9. Transport in Animals Flashcards
Circulatory system definition
The circulatory system is a system of blood vessels with a pump and valves to ensure one-way flow of blood
What type of circulatory system do fish have?
Fish have a two-chambered heart and a single circulation
What does single circulation mean?
This means that for every one circuit of the body, the blood passes through the heart once
What type of circulatory system do mammals have?
Mammals have a four-chambered heart and a double circulation
What does double circulation mean?
This means that for every one circuit of the body, the blood passes through the heart twice
What does the right side of the heart do?
The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs
What is the blood flowing in the lungs called?
Pulmonary circulation
What does the left side of the heart do?
The left side of the heart receives oxygenated blood from the lungs and pumps it to the body
What is the blood flowing through the body called?
Systemic circulation
What is the advantage of a double circulatory system?
Blood travelling through the small capillaries in the lungs loses a lot of pressure that was given to it by the pumping of the heart, meaning it cannot travel as fast
By returning the blood to the heart after going through the lungs its pressure can be raised again before sending it to the body, meaning cells can be supplied with the oxygen and glucose they need for respiration faster and more frequently
In what direction do veins carry blood?
Blood is pumped towards the heart in veins
In what direction do arteries carry blood?
Blood is pumped away from the heart in arteries
What separates the two sides of the heart?
The two sides of the heart are separated by a muscle wall called the septum
What is the heart made of?
The heart is made of muscle tissue
What supplies the heart muscle with blood?
supplied with blood by the coronary arteries
Do ventricles or atria have thicker muscle walls? Why?
VENTRICLES
The ventricles have thicker muscle walls than the atria as they are pumping blood out of the heart and so need to generate a higher pressure
Does the left ventricle or the right ventricle have a thicker muscle wall? Why?
The left ventricle has a thicker muscle wall than the right ventricle as 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
What is the role of the septum?
The septum separates the two sides of the heart and so prevents mixing of oxygenated and deoxygenated blood
What is the basic function of valves?
The basic function of all valves is to prevent blood flowing backwards
What are the 2 sets of valves in the heart?
atrioventricular (bi and tricuspid)
- semilunar valves
What do the atrioventricular valves separate?
The atrioventricular valves separate the atria from the ventricles
What is the valve in the right side of the heart called?
Tricuspid valve
What is the valve in the left side of the heart called?
Bicuspid valve
When are the atrioventricular valves opened and closed?
These valves are pushed open when the atria contract but when the ventricles contract they are pushed shut to prevent blood flowing back into the atria
Where are the semilunar valves found?
The semilunar valves are found in the two blood arteries that come out of the top of the heart
What is unusual about the semilunar valves?
They are unusual in that they are the only two arteries in the body that contain valves
When do the semilunar valves open and close?
These valves open when the ventricles contract so blood squeezes past them out of the heart, but then shut to avoid blood flowing back into the heart
- What type of blood comes from the body and where does it go?
Deoxygenated blood coming from the body flows into the right atrium via the vena cava
- What happens once the right atrium has filled with blood?
Once the right atrium has filled with blood the heart gives a little beat and the blood is pushed through the tricuspid (atrioventricular) valve into the right ventricle
- What happens when the blood enters the right ventricle?
The walls of the ventricle contract and the blood is pushed into the pulmonary artery through the semilunar valve which prevents blood flowing backwards into the heart
- Where does the blood go when it’s pushed through the pulmonary artery? What happens here and what process occurs?
The blood travels to the lungs and moves through the capillaries past the alveoli where GAS EXCHANGE takes place
- Why does there have to be a low pressure on the right side of the heart?
blood is going directly to capillaries which would burst under higher pressure
- What happens to the blood which has travelled from the lungs?
Oxygen-rich blood returns to the left atrium via the pulmonary vein
- What happens to the blood once it enters the left atrium?
It passes through the bicuspid (atrioventricular) valve into the left ventricle
- How is the blood transported around the body from the left ventricle?
The thicker muscle walls of the ventricle contract strongly to push the blood forcefully into the aorta and all the way around the body
- What prevents the blood from flowing back into the heart?
The semilunar valve in the aorta prevents the blood flowing back down into the heart
How can heart activity be monitored?
Heart activity can be monitored by using:
an ECG,
measuring pulse rate - listening to the sounds of valves closing using a stethoscope
What is heart rate measured in?
Immediately after they do some exercise, record the pulse rate every minute until it returns to the resting rate
How can you investigate the effects of exercise on heart rate?
To investigate the effects of exercise on heart rate, 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
What should this experiment show? (investigating the effects of exercise on heart rate)
This experiment will show that during exercise the heart rate increases and may take several minutes to return to normal
Why, (generally), does heart rate increase during exercise?
So that sufficient blood is taken to the working muscles to provide them with enough nutrients and oxygen for increased respiration
What does an increased heart rate allow the removal of?
An increase in heart rate also allows for waste products to be removed at a faster rate
- Following exercise, the heart continues to beat faster for a while to ensure that all excess waste products are removed from muscle cells
In what way will muscles likely have been respiring? What does this cause?
It is also likely that muscle cells have been respiring anaerobically during exercise and so have built up an oxygen debt
How can an oxygen debt be “repaid”?
This needs to be ‘repaid’ following exercise and so the heart continues to beat faster to ensure that extra oxygen is still being delivered to muscle cells
What is the extra oxygen produced by the rapid beating of the heart also used for?
The extra oxygen is used to break down the lactic acid that has been built up in cells as a result of anaerobic respiration
What can happen to coronary arteries if a person has a diet high in saturated fats/cholesterol?
