kidney which goes into the bone marrow and stimulates hemocytoblasts to make more RBCs through erythropoesis. this increases the oxygen capacity and levels
why do athletes train at high altitudes?
when at high altitudes, there is less oxygen in the air, so the kidneys release more enrythropoeitin to make more RBCs to make the oxygen capacity bigger and get more oxygen to the body. Then they will have more RBCs than they need when competing at normal altitude so they will be more efficient/have more capacity than if they trained at level.
