4.3-circulation Flashcards
oxygen- where it enters and leaves blood
enters= capillaries of lungs
leaves= respiring tissues
carbon dioxide- where it enters and leaves blood
enters= respiting tissues
leaves= capillaries of lungs
glucose- where it enters and leaves the blood
enters= small intestine
leaves=respiring tissues
amino acids- where it enters and leaves blood
enters=small intestine
leaves=respiring tissues
hormones- where it enters and leaves blood
enters= glands
leaves= target cells
urea- where it enters and leaves the blood
enters= liver
leaves= kidney
mass transport in fish
-closed circulatory system
-2 chambered heart
-blood is oxygenated at gills and deoxygenated as it travels round body
mammalian mass transport- double circulatory system
- pulmonary- takes blood to lungs
2.systemic- takes blood around rest of body
4 things blood is made up of
-erythrocytes
-leukocytes
-platelets
-plasma
what can blood smears be used to diagnose
- anemia
- sickle cell disease
- blood cancers
- malaria
blood vessels- veins
-function to carry blood from tissues to the heart
-thin walls, mainly collagen aince blood at low pressure
-large lumen to reduce resistance flow
-valves prevent back flow
-low p
-blood usually deoxygenated (except pulmonary vein)
blood vessels- capillaries
-allows exchange of materials between blood and tissues
-very thin, permeable walls only one cell thick to allow exchange of materials
-very small lumen, blood cells must distort to pass through
-no valves
-blood p falls
-changes from oxygenated to de (except in lungs)
blood vessels- arteries
-carry blood from heart to tissues
-thick walls w smooth elastic layers to resist high pressure, muscle aids pumping
-small lumen
-no valves (except in heart)
-vessels at high p
-blood usually oxygenated (except pulmonary artery)
advantages of double circulatory system
-carries oxygen rich blood from heart to cells where oxygen is used
-carries deoxygenated blood to heart
-pulmonary circulation carries de blood from heart to lungs to be oxygenated
-makes sure oxy and deoxy cannot mix, so tissues receive as much as possible
-also means blood can be delivered at higher pressures
what are platelets
-tiny fragments of large cells called megakaryocytes, found in bone marrow
-involved in clotting of blood
erythrocytes (red blood cells)
-contain haemoglobin
-formed in bone marrow
-do not contain nucleus and only live around 120 days when matured
-transport oxygen from lungs to cells
-biconcave disc shape means large SA:V ratio so oxygen can diffuse in and out rapidly
-haemoglobin also carries CO2 produced in respiration to lungs
leukocytes (white blood cells)
-much larger than erythrocytes
-can still squeeze through blood vessels and change shape
-main function to defend against infection
-all contain a nucleus and colourless cytoplasm
types of leukocytes- granulocytes
-leucocytes with granules in cytoplasm that take up sain and have lobed nuclei
1. neutrophills- part of non specific, engulf and digest pathogens, make up to 70% leukocytes
2.eosinophills- non specific, stained be eosin stain, against parasites, allergic reactions and inflammation, develop immunity to disease
3.basophills- 2 lobed nuclei, non specific, produce histamines in inflammation and allergic reaction
types of leucocytes- agranulocytes
-do not have granules to take up stain, unlobed nuclei
1.monocytes- specific, largest of leukocytes, can move out of blood into tissues to form macrophages which engulf pathogens by phagocytosis
2. lymphocytes- small leukocytes- with very large nuclei vitally important in specific immune response
root of blood from vena cava (9 places)
1.vena cava
2.right atrium
3.right ventricle
4.pulmonary artery
5.lungs
6.pulmonary veins
7. left atrium
8.left ventricle
9.aorta
components of blood- plasma
major role in transporting;
-digested food products from small intestine
-nutrient molecules from storage to cells
-excretory products
-chemical messages
-also helps maintain steady body temp by transferring heat around system from deep rooted organs or very active tissues#
-acts as buffer to pH change
what is haemoglobin?
-protein made up of 4 polypeptide chains each with a haem (iron) group
-globular
-each haem can pick up 4 O2 molecules
-reversible reaction
-has an affinity for oxygen
-makes oxyhaemogloin
loading of oxygen on to haemoglobin- step by step
1.after first O2 binds, Hb changes shape, making it easier for polypeptide chains to bind to O2 molecules
2.therefore takes smaller inc in pO2 to bind second oxygen. (positive cooperativity) gradient of curve steepens
3.after third binds, should be easier for 4th
4. more difficult due to probability, with most binding sites occupied. gradient of curve flattens
the role of haemoglobin
-readily associates with oxygen at the surface where gas exchange takes place
-readily dissociates from oxygen at the respiring tissues to release oxygen in to respiring tissues