Circulation Flashcards
Organs for diffusion
LET-GC
Entire Outer skin (frogs), tracheae, cell surface, gills and lungs.
What do molluscs and crustacea have?
A diffusion lung.
What do sand crabs have?
Cutaneous patches on upper limbs
What do soldier crabs have?
Bronchial chamber.
What does circulation move?
Respiratory gases, nutrients, water, salts, metabolites and waste, hormones, RBCs and WBCs, and platelets.
Haemoglobin
Blood Protein
Has 2 alpha and beta globins, along with 4 haem making a heterotetrameric complex, blood: red colour.
(See Quizlet Image)
What animals use haemoglobin?
Humans and majority of vertebrates.
Chlorocruorin
Very large free-floating multimeric complex of myoglobin like subunits, containing porphyrin, gives blood a green colour.
(See Quizlet Image)
Light green= deoxy
Green= oxygenated
When more concentrated appears light red
What animals use chlorocruorin?
Some segmented worms, leeches and marine worms.
Haemocyanin
Monomer/hexamer in arthropods and polymer in molluscs, has no porphyrin, it uses copper instead of iron.
(See Quizlet Image)
deoxy= colourless
oxy= blue
Haemocyanin in blood
It is free-floating, and gives blood a blue colour when oxygenated.
What stabilises the copper in haemocyanin?
6 Histidines.
What animals use haemocyanin?
Spiders, crustaceans, some molluscs, octopuses and squids.
Haemorythrin
A homo/hetero octamer with no porphyrin, 1/4 as efficient as haemoglobin, gives blood a violet colour.
(See Quizlet Image)
What animals use haemorythrin?
Marine worms.
Open circulation
Blood bathes tissues directly, low pressure, low oxygen delivery, cannot regulate flow, but metabolically cheap and less risk of blood loss when injured.
What animals have open circulation?
Many invertebrates such as nematodes, arthropods, molluscs and tunicates.
Closed circulation
Blood is contained in vessels, high pressure, high oxygen delivery, can regulate flow but metabolically expensive and vulnerable to injury.
What animals have closed circulation?
Mammals.
Open circulatory systems
Diffusion occurs in sinuses, blood percolates through and diffuses under low pressure.
Insect circulation
Dorsal, tubular heart with anterior arteries and multiple ostia bring blood back to heart.
Dorsal vessel in insects
Main insect vessel that runs longitudinally through thorax and abdomen along inside of dorsal body wall, fragile and collects haemolymph in the abdomen and drives it to head.
What drives movement of haemolymph in insects?
Peristalsis of ciliary muscles.
What allows return of insect haemolymph?
In the diastolic phase, the ostia open up to allow influx.
Purpose of insect circulation
Blood is not used to carry O2, but does all other roles.
Insect tracheal system
Network of air filled tubes, reduces water loss and can be shut off, allows recovery of water vapour, it delivers O2 to the tissues with ends permeable to gases.
Where does diffusion occur in closed circulatory systems?
Capillaries.
Two basic types of hearts
Chambered heart and tubular hearts.
What animals have a chambered heart?
Molluscs and vertebrates.
What animals have a tubular heart?
Arthropods.
Tubular heart
Peristaltic, aortic arches in annelids with accessory hearts.
Accessory hearts
Pump hemolymph into wings, legs, and other remote structures.
What species have accessory hearts?
Insects, fish and amphibians.
Three layers of the artery
Endothelium, smooth muscle and connective tissue.
What must arterial walls be able to do?
Contract and expand.
How do veins move blood?
By nearby muscular contractions.
Valves in veins
To stop backflow.
What circulatory system features are shared in teleosts, amphibians, reptiles, birds and mammals?
A heart that connects to the systemic circulation via one or more aortic arches.
Examples of animals with 2 chambered heart
Zebrafish and lamprey.
Examples of animals with 3 chambered heart
Frog and pufferfish.
Examples of animals with 4 chambered heart
Chicken, mouse and humans.
Hagfish
Primitive, jawless eel-like vertebrate with a partially open circulatory system and several muscularised vessels that act as hearts.
Hagfish heart
Caudal with 2 chambers separated by a cartilaginous rod, muscles contract to bend rod and change volume of each chamber, one side expands to fill with blood and the other contracts to expel.
