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The cardiovascular system - Coggle Diagram
The cardiovascular system
Structure
Vena cava
- transports deoxygenated blood from the body to the right atrium - inferior and superior
Right atrium
- top chamber of the heart that holds deoxygenated blood
Tricuspid valve
- stops the blood flowing back into the right atrium
Right ventricle
- bottom chamber that holds deoxygenated blood
Semilunar valve
- stops the blood flowing back into the right ventricle
Pulmonary artery
- transports deoxygenated blood from the heart to the lungs
Pulmonary vein
- transports oxygenated blood from the lungs to the heart
Left atrium
- top chamber of the heart that holds oxygenated blood
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Functions
Delivering oxygen and nutrients
- delivers the nutrients and oxygen to the tissues of the body. During exercise the demand for oxygen increases the blood will deliver this oxygen
Removing waste products - carbon dioxide and lactate
- transports waste products to the kidneys and liver. Also returns Co2 to the lungs. During exercise lactate and Co2 increases
Fighting infection
- white blood cells are produced in bone marrow and stored in blood. Ingest pathogens and destroy them. Produce antibodies that destroy pathogens
Clotting blood
- platelets in blood gather together to cut and stick together they plug the wound and stop bleeding
Thermoregulation
- responsible for the distribution of heat within body. Maintains body temperature and ensures you don't overheat. Uses vasodilation and vasoconstriction
Vasoconstriction
- narrows the diameter of the blood vessels near the skin. Reduces the blood flow resulting in and increase in temperature as the heat loss is prevented
Vasodilation
- widens the diameter of the blood vessels near the skin. Increases the blood flow resulting in an increase in temperature as heat is carried to the skins surface
Nervous control of the cardiac cycle
Sinoatrial node (SAN)
- often known as the hearts pacemaker. The SAN sends an impulse to the right atrium causing the muscular walls to contract. Contraction forces blood from the atrium down into the ventricles
Atrioventricular node (AVN)
- located between the atria and ventricles. Acts as a buffer that slows down the signal from the SAN. Allows the ventricles to fill with blood before contraction
Bundle of his and purkinje fibres
- bundle of his is a specialist muscle cell that transports the impulses from the AVN. Found in the walls of the ventricles. Impulse travels down the bundle of his to the purkinje fibres that allows the ventricles to contract causing the blood to be pushed out of the heart
Sympathetic and parasympathetic nervous system
- during exercise the heart rate increases, controlled by the parasympathetic and speeds up the heart rate. After exercise the heart rate slows down and this is controlled by the parasympathetic nervous system
Short term exercise
Anticipatory rise in heart rate prior to exercise
- heart rate increases prior to a sports match or event due to a release of adrenaline, know as an anticipatory rise. Preparing the body for the increased demands that are about to be put on the body
Increased heart rate
- heart rate increases due to the rise in carbon dioxide picked up by the chemoreceptors. An increase in heart rate is needed due to increase in demand for oxygen
Increased cardiac output
- cardiac output = stroke volume x heart rate. Stroke volume = amount of blood ejected from the heart per beat. Heart rate = how many times the heart beats per minute. Cardiac output = amount of blood pumped from the heart in one minute. When exercising the demand for oxygen increases, therefore heart rate, stroke volume and cardiac output increases
Increased blood pressure
- blood pressure increases during exercise as more blood is pumped through the blood vessels. Blood pressure = the pressure of the blood against the walls of your arteries. Blood pressure has two readings - 12/80 systolic and diastolic. Systolic - top number, the pressure on your artery wall when the heart contracts. Diastolic - bottom number, the pressure on your artery when the heart relaxes
Redirection of blood flow
- blood is directed where its needed the most, when exercising the blood is needed for the working muscles the blood vessels will vasodilate to allow this extra blood flow
Adaptations
Cardiac hypertrophy
- where the walls of the heart gets thicker, increases the strength of its contractions
Increase in resting and working stroke volume
- more blood can pump per beat. More blood means that more oxygen can be transported to the working muscles during exercise
Decrease in resting heart rate
- as the heart is bigger and can pump more blood per beat, the heart does not have to work as hard which results in reduced resting heart rate
Reduction in resting blood pressure
- training reduces blood pressure, this reduces the risk of heart disease and strokes. Exercise keeps our blood vessels healthy
Capillarisation of skeletal muscle and alveoli
- exercise increases the capillarisation both around the muscle and alveoli. More oxygen and nutrients can be diffused into the blood from the alveoli and into the muscles
Increased blood volume
- training increases blood volume this is mainly due to capillarisation through training. Allows more oxygen and nutrients to be delivered around the body. Body temperature can also be regulated more efficiently
Additional factors
Sudden arrhythmic death syndrome (SADS)
- a heart condition that can cause sudden death. It is usually caused by an irregular heart beat (cardiac arrhythmia). There are often no clear symptoms and when people participate in strenuous exercise, even though they appear fit and healthy can die due to SADS
High blood pressure
- the pressure exerted on the arteries. High blood pressure can be a risk factor for heart disease and stroke. Low blood pressure can be dangerous, symptoms include dizziness, lightheadedness, nausea and fainting. High blood pressure is called
hypertension
. Low blood pressure is called
hypotension.