LO1 The Cardiovascular System Flashcards
What is the blood made up of?
55% Plasma
4% White blood cells and platelets
41% Red blood cells
What are white blood cells also known as?
Leucocytes
Which molecules do plasma carry?
- Electrolytes
- Proteins
- Hormones
- Glucose
- Urea
- Vitamins and minerals
What is plasma good for?
- 90% of plasma is made up of water, making it good for transportation as other molecules can dissolve within it very easily
What are leucocytes (white blood cells) responsible for?
- they are responsible for identifying and fighting off infection that enters the body in the form of bacteria, viruses or fungi.
What are the 3 types of leucocytes (white blood cells)?
Neutrophils - ‘they are the ‘first response’ to infection. They recognise and engulf bacteria and fungi, then die and living only a few hours at a time. This process is called phagocytosis. Pus is made up of collections of dead neutrophils.
Monocytes - fight off bacteria, viruses and fungi, but last longer than neutrophils. They help to clear up dead cells from the bloodstream.
Lymphocytes - produce antibodies, fight viruses and destroy cancerous cells by producing ‘b-cells’ and ‘t-cells’
What is the structure of leucocytes (white blood cells)?
- Contain a nucleus
What is the function of erythrocytes (red blood cells)?
- filled with hemoglobin, used to transport oxygen and carbon dioxide from the lungs to all other tissues within the body
What is the structure of erythrocytes (red blood cells)?
- made inside bone marrow
- Biconcave shape
- no nucleus
- they have a large surface area to allow these gases to move in and out of the cell
- very flexible meaning they can move around narrow capillaries to deliver oxygen to body tissues
What are platelets?
- cell fragments that are responsible for travelling to and repairing damaged blood vessels (arteries, veins and capillaries)
- don’t have a nucleus
What is the function of platelets?
- they work alongside fibrinogen (a protein found in plasma) to deal damaged blood vessels
- the platelets detect a tear in the vessel wall and travel to the area. They react with the collagen in the torn vessel wall and become sticky. The fibrinogen fibers act as a mesh and pull the wound together forming a clot.
What is fibrinogen?
a protein found in plasma
What is the internal temperature of humans and mammals? Why does it need to be maintained?
- 37 degrees Celsius
- Needs to be maintained so the chemical functions within cells can work properly
What are the four functions of the blood?
- transporting and exchanging molecules
- temperature regulation
- prevents infections
- blood clotting
How does the blood transport and exchange molecules?
- blood is taken from the arteries to the capillaries to allow the exchange of substances
- when it reaches the capillaries, the high pressure causes pressure filtration which results in plasma passing through the capillary wall into covering all the cells in the body tissue.
What is the bloods function for regulating temperature
- The chemical reactions within cells generate heat so the blood disperses it and redistributes it round the body
How is blood tissue formed?
when the blood reaches the capillaries, the high pressure causes pressure filtration which results in plasma passing through the capillary wall into covering all the cells in the body tissue, which becomes blood tissue
What does the blood and blood vessels do when we are too hot?
- blood vessels widen
- blood gets sent to the skin surface so that heat can escape which is why we look red
What does the blood and blood vessels do when we are too cold?
- blood vessels constrict
- more blood is kept further within the body which is why we look pale
What is the bloods function for preventing infections?
- pathogens contain antigens which are recognised by neutrophils and lymphocytes, which will produce antibodies
- they target the pathogen and break it down so monocytes can attack them
- lymphocytes remember the code for making these antibodies so they can be used again
What is the bloods function for blood clotting?
- the vessel will constrict to slow down blood flow
- platelets gather at the site of injury, creating a plug to stop blood leaking, a process known as coagulation
- the tear in the vessel wall reacts with the platelets making them sticky
- fibrinogen forms a mash the traps the platelets and blood cells
- this then pulls the wound together to close the vessel wall
What is the pulmonary circulation?
the blood circulation to and from the lungs
RIGHT side of the heart
What is systematic circulation?
the blood circulation to and from the body
LEFT side of the heart
What does the circulatory system ensure?
