Cardiovascular System Flashcards
What does the cardiovascular system consist of?
Heart, blood vessels and blood
What is the function of the cardiovascular system?
To transport important substances around the body EG oxygen and glucose
What is the function of the heart?
To pump blood around the body
What type of system does the heart consist of?
A double circulatory system (blood passes through the heart twice)
What is pulmonary circulation?
Blood is pumped through the heart to the lungs and back to the heart
What Is systemic circulation?
When blood is passed through the heart for a second time (re-pressured) and to the body organs then back to the heart
What is an example of mass flow?
Blood passing through the body due to pressure difference (pressure in the heart is high and pressure in the blood vessels is low)
Define myogenic
Myogenic means it can beat/contract without any nervous stimulation. Is also able to depolarise/generate own electrical impulses.
What is an example of myogenic?
The heart (cardiac muscle is myogenic)
State the four chambers
Right atrium, right ventricle, left atrium and left atrium
Describe the blood flow through the right side of the heart
Deoxygenated blood enters through the inferior and superior vena cava into the right atrium. The pressure increases and the blood passes through the tricuspid atrioventricular into the right ventricle. The pressure builds and the blood passes through the semi-lunar valve into the pulmonary artery to the lungs.
Describe the blood flow through the left side of the heart
Oxygenated blood enters through the pulmonary vein into the left atrium. When sight pressure builds up the blood passes through the bicuspid atrioventricular into the left ventricle. Pressure builds again and the blood passes through the semi-lunar valve into the aorta then to the whole body.
Which side of the heart has thicker walls?
Left (left ventricle)
Which side of the heart requires higher pressure and why?
The left side requires higher pressure as the blood is transported all around the body (needed to travel longer distance than right side)
What is cardiac output?
The volume of blood expelled from the left ventricle per minute
What is stroke volume?
The volume of blood expelled from the left ventricle on one cardiac cycle (heart beat)
What is heart rate?
The number of cardiac cycles (heart beats) per minute
What is the calculation formula for cardiac output?
Cardiac output (dm3 min-1) = stroke volume x heart rate
What is the name of the node that initiates electrical impulses?
Sinoatrial node (SAN)
What is the name of the node that picks up the electrical impulses after 0.1 sec delay?
Atrio-ventricular node (AVN)
What prevents the electrical signal from passing to the ventricles and why?
Insulating connecting tissue so the atria and ventricles don’t contract at the same time
Wave of __________ spreads through both atria causing the atria walls to contract simultaneously
Depolarisation
Where does the electrical signal pass through before the ventricles contract?
Down the bundle of his (in the septum) then into the purkinje fibres where the ventricle walls then contract
What is the structure of the arteries?
Thick walls, narrow lumen, many muscle, elastin fibres, large amount of elastin and outer layer of fibrous protein
What is the structure of the capillaries?
Wall only has endothelial layer (one cell thick), lumen is small and pores which allow diffusion
What is the structure of veins?
Large lumen, thin muscle and elastic layer, semi-lunar valves
What are the adaptations of arteries?
•The arteries have thick walls to withstand high pressure
•They have muscle and elastin fibres to withstand high pressure from the left ventricle
•large amounts of elastin to allow pulsation
What are the adaptions of capillaries?
•very thin walls to increase the rate of diffusion
•numerous and branched to increase the overall surface area
• narrow diameter to ensure the red blood cells touch the wall (reduces distance for diffusion
What are the adaptations of veins?
•Thinner walls as the blood is under low pressure
•Large lumen to give low resistance
•Thin muscle and elastin layers as there is no need for contractions and wall won’t need to stretch and recoil
•Semi-lunar valves to prevent back flow
Name all the blood groups
A+, A-, B+, B-, AB+, AB-, O+, O-
What does ECG stand for?
Electrocardiogram
how is atherosclerosis formed
When there is build up of plaque overtime which reduce the blood flow
What are the causes of atherosclerosis
•obesity as you’re not able to exercise
•smoking as the nicotine can the heart rate and carbon monoxide can impact how much oxygen haemoglobin carries
•high cholesterol can cause this as having high levels of LDL can cause a build up
What are the treatments of atherosclerosis
•statins as they lower the levels of cholesterol meaning that plaque is less likely to build up
What are the risk factors of CVD
•age as you get older the risk of CVD increases
•Gender males are at a higher risk of dying of CVD than women, however women have a higher risk after menopause due to lack of oestrogen production
•diet consumption of high levels of salt, cholesterol and limited consumption of healthy fats increases risk of CVD
Treatments of CVD
•statins are medications which are taken to lower cholesterol levels in blood as high cholesterol can lead to build up of plaque
•beta blockers lower blood pressure
•calcium channel blockers lowers blood pressure
Why Heart transplant
This is given as the final option to ensure survival.
Disadvantage of heart transplant
•infection as immunosuppressants are given to prevent rejection but they weaken the immune system making you more vulnerable to infection
•rejection as your body can mistake it as foreign so attack it
What does the p wave represent
Wave of depolarisation through atria and contraction (atrial systole)
What does the QRS wave represent
Wave of depolarisation in ventricles and contraction (ventricular systole)
What does t wave represent
Wave of repolarisation in ventricles so they relax (ventricular diastole)
Trachycardia
When that heart rate is fast and the p waves are evenly spread but closer than should be
Bradycardia
When the heart rate is slow and the p waves are evenly spread out but further apart than they should be
Ventricular fibrillation
Is when the ventricles contract with out control and when the ventricles fibrillate little to no blood is being pumped from the heart
Sinus arrhythmia
When heart rate cycles with breathing. The heart rate increases when you breathe in and decreases when breathe out
What is the function of the coronary artery
To supply oxygen rich blood to the heart muscle
Beta blockers advantage and disadvantage
Advantage: safer during pregnancy, can be used if you do not respond to other drugs
Disadvantage: can cause cold hands and feet, nausea, and nightmares
Calcium channel blockers advantages and disadvantages
Advantage: effective for those who are 55 or older
Disadvantage: not suitable for those with a history of heart and lung disease. And can cause dizziness, tiredness, headaches
What can immunosuppressants cause
Weakens your immune system which makes you more vulnerable to infection.
Kidney problems, high blood pressure and diabetes
Cardiac muscle
•Cardiac muscle is striated and resembles skeletal muscle but the fibres are less wide
•the heart muscle is connected by intercalated discs which allow the swift transmission of impulses
•the cardiac muscle needs Ca2+ ions for contraction
•although the heart is myogenic the heart has a conductionsystem to coordinate the contraction of the muscles
Effect of caffeine in heart rate
Caffeine increases the heart rate by increasing the electrical activity in the SAN node. It also increases the rate of contraction and relaxation and increases the volume of blood pumped out at every heart beat
How does a centrifuge separate the blood
It spins the blood which separates the blood in to plasma, WBC and platelets and RBC
What is in the plasma
90% water and rest amino acids, glucose, vitamins etc
What is the risk of blood transfusion
infection
Transfusing wrong blood
Reaction of blood
