B7.2 - Transport in Animals Flashcards
What are the four chambers of the heart?
- Left Ventricle
- Right Ventricle
- Left Atrium
- Right Atrium
Left Atrium
Receives blood full of oxygen from the lungs and then empties the blood into the left ventricle
Left Ventricle
Has to pump blood at high pressure around the entire body
Right Atrium
Receives blood low in oxygen from the body and then empties the blood into the right ventricle
Right Ventricle
Pumping blood at lower pressure to the lungs
Why does the left ventricle have a thicker wall than the right ventricle?
It has to pump blood at high pressure around the entire body, whereas the right ventricle is pumping blood at lower pressure to the lungs
Septum
Separates the two sides of the heart and so prevents mixing of oxygenated and deoxygenated blood
What is the route of circulation from the lungs through the valves? (11)
- Lungs: gas exchange occurs and oxygenated blood is moved on
- Pulmonary vein
- Left atrium
- Through the bicuspid valve to the left ventricle
- Through the semilunar valve to the aorta
- Arteries
- Capillaries: nutrient + gas exchange between blood and cells/tissue
- Deoxygenated blood is collected by veins into the vena cava
- Right atrium
- Through the tricuspid valve to the right ventricle
- Through the semilunar valve to the pulmonary artery
Pulmonary Vein
transport oxygenated blood from the lung alveoli into the left atria
Vena Cava
bring deoxygenated blood to your heart from the rest of your body to get oxygen
Aoarta
carries blood away from your heart to the rest of your body
Pulmonary Artery
transport deoxygenated blood from the right side of the heart to the lungs for oxygenation
Function of artery
- Carry blood at high pressure away from the heart
- Carry oxygenated blood (other than the pulmonary artery)
- Speed of flow is fast
Adaptations of arteries
- Have thick muscular walls containing elastic fibres to withstand the high pressure of blood and maintain the blood pressure as it recoils after the blood has passed through
- Have a narrow lumen to maintain high pressure
Function of vein
- Carry blood at low pressure towards the heart
- Carry deoxygenated blood (other than the pulmonary vein)
Adaptations of veins
- Have a large lumen as blood pressure is low
- Contain valves to prevent the backflow of blood as it is under low pressure
- Have thin walls as there is no need for a muscular structure
Valves
Basic function of all valves is to prevent blood from flowing backwards
Tricuspid and Bicuspid valve
These valves are pushed open when the atria contract but when the ventricles contract they are pushed shut to prevent blood from flowing back into the atria
Semilunar valves
Found in the two blood arteries that come out of the top of the heart
- aorta and plumonary artery
- the only two arteries in the body that contain valves
Three ways you can measure heart rate
- ECG (electrocardiogram)
- measuring pulse rate
- listening to the sounds of valves closing using a stethoscope
How to investigate the effects of exercise on the heart?
- Record the pulse rate at rest for a minute
- Immediately after they do some exercise, record the pulse rate every minute until it returns to the resting rate
- This experiment will show that during exercise the heart rate increases and may take several minutes to return to normal
Double circulation meaning and benefits
Blood passes through the heart twice per circuit
Advantage: it supports a strict separation of both oxygenated and deoxygenated blood
* ensures that the body always has a dedicated supply of oxygen and also, it improves body efficiency
* is also one of the reasons why mammals can maintain their body temperatures.
What is coronary heart disease?
- a coronary artery becomes partially or completely blocked by fatty deposits called ‘plaques’ (mainly formed from cholesterol),
- the arteries are not as elastic as they should be and therefore cannot stretch to accommodate the blood which is being forced through them
Partial blockage
Creates a restricted blood flow to the cardiac muscle cells and results in severe chest pains called angina
Complete blockage
Cells in that area of the heart will not be able to respire and can no longer contract, leading to a heart attack
What factors may lead to coronary heart disease? (6)
- Poor diet
- Stress
- Smoking
- Age
- Gender
- Genetic predisposition
Atrioventicular valves
Separate the atria from the ventricles
- bicuspid and tricuspid
How does physical activity help circulation?
- Sufficient blood is taken to the working muscles to provide them with enough nutrients and oxygen for increased respiration
- An increase in heart rate also allows for waste products to be removed at a faster rate
- The extra oxygen is used to break down the lactic acid that has been built up in cells as a result of anaerobic respiration
Hepatic artery
brings oxygenated blood from the heart to the liver
Structure of plasma
Straw coloured liquid
Hepatic vein
brings deoxygenated blood from the liver back to the heart
What can reduce the risks of developing coronary heart disease?
- Quit smoking
- Diet: reduce animal fats and eat more fruits and vegetables - this will reduce cholesterol levels in the blood and help with weight loss if overweight
- Exercise regularly: will help with weight loss, decrease blood pressure and cholesterol levels and help reduce stress
Hepatic portal vein
transports deoxygenated blood from the gut to the liver
Renal vein
blood vessels that return blood to the heart from the kidney
Renal artery
large blood vessels that carry blood from your heart to your kidneys
Mesenteric artery
carry blood from the heart to the guts
Structure of red blood cell
Biconcave disc containing no nucleus but plenty of the protein haemoglobin
Structure of white blood cell
Large cells containing a big nucleus, different types have slightly different structure
Structure of a platelet
Fragments of cells
Function of RBC
Red blood cells transport oxygen around the body from the lungs to cells which require it for aerobic respiration
- They carry the oxygen in the form of oxyhaemoglobin
Function of WBC
White blood cells defend the body against infection by pathogens by carrying out phagocytosis and antibody production
Function of plasma
Plasma is important for the transport of carbon dioxide, digested food (nutrients), urea, mineral ions, hormones and heat energy
Function of platelets
Platelets are involved in helping the blood to clot
How does blood clotting occur?
- When the skin is broken (i.e. there is a wound) platelets arrive to stop the bleeding
- Platelets release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin and form an insoluble mesh across the wound, trapping red blood cells and therefore forming a clot
- The clot eventually dries and develops into a scab to protect the wound from bacteria entering
Pathogenic
A microorganism causing disease
Phagocytes
Carry out phagocytosis by engulfing and digesting pathogens
Structure of phagocytes
Phagocytes have a sensitive cell surface membrane that can detect chemicals produced by pathogenic cells
- They can be easily recognised under the microscope by their multi-lobed nucleus and their granular cytoplasm
How is phagocytosis carried out?
- Once the phagocytes encounter the pathogenic cell, they will engulf it and release digestive enzymes to digest it
Lymphocytes
Produce antibodies to destroy pathogenic cells and antitoxins to neutralise toxins released by pathogens
Structure of lymphocytes
large round nucleus which takes up nearly the whole cell and their clear, non-granular cytoplasm
Capillaries
- Carry blood at low pressure within tissues
- Carry both oxygenated and deoxygenated blood
- Speed of flow is slow
Adaptations of capillaries
- Have walls that are one cell thick so that substances can easily diffuse in and out of them
- Have ‘leaky’ walls so that blood plasma can leak out and form tissue fluid surrounding cells
Arterioles
The narrow vessels that connect arteries to capillaries
Venules
The narrow vessels that connect capillaries to veins
