Circulation Flashcards
Circulation system 5 functions
Respiratory gas transport
Nutrient transport
Nitrogenous waste transport
Hormone transport
Heat transport
Circ system is required in…
Animals larger than a certain size
Animals with more minimal oxygen demands (high metabolism)
Circ system consists of…
Pumping mechanism (e.g. heart)
Plumbing (arteries and veins)
Surfaces for diffusion (capillaries)
Two basic designs of circ system
Open vs. Closed circulatory systems
Open circulatory system
Hemocoel
Interstitial space
Blood flows from arteries into diffuse spaces between cells (interstitial space) or into special blood cavities surrounding organs then returns to the heart via ostia
Blood in open systems is called hemolymph
Hemocoel is the body cavity of an open circulatory organism
Closed circulatory system
Blood confined to vessels at all times
Materials pass into and out of blood via diffusion
Artery vs Vein
Carries blood away from heart artery
Carries blood to heart vein
Veins are thinner walled,
less elastic,
have much less smooth muscle,
and are of larger diameter
Makeup of plumbing for circ system
Artery -> arteriole -> capillary -> venule -> vein
Arterioles
Small arteries made up primarily of smooth muscle
Circular smooth muscle can contract, reduce blood flow to particular organs
Serves as a control mechanism to divert blood to where it is most needed
Pressure of blood when it reaches veins
By the time blood reaches veins, pressure has decreased to zero
How does blood return to the heart?
Skeletal muscle surrounding veins applies pressure when those muscles contract
One way valves direct blood anteriorly, restrict flow posteriorly
Differences between vertebrate circulatory patterns is related to:
Location of respiratory organs
Structure of Heart
Amphibian circulatory system
Double circuit
Pulmonary/Systemic
Two atria, single ventricle
Both oxygen-rich and oxygen poor blood travel through the ventricle
Trabeculae prevents oxygenated and deoxygenated blood from mixing to any great extent
Bird-mammal circulatory systems
atria/ventricle relation?
circulation?
Complete separation between atria and ventricles
Double Circulation - complete separation between pulmonary and systemic circuits
Portal system
which 3?
Connects two capillary beds
Hepatic portal system
Renal portal system
Hypophyseal portal system (connect hypothalamus to anterior pituitary)
Blood supplies to heart
Left ventricle -> aorta -> coronary arteries (left/right) -> coronary veins (left/right) -> coronary sinus -> right atrium
CAD
death?
what builds up?
what do plaques do?
what does restricted blood flow do?
solutions?
Leading cause of death, killing 370,000 anually
Fat, cholesterol, and other substances collect in the artery walls
Plaques damage artery walls and block blood flow
Severe buildup of plaques lead to restricted blood flow in the muscle and then a heart attack
stent or bypass
Hepatic portal system
what does it collect from?
where does that stuff go?
what does the stuff contain?
Where do those things go after the liver?
Collects venous blood from digestive tract and spleen
Delivers blood to the liver via the hepatic portal vein
portal blood contains the substances absorbed by the digestive tract
substances are processed in the liver before being either … released into hepatic veins, or store in the liver for later use
Placenta
O2 and nutrients come from mother via the placental interface
Fetal wastes are passed in blood to mother via placenta
Fetal circulation
Placenta -> umbilical vein -> ductus venosus -> inferior vena cava -> right atrium -> foramen ovale -> left atrium -> left ventricle -> aorta -> systemic body circulation
Function of lungs in the fetus
Not functional, and some blood passes through the pulmonary trunk, which bypasses to the aorta via the ductus arteriosus
Ductus venosus does what?
carries oxygenated blood and bypasses the liver, dumping oxygenated blood into the inferior vena cava