The circulatory system ensures a continuous flow of blood to all cells - without this, cell death can occur which is why diseases of the cardiovascular system system have consequences for all body systems.
What does the right side of the heart do?
Carries DEOXYGENATED blood to the LUNGS
What does the LEFT side of the heart do?
Carries OXYGENATED blood to the cells and tissues in the rest of the body
What are the two top chambers of the heart called?
Atrium
What are the two bottom chambers of the heart called?
Ventricles
What does the pulmonary vein do?
Brings oxygenated blood from lungs to LEFT atrium of the heart
What does the inferior and superior vena cava do?
Brings deoxygenated blood to RIGHT atrium
What does the pulmonary artery do?
Takes deoxygenated blood from RIGHT ventricle to lungs
What does the aorta do?
Takes oxygenated blood from LEFT ventricle to other organs
What does the coronary artery do?
Hearts own oxygenated blood supply from aorta
What does the tricuspid valve do?
Prevents blood flowing back into the right atrium from right ventricle
What does the pulmonary arterial (semi lunar) valve do?
Located at the entrance of pulmonary artery allows blood flow out the heart but not back in
What does the bicuspid (mitral) valve do?
prevents blood flowing back into left atrium from left ventricle
What does the aortic (semi lunar) valve do?
located at the entrance of the aorta allows blood to flow out of the heart but not back in
How does the structure of the atrium enable the function of the heart?
Atriums are less muscular as they receive blood returning from the body under lower pressure
What is the function of valves?
Valves prevent backflow of blood in various areas of the heart including from the atria to ventricle and entrance to aorta/pulmonary artery
How does the structure of the right ventricle enable the function of the heart?
Right ventricle is less muscular than the left to prevent blood entering the lungs under too much pressure, which would cause the lungs to become flooded
How does the structure of the heart and its blood supply enable the function of the heart?
The heart has its own oxygenated blood supply through the pulmonary artery which provides it with nutrients and oxygen for cellular activity
What is the main function of the heart?
To pump blood throughout the body
True or False: The heart is a muscle.
True
Fill in the blank: The heart has __ chambers.
4
What are the four chambers of the heart called?
Atria and ventricles
What is the purpose of the atria in the heart?
To receive blood
What is the purpose of the ventricles in the heart?
To pump blood out of the heart
What is the name of the valve between the left atrium and left ventricle?
Bicuspid valve
What is the name of the valve between the right atrium and right ventricle?
Tricuspid valve
What is the name of the valve between the left ventricle and aorta?
Aortic valve
What is the name of the valve between the right ventricle and pulmonary artery?
Pulmonary valve
True or False: The heart pumps oxygen-rich blood to the lungs.
False
True or False: The heart pumps oxygen-poor blood to the body.
False
What is the name of the blood vessels that carry blood away from the heart?
Arteries
What is the name of the blood vessels that carry blood back to the heart?
Veins
What is the name of the blood vessels that connect arteries and veins?
Capillaries
What is the purpose of the coronary arteries?
To supply blood to the heart muscle
True or False: The heart is responsible for regulating blood pressure.
True
What is the name of the electrical system that controls the heart’s rhythm?
Cardiac conduction system
What is the name of the natural pacemaker of the heart?
SA node (sinoatrial node)
What is the name of the part of the heart that has deoxygenated blood from the body and pumps it to right ventricle?
Right atrium
What is the name of the part of the heart that contains oxygenated blood and pumps it out to where?
Left ventricle pumps oxygenated blood to the aorta
What is the name of the condition where the heart is unable to pump enough blood to meet the body’s needs?
Heart failure
Fill in the blank: The heart contracts and relaxes in a coordinated manner called __.
Cardiac cycle
What is the name of the process where the heart fills with blood?
Diastole (relaxed)
What is the name of the process where the heart pumps blood out?
Systole (contracted)
What are arteries?
These are blood vessels that transport blood AWAY from the heart
What are the three layers of an artery?
