lecture 13 Flashcards
what are the three general functions of blood
transportation, immune response, coagulation
what sort of transport does blood do
transports oxygen and nutrients to the tissues, takes away wastes and CO2. carries lipid soluble hormones to the effector cells, also transports heat around the body.
what in blood helps it to coagulate
platelets and coagulation factors
what does coagulation mean
blood can coagulate when we need it to, like stopping bleeding
what are formed elements
the cells and cell fragments which we find in cells
what in blood is in greatest proportion
plasma, just over half of it
what do plasma proteins do
Maintain osmotic pressure
Immune response
Coagulation factor
Lots of functions; varies by person
what do plasma electrolytes do
Maintain pH and ion balance
Cells need these to function!
Cells are getting rid of this
what do platelets do
Cell fragments that participate in
clotting to stop bleeding
define haematopeisis and where does it occur
formation of blood cells, Initiated in red bone
marrow, which contains blood stem cells
Blood stem cells are the progenitors for all blood
cells, what does this mean
All formed elements of blood originate from the “blood stem cell” the haemocytoblast. The haemocytoblast cells divide into lymphoid stem cells- which give lymphocytes. The Hemocytoblasts also divide into myeloid stem cells which give the platelets, white blood cells and red blood cells.
define progenitor
Progenitor cells are those that descend from a stem cell and further divide into more specialised cells, an intermediate cell if you will.
what are the division pathways for the haemoblastocyte
The haemocytoblast cells divide into lymphoid stem cells- which give lymphocytes. The Hemocytoblasts also divide into myeloid stem cells which give the platelets, white blood cells and red blood cells.
when is the nucleus lost from the red blood cell
erythroblast cell stage
What does erythropoietin (EPO) do?
RBC is stimulated by EPO, erythropoietin. EPO goes to the bone marrow and stimulates the production of more RBC to carry more blood.
what releases EPO
the kidneys in low oxygen state
what does the biconcave shape of red blood cell allow
This shape is adventageous as it gives a large SA:V ratio. This ratio allows for efficient diffusion of gases to tissues as it creates a short diffusion distance.
The shape also allows the Red Blood cells to become flexible as they move through capillaries. So they can bend and fold as the move through. Squeezing into tight capillaries makes a good short diffusion distance.
red blood cell has no nucelus, what does this mean. also what makes 1/3 RBC weight
haemoglobin makes 1/3 weight, As red blood cells have no nucleus they cannot divide to generate more red blood cells. Instead once the lifespan of one of the cells is complete the cells will just be regenerated vie haematopoiesis.
what is the generation of red blood cells called?
Erythropoiesis is the generation of red blood cells.
what is the hematocrit level
The fraction of blood occupied by the red cells is called the haematocrit or packed cell volume (PCV).
how do we get haemocritic levels and what are normal levels
To determine this we can centrifuge blood. Spinning it fast results in the formed elements separating from plasma. With the heaviest RBCs going to the bottom. From there we can determine RBC component by looking at the blood. Typically about 50%, so haematocrit is around 0.5.
what is anemia and give causes and consequences
Low haemoglobin levels = Anaemia
This means our blood carries less oxygen, which reduced amount of O2 tissues receive, which reduces exercise ability and makes us more fatigued.
This low haemoglobin count can come from Fe deficiency in our diets.
what is needed to make a red blood cell
iron for the haemoglobin
why do males have more haemoglobin
process of making RBC and haemoglobin can be increased by testosterone, men have more testosterone