A coronary artery becomes partially or completely blocked by fatty deposits called ‘plaques’/ atheromas (mainly formed from cholesterol),
Why are atheromas harmful?
the arteries are not as elastic as they should be and therefore cannot stretch to accommodate the blood which is being forced through them – leading to coronary heart disease
What does partial blockage of the coronary arteries cause? What is this called?
Partial blockage of the coronary arteries creates a restricted blood flow to the cardiac muscle cells and results in severe chest pains called angina
What does complete blockage of the coronary arteries cause? What is this called?
Complete blockage means cells in that area of the heart will not be able to respire and can no longer contract, leading to a heart attack
How does a poor diet affect your chance of developing coronary heart disease?
eating more saturated fat increases cholesterol levels, increasing the chance of the buildup of fatty plaques
How does stress affect your chance of developing coronary heart disease?
when under stress, hormones produced can increase blood pressure, increasing the chance of a blockage in the coronary arteries
How does genetic predisposition affect your chance of developing coronary heart disease?
studies show that people with a history of coronary heart disease in their family are more likely to develop it themselves, suggesting it partly has a genetic basis
How does smoking affect your chance of developing coronary heart disease?
nicotine in cigarettes will cause blood vessels to become narrower, increasing blood pressure which will cause the buildup of fat globules. if this occurs in the coronary artery, this will cause coronary heart disease
How does age affect your chance of developing coronary heart disease?
the risk of developing coronary heart disease increases as you get older
How does gender affect your chance of developing coronary heart disease?
males are more likely to develop coronary heart disease than females
What factors can effect your chance of developing coronary heart disease? (6)
a poor diet
stress
genetic predisposition
smoking
gender
age
In what 3 ways can you reduce the risk of developing coronary heart disease?
Quit smoking
Reduce animal fats in diet and eat more fruits and vegetables
Exercise regularly
How does reducing animal fats help to reduce the risk of developing coronary heart disease?
this will reduce cholesterol levels in the blood and help with weight loss if overweight
How does exercising regularly help to reduce the risk of developing coronary heart disease?
this will help with weight loss, decrease blood pressure and cholesterol levels and help reduce stress
In what ways can coronary heart disease be treated?
Aspirin can be taken daily to reduce the risk of blood clots forming in arteries
surgical methods such as angioplasty or a coronary bypass
- During angioplasty, what is inserted and where?
A narrow catheter (tube) is threaded through the groin up to the blocked vessel
- What is in the catheter and what does this do?
angioplasty
A tiny balloon inserted into the catheter is pushed up to the blocked vessel and then inflated
This flattens the plaque against the wall of the artery, clearing the blockage
- What is inserted to keep the artery clear?
angioplasty
To keep the artery clear, a stent (piece of metal / plastic mesh) is also inserted which pushes against the wall of the artery
- What may the stent be coated in?
angioplasty
Sometimes the stent is coated with a drug that slowly releases medication to prevent further build-up of plaque
How is a coronary bypass surgery carried out?
A piece of blood vessel is taken from the patient’s leg, arm, or chest and used to create a new passage for the flow of blood to the cardiac muscle, bypassing the blocked area
What gives rise to the name of the surgery?
coronary bypass surgery
The number of bypass grafts gives rise to the name of the surgery, so a ‘triple heart bypass’ would mean three new bypass grafts being attached
What is the difference between the pressure and direction of the blood carried by veins and arteries?
A- Carry blood at high pressure away from the heart
V - Carry blood at low pressure towards the heart
What is the difference between the type of blood carried by veins and arteries?
A - Carry oxygenated blood (other than the pulmonary artery)
V - Carry deoxygenated blood (other than the pulmonary vein)
What is the difference between the walls of veins and arteries?
A - Have thick muscular walls containing elastic fibres
V - Have thin walls
What is the difference between the lumen of veins and arteries?
A - Have a narrow lumen
V - Have a large lumen
What is the difference between the flow of blood carried by veins and arteries?
A - Speed of flow is fast
V - Speed of flow is slow
What is one feature that veins have that arteries do not?
VALVES
What are 5 features of capillaries?
Carry blood at low pressure within tissues
Carry both oxygenated and deoxygenated blood
Have walls that are one cell thick
Have ‘leaky’ walls
Speed of flow is slow
How is an artery adapted to its function?
Have thick muscular walls containing elastic fibres to withstand 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
How is a vein adapted to its function?
Have a large lumen as blood pressure is low
Contain valves to prevent the back-flow of blood as it is under low pressure
How is a capillary adapted to its function?
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
What happens to arteries as they get further away from the heart?
As arteries divide more as they get further away from the heart, they get narrower
What are arterioles?
The narrow vessels that connect arteries to capillaries are called arterioles
What happens to veins as they get further away from the heart?
Veins also get narrower the further away they are from the heart
What are venules?
The narrow vessels that connect capillaries to veins are called venules
What does the cardiovascular system sometimes need to do during exercise or when we are hot?
Sometimes the cardiovascular system needs to redistribute the blood to specific areas of the body
Why does the cardiovascular system needs to redistribute the blood to specific areas of the body during exercise?
More of it goes to the working muscles and less of it goes to other body organs such as the digestive system
Why does the cardiovascular system needs to redistribute the blood to specific areas of the body when we are hot?
When we are hot, more blood flows through the surface of the skin and when we are cold less blood flows through the surface of the skin
What is the redirection of blood flow caused by?
This redirection of blood flow is caused by the use of a vascular shunt vessel
What can shunt vessels do?
The shunt vessels can open or close to control the amount of blood flowing to a specific area
What is the vein carrying blood from the lungs to the heart called?
