Circulatory system Flashcards
What doesnt have a circulatory system
parazoans and simple metazoans(flat worms)
-exchange of 02 and nutrients with environment is achieved via moevemtn of water
Nematodes-fluids within bgody cavity are used for circulation
Open circulatory system
no distraction between blood and the extracellular (interstitial) fluids of body tissues eg) arthropods, and mollusks except cephalopods)
insect circulatory system
Open
blood is pumped through vessels into body cavity
Hemolymmph transports nutrients and metabolic waste, but ton o2 and CO2
heart with ostia
crustacean and chelicerates circulatory system
open ssystem
Hemolypm also transports o2 and co2. blood has oxygen-binding pigments, hemocyanin, not hemoglobin)
Function of blood (in vertebrates)
Transportation-all substances essential to cellular metabolism are transported by the circulatory system
-red blood cells transport oxygen to tissues
-blood carries absorbed products of digestion to cells in the body
-metabolic wastes and excess water in the blood are filtered through the kidneys
regulation-transports hormones participates in temp regulation
protection-circulatory system protects against injury and foreign substances
1)blood clotting platelets adhere to the damaged area
2)immune defense-white blood cells
closed circulatory system
blood is enclosed within vessels that transport the blood away from and back to heart, transports nutrients metabolic waste, and o2/co2
eg) annelids, cephalopod mollusks,
Fish circulatory system
single-looped circulation; low blood pressure
heat-gills body, back to heart
-in the transition to lungs some aortic arches of the kills were repurposed to deliver deoxygenated blood to paired air sacs associated with pharynx
tetrapods circulatory system
-the evolution of lungs coincided with the evolution of double-looped circulation
-blood is pumped via the pulmonary circuit from the heart to the lungs and back
-blood is pumped via the systemic circuit from the heart to the tissues and back
Mammals, birds, crocodiles-4 chambered heart so deox blood and ox blood don’t meat
Amphibians and most reptiles circulatory system
reptiles amphibians- 3 chamber heart so deox and o blood meet(two atria and one ventricle)
crocodiles, birds and mammals reptiles amphibians- 3 chamber heart so deox and o blood meet(two atria and one ventricle)
Mammals, birds, crocodiles-4 chambered heart so deox blood and ox blood don’t meat
Which chamber pumps oxygenated blood out ot body tissue
Left ventricle-thicker walls, high pressure
Right ventricle pumps deox blood to the lungs at low pressure
Mammal, bird croco heart
veins return blood, arteries take blood way from heart
1)Right atrium receives venous blood
2)blood flows to right ventricle and is pumped to lungs
3)left atrium receives ox blood from lungs
4)blood flows to left ventricle and is pumped to organs in body(via aorta)
- 2 cycle pump: atrial chambers pump simultaneously followed by ventricular chambers
blood vessels
arteries and arterioles
-blood leaves the heart via arteries and then to arterioles
-contain more elastic fibers than other blood vessels.. When they contract they reduce heat loss and limits blood flow to injured vessels
Capillaries
-upon leaving the arterial system blood then enters an elaborate network of capillaries
o2 is released to cells and co2 and other waste products are picked up
Venules and veins
-blood flows from venues and veins back to heart, aided by contractions of skeletal muscle
-low pressure, most of body blood is contained in veins, pooling of blood causes varicose veins (bed ridded)
Vasoconstriction
arteries and arterioles
When they contract they reduce heat loss and limits blood flow to injured vessels
Vasodilation
Increases heat loss, more blood flow
Capillaries
Capillaries
-upon leaving the arterial system blood then enters an elaborate network of capillaries
o2 is released to cells and co2 and other waste products are picked up
Venules and veins
Venules and veins
-blood flows from venues and veins back to heart, aided by contractions of skeletal muscle
-low pressure, most of body blood is contained in veins, pooling of blood causes varicose veins (bed ridded)
lymphatic system
-the circulatory system is a closed system; however some water and solutes of blood plasma filter through capillaries and form interstitial fluid
-the amount of fluid that flows out of capillaries is greater than what flows in. The remainder renters the lymphatic system(open system)
-excess interstitial fluid drains into lymph capillaries, which eventually passes to lymph nodes (in neck) and drained back into veins
Gas exchange across respiratory surfaces
respiration involes the diffusion of gases across plasma membrane
-diffusion is passive, driven by the difference in o2 and co2 concentrations across a membrane.
-ficks law of diffusion
ficks law of diffusion
R= (DxAxDeltap)/d
r=rate of diffusion
D=diffusion constant
A=surface area
deltap=difference in concentration on either side of membrane
d=width of membrane
-R can be increased by increased A, deltap or lowering d
Aquatic breathers
Undirectional- in mouth out gills
Terestial air-breathers
bidirectional or tidal in mouth, goes out the opposite way
birds have one way airflow
Gills
-gills are specialized vascularized filamentous structures that project into water. their design increased surface area (A) and minimized membrane width (d) for efficient gas exchange
-papulae and tube feet in echinoderms serve as gills
-naked gills in nudibranch(type of gastropod
-many marine annelids breathe through their skin
-aquatic insect larvae have external gills that connect to their tracheal system, lost as an adult
-gills are found in most encrustations, many mollusks and annelids, as well as larval salamanders and fish
-numerous groups of fish have evolved accessory breathing organs to cope with low dissolved o in water
Countercurrent exchange and fish law of diffusion
if fished used concurentis fish would have no diffusion as water and blood would be 50/50
