Cardiovascular System Flashcards
Explain the flow of blood in the Right side
Deoxygenated blood enters the vena cava then the right atrium past the tricuspid valve into the right ventricle past the semi-lunar pulmonary valve into the pulmonary artery to the lungs. The blood is then oxygenated during gaseous exchange. This is the pulmonary circuit
Explain the flow of blood in the Left side
Oxygenated blood enters the pulmonary vein then the left atrium past the bicupsid valve into the left ventricle past the semi-lunar aortic valve into the aorta to the body. This is the systemic circuit
Details about the Tricuspid valve
Prevents back flow of blood into the right atrium
Details about the Vena cava
Transports deoxygenated blood from the body to the right atrium
Details about the Pulmonary artery
Transports deoxygenated blood to the lungs to become oxygenated during gaseous exchange
Details about the Semi-lunar pulmonary valve
Prevents back flow of blood into the right ventricle
Details about the Semi-lunar aortic valve
Prevents back flow of blood into the left ventricle
Details about the Pulmonary vein
Carries oxygenated blood from lungs to the left atrium
Details about the Right ventricle
Contracts to pump deoxygenated blood to the lungs
Details about the Aorta
Carries oxygenated blood from the left ventricle to the body
Details about the Left atrium
Receives oxygenated blood from the pulmonary vein
Details about the Left ventricle
Contract to pump oxygenated blood into the aorta
Details about the Bicuspid valve
Prevents back flow of blood into the left atrium
Details about the Right atrium
Receives deoxygenated blood from vena cava
What is Cardiac output?
The volume of blood pumped out the heart per minute
What is the resting value for Cardiac output?
4000-6000ml or 4-6l
Formula for Cardiac output
Stroke volume x Heart rate
What is Stroke volume?
The volume of blood pumped out the left ventricle per beat
What is the resting value for Stroke volume?
60-80ml per beat
Explain why the Stroke volume of a trained athlete is different to an untrained individual
Trained athlete has…
- Stronger cardiac muscle
- Improved venous return
- More blood in the left ventricle
- Increased elasticity of ventricles
- Increased ejection fraction
What is Heart rate?
The amount of times the heart beats per minute
What is the resting value for Heart rate?
60-80 beats per minute
Formula for max Heart rate
220 - age
Explain why an untrained individual has a higher resting Heart rate
- Weaker cardiac muscle
- Less hypertrophy
- Lower venous return
- Lower stroke volume
What is Stroke volume dependant on?
Venous return as increasing stroke volume increases venous return
What can help Venous return?
Pocket valves in veins = prevent the back flow of blood
Vein placement = muscle squeezes on veins
Increased blood flow back to heart = faster removal of waste products
Changes to Heart rate during exercise
Before - anticipatory rise due to release of adrenaline
During - increases as demand for more oxygen
During - oxygen demand meets supply
After - removal of waste products
Structure of Veins
- Large lumen
- Thin muscular walls
- Thin tunica media
- Contains valves
Function of Veins
Carries blood at the lowest pressure and contains pocket valves to assist the blood flow. They carry blood back into the heart.
Structure of Arteries
- Thick muscular walls
- Thick tunica media
- Small lumen
Function of Arteries
Carries blood at the highest pressure away from the heart. Their walls extend and recoil to withstand the pressure.
Structure of Capillaries
- 1 cell thick = short diffusion distance
- Tunica intima only
- Very small lumen
- Single layer of cells
- No muscular walls
Function of Capillaries
Blood pressure here is low so diffusion can take place enabling oxygen , carbon dioxide and nutrients to pass into cells
Details about Pocket valves
- Formed from tunica intima
- Prevents back flow of blood
- As blood moves through the veins the valve opens and as blood flow slows or stops the valve then closes until the flow increases again
Details about Respiratory pump
- Breathing helps to increase the flow of blood back to the heart
- Breathing in causes pressure inside your thoracic cavity to decrease and pressure inside your abdominal cavity to increases as the diaphragm contracts
Details about Vein placement
- Located in muscles or between muscle and bone
- As the muscle contracts it squeezes the vein so is a good way of returning venous blood back to the heart
Function of Arterioles
Connects arteries to capillaries and have muscular walls to help carry blood away from the heart
Details about Veinules
Connects capillaries to viens and are smaller versions of veins without valves. They receive blood from capillaries at low pressure
What is Blood?
The body’s mean of transporting substances around the body
What does Blood transport?
