Unit 9 - transport in animals Flashcards
What is the purpose of the circulatory system?
- Supply all cells with oxygen from the lungs and nutrients from the small intestine.
- Remove waste products such as carbon dioxide and urea (from which urine is made from) from the cells
What 3 things does the circulatory system consist of?
- A pump (heart) to keep the blood moving
- Blood vessels to carry blood
- Valves to make sure that blood flows in one direction only
Explain single circulation
Fish have single circulation, in which..
- the blood flows from the heart to the gills for oxygenation
- and from the gills to the rest of the body
As the blood only flows through the heart once, it is known as single circulation.
What does red/blue blood represent in diagrams?
Red blood - oxygenated
Blue blood - deoxygenated
Explain double circulation
In humans and other mammals, blood flows through the heart twice. It follows two circuits:
- in the first, blood flows from the heart to the lungs for oxygenation and back to the heart
- in the second, blood flows from the left side of the heart to other parts of the body where oxygen diffuses from the blood to the body cells and then back to the right side of the heart
What does a higher pressure applied by the heart result in?
- greater flow of blood
- ability for the blood to travel further in the body
What is metabolism?
All chemical reactions that happen inside living cells, including respiration
State 3 advantages of double circulation
- Oxygen and glucose for respiration are supplied quickly to the cells in the body, while the CO2 and water are removed quickly
- Blood can be supplied to distant parts of a large animal
- Allows mammals to maintain a near constant body temperature
Explain the structure of the heart (consult diagram)
- Left top part - the right atrium. Superior vena cava brings blood into heart from upper body. Pulmonary artery carries deoxygenated blood to lungs.
- Left bottom part - right ventricle. Inferior vena cava brings blood into heart from lower body
- Right top part - left atrium. Aorta which carries blood from heart to body. Pulmonary vein which receives blood from lungs to heart
- Right bottom part - left ventricle
What separates the left and right side of the heart?
The septum
How is heart activity monitored?
- Electrocardiogram - small electrodes are fastened over the heart and other areas of the body to record the electrical activity of the heart
- Listening to the sounds of the valves closing
- Determining the pulse rate - each time your left ventricle contracts, it creates a pulse
State the order of actions in a heartbeat
- Blood flows from veins into the atria
- The atria contracts, pushing blood into ventricles
- Pressure inside atria drops, causing the valves in between the ventricles and atria to close. This prevents blood flowing back.
- The ventricles contract, pushing blood into the artery
- Pressure inside ventricle drops, causing the valves between the arteries and ventricles to close.
What are coronary arteries?
Blood vessels that supply blood to the muscles of the heart; branch from the aorta
What is the coronary heart disease?
The disease that arises when the coronary arteries are unable to supply oxygen rich blood to the heart muscles due to blockages in them. This may result in damage or death of said muscles.
Risk factors include: age, diet, genetic predisposition, gender, smoking, stress
How to decrease the risk of getting CHD?
- Eat a balanced diet, reduce amount of animal fat and cholesterol consumed
- Keep body mass at safe level, exercise regularly
What is a lumen?
Internal space of a blood vessel
State the properties of arteries
- carry oxygynated (mostly) blood away from the heart
- divide again and again to form capillaries
- thick walls - can withstand pressure
- narrow lumen - helps maintain pressure of blood
- no valves (force at which heart pumps is enough, except for aorta and pulmanory artery which need to prevent backflow to heart)
- thick layer of muscle, elastic tissues
- high pressure
- e.g. aorta (oxygen rich), pulmonary artery (oxygen poor)
State the properties of veins
- carry deoxygenated blood back to the heart
- capillaries join up together to form veins
- thin wall
- thin layer of muscle
- very wide/large lumen
- have valves
- low pressure
- e.g. superior & inferior vena cava (no valves), pulmonary vein (valves)
State the properties of capillaries
- tiny blood vessels which allow the exchange of materials between the blood and body cells
- very narrow lumen
- very thin walls, 1 single layer of cells
- no valves
State the major blood vessels + direction
Pulmonary vein - from lungs to heart
Vena cava - from the body to heart
Pulmanory artery - from heart to lungs
Aorta - from heart to body
State the 4 components of blood
- plasma: watery fluid which transports blood cells, ions, soluble nutrients, etc in the blood
- platelet - fragments of cells that are involved in clotting (is skin is damaged)
- red blood cells
- white blood cells
State the purpose and adaptations of red blood cells
Function: transport oxygen in the blood
- Have a biconcave disc shape to maximize sa:volume ratio to increase rate of oxygen diffusion
- No nucleus to have more space for hemoglobin molecules (combine with oxygen when oxygen levels are high, release it when oxygen levels are low)
State the purpose and adaptations of white blood cells
- large, lobed nucleus
- part of the body’s immune system
- more red blood cells than white blood cells
- 2 main types: phagocytes (destroy pathogens, multi-lobed nucleus) and lymphocytes (produce antibodies, round nucleus)
What is blood clotting?
The process by which blood turns from a liquid into a gel, plugging the blood vessels at the site of a wound and stopping the blood loss.
The platelets form the plug, preventing excessive blood loss and pathogens entering the body due to the barrier breaking.
