Cardiovascular System Flashcards
What is the role of plasma?
Transports dissolved substances
What is the role of erythrocytes (RBC’s)?
Carries oxygen and some carbon dioxide
What is the role of leukocytes (WBC’s)?
Helps destroy bacteria
What is the role of thrombocytes (platelets)?
Triggers blood clotting
What are antibodies?
Proteins made by the immune system
What is urea?
Poisonous waste product from protein
What do leukocytes (WBC’s) contain?
Neutrophils - b-type cells that produce antibodies
Lymphocytes - t-type cells that destroy viruses and cancer cells
Monocytes - remove dead cells and bacteria
Where does blood transport materials?
Either erythrocytes (RBC’s) or plasma
What do erythrocytes (RBC’s) have?
Iron-containing protein called haemoglobin
What substances dissolve in plasma?
Glucose, amino acids and hormones
What is the body made of and what does it do?
Millions of chemical reactions which are regulated by enzymes
Produces heat, eg muscle tissues
What must the core temperature of the body be?
37 degrees celsius
Why can the core temperature not be any more or less?
The enzymes breakdown ‘denature’ at high temperatures, and slow down at low temperatures
What happens if it is too hot?
The skin blood vessels widen (vasodilate) and lose heat
What happens if it is too cold?
The skin blood vessels narrow (vasoconstrict) and save heat
How can you exchange materials in body tissues?
Using your cardiovascular system
How do materials exchange?
Between blood and tissues by diffusion
Define diffusion
When you go from a high concentration to a low concentration
How many litres of blood do we have (estimated)?
5 litres
If you lose _ litres it may lead to death.
2
How do platelets help broken skin heal and prevent pathogen access?
Convert soluble fibrinogen -> insoluble fibrin -> process called coagulation (turning liquid to gel)
This then forms a net-like structure -> traps platelets and erythrocytes (RBC’s) -> forms clot and seals broken skin
What is the reason of erythrocytes (RBC’S) being small?
It lets red blood cells pass through narrow capillaries
What is the reason of erythrocytes (RBC’s) having a flattened disc shape?
It provides a large surface area, which allows rapid diffusion of oxygen
What is the reason of erythrocytes (RBC’s) containing haemoglobin?
Haemoglobin absorbs oxygen in the lungs and releases oxygen in the rest of the body
What is the reason of erythrocytes (RBC’s) not containing a nucleus?
It increases the amount of space inside of the cell for haemoglobin
What is atheroma (atherosclerosis)?
This is when the walls of the coronary arteries become blocked with fatty deposits - a process called atherosclerosis
What are the symptoms of angina?
Breathlessness, nausea, dizziness, chest pain/tightness - can spread to arms, neck and jaw
How do heart attacks (myocardial infarction) happen?
When the arteries become completely blocked, it can lead to a heart attack which can permanently damage the heart muscle and lead to death
3 types of CHD (Coronary Heart Disease)
Atheroma
Angina
Heart attack
Risk factors for CHD
Increasing age
Family history
Lack of exercise
High dietary salt intake
Being overweight/obese
Smoking and alcohol
What medications can help atheroma?
Statins - cholesterol lowering medicine
What medications can help angina?
Nitrates - relaxes the coronary arteries, which allows more blood to reach the heart muscle
What medications can help a heart attack?
ACE inhibitors - lowers blood pressure, making heart attacks less likely
Aspirin - an anti platelet medicine which makes blood less likely to clot, reducing risk of heart attack
What monitoring/treatment can you get for CHD?
Angiogram - type of x-ray where dye is injected into the blood so narrowing of coronary arteries can be seen
Angioplasty - a microscopic deflated balloon is passed into the narrowed artery and inflated to push it open (sometimes microscopic mesh tube ‘stent’ is inserted to keep artery open)
Coronary bypass - using a piece of artery taken from somewhere in the body to bypass/bridge a blocked region of coronary artery (allows blood to flow beyond blockage)
What are the pros and cons of coronary bypass?
Pros -
• 2-3 days in hospital
• small incision in wrist/thigh - therefore low risk of infection
Cons -
• long healing process (several months)
• can’t drive for 6 weeks
What are the pros and cons of angioplasty?
Pros -
• can drive the next days
Cons -
• doesn’t always work
• may need several procedures
What does a blood test inform an individual on linked to CHD?