Pulmonary vein
What is the artery carrying blood from the heart to the body called?
aorta
What is the artery carrying blood from the heart to the liver called?
hepatic artery
What is the artery carrying blood from the heart to the gut (intestines) called?
Mesenteric artery
What is the artery carrying blood from the heart to the kidneys called?
renal artery
What is the vein carrying blood from the kidneys to the heart called?
renal vein
What is the vein carrying blood from the liver to the heart called?
hepatic vein
What is the vein carrying blood from the body to the heart called?
vena cava
What is the vein carrying blood from the gut (intestines) to the liver called?
Hepatic portal vein
What is the artery carrying blood from the heart to the lungs called?
pulmonary artery
What can happen as a result of the capillary walls being so thin?
The walls of the capillaries are so thin that water, dissolved solutes and dissolved gases easily leak out of them / pass through the walls from the plasma into the tissue fluid surrounding the cells
What is the purpose of the tissue fluid?
Cells exchange materials (such as water, oxygen, glucose, carbon dioxide, mineral ions) across their cell membranes with the tissue fluid surrounding them by diffusion, osmosis or active transport
What happens to the excess fluid surrounding the capillaries?
More fluid leaks out of the capillaries than is returned to them, and this excess of leaked fluid surrounding the capillaries then passes into the lymphatic system, becoming lymph fluid
What is the lymphatic system?
The lymphatic system is formed from a series of tubes which flow from tissues back to the heart
What does the lymph system connect with? Why?
It connects with the blood system near to the heart, where lymph fluid is returned to the blood plasma
What are lymph nodes?
Lymph nodes are small clusters of lymphatic tissue found throughout the lymphatic system, especially in the neck and armpits
What is found in lymph nodes?
Large numbers of lymphocytes are found in lymph nodes
What produces lymphocytes?
Tissues associated with the lymphatic system, such as bone marrow, produce these lymphocytes
What is the role of lymphocytes?
Lymphocytes play an important role in defending the body against infection
What does blood contain? (4)
Blood consists of red blood cells, white blood cells, platelets and plasma
What is the structure of red blood cells?
Biconcave discs containing no nucleus but plenty of the protein haemoglobin
What is the structure of white blood cells?
Large cells containing a big nucleus, different types have slightly different structures and functions
What is the structure of platelets?
Fragments of cells
What is the structure of plasma?
straw coloured liquid
What is the role of white blood cells?
White blood cells are part of the body’s immune system, defending against infection by pathogenic microorganisms
What are the two main types of white blood cells?
There are two main types, phagocytes and lymphocytes
What do phagocytes do?
Carry out phagocytosis by engulfing and digesting pathogens
- How do phagocytes detect pathogens?
Phagocytes have a sensitive cell surface membrane that can detect chemicals produced by pathogenic cells
- What do phagocytes do once they encounter a pathogenic cell?
Once they encounter the pathogenic cell, they will engulf it and release digestive enzymes to digest it
How can phagocytes be recognised? (using a microscope)
They can be easily recognised under the microscope by their multi-lobed nucleus and their granular cytoplasm
What do lymphocytes do?
Produce antibodies to destroy pathogenic cells and antitoxins to neutralise toxins released by pathogens
How can lymphocytes be recognised? (using a microscope)
They can easily be recognised under the microscope by their large round nucleus which takes up nearly the whole cell and their clear, non-granular cytoplasm
Why is plasma important?
Plasma is important for the transport of carbon dioxide, digested food (nutrients), urea, mineral ions, hormones and heat energy
What is the role of red blood cells?
Red blood cells transport oxygen around the body from the lungs to cells which require it for aerobic respiration
In what form do red blood cells transport oxygen?
They carry the oxygen in the form of oxyhaemoglobin
What is the role of white blood cells?
White blood cells defend the body against infection by pathogens by carrying out phagocytosis and antibody production
What is the role of platelets?
Platelets are fragments of cells which are involved in blood clotting and forming scabs where skin has been cut or punctured
Why is blood clotting important?
Blood clotting prevents continued / significant blood loss from wounds
Why is scab formation important?
Scab formation seals the wound with an insoluble patch that prevents entry of microorganisms that could cause infection
For how long do scabs remain?
It remains in place until new skin has grown underneath it, sealing the skin again
- What happens when the skin is broken?
blood clotting
When the skin is broken (i.e. there is a wound) platelets arrive to stop the bleeding
- Where do the series of reactions involved in blood clotting take place?
A series of reactions occur within the blood plasma
- What types of chemicals do platelets release? What do these chemicals do?
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
- What happens to the clot once the process is over?
The clot eventually dries and develops into a scab to protect the wound from bacteria entering
What is the circulatory system?
The circulatory system is a system of blood vessels with a pump and valves to ensure one-way flow of blood.
Fish have a single circulatory system. What does this mean?
This means that their heart only has two chambers (consisting of an upper atrium and a lower ventricle), and
blood passes through the heart only once on its circuit around the body.
Why do fish not have lungs?
Oxygen is absorbed as blood
passes the gills, thus fish do not have lungs.
Describe the pathway of blood with the single circulatory system in fish.
Heart → gills → body → heart.
Mammals have a double circulatory system. What does this mean?
This means that for every one circuit of the body, the blood passes through the heart twice. This means that the mammalian heart must have four chambers to keep oxygenated and
deoxygenated blood separate.
What is the purpose of the right side of a mammalian heart?
The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs (the pulmonary circulation).
What is the purpose of the left side of a mammalian heart?
The left side of the heart receives oxygenated blood from the lungs and pumps it to the body (the systemic circulation).
What is the advantage of a double circulatory system?
Double circulatory systems can maintain a higher blood pressure which increases the speed at which the blood flows so nutrients can be delivered and waste can be removed more quickly.
