'Other' Flashcards
What factors decrease oxygen a affinity to haemoglobin?
Increased temp, increased co2 conc and decreased ph
What is the tendency for oxygen to bind to haemoglobin?
O2 not v soluble, so bind to hb
Binding of 1st mol inc affinity so 2nd and 3rd easier, 4th harder due to overcrowding and tendency of O2 to dissociate
What are the 3 ways co2 is transported around the body?
Dissolved in plasma
Loosely bound to hb and prot
As HCO3-
What are the 2 ways co2 products are removed,
Chloride shift and at the lungs
What are metarterioles and give and example of where they are used
Branches of arteriolar connecting directly to venue so if per capillary sphincter a close can bypass (ie skin or gut when not digesting)
What type of junctions do capillaries in the brain have and what are they normally?
Tight junctions in brain Normally leaky (fenestrated)
What is bulk flow and how does it work?
Mass movement of fluid due to opposing hydrostatic pressure and osmotic pressure
At start of capillary Hydro press more than osmotic press so net filtration
At end = opp so net absorption
What are glial cells?
Support cells of the nervous system (ie schwann)
how does contraction occur?
Ca2+ binds to troponin, allowing actin-myosin bonding
Myosin head executes power stroke
Actin filament slides to centre sarcomere
ATP needed for myosin head to release
What does myoglobulin do and what type of muscle is it mostly found in?
Transfers oxygen to interior of muscle fibres
Red pigment
Found in red muscle
Not much in white muscle
What are the differences in speed of communication of the different types of muscles?
Skeletal is faster than cardiac which is a lot faster than smooth
How is ca2+ removed from the cytoplasm?
SR pumps back into SR
Ca2+ ATPase pumps ca out of cytoplasm
NaCa exchanger exchanges ca2+ for na2+
Why does foetal haemoglobin have a higher affinity for oxygen than adults?
Has 2 y chains instead of two beta chains so that placental transfer can occur
What is erythropoiesis
Production of new RBC
Where and why are platelets produced?
Prod from megakaryocytes in bone marrow in response to increased free thrombopectin in liver