Can detect LDL/HDL cholesterol and proteins in blood
What does an ECG scan inform an individual on linked to CHD?
Analyses functioning of the heart from electrical signals
What does an angiogram inform an individual linked to CHD?
Pinpoints blockages to coronary arteries by using dye in x-ray
What does a BP test inform an individual linked to CHD?
The readings indicate raised levels and risk of hypertension damage
What is an ideal blood pressure rating?
Up to 120/80mmHg
What simple measures could an individual take to minimise the possibility of developing heart disease/experiencing a stroke?
- Exercise more frequently - lack of exercise is a CHANGEABLE factor and ensures they raise their heartbeat regularly and keeps blood pressure at an ideal rating - also helps lose weight and lower blood pressure
- Reduce fat in diet - reduces risk of atheroma
- Stop smoking - reduces pressure and prevents damage to arterial walls
- Reduce alcohol intake - lowers pressure and reduces weight
- Reduce stress
What 2 numbers is blood pressure recorded with?
- Systolic pressure - when your heart pumps around the body (higher number)
- Diastolic pressure - when it is filling showing the resistance of the blood in the blood vessels (lower number)
What damages blood vessels?
Prolonged high blood pressure
What is a high blood pressure rating?
Over 140/90mmHg
- increases risk of stroke, heart attacks and kidney damage
Which structure is located in the upper wall of the right atrium of the heart?
Sinoatrial node (SAN)
Which structure is responsible for delaying the transmission of electrical impulses?
Atrioventricular node (AVN)
Which structure can be described as the ‘pacemaker’?
Sinoatrial node (SAN)
Which structure ensures that impulses are spread rapidly through the ventricles?
Purkyne fibres
Which component of blood enables clotting after an injury?
Platelets
Which component of blood carries dissolved food molecules around the body?
Plasma
Which component of blood produces antibodies to fight infection?
Lymphocytes (WBC’s)
What is the function of the coronary arteries?
It supplies oxygen and nutrients to the heart muscle
What other malfunctions (beside CHD) are there of the cardiovascular system?
- hypertension
* angina
What options are available to monitor and treat CHD? Include medical and lifestyle
To treat hypertension -
• monitoring includes blood pressure measurements and regular blood pressure checks
• treatments/lifestyle changes include regular exercise, diet changes, reduce stress, reduce alcohol intake, stop smoking and medication (beta blockers)
To treat CHD -
• monitoring includes blood tests (for cholesterol levels) and ECGs
• treatments/lifestyle changes include the same as above, except medication would be statins, and additionally surgery (bypass)
What is the main component of blood?
Plasma
Where does plasma help in the body?
Temperature regulation
What are red blood cells (erythrocytes) responsible for?
Transporting oxygen and carbon dioxide
Give 1 example of what infections white blood cells (leukocytes) prevent?
Neutrophils - engulf microorganisms
What can platelets be described as?
Cell fragments
What are platelets responsible for?
Blood clotting
How does the structure of a red blood cell allow it to transport oxygen within the body?
- small and flexible so helps them fit through narrow blood vessels
- no nucleus so that they can contain more haemoglobin (iron containing protein)
- disc shape increases the surface area for uptake of oxygen
What are coronary arteries?
They run on the surface of your heart and send smaller branches into the heart muscle
What 2 things do coronary arteries supply?
- oxygen
* nutrients
What can build up in the coronary arteries?
Lumen - a hole in the middle
A heart attack
What function of the heart takes blood from anything above your heart?
Superior Vena Cava
What function of the heart takes blood from anything below your heart?
Inferior Vena Cava
What are some differences between arteries and veins?
Arteries -
• blood is carried AWAY from the heart
• usually carries OXYGENATED blood
• blood flows QUICKLY under HIGH pressure
• blood flows in pulses
• artery walls are ELASTIC and muscular and THICK
• arteries DO NOT have valves beyond the heart
• their internal lumen diameter is NARROW
Veins - • blood is carried TOWARDS the heart • usually carries DEOXYGENATED blood • blood flows SLOWLY under LOW pressure • blood flows smoothly with squeezing action • vein walls are THIN with little muscle • veins HAVE valves to prevent back flow • their internal lumen diameter is WIDE
What side of the heart is deoxygenated?
The right side
What is the role of the pulmonary circuit?
oxygenate the blood
What is the path of blood through the pulmonary circuit?
deoxygenated blood -> pumped out -> right ventricle -> PA -> through lungs -> PV -> returns to left atrium -> oxygenated
What is the role of the systematic circuit?
