Transport In Animals Flashcards
What is the function of the circulatory system ?
To transport substances around the body
What are the three things that the circulatory system requires ?
- a liquid to transport substances in - the blood
- A pump to move the liquid - the heart
- A series of pipes to direct the liquid on me that efficiently-the blood vessels
What are the two circulatory system ?
- pulmonary circulation
* systemic circulation
What is the pulmonary circulation ?
Blood returning from the body, deoxygenated, is pumped to the lungs where oxygen is gained and carbon dioxide is lost, and then returned to the heart
What is the systemic circulation ?
Blood that is oxygenated and pumped around the rest of the body, where the cells absorb oxygen and release carbon dioxide, before being returned to the heart
What vessels go to and from the heart ?
The vena cava goes to and the aorta goes from the heart
What vessels go to and from the lungs ?
The pulmonary vessels
What vessels go to and from the liver ?
The hepatic vessels
What vessels go to and from the kidney ?
The renal vessels
What does the blood consist of ?
Plasma, platelets and red and white blood cells
What is plasma ?
• plasma is a straw coloured liquid made up of mainly water.
Plasma carries the blood cells, it carries dissolved nutrients such as glucose and amino acid’s, dissolve waste products including urea and carbon dioxide, hormones, a wide range of proteins.
• The plasma also distribute heat energy around the body
What are platelets and what do they do ?
- they help to form clots, preventing blood loss and infection
- they are small cell fragments
What do white blood cells do?
They destroy pathogens
Where red blood cells made and what is their function ?
- they are made in the bone marrow and only live 100 days before being destroyed by the liver or spleen
- their function is to transport oxygen
What do you red blood cells contain and what does this do ?
- They contain Haemoglobin, this is an iron containing protein which combines with oxygen to form oxyhaemoglobin when there is a high oxygen concentration in the surrounding ( the lungs )
- when the concentration of oxygen decreases (in the respiring tissue), the oxyhaemoglobin releases the oxygen
What shape are red blood cells and what does this help ?
- they are biconcave
- this increases the surface area to volume ratio and decreasing the distance from the centre of the cell. This allows for efficient diffusion of oxygen in and out of the cell
- they have no nucleus
- meaning that more haemoglobin can be packed into each cell and so more oxygen can be transported
What supplies oxygen, glucose and other molecules to the heart ?
Coronary blood vessel
Why does the left ventricle have much thicker muscular walls ?
Because the blood must be pumped at a much higher pressure for it go go around the entire body
Describe the pulmonary circulation
- deoxygenated blood enters the right atrium through the superior and inferior Vena cava
- The walls of the atrium contract, increasing the pressure. Blood then flows into the right ventricles through the tricuspid valve
- The ventricle contracts, increasing pressure. The tricuspid valve closes, preventing the flow of blood back into the atria
- The right ventricle continues to contract. The rising pressure forces the semilunar valve to open and blood flows out of the heart through the pulmonary artery
- The pulmonary artery carries the blood that is very low in oxygen to the lungs, where it becomes oxygenated
Describe the systemic circulation
- oxygenated blood enters the left atrium via the pulmonary vein
- The walls of the atrium contract, increasing the pressure. Blood flows into the left ventricle through the bicuspid valve
- The left ventricle contracts increasing the pressure. The bicuspid valve closes, preventing the flow of blood back into atrium
- The ventricle continues to contract. The rising pressure forces The semilunar valve to open and blood flows out of the heart through the aorta
- The aorta pumps the blood around the body to muscles that need the oxygen
Describe arteries
- they transport blood away from the heart all regions of the body
- blood flows at high pressure
- arteries are able to expand and are not damaged by the high-pressure
- they have elastic muscular walls
- they have small lumen
Describe veins
- veins carry blood back to the heart
- at low pressure
- they have large lumen
- they have valves
- they have thin outer walls
Describe capillaries
- they carry blood through organs
- walls are a single cell thick
- this means short diffusion distance, speeding up movement of molecules
Describe the Effects of exercise
- heart rate and stroke volume must increase to provide more bloodflow to the muscles for respiration
- The increased flow of blood also provides extra glucose and remove excess heat energy as well as the carbon dioxide produced in respiration
- muscles produce more CO2
- blood pressure increases
What nerve impulse controls your heart rate ?
A part of your brain called the medulla sends nerve impulses
Chain of response to exercise
- The muscles produce more CO2 in aerobic respiration
- sensors in the aorta detect this increase
- they send nerve impulses to the medulla
- then the medulla responds by sending nerve impulses along the accelerator nerve
- The accelerated nerve increases the heart rate and also causes the heart beat with more force and so increases blood pressure
- more blood supply to the muscles to meet the demands of increased aerobic respiration
What happens when exercise stops ?
- carbon dioxide production returns to normal and the medulla receives fewer impulses
- this responds by sending nerve impulses along a deceleration nerve
- The decelerator nerve decreases the heart rate and reduces stroke volume
- blood pressure returns to normal
