Composition of blood Flashcards
3 general functions of blood
Transport, immune response and coagulation
Transport
- O2, water, nutrients
- CO2, waste products
- Ions associated with pH and
homeostasis - Heat - a product of
oxidative reactions in cells - Hormones - co-ordinate the
activities of organs of the body - Immune cells
- Coagulation factors
Why need to get rid of CO2
Accumulation of CO2 forms a weak acid, makes our pH acidic
Immune
Fighting infection and production of the
immune response
* White blood cells
* Immunoglobulins
Coagulation
Stop bleeding
* Platelets
* Coagulation factors in plasma
What do platelets do?
Little bits of blood that form a plate
What forms a mesh in the plasma?
The protein fibres in the plasma
What is diff about morbidly obese people
They have more adipose tissue which doesnt have a lot of blood so their ratio changes
What is plasma made of mostly
H20, stores heat and allows solubility, very neutral
Plasma proteins and what they do
7%
Albumins - Maintain osmotic pressure
IImmunoglobulins - mmune response
Fibrinogens - Coagulation factor
Enzymes and hormones - Lots of functions; varies by person
Why are hormone concs. very low
They are very powerful
Other solutes 1%
Electrolytes - the salty stuff, Maintain pH and ion balance, me potential
Organic nutrients - Cells need these to function!
Organic wastes - Cells are getting rid of this
Formed elements of blood 45%
Platelets - productt of a big cell breaking up, Cell fragments that participate in clotting to stop bleeding, very small no.s
WBCs - less that 0.1%, Immune response and defense mechanisms; these seek and destroy invading pathogens
RBCs - 99.9%, By far the most common cell
found in blood; highly specialized
to transport oxygen
What is haematopoiesis?
Formation of blood cells
What is unique about blood cells
They dont divide and keep having to be made
Where are blood cells initiated
Initiated in red bone marrow, which contains blood stem cells
Progenitors of all blood cells
Blood STEM cells, they are pluripotent
Formation of RBCs are stimulated by
EPO (erythropoietin)
Unique of RBCs
Dont have nucleus and many organelles because they have one specific function and dont need to divide
Functions and characteristics of RBCs
Biconcave Disc shape (2 dips)
- large surface area:volume ratio
- allows for efficient diffusion of gases due to short distance between the biconcave
- flexibility for movement through narrow capillaries as it can bend
O2 transport
- Contain large amounts of
haemoglobin (4 protein chains) - One-third weight of RBC
- Uses iron as part of the haem
structures to bind oxygen - Four haem units, so each
haemoglobin can bind four
oxygen molecules
What is Haematorcrit or PCV?
The fraction of blood occupied
by the red cells is called the
haematocrit or packed cell volume (PCV).
Centrifuged blood separates
into its main components.
Typically red cells make up
about 50% of blood volume
i.e. Haematocrit ~0.5
(The rest is plasma / white cells)
What does Anaemia do?
Blood carries less O2
Reduces amount delivered to tissues
Reduces exercise ability
e.g. Fe deficiency in diet
What is needed to make Hemoglobin?
Iron
