Mass Transport in Animals - Structure of the Heart Flashcards
Why do large organisms have a transport system?
- As the surface area to volume ratio decreases with increasing size, exchanging materials cannot occur from the body surface alone.
- Required to exchange materials between cells and exchange surfaces.
- Materials have to be transported between different parts of the organism due to specialised tissues and organs.
Which two factors determine whether there is a specialised transport system and whether or not it is circulated by a pump?
- Surface Area to Volume ratio
- How active the organism is
What does a low surface area to volume ratio and an active organism require?
A specialised transport system with a pump
What are the common features of transport systems?
- A suitable medium to carry materials. (Blood, air)
Usually water based as water can readily dissolve substances and can be moved around easily. - Transport medium can be moved around in bulk over large distances, more rapid than diffusion.
- A closed system of tubular vessels that contain the transport medium and forms a branching network to distribute the medium to all parts of the organism.
- A mechanism for moving the transport medium within vessels, requiring a pressure difference between one part of the system and another.
Achieved through one of two ways:
1) Animals use muscular contraction, either of body muscles or of a pumping organ such as the heart.
2) Plants rely on natural, passive processes such as the evaporation of water. - A mechanism to maintain mass flow movement in one direction (e.g valves)
- A means of controlling the flow of the transport medium to suit the changing needs of different parts of the organism.
- A mechanism for the mass flow of water or gases. (e.g Intercostal muscles and diaphragm during the breathing of mammals).
Why do mammals have a double circulatory system?
- When blood is passed through the lungs , its pressure is reduced as the blood has to pass through the capillaries which are small but have a large surface area. This makes blood circulation very slow.
- Another pump allows substances to be delivered to the rest of the body quickly which is needed as mammals have a high right of metabolism
What type of circulatory system do mammals have?
- Closed meaning blood is confined to vessels
- Double meaning blood pass through the heart twice
What are the types of blood vessels?
Veins, arteries and capillaries
What are the chambers or the heart?
Right/Left Atrium
Right/Left Ventricle
What are the features of the atrium chamber?
- Thin-walled
- Elastic and stretches to collect blood from the veins.
What are the features of the ventricle chamber?
- Has much thicker muscular walls to contract strongly so that blood can be pumped into arteries.
(Either to the lungs or to the rest of the body)
Where does the oxygenated blood go to in the heart?
The left side
Where does the deoxygenated blood go to in the heart?
The right side
What does the right ventricle do?
Pumps deoxygenated blood to the lungs.
What does the left ventricle do?
- Pumps blood to he rest of the body.
- Does this by having a thicker muscular wall which provides strong contractions.
How do the atria and ventricle contract?
- Both of the same chambers contract at the same time (Both atria or both ventricles).
- This allows the same volume of blood to be pumped.