In what direction from the heart is blood pumped in arteries and veins?
Blood is pumped from the heart in arteries and returns to the heart in viens.
How can heart activity be monitored?
Heart activity can be monitored by using an ECG, measuring pulse rate, or listening to the sounds of valves closing using a stethoscope.
How are heart rate/ pulse rate and breathing rate measured?
Heart rate (and pulse rate) is measured in beats per minute.
Breathing rate can be measured by counting the number of breaths per minute.
State the effect of physical exercise on heart rate.
Physical exercise increase heart rate.
Explain the effect of physical exercise on heart rate.
When physical activity is carried out, muscles respire to release energy for movement. Aerobic respiration requires oxygen, thus the heart rate
speeds up so that blood is pumped around the body more quickly, allowing more oxygen to be delivered to respiring tissues and removing the carbon dioxide quickly.
What is coronary heart disease?
Coronary heart disease is caused by a buildup of cholesterol in the coronary artery which narrows the artery thus limiting blood flow to the heart.
What are the five common risk factors for coronary heart disease?
Poor diet ( too much-saturated fat and cholesterol).
Poor lifestyle (lack of exercise, smoking, obesity, stress).
Age - as you get older the risk of getting coronary heart disease increases.
Gender - males are more likely.
Genetic disposition.
Reducing the risks of developing coronary heart disease:
Diet - reduce animal fats, salty foods and stop drinking and smoking and eat more fruits and vegetables.
Exercise regularly - exercise can reduce the risk of CHD, as it increases the blood supply to the heart and reduces cholesterol levels.
Explain the relative thickness of the muscle walls of the left and right ventricles.
The wall of the left ventricle is much thicker than the right side, as it must be able to pump blood at high pressure around the entire body, rather than just to the lungs.
Explain the relative thickness of the muscle walls of the atria compared to those of the ventricles.
The ventricles need to pump blood at a higher pressure to pump it out and round the body and to the lungs whereas the atria only need to pump the blood to the ventricles (a shorter distance) so do not need to generate as high of a pressure.
Explain the importance of the septum in separating oxygenated and deoxygenated blood.
The left and right sides of the heart are separated by the septum, which makes sure that oxygenated and deoxygenated blood remains separate.
What is the function of the heart (step-by-step)?
Deoxygenated blood coming from the body flows into the right atrium via the vena cava
The right atrium contracts and blood moves through a one-way valve (tricuspid valve) to the right ventricle.
The ventricle contracts and blood exits the heart through a one-way valve (semilunar valve) to the lungs via the pulmonary artery.
Blood becomes oxygenated in the lungs and then returns to the heart via the pulmonary vein, entering the left atrium.
The left atrium contracts and blood moves through a one-way valve (bicuspid valve) into the left ventricle.
The left ventricle contracts and oxygenated blood exits the heart past the semilunar valve through the aorta (artery) and travels around the body, becoming deoxygenated.
Give the summarized functioning of the heart.
Vena cava → Right atrium → Right ventricle → Pulmonary artery → Lungs → Pulmonary vein → Left atrium → Left ventricle → Aorta → The body.
State the name of the main type of tissue that forms the wall of the heart.
Cardiac muscle.
What is the circulatory system made up of
Blood
Blood vessels
Heart
Valves that make sure the blood is flowing in the right direction
What does double circulatory system mean?
The blood passes through the heart twice on one complete circuit of the body.
Where is a double circulatory system found?
All mammals and in birds and reptiles
What does a single circulatory system mean?
The blood passes through the heart only once on a complete circuit
Which animal has a single circulatory system?
Fish
What is the function of the heart?
To pump blood around the body.
What is the heart made of?
It is made of a special type of muscle called cardiac muscle which contracts and relaxes
What are the two upper chambers called?
Atria
What are the two lower chambers called?
Ventricles
What separates the two sides of the heart?
The septum
What contracts first and what happens?
The walls of the atria and force blood into the ventricles
What contracts after the atria?
The ventricles and they send blood to the arteries
What do valves do?
They prevent blood flowing backwards during or after heart contractions
What is the heart muscle supplied with?
Food and oxygen by the coronary arteries
Where does the pulmonary vein come from?
The lungs
Where does the vena cava come from?
The rest of the body
Where does the aorta go?
Takes the blood around the body
Where does the pulmonary artery go?
To the lungs
Name the two blood vessels on the right side of the heart
vena cava and pulmonary artery
Name the two blood vessels on the left side of the heart
aorta and pulmonary vein
Why does the artery have a thick layer of muscle?
To withstand high pressure
What is the function of the atria?
Atria receives blood and supply it to the ventricles
What is the function of the ventricles?
Ventricles pump blood out of the heart and around the body. Ventricles have much thicker more muscular walls than the atria.
What is the pressure of the right ventricle?
Low pressure as it pumps to the lungs
What helps the left ventricle pump blood?
The thick wall of muscle as it has to pump blood around the body.
What are atrioventricular valves?
Valves that separate each atrium from the ventricle
What is the valve called on the left side of the heart?
Bicuspid valve
What is the valve called on the right side of the heart?
Tricuspid valve
What happens to the valves when the ventricles contract?
The pressure of the blood pushes the valves upwards. The tendons attached to them stop from going up too far.
What valves are found in the pulmonary artery and the aorta?
Semi-lunar valves
Describe the blood flow
Blood from the body- vena cava- right atrium-tricuspid valve-right ventricle-pulmonary semi lunar valve- pulmonary artery- lungs -pulmonary veins-left atrium-bicuspid valve-left ventricle-aortic semi lunar valve- aorta- body
What is the average bpm?
