3.1.2 Transport in animals Flashcards
How many chambers in the human heart?
4 chambers
Name the chambers of the human heart
right atrium, left atrium, right ventricle, left ventricle
What is the all of muscular tissue separating the two halves of the heart called?
The septum
What is the purpose of the septum?
prevent oxygenated blood from mixing with deoxygenated blood
Name the 4 valves of the heart
tricuspid, bicuspid, 2x semi lunar
What is the bottom of the heart called?
Apex
How do the valves in the heart know when to open and close?
Valves open when the pressure of blood behind them is greater than the pressure in front of them.
What are the blood vessels on the surface of the heart called?
coronary arteries
What do arteries do?
carry blood away from the heart at high pressures to tissues.
What do veins do?
Carry blood at low pressures to the heart
Are the lumen of arteries narrow or wide?
Narrow to maintain a high blood pressure.
Are the lumen of veins narrow or wide?
wide to carry blood at high speeds
Name the layers of blood vessels
endothelium, elastic tissue, smooth muscle, collagen
What does collagen do in blood vessels?
Provides structural support to maintain the shape and volume of the vessel
Why do arteries have thick smooth muscle?
Strengthens the arteries so that they can withstand high pressures and also contract for reduced blood flow.
Why is there no need for thick smooth muscle in veins?
Blood is travelling at low pressures.
Which blood vessel has valves?
veins
Do veins or arteries have more collagen?
Veins
Function of capillaries
to exchange of materials such as oxygen & carbon dioxide between the blood and tissue cells.
What type of walls do capillaries have?
very thin leaky walls
How thin is the lumen of capillaries?
1 cell thick
Why is the lumen of capillaries 1 cell thick?
So 1 RBC can travel through at a time to maintain slower diffusion.
What are capillary networks calledl?
Capillary beds
What is the order of the blood vessels that a red blood cell would pass through as the blood leaves the heart, travels to a tissue, and then returns to the heart?
Arteries, arterioles, capillaries, venules, veins.
Function of venules.
Transport blood from capillaries to veins.
Function of arterioles.
Transport blood from arteries to capillaries.
What is the contraction of the heart called?
systole
What is the relaxation of the heart called?
diastole
Explain the cardiac cycle.
1) Diastole- the heart relaxes.
-The atria fill up with blood from the veins.
-Blood trickles into the ventricles.
2) Atrial systole- the atria contract.
-The atria contract and blood is forced into the ventricles.
3) Ventricular systole- the ventricles contract.
-A fraction of a second later the ventricles contract and the valves between the atria and ventricles close so blood can only be squeezed into the arteries.
The heart is myogenic, what does this mean?
The heart has the capacity to create its own impulses
Where is the sinoatrial node found?
wall of right atrium