4.4 circulation Flashcards
what are common features of mass transport systems?
-system of vessels
-way of making sure the substances are travelling in the right direction
-a way of moving materials fast enough to supply the needs of an organism
-suitable transport medium
what is the difference between open and closed circulatory systems?
-open is when blood circulates in large open spaces
-closed is when blood is contained within tubes
what type of transport system do fish have?
single circulation system
what type of transport system do humans and birds have?
double circulatory system
what part of the system carries oxygenated blood from the heart to the body and deoxygenated blood back to the heart?
systematic circulation
what part of the system carries deoxygenated blood from the heart to the lungs?
pulmonary circulation
what are the advantages of having a double circulatory system?
- concentration gradient is maintained as oxygenated and deoxygenated blood do not mix
- oxygenated blood can be delivered quickly
-low pressure in lung capiliaries to allow gas exchange without damaging them
-organisms can develop larer bodies
what is the role of the blood in the circulatory system?
- transport medium
- carries hormones
- forms part of the defence system in the body
- distributes heat
what is the role of the plasma?
transporting:
- digested food products (glucose and amino acids) from the small intestine to all parts of the body
- nutrient molecules from storage areas to where they are needed
- excretory products from cells to organs
- hormones
(ACTS AS A BUFFER TO pH CHANGES)
what is the role of erythrocytes?
-contain haemoglobin
-transport oxygen from the lungs to the cells in the body
-biconcave disk shape and no nucleus means large SA:Vol and more space
what is the role of leucocytes?
-can change shape to fit through tight blood vessels
-defend body against infection
what are the two types of leucocytes?
- agranulocytes
- granulocytes
what are granulocytes?
-have granules in the cytoplasm of the cells and take up stains
-lobed nuclei
what are the three types of granulocytes?
-neutrophils: non-specific immune system that engulf and digest pathogens by phagocytosis
-eosinophils: non specific immune system and important in the response of the body against paracites, allergic reactions and inflammation.
-basophils: part of the non-specific immune system and produce histamines involved in inflamation and allergic reactions.
what are agranulocytes?
- no granules to take up stain