60 to 75
What instrument allows you to hear the heartbeat?
the stethoscope
What causes the sound of the heart beating?
Valves closing
first lub sound is from the valves that separate the atria and ventricles
second dub sound is from the valves at the entrance of the aorta and pulmonary artery
What is systole?
The heart muscle contracting, becoming smaller and pushing blood out
What is diastole?
The muscles relax becomes larger and blood flows in.
What causes a pulse?
The expansion and relaxation of an artery caused by the heart pushing blood through it.
How can you record the activity of the heart in a hospital?
ECG- electrocardiography- little electrodes stuck onto a person’ body
Why does the heart beat faster during exercise?
Muscles require oxygen for respiration in order to release energy.
What is coronary heart disease?
When a healthy coronary artery is narrowed by atheroma so blood flow is restricted. The heart muscle is deprived of glucose and oxygen and toxins such as lactic acid builds up.
Risk factors that increase the likelihood of developing CHD
a diet full of cholesterol, saturated fats, sugar
tobacco cigarettes
being a man
inherited genetic heart disease
drinking excessively
too much stress raises blood pressure
How can someone with CHD be treated?
Regular does of aspirin which prevents the formation of blood clots
What is a stent?
A little mesh tube inserted in the artery to keep it open
In terms of surgery, how can you prevent CHD?
stent
angioplasty
coronary bypass operation
What is angioplasty?
A tiny balloon is inserted and inflated using water to push the artery open
What is coronary bypass operation?
Severely damaged coronary artery can be replaced with a length of blood vessel taken from another part of the body
How can you prevent CHD?
Avoid smoking
intake of nitroglycerin
diet low in sugar and saturated fat
exercising a few times a week- aerobic and strength training
no excessive consumption of alcohol
blood pressure under control
How does smoking increase the likelihood of getting CHD?
Smoking increases the formation of plaque in blood vessels and may be blocked with a clot.
What are the main blood vessels in the heart?
Vena Cava,
aorta
pulmonary artery
pulmonary vein
What are the main blood vessels in the lungs?
Pulmonary artery and pulmonary vein
What are the main blood vessels in the kidney?
Renal artery and renal vein
What are the main blood vessels in the liver?
Hepatic artery and hepatic portal vein
What is tissue fluid?
The fluid leaking out of capillaries
Why do capillaries leak?
Their cells in their walls do not fit together. Plasma can leak out from the blood. WBC can also get through these gaps. RBC cannot get out.
What does tissue fluid supply cells?
Oxygen and nutrients which diffuse from the blood
Waste products diffuse in the opposite direction
What drains into the lymphatic capillaries?
tissue fluid
What is lymph?
The tissue fluid that drains into the lymphatic capillaries
What do lymphatic capillaries join up to be?
They form larger lymphatic vessels which carry lymph to the subclavian veins
What are subclavian veins?
They bring blood back from the arms.
Describe the structure of lymph vessels
They have valves
Describe the movement of lymph
Moves slower than blood.
What are lymph nodes?
Where lymphocytes are stored
Where are lymphocytes released?
Into the lymph to eventually reach the blood system
What are the functions of lymphatic system?
Return fluid to heart
Helps large molecules enter the blood
immune surveillance
What is the function of the artery?
Carries oxygenated blood away from the heart
What is the structure of the arteries?
Thicker outer wall
Thicker layer of muscle and elastic fibres
What is the width of the arteries lumen?
Relatively narrow- it stretches and recoils
How does the structure fit the arteries function?
Thick walls withstand high blood pressure
rings of muscle control the blood flow in it according to the body’s need
What is the structure of the capillaries?
very thin- one cell thick
What is the function of the capillaries?
Takes nutrients, oxygen and other materials to the cells and take away waste materials
What is the width of the capillaries lumen?
Very small
How does the structure fit the capillaries function?
thin walls all blood to have close contact with body tissues
substances diffuse into and out due to thin walls
What is the function of the veins?
Carries deoxygenated blood from the tissues to the heart
What is the structure of veins?
Quite thin- contain less muscle and elastic tissue
What is the veins width of lumen?
Wide central tube and has valves
How does the structure fit the veins structure?
Large diameter and thin walls reduce resistance to the flow of blood. They have valves in order to prevent back flow
few muscle and elastic fibers because there is low blood pressure
What is the structure of plasma?
Straw colored liquid- mostly water
What is the structure of the red blood cells?
Contain hemoglobin to carry oxygen
biconcave shape to provide a large surface area for diffusion of oxygen
No nucleus to provide space\
small size means they can go through capillaries
What is the structure of white blood cells?
Variable shapes with nucleus
Sensitive cell surface membrane to detect easily microorganisms
What is the structure of platelets?
Cell fragments with no nucleus
What is the function of plasma?
Transport co2
Transport nutrients
Transport urea
Transport hormones
Transport heat
Transport proteins
Transport antibodies
What is the function of the red blood cells?
Transport oxygen
prepare carbon dioxide for transport
What is the function of white blood cells?
Fight and remove pathogens by
releasing antibodies
engulfing microorganisms
What is the function of platelets?
Convert fibrinogen to fibrin. Fibrin forms a mesh that traps blood. Important in blood clotting and scab formation.
Advantages of double circulatory system
Blood flow loses pressure in mammal’s lungs so this low pressure blood is delivered to heart to raise the blood pressure again. This increases speed at which oxygen and nutrients are supplied.
What is the purpose of clotting?