- Outer = fibrous tissues made of collagen
- Middle = smooth muscle elastic fibres
- Inner = a layers of cells called the endothelium - the ‘lining’ of the artery
What is the inner part of the vessel?
Lumen
Describe the walls of an artery?
thick and muscular
How does the structure of an artery help it to form its function?
- The thick muscular walls contract to push the blood along to where it is needed
- This means the blood is travelling at high pressure
What are arterioles?
- Smaller arteries that eventually link up to capillaries
- The muscle in the arterioles is thinner which lets the arterioles diameter be precisely controlled and allows the pressure to be maintained in them
What are veins?
-They are vessels that carry blood TOWARDS the heart
Do veins have wider lumen than arteries?
Veins have a wider lumen than arteries and because there is less muscle in the walls, the blood travelling through them is at low pressure.
Does veins have valves?
Yes
What is the sinoatrial node?
- located in the upper wall of the right atrium near the opening of the vena cava
- generates an electrical impulse which causes the muscle of the heart to contract
- It also ensures the heart beats in a regular rhythm
- known as the ‘pacemaker’
Where can the atrioventricular node be found?
At the top of the wall of muscle that separates the two ventricles
What does the atrioventricular node do?
Acts like a turnstile that briefly delays the electrical current coming from the AV node so the atria have time to empty and the ventricles have time to fill up with blood before they contract
How does the SA node impulse pass through the AV node?
- The impulse from the SA node passes through the AV nodes and then across the walls of the ventricles via purkinje fibres.
- These carry the current down to the base of the heart, causing it to contract from the bottom up, meaning the blood is pushed up and out of the ventricle
What is the P wave?
The SA node is triggered. Electrical depolarisation of atria occurs meaning atrial contraction and emptying the blood into ventricles
What is the PR interval in the ECG graph?
AV node delays the signal to allow ventricles fillings
What is the QRS spike in an ECG graph?
heart is in systole (contracted) as ventricles are contracting as they push blood up and out pulmonary artery/aorta (high pressure)
What is the T wave in an ECG graph?
heart is in diastole (relaxed) as ventricles relax and expand repolarising
What does an ECG tell us?
- which part of the heart is malfunctioning, as it looks for abnormal signs
- records the electrical signal in the heart
What is the pressure called that forces blood plasma out of the capillary?
hydrostatic pressure
What is osmosis?
passage of water from high concentration to a low concentration through a semi-permeable membrane
Explain the lymphatic system process?
- hydrostatic pressure forces water out of the capillary
- proteins are too large to leave the capillary with the water
- water in the plasma goes into tissue fluid leaving behind proteins.
- the capillary has a high concentration of proteins and a low concentration of water
- this creates osmotic pressure
- water is attracted back into capillary one it has offloaded oxygen and nutrients, and picked up carbon dioxide and waste
- once water has left, 10% of the tissue fluid remains. This is taken out of the cell by then lymphatic system and drains into lymph vessels
What is lymph?
a clear, colourless stick fluid that runs through the lymphatic vessels, lymph nodes, contains high numbers of lymphocytes
What does lymph contain?
Lymph contains a high number of white blood cells (lymphocytes), which fight infection and destroy damaged or abnormal cells
What is the function of the coronary arteries?
supply blood to the heart
What is a coronary bypass?
a surgical procedure that improves blood flow to the heart by creating a new rout around the blocked or narrowed coronary arteries
What is the liquid part of the blood?
plasma
Which is a cell that transports oxygen in the blood?
erythrocyte
Which is the largest type of white blood cells that helps to prevent infection?
neutrophil
Which is a cell fragment important in the clotting of blood?
platelet
What is the role of hydrostatic pressure in the formation of tissue fluid?
forces water and dissolved substances into surrounding tissues
What is the role of the atrioventricular node?
delays impulses to allow time for atria to empty blood into the ventricles
What is the role of the purkyne fibres?
specialised cardiac muscles that transits impulses through ventricle walls
What is the role of the sinoatrial node?
initiates contraction of heart muscle, it’s known as the ‘pacemaker’
