BLOOD AND CIRCULATION Flashcards
(25 cards)
What is a buffy coat
white blood cells and platelets
How is blood made
Made from bone marrow stem cells in adult humans.
Functions of blood
- Transport
- hydraulic transmission of force(helps when no bones present)
- coagulation (doesn’t leak)
- maintenance of cell environment
outline plasma
Solutes tightly regulated
outline erythrocytes
red blood cells no nucleus and bi concave shape to increase SA transport oxygen and lack mitochondria rely on -ve feedback flexible erythroprotein (epo) generated in liver limited life span approx 120 days
outline leukocytes
white blood cells
5 major types of leukocytes: neutrophils, lymphocytes, monocytes, eosinophils, basophils.
increase with infection and can leave the bloodstream when body is stressed. Remain circulating to be prepared for communicable disease.
outline thrombocytes
platelets
pinched off from megakaryocytic in bone marrow, short life span
too many=thrombosis
clotting functions where fibres and red blood cells are joined
what are respiratory pigments
molecules that specifically relate to O2 transport. Haemoglobin is the respiratory pigment in humans and increase in O2 on haem = increase in red colour.
haemoglobin also assists with CO2 transport and pH buffering.
decrease in pressure of O2 = more likely to release O2 of haem
decrease in pH = drop more O2
shift in pressure of O2 compared to haem saturation
mothers graph shifts up and to the left to produce foetus graph. This is because foetus has an increased affinity to accept O2 and mother decreased affinity so it is easer to give away.
what is an open circulatory system
not fully enclosed, low pressure to keep fragile areas from collapsing, can’t direct fluid easily.
what is a closed system
fluid entirely enclosed, direct blood to particular places, not homogenous throughout the body (more dense in different places)
2 types of pump
peristaltic pump
chamber pump
fish system
single circuit
2 chambered pump, atrium collect and ventricle pumps. low blood pressure so gills aren’t ruptured.
amphibian system
single circuit
3 chambered, single ventricle, have a low metabolism and therefore oxygenated and deoxygenated blood mix and it doesn’t really matter.
mammal and bird system
double circuit
4 chambered heart, complete division of ventricle.
systole refers to
blood flow in contraction
systole =s for speed which is faster in contraction
diastole refers to
blod flow in relaxation
output of heart
rate x volume of blood.
why do we have different atrial and ventricle values of blood flow
this is because they contract and expand in a sequence
increase in metabolic rate =
increase in fluid pumped around (moved)
steps of heart contraction
- SA node signals for contraction
- AV node delays signal
- Signal passes to heart apex (bottom)
- Signal spreads throughout ventricles causing contraction
CLOSER TOGETHER OF THIS CYCLE=HEART RATE HAS INCREASED.
NOTE: atrial repolarisation is hidden by the large peak of ventrical depolarisation.
smooth muscle blocks gas exchange on
veins and arteries but smooth muscle is not on the capillaries
outline artery structure
- thick, circular
- lower compliance therefore higher pressure for same vol compared to veins
- holds less blood
- elastic walls due to smooth muscle
outline vein structure
- thin, irregular
- high compliance therefore lower pressure for same volume compared to arteries
- holds more blood
- elastic walls due to smooth muslce