Prevent excess blood loss
Prevent the entry of pathogens
What are veins
Veins carry blood towards the heart under low pressure and velocity
The arteries that branch out into smaller vessels are called …
arterioles
The veins that branch out into smaller vessels are called …
venules
What are capillaries
Capillaries are very small vessels linking to the arterioles and the venules. They branch out many times and lie in the tissues of the body, amongst the cells. They have a very small diameter but the walls are thin.
It is here that diffusion of substance occurs between blood and the fluid which surrounds the cells.
What colour is oxygenated blood usually represented as ?
Red.
It is actually dark red
What colour is deoxygenated blood usually represented as?
Blue.
It is actually a light red
What are the lymphatic vessels for?
The fluid that inevitably leaks out of thin walled capillaries is collected by the lymphatic vessels and eventually drains back into the bloodstream
What are arteries
Arteries carry blood away from the heart under high pressure and velocity
Pulmonary is to do with …
Lungs
Hepatic is to do with ..
Liver
Renal is to do with ..
Kidneys
What is the lumen
The space inside a blood vessel
What is the structure of an artery
Round shape
Thick outer wall
Thick layer of muscle + elastic fibres (so that it can recoil and doesn’t burst)
Smooth lining
Small lumen
What is the structure of a vein
Misshapen
Fairly thin outer wall
Thin layer of muscle & elastic fibres
Smooth lining
Large lumen
What is the structure of a capillary (all cells are very close to a capillary)
Very small lumen
Wall made of a single layer of cells (so that diffusion happens quickly and easily)
Why do we need a circulatory system
To ensure all cells have fresh nutrients and that waste products are removed
What are the 3 main components of the circulatory system
Heart
Blood
Blood vessels
All mammals have a double circulatory system. What does this mean?
For every complete circuit of the body, the blood passes through the heart twice
Coronary is to do with …
The heart
What are the two types of white blood cells?
Lymphocytes and phagocytes
Describe a phagocyte (appearance)
Weirdly shaped,
Lobed nucleus
Grainy cytoplasm (sacks of enzymes that digest materials/pathogens taken into the cell)
How do lymphocytes work?
Lymphocytes produce specific antibodies to fight particular pathogens. The antibody slots into the pathogen in a lock and key way. Lymphocytes remember which antibodies to produce so if the pathogen returns it can be fought off quickly as the lymphocyte will produce them quickly
How do phagocytes work?
Phagocytes ingest pathogens and then digest them
What does blood contain?
Red blood cells, white blood cells, platelets and plasma
Why do larger organisms have respiratory systems e.t.c but unicellular organisms don’t
Larger organism need help with diffusion because their volume to surface area ration is smaller
What are the three main components of the circulatory system?
Heart, blood and blood vessels
Hepatic vein and artery are connected to what?
The liver
What does the hepatic portal vein connect?
The ileum to the liver
What do the renal vein and artery connect to?
The kidneys
What are the two vena cavas?
Vena cava from head
Vena cava from body
Why is the circulatory system called a double circulatory system?
It passed through the heart twice.
What does plasma do?
Plasma is a straw-coloured liquid. It transports dissolved substances around the body, including:
hormones
nutrients, such as water, glucose, amino acids, minerals and vitamins
waste substances, such as carbon dioxide and urea
Red blood cells
Adaptions of red blood cells
Flexible membrane
Dip in middle gives a high surface area to volume ratio so lots of exchange sites
No nucleus so can keep more haemoglobin which carries oxygen
How do vaccinations work?
A damaged or dead virus is injected into the body. It results in the manufacturing of memory cells which enables future antibody production to the pathogen to occur sooner, faster and in greater quality
Platelets are involved in blood clotting. Why do we need blood clots?
Prevents blood loss and entry of microorganisms into the body
Process of blood clotting?
Damage platelets which starts a series of reactions, fibrinogen (made in liver, present in plasma. Large protein) goes to fibrin (insoluble thread which form clots)
FIBRINOGEN TO FIBRIN
General points in arteries
Arteries carry blood away from the heart
Carry oxygenated blood (except pulmonary artery)
Arteries tend to be deeper in the body for protection (blood loss from a would in an artery would be fatal as there is high pressured blood)
General points about veins
Veins carry blood towards the heart
Carry deoxygenated blood (except pulmonary vein)
Veins near the surface of the skin. Appear blue but the blood they carry is actually dark red
What muscle contracts and releases to make pump blood around the body
The heart
What is the valve found between the right atrium and right ventricle
Tricuspid
The valve found between the left atrium and left ventricle is the
Bicuspid
What are the four chambers of the heart
Left ventricle and left atrium, right ventricle and right atrium
What general term is sometimes used to describe both the sets of valves?
Atrioventricular valves
What stops the valves being turned inside out when the ventricles contract
Tendons supporting the valves
What general term describes the valves found just inside the aorta and pulmonary artery
Semilunar
What is the function of the semilunar valves
To keep the blood flowing in the right direction
What factors could lead to heart disease
Blockages in cardiac/coronary blood supply caused by fatty deposits and can also occur in other blood vessels.
Lifestyles like lack of exercise can lead to obesity, as well as a poor diet (high in fat) smoking and Gentiles diseases.
What factors could change heart rate
Heart rate can change during exercise and the influence of adrenaline
Why is cardiac muscle special?
It never tires and contracts and relaxes regularly throughout life
What is the heart made of
Cardiac muscle
Describe the structure of arteries:
The relative thickness of the wall.
The diameter of the lumen.
Blood type and exceptions.
The pressure of blood.
Have thick muscular walls containing elastic fibers.
Have a narrow lumen to maintain high pressure.
Carry oxygenated blood (other than the pulmonary artery).
Carry blood at high pressure away from the heart.
Describe the structure of veins:
The relative thickness of the wall.
The diameter of the lumen.
