Created by Kyra Wilson
over 6 years ago
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Question | Answer |
cardiovascular system | |
The composition of blood | Blood is composed of cells (erythrocytes, leucocytes and platelets) and plasma. Blood is the transport vehicle for electrolytes, proteins, gases, nutrients, waste products and hormones. |
Composition of blood | -Transports nutrients, oxygen, carbon dioxide, waste products and hormones to cells and organs around the body. -Protects us from bleeding to death, via clotting, and from disease, by destroying invasive micro-organisms and toxic substances. -Acts as a regulator of temperature, the water content in cells, and body pH. |
Erythrocytes | Make up 40-45% of the blood volume known as hematocrit. Contain an oxygen-carrying pigment called haemoglobin, which gives blood its red color. |
leucocytes | White blood cells <1% of blood volume, primarily involved in immune fuction and protecting body from infection. They do this by ingesting foreign microbes in a process called phagocytosis. |
Platelets | <1% of blood volume. Assist in the provess of repair following an injurt |
The anatomy of the heart (4 chambers) | 4 chambers.. Right atrium Right ventricle Left atrium Left ventricle |
The anatomy of the heart (process) | Superior vena cava Right atrium Tricuspid valve Right ventricle Pulmonary valve Pulmonary artery Lungs (deoxygenated gets oxygenated) Pulmonary veins Left atrium Mitral valve Left ventricle Aortic valve Aorta |
Autonomic Nervous System | Responsible for control of involuntary or visceral bodily functions. The atonomic nervous system comprises of the sympathetic system and the parasympathetic system. The sympathetic system stimulates the heart to beat faster. The parasympathetic system returns the heart to its resting rate. The cardiac control centre controls these two systems. The cardiac control system is located in the medulla oblongata of the brain. |
Sympathetic Nervous System | Sympathetic system stimulates the heart to beat faster; due to multiple factors. During exercise, 3 receptors are stimulated; proprioceptors, baroreