Lecture 13 Flashcards
What are the three general functions of blood?
Transport, Immune response, coagulation
What are the general functions of blood - transport?
Deliver O2, water and nutrients; Remove CO2 and waste; carry ions associated with pH and homeostasis; Heat; Hormones; deliver Immune cells and coagulation factors
What are the general functions of blood - immune?
Fight infection and production of the immune response largely via white blood cells
What are the general functions of blood - coagulation?
For preventing bleeding via platelets and ‘coagulation factors’ in plasma
What is the composition of blood?
55% Plasma and 45% Formed elements
What is the relationship between blood volume and body mass?
Generally proportional
What is plasma?
Liquid component of blood
What is plasma composed of?
Water, plasma proteins and other solutes
What are the formed elements?
Cells and cell fragments
What are the three types of formed elements?
Platelets, white blood cells and red blood cells
What are platelets?
Cell fragments
What is hematopoiesis?
The fraction of blood occupied by red blood cells
Where is hematopoiesis initiated?
In the red bone marrow which contains hemocytoblasts
What are hemocytoblasts?
The blood stem cells that are progenitors for all blood cells
What is the shape of the red blood cell?
Biconcave disc shape
What is the function of the shape of the red blood cell?
To have a large surface area : volume ratio, allow for efficient diffusion of gases and be flexible for movement through narrow capillaries
What is the make up of the red blood cell?
1/3 of weight is hemoglobin which used iron as part of the haem to bind O2. 4x haem so 4x O2 binding sites
What is hematocrit / PCV
The fraction of blood occupied by the red blood cells
What does PCV stand for?
Packed cell volume
What does anemic mean?
Low levels of RBC in blood
What does polycythemic mean?
High levels of RBC in blood
What is erythropoiesis?
The generation of red blood cells
What is erythropoietin (EPO)?
The chemical released within the system to stimulate more RBCs
What does erythropoiesis require?
Iron to make haemoglobin
What is erythropoiesis augmented by?
Testosterone
Why does altitude have an effect on erythropoiesis?
There is less O2 available in the air
What are the short-term effects of high altitudes with erythropoiesis?
Increased heart and breathing rate
What are the long-term effects of high altitudes with erythropoiesis?
Kidneys release more EPO to stimulate the production of more RBCs -> increased hematocrit!