Blood type and exceptions.
The pressure of blood.
Have thin walls.
Have a large lumen as blood pressure is low.
Contains valves.
Carry deoxygenated blood (other than the pulmonary vein).
Carry blood at low pressure towards the heart.
Describe the structure of capillaries:
The relative thickness of the wall.
The diameter of the lumen.
Blood type and exceptions.
The pressure of blood.
Have walls that are one cell thick.
Very small lumen.
Carry both deoxygenated and oxygenated blood.
Carry blood at low pressure within tissues.
What are the functions of capillaries?
Capillaries are thin blood vessels that are used to exchange substances with tissues, such as oxygen, carbon dioxide, and other nutrients.
Explain how the structure of the capillaries is related to their function.
Capillaries have walls that are one cell thick and have a small lumen too keep short diffusion distances so substances can easily diffuse in and out of them
Capillaries have a large area and are branched.
Explain how the structure of arteries is related to the pressure of the blood that they transport.
Have thick muscular walls containing elastic fibers to withstand the high pressure of blood.
Explain how the structure of veins is related to the pressure of the blood that they transport.
Contain valves to prevent the backflow of blood as it is under low pressure.
What carries blood back towards and away from the heart?
Towards heart: Vena cava, Pulmonary vein.
Away from heart: Aorta, Pulmonary artery.
What carries blood back towards and away from the heart from the liver?
Towards heart: Hepatic vein.
Away from heart: Hepatic artery.
Takes blood from digestive system to liver: Hepatic portal vein.
What carries blood back towards and away from the heart from the lung?
Towards heart: Pulmonary artery.
Away from heart: Pulmonary vein.
What carries blood back towards and away from the heart from the kidney?
Towards heart: Renal artery.
Away from heart: Renal vein.
List the components of blood.
Red blood cells.
White blood cells.
Platelets.
Plasma.
What is the structure of a red blood cell?
Biconcave discs containing no nucleus for more space for the red pigmented protein hemoglobin.
What is the structure of a white blood cell?
Large cells containing a large/lobed nucleus.
What is the structure of platelets?
Small fragments of cells.
What is the structure of plasma?
The liquid in blood vessels which contains blood cells, ions, soluble nutrients, hormones, water and carbon dioxide.
What is the function of red blood cells?
Red blood cells transport oxygen around the body from the lungs to cells that require it for aerobic respiration.
What is the function of white blood cells?
White blood cells defend the body against infection by pathogens by carrying out phagocytosis and antibody production.
What are the two types of white blood cells?
Lymphocytes.
Phagocytes.
What is the function of platelets?
Platelets are involved in helping the blood clot.
What is the function of plasma?
Plasma is important for the transport of waste products, soluble nutrients, mineral ions, hormones, and heat energy.
What are the roles of blood clotting?
Blood clotting prevents blood loss and the entry of pathogens.
Define phagocytosis.
The process by which a phagocyte (a type of white blood cell) engulfs and destroys pathogens.
What are the functions of lymphocytes and phagocytes?
Lymphocytes - antibody production.
Phagocytes - engulfing pathogens by phagocytosis.
What is the process of clotting?
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.
What is the purpose of blood clotting?
Blood clotting prevents continued / significant blood loss from wounds.
Prevents entry of microorganisms that could cause infection.
circulatory system
a system of blood vessels with a pump (the heart) and valves that ensure the
one-way flow of blood.
Single Circulation
Fish have single circulatory systems. In such systems, blood passes through the
the heart only once in one complete circulation.
Double circulation
This means that blood flows through
the heart twice in one complete circulation
mammals have a
double circulatory system
how does deoxygenated blood entering the right ventricle reach the lungs
Deoxygenated blood enters the right atrium
and is then pumped to the lungs, where it is oxygenated. It then returns to the left
and is then pumped around the body
Double circulatory systems transport
substances faster than
single ones
septum
prevents the mixing of oxygenated and deoxygenated blood, maintains high blood pressure
Order of thickness
1)Left ventricle
2)Right ventricle
3)Atria
The left ventricle
pumps blood the furthest (all around the body), so thickest walls.
The right ventricle
pumps to the lungs, closer to the heart
Atria
pump only within the heart, so the wall is the least thickest
All chambers of the heart relax,
and
blood flows into the heart.
Atria contract and ventricles are
relaxed,
blood moves into
ventricles
Atrioventricular valves close,
preventing backflow into the
atria
After the atria relax, the
ventricles contract
pumping
blood into arteries
Semilunar valves then close,
preventing backflow into the
ventricles
Heart rate can be monitored using an
electrocardiogram (ECG) , pulse rate, and hearing the sound of the valves opening and closing
During exercise
muscles require more energy from respiration to contract.
Therefore the heart beats faster. As a result, arteries dilate (widen), increasing blood flow.
This results in:
● Increase in supplies of O 2 and glucose
● Increase in the removal of CO 2
pulse rate.
The number of heartbeats in a minute
Resting pulse rate
gives an idea of a person’s
fitness. Always link to oxygen debt, lactic acid, and anaerobic respiration
Coronary arteries transport
blood to these heart muscles,
heart muscles
require O 2 and glucose for respiration.
Coronary heart disease (CHD
The narrowing of coronary arteries as a result of excess cholesterol sticking to the wall is known as atherosclerosis. Artery walls become rough and platelets in the blood clot block the vessel, forming a thrombosis. A total thrombosis of the coronary artery means that no oxygen gets to the heart muscles,and the heart stops beating altogether. This is known as cardiac arrest
causes of CHD
high cholesterol diet, a lack of exercise, smoking, and stress
factors that make CHD unavoidable
genetic predisposition, age, and gender
CHD Treatment
❖ Coronary artery bypass
➢ An artery from another part of the body (arms or legs) is taken and attached above and below the
blocked area. Several grafts may be required if it is a serious case.
