circularity system Flashcards
(152 cards)
The circularity system transports Urea from the ……….. to ………………
Liver , Kidneys
The blood is pumped from the hearts to the gas exchange organ and then directly to the rest of the body.
single circularity
The blood is pumped from the heart to the gas exchange organ, back to the heart and then to the rest of the body.
double circularity
Which blood vessels contain valves?
Only veins and venules have valves
The ratio of supply to demand can be written as
surface area/ volume
Examples of unicellular organisms
amoeba, paramecium ,Euglena
Deoxygenated blood leaves the heart and circulated through the lungs, then it becomes oxygenated . The oxygenated blood returns to the heart.
Pulmonary circulation.
Carry blood away from the heart and towards other organs.
arteries
Carry blood towards the heart and away from other organs.
veins
Carry blood through organs , linking the arteries and veins
capillaries
Pulmonary means…
related to the lungs
Cardiac means…..
related to the heart
Controls the passage of blood from an atrium to a ventricle
The bicuspid and tricuspid valves
The transport medium in the circularity system
Blood
Septum
A wall separating two sides of the heart so to prevent mixing of oxygenated and deoxygenated blood
How the structure of the heart is adapted to its function?
mention 5 points.
1- It is divided into a left side and a right side by a wall of muscles called the septum.
2- Left ventricle wall is thicker than right ventricle, because the right ventricle pumps blood to lungs only while the left ventricle pumps blood to the rest of the bod which required more pressure.
3- Valves ensures that blood can flow only in one direction through the heart.
4- the walls of the atria are thin, they can be stretched to receive blood as it returns to the heart but can contract with enough force to push blood through the bicuspid and tricuspid valves into the ventricles.
5- the walls of the heart are cardiac muscle, which can contract and then relax continuously without becoming fatigued.
6- the cardiac muscle has its own blood supply through coronary arteries which supplies the heart muscle with oxygen and nutrients.
In the single circulation of a fish, as blood flows through capillaries it (decreases/ increases) in pressure
decreases
Which prevents the backflow of blood from the left ventricle to the left atrium as blood flows through the heart?
atrioventricular valves
Explain why the wall of the left ventricle is much thicker than that of the right ventricle?
Because the right ventricle pumps blood only to the lungs while the left ventricle pumps blood to all other parts of the body, and this requires much more pressure.
waste materials (products of excretion) from cells are:
carbon dioxide, urea
Why is a double circulation better?
The heart pumps the blood twice, so higher pressure can be maintained. the blood travels more quickly to organs . in single circulation , the blood loses pressure as it passes through the gills, it then travels more slowly to the other organs.
What are the two jobs that the heart carries out during this double circulation?
1-pumps blood to the lungs
2-pumps blood to the body
Why is the journey
of blood through the circulatory system called a double circulation?
For every circuit of the body, blood passes through the heart twice
Advantages of the Double Circulatory System
1-blood to be pumped at low pressure to the lungs
2-blood to be pumped at high pressure to the body
3-oxygenated and deoxygenated blood to be kept separate



















