circulatory systems Flashcards
why do some organisms need a circulatory and respiratory system that interact?
- because they have large body plans (such as mammals)
- for most cells direct contact with environment is not possible
- diffusion is slow and insufficient for distances over a few mm
- Oxygen and minerals need to be in liquid to be diffused
why do sponges, cnidarians, and flatworms not need a circulatory system?
- because their body size and shape bring many or all cells in direct contact with the environment
- eg. many cnidarians are only 2 cell layers thick, with both the outer and inner layers exposed to water, so diffusion is possible
what is the purpose of a circulatory system?
to bring fluid from the site of exchange (eg. lungs) to all the other cells of the body (eg. fingers, brain)
what are the 2 types of circulatory systems, and what 3 things do they both have in common?
- open and closed circulatory systems
1. a circulatory fluid –> blood or hemolymph
2. a set of tubes –> blood vessels
3. a muscular pump –> heart
open circulatory systems:
- what is it/how is different from closed systems:
- what organisms have it:
- advantage:
- disadvantage:
-system in which Hemolymph bathes the organs directly
-Low pressure system – low flow rate
-No distinction between blood and interstitial fluid
-found in arthropods and most molluscs
advantage:
-Requires less energy to build and maintain
disadvantage:
-Not useful for rapid metabolic requirements
closed circulatory systems:
- what is it/how is different from open systems:
- what organisms have it:
- advantage:
- disadvantage:
-system in which Blood is confined to vessels
-High pressure system
-blood is distinct from the interstitial fluid
-Necessary for high metabolic demand in larger, active
animals
-found in Annelids, cephalopods and vertebrates
advantage:
-More efficient at transporting circulatory fluids to tissues and cells
disadvantage:
-takes a lot to maintain system
what type of circulatory system do vertebrates have?
closed
what are the three types of blood vessels, and what do they do?
- arteries –> take blood out of the heart
- veins –> take blood into the heart
- capillaries –> sites of gas exchange
blood moving away from the heart travel from heart … to … to …
heart –> arteries –> arterioles –> capillaries
blood moving to the heart travels from … to … to … to the heart
capillaries –> venules –> veins –> heart
what is the pulmonary circuit?
-the portion of the circulatory system that carries blood between the lungs and heart
what is the systemic circuit?
- the portion of the circulatory system that carries blood between the heart and tissues
Blood enters the heart through the left or right … and is pumped out through the left or right …
the left side of the heart only pumps … blood and the right side of the heart only pumps … blood
- atrium
- ventricle
- oxygenated blood
- deoxygenated blood
what are the two types of closed circulatory systems?
- single circulation
2. double circulation
Single circulation:
- what type of organisms have it
- how many loops/what does it travel through
- what kind of heart is this associated with
- what kind of creatures does this work for
- how is blood flow aided
- bony fish, sharks
- 1 loop; from heart -> through two capillary beds -> heart
- 2 chambered heart
- Only works for creatures that are smaller or have lower metabolic need, and creatures that do not have to fight gravity (b/c of living in water)
- Blood flow is aided by muscle movements
Double circulation:
- what type of organisms have it
- how many loops/what does it travel through
- what kind of heart is this associated with
- what kind of creatures does this work for
- how is blood flow aided
- amphibians, reptiles, mammals
- 2 loops → heart -> lungs -> heart -> tissues
- 3 or 4 chamber heart
- works for creatures that have a higher metabolic need, and creatures that are larger and need more pressure for blood flow
what happens when blood goes through a capillary bed?
the pressure drops
what special kind of blood circuit do amphibians have, how is it different than the pulmonary circuit?
- pulmocutaneous circuit
- different than pulmonary because it picks up oxygenated blood from from the lungs and the skin, because amphibians preform gas exchange through their skin
what kind of hearts do amphibians have, do they have septums?
what does the left/right side of the heart do?
what happens when amphibians go under water?
what 2 blood circuits do amphibians have?
- 3 chambered heart, No septum in heart
- Right and left side of heart contract asynchronously
- When underwater, blood flow to lungs is nearly shut off
- pulmocutaneous circuit and systemic circuit
what kind of hearts do reptiles have, do they have septums?
what happens when reptiles go under water?
what 2 blood circuits do reptiles have?
-3 chambered hearts (except crocs), partial septum in the ventricle
-reptiles have a right systemic aorta which connects back to the systemic capillaries and allows for shunting
blood away from lungs while underwater
-pulmonary circuit and systemic circuit
what kind of hearts do mammals/birds have, do they have septums?
what does the left/right side of the heart do?
what 2 blood circuits do mammals/birds have?
- 4 chambered heart, full septum –> which means they have 2 atriums and 2 ventricles
- both sides pump separately
- Left side pumps and receives –> only oxygenated rich blood
- Right side receives and pumps –> only oxygen poor blood
- pulmonary circuit and systemic circuit
compare/contrast arteries and veins
Similar:
-both are types of blood vessels, and both can be found in the pulmonary and systemic circuits in mammals/birds
Differences:
Arteries
-carry blood away from heart
-Usually carry oxygenated blood, with the exception of pulmonary artery
-Thicker layer of smooth muscle (to protect from pressure from heart)
-arteriole (small arteries)
Veins
-carry blood to heart
-Usually carry deoxygenated blood, with the exception of pulmonary vein
-thinner layer of smooth muscle (blood in veins under lower pressure)
-have valves to prevent backflow
-venule (small veins)
capillaries are:
thick or thin?
the site of ..
contain 2 layers, the.. and the ..
- v. thin
- the site of gas exchange between blood and cells
- endothelium (inside layer) and the basement membrane (outside layer)
what are the 2 components (and percentage) of mammalian blood?
- plasma - 55%
2. cellular elements - 45%
what is the composition of plasma?
- water –> solvent for other substances
- ions –> sodium, potassium
- plasma proteins –> clotting, defense
- substances transported by blood –> waste products, nutrients
what is the composition of cellular elements in blood?
- red blood cells –> transport of O2 and CO2
- white blood cells –> defense and immunity
- platelets –> blood clotting
what is the lymphatic system?
one way system of closed vessels that collect fluid that has leaked from capillaries (lymph) and then returns it to the vascular system
what is the lymphatic system responsible for?
- Regulates body fluid balance
- Defends against infection
- Carries some wastes to the circulatory system
- Carries absorbed lipids from the digestive tract to the circulatory system