Supply oxygen to all different tissues and cells in the body
Describe the path of blood through the systematic circuit
Oxygenated blood -> pumped out left ventricle -> aorta -> around body tissues and head -> vena cava -> returns to right atrium -> deoxygenated
What is meant by the heart being a ‘double pump’?
- the 2 sides beat together
- heart is a single organ but acts as a double pump
- each half pumps blood around a different circulation system
What can an ECG trace tell us about what is happening in the heart?
The waves represent the electrical activity of the heart - the P wave at the beginning shows atrial contraction. If the waves are discorded/out of rhythm it indicates which part of the heart beat is wrong.
It shows if heart rate is too slow/fast
It indicates an abnormal heart condition (heart valve conditions)
How does blood plasma become tissue fluid and lymph?
Blood plasma is forced through capillary walls (caused by hydrostatic pressure) and carries nutrients and oxygen into the tissue cell.
Once the plasma enters the cell, it is known as tissue fluid.
If the fluid stays in the cell, tissue oedema (swelling) occurs.
The majority of the fluid opes back into the capillary, with the remaining 10% draining into lymph vessels.
This fluid forms lymph.
What occurs in the heart during systole?
Muscles of ventricles contract and the blood is distributed into the body and lungs
What occurs in the heart during diastole?
Muscles of ventricles relax and blood enters the atria from the body and lungs
Identify 2 functions of the Sino Atrial (SA) node of the heart
1- receives info from accelerator and braking nerves (speeds up/slows down heart beat)
2 - ensures both atria contract simultaneously
What happens to blood plasma in the capillaries?
Forced through “leaky” capillary walls
Hydrostatic pressure (pressure from heart pumping hard)
What does the plasma carry into the tissue cell?
The fluid carries nutrients and oxygen to cells of tissues
When the plasma enters the cell it is known as ____
Tissue fluid
What happens if the fluid stays in the cell?
Tissue oedema (swelling) occurs
What % of fluid goes back into the capillary?
90%
What happens to the remaining 10%? Where does it go?
Drains into lymph vessels
What type of fluid does it form?
Lymph
What happens to this fluid?
Filtered and cleaned by WBC’s the in lymph nodes
Where does it eventually end up?
Rejoins the circulatory system
What blood vessel takes blood from the lower body into the heart?
Inferior Vena Cava
What blood vessel takes blood from the upper body into the heart?
Superior Vena Cava
What is the chamber where deoxygenated blood collects in the heart?
Right atria
What valve does deoxygenated blood go through between the top and bottom chambers that prevent backflow?
Tricuspid Valve (AV Valve)
What chamber has deoxygenated blood pumped into the lungs?
Right ventricle
What blood vessel carries blood to the lungs?
Pulmonary artery
What vessel is it that blood returns from the lungs to the heart?
Pulmonary vein
What chamber collects oxygenated blood in the heart?
Left atria
What valve is it that oxygenated blood goes through between the top and bottom chambers that prevents backflow?
Bicuspid Valve (AV Valve)
What chamber pumps oxygenated blood into the body?
Left ventricle
What is the name of the 2 sets of valves that prevent backflow of blood into the heart once pumped out?
Semi-lunar Valves
What is the blood vessel that carries blood from the heart to the body?
Aorta
What happens in the cardiac cycle during diastole?
Heart relaxes and refills
Atria fills up first and then the weight of the blood forces the AV Valves open and the ventricles then fill
What happens in the cardiac cycle during atrial systole?
Atria contract, pushing the blood down into the ventricles through the AV Valves which then close behind the blood
What happens in the cardiac cycle during ventricular systole?
Ventricles contract, pushing the blood out of the heart through the S-L Valves which prevent backflow
Outline the order that the heart’s electrical conduction system works in
Sino Atrial (SA) Node - initiates heart beat and sends to:
Atrioventricular (AV) Node - atria contracts and signal sent down to:
Bundle of His - to the:
Purkinje Fibres - causing the ventricles to contract
Where do the atria contract in and ECG trace?
The P Wave
Where do the ventricles contract in and ECG trace?
The QRS complex
Where does the heart release (diastole) in an ECG trace?
The T Wave
What is the order of flow of blood vessels leaving the heart and returning to the heart?
Heart - arteries - capillaries - veins - heart