❖ Angioplasty - A balloon is inflated to widen the artery, and a stent holds it in place
❖ Aspirin - thins the blood
important arteries and veins in the heart
Heart -> Coronary artery -> heart muscles -> coronary vein -> heart
important arteries and veins in lungs
Heart -> pulmonary artery -> lungs -> pulmonary vein -> heart
important arteries and veins in liver
Heart -> aorta -> hepatic artery -> liver -> hepatic vein -> vena cava -> heart
important arteries and veins in the kidney
Heart -> aorta -> renal artery -> kidneys -> renal vein -> vena cava -> heart
important arteries and veins in the small intestine
Heart -> aorta -> mesenteric artery -> small intestine -> hepatic portal vein -> liver -> hepatic vein -> vena cava -> heart
3 types of blood vessels
1) arteries
2) veins
3) capillaries
arteries structure
● Thick, muscular wall consisting
of muscles and elastic tissues allowing it to stretch and recoil
● Narrow lumen, to maintain high blood pressure
arteries function
● To withstand blood pressure,
preventing bursting of the blood vessel
● Ensuring the one-way flow of blood
veins structure
● Thin walls with little fibrous and muscular tissue
● wider lumen to transport large volumes of blood
● Contain valves to prevent backflow of blood
veins function
● Necessity for a thick wall is
gone as blood pressure has
been lost
● Less resistance to blood flow
● Valves prevent backflow
CAPILLARIES structure
● One cell thick walls
● Narrow enough for one RBC to
get through only
capillaries function
● Reduce substances’ diffusion
distance
● Vessels can squeeze around
every cell in the body
Arterioles
branches of arteries, which allows the transport of blood to all parts of the body
Venules
branches that connect to veins, which receive ‘used’ blood from all parts of the body
Shunt vessels
vessels that direct blood directly from an artery to a vein
circulatory system
system of blood vessels with a pump and valves to ensure one-way flow of blood.
In single circulation of fish
The blood passes through the heart once for one
complete circuit. It moves from the heart to the gills and then to the rest of the body.
Mammals have double circulatory system
One pulmonary loop and one systematic
loop happens in mammals. Blood passes through the heart twice for one complete
circuit.
Advantage of double circulation
high(er), blood pressure / flow rate (than single circulation) ;
allows different blood pressure in each loop ;
prevent mixing of oxygenated and deoxygenated blood ;
allows animals to have high metabolic rates ;
allows animals to be, large / tall ;
Blood is pumped away from the heart in
arteries and returns to the heart in veins.
ECG, pulse rate and listening to
sounds of valves closing.
ECG, pulse rate and listening to
sounds of valves closing.
Coronary heart disease is the blockage of
coronary arteries
diet, lack of exercise, stress, smoking, genetic predisposition, age and sex.
diet, lack of exercise, stress, smoking, genetic predisposition, age and sex.
helps to reduce the risk of coronary heart disease
Balanced diet and exercise,They
reduce stress, lower blood pressure, make heart muscles stronger.
Atria
receives blood from either the lungs or the body and supply it to the ventricles. The ventricles pump blood out of the heart and all around the body. So pressure applied by the ventricles must be high. To help them do this, the ventricles have much thicker, more muscular walls than the atria.
The right ventricle
pumps blood to the lungs, which are very close to the heart
The left ventricle,
however, pumps blood to the rest of the body. The left ventricle has an
especially thick wall of muscle to enable it to do this.
Septum
separates oxygenated and deoxygenated blood in the heart.
As physical activity increases heart rate increase because
muscles contract more.
Muscles require more energy. More aerobic respiration takes place. More oxygen is
required. More blood is required to be transported to muscles for more oxygen.
Heart beats faster to supply more oxygen to the muscles.
Arteries:
Have thick walls
The diameter of lumen is small
No valves are present
Veins
Have relative thin walls
Diameter of lumen is large
Valves are present to prevent back flow of blood.
Blood pressure in arteries is
high because it has just been forced out of the heart by
the contraction of muscles of the ventricles. Arteries need very strong walls to
withstand this high pressure.
Blood in arteries doesn’t flow smoothly, it
pulses through. When ventricles contract
pressure in arteries is high and when ventricles relax pressure in arteries is reduced.
Arteries have elastic tissues in their walls which can stretch and recoil with the force
of the blood making the blood flow smoother.
Capillaries
very small and penetrate to every part of the body so that they can reach every cell.
The function of the capillaries is to
take nutrients, oxygen and other materials to all the
cells in the body, and to take away their waste materials. To do this, their walls must
be very thin so that substances can get in and out of the capillaries easily.
Veins function
return blood to the heart.
veins adaptation
Walls of veins (muscle and elastic tissue) are thin because there is no need for
strong walls as most of the blood pressure has been lost.
They have a wide lumen because it offers less resistance to blood flow.
Contain valves, that prevent backflow of blood.
Components of blood are
red blood cells, white blood cells, platelets and plasma
Red blood cells function
transporting oxygen. Haemoglobin is present in RBC and it combines with oxygen transports it.
White blood cells function
phagocytosis and antibody production
Platelets function
clotting
Plasma function
transport of blood cells, ions, nutrients, urea, hormones and
carbon dioxide
The roles of blood clotting are
preventing blood loss and prevent entry of pathogens.
Lymphocytes have
one big nucleus which covers almost the entire cell. Phagocytes
have a nucleus that divides into small connected balls.
Function of lymphocytes
is antibody production