- Carbon dioxide
- Oxygen
- Materials like hormones
- Nutrients and minerals
- Waste products
What are the 4 components of blood?
- Red blood cells
- White blood cells
- Plasma
- Platelets
Details about White blood cells
- Fight infections
- Bigger than red blood cells
- Large nuclei
- Produced in bone marrow
- Stored in the blood
- Acts as body’s defence system
- Identify , destroy and remove pathogens
- Produce antibodies to fight the infection
Details about Plasma
- Liquid that transports blood cells and nutrients
- Blood cells and platelets are suspended in plasma
- Plasma consists of 90% water, inorganic salts, glucose, antibodies, urea and other waste products and plasma proteins
Details about Red blood cells
- Transport oxygen around
- Disc shapes so large surface area
- Produced in the marrow
- Oxygen is carried by a protien called haemoglobin which is a red coloured compound
- Also carries carbon dioxide out of the body
- Haemoglobin can also bind with oxygen forming oxyhaemoglobin
Details about Platelets
- Aid in blood clotting
- Prevent blood loss by repairing tissue and closing wounds
- Formed in red bone marrow
- Yellow
- Can grow into irregular shapes and stick together to form a plug over wounds
- Produce thrombokinase which is needed for the clotting process
Structure of Arterioles
- Thick walls
- Large diameter
- Tunica media has elastic fibres and smooth muscle
- Smooth muscle contracts to reduce size of lumen (vasoconstriction) and relaxes to increase its width (vasodilation)
What do Arterioles do during exercise?
Vasodilate to the working muscles and vasoconstrict to non essential organs such as the gut
Role of Pre capillary sphincters
Regulate the flow of blood into the capillaries
- Dilate to the working muscles
- Constrict to non essential organs e.g. gut
What is the Vascular shunt mechanism?
The redistribution of blood during exercise
- Arterioles vasodilate to the working muscles and vasoconstrict to non essential organs such as the gut
- Pre capillary sphincters dilate to the working muscles and constrict to non essential organs e.g. gut
Explain Vasoconstriction and what it results in
The diameter of the blood vessel narrows which reduces the blood flow resulting in an increase in temp as heat loss is prevented
Explain Vasodilation and what it results in
The diameter of the blood vessel near the skin widens which increases the blood flow resulting in a decrease in temp as heat is carried to the skins surface
Short term effects
- Increases cardiac output
- Increases stroke volume
- Increases heart rate
- Increases blood temp
- Increases blood pressure
- Vasoconstriction and Vasodilation of arterioles
Effects of a cool down
- Keeps capillaries dilated
- Quicker removal of lactic acid
- Increases venous return which prevents blood pooling
- Gradually reduces HR , BR and BP
Effects of a warm up
- Increases cardiac output
- Increases stroke volume
- Increases heart rate
- Increased blood flow to muscles so more oxygenated blood
- Activates VSM
- Increases venous return
Long term effects (positive and negative)
Positive
Stronger heart
• Myocardial hypertrophy
• Thicker left ventricle walls
• More blood can be pumped to working muscles during exercise
• Increased stroke volume
• Increased cardiac output
Lower resting heart rate
• Bradycardia
• Lower working heart rate
• Faster HR recovery after exercise
Increased capillarisation
• More oxygen to muscles/tissues
• Increased gaseous exchange
• More efficient vascular shunt mechanism
• Improved vasodilation/vasoconstriction
Increased number of red blood cells
• More haemoglobin
• Increased haematocrit levels
• More oxygen can be transported to muscles
• Reduced blood viscosity
• Increase in plasma levels
• More white blood cells so less illness
Lowers blood pressure
• Reduced risk of high blood pressure
• Systolic/diastolic pressure lower
• Reduced cholesterol
• (Cholesterol/plaque) lines walls of blood vessels reducing blood flow
• Prevent hardening of artery walls
Reduced risk of cardiovascular disease
• Coronary Heart Disease (CHD)
• Heart attack/myocardial infarction
• Angina / strokes
Negative
Too much exercise can put increased strain on heart
• Cardiac hypertrophy can be dangerous
• Heart attack
• Arrhythmia
• Sudden cardiac death
• Often linked to genetic factors
Exercise at higher temperatures can cause thickening of blood
• Increased blood viscosity
• Increasing blood pressure
• Due to dehydration
lifting heavy weights causes greatest strain on heart
• Causes highest blood pressure readings
• Ruptured blood vessels
Importance of health screening before starting exercise programme
• Medical check-up
• Regular ECG/
• Principles of training correctly applied