Fish circulatory system
Simple closed system, with heart pumping deoxygenated blood through gills, where it is reoxygenated and goes through tissues.
Fish heart
One atrium and one ventricle, all venous blood goes through the sinus venosus and returns to atrium which are then passed into ventricle from there pumped into gills.
What are gills made of?
Gill arches (for rigid support) and gill filaments (paired) along with secondary lamellae.
Oxygen content of water
5ml O2/L.
Oxygen content of air
210ml O2/L.
How has gill adapted to increase oxygen absorbed?
It has counter-current gas exchange so water flow is opposite to blood flow.
Why is the counter-current used?
Same current blood and water would reach an equilibrium with oxygen so no further diffusion, opposite direction allows water to always have more oxygen than blood.
Why do fish suffocate out of water?
Gill arches collapse so they have no surface area for diffusion.
Speed of counter-current gas exchange
Slow but stable.
How does heart pump blood to gills?
Through aortic arches.
What do aortic arches join?
Dorsal and ventral aorta.
What carries blood downstream?
Single dorsal aorta.
Lungfish
Live in low oxygen water, use gills and lungs, normally uses gills but if oxygen low it gulps air into lungs.
Lungfish blood path
Heart to gills to head and body, then some goes to the lungs, so some reoxygenated blood returns to heart unlike other fish.
Lungfish heart
2 atria to separate oxygenated and deoxygenated blood, with only one ventricle with folds and flaps to channel flow.
Where does oxygenated blood go to in lungfish?
To the left atrium and then goes to front end of gills and head.
Where does deoxygenated blood go in lungfish?
To the right atrium and then goes to back end of gills where it is oxygenated and then goes to rest of body.
Water breathing lungfish circulation
Single circulation with deoxygenated blood going through arches 2, 5 and 6.
Air breathing lungfish circulation
Double circulation with deoxygenated blood through arch 6 to the lung while oxygenated blood goes through arches 3 and 4 along with external carotid artery.
Land vertebrate circulation
2 circulatory circuits- pulmonary and systemic along with increased metabolic rate.
Pulmonary circuit of land vertebrates
Conveys blood between heart and gas-exchange tissues.
Systemic circuit of land vertebrates
Carries blood between heart and rest of body.
Amphibian heart
Two atria, left is deoxygenated, right is oxygenated which then mix in ventricle, pumping mixed blood to lungs for oxygenation and to the body.
Turtle heart
Similar to amphibian but is septated and has folds and grooves in ventricles to keep blood from mixing.
Bird and mammal heart
2 atria and 2 ventricles, right side is deoxygenated, left side is oxygenated, mammals have one systemic arch.
How do adult amphibians respire?
Lungs and skin.
What happens to frog respiration in summer?
More dependent on lungs as higher temperature increases metabolic rate which means more oxygen needed- cannot speed up diffusion.
Frog circulation
Lungs in adult, gills in larvae, can absorb oxygen through skin, pulmonary artery supplies lungs with a branch supplying skin.
Where does oxygenated blood go in frogs?
To left atrium.
Where does skin oxygenated blood go in frogs?
Mixes with deoxygenated blood from body.
Adult amphibian aortic arches
Deoxygenated blood goes through arch 6 while oxygenated blood goes through arches 2 (carotid body) and 4.
Frog heart
2 atria and 1 ventricle, less developed separation of pulmonary and systemic circulation but blood still relatively unmixed as they are ejected from heart.
Crocodile blood path
Right ventricle to lungs to left atrium to left ventricle to systemic circulation to right atrium to right ventricle.
Crocodile blood supply
Right systemic arch from left ventricle and left systemic arch from right ventricle.
Crocodile left systemic arch
Supplied with oxygenated blood from left ventricle via the foramen of Panizza, high pressure in systemic circulation keeps valve between left systemic arch and right ventricle close, maintaining separation of oxygenated and deoxygenated blood.
Bird and mammal circulation
Completely separated pulmonary and systemic circulation, systemic has much higher pressure, LV larger than RV
Bird and mammal aortic arches
3 (carotid artery), 4 (aorta) and 6 (pulmonary artery).
Difference in bird and mammal aortic arch?
Mammals have the left aortic arch while birds have right.
How can capillary beds be bypassed?
Arteriolar-venular anastomoses which connect arterioles and venules.
How does blood enter the microcirculatory bed?
By arteriole.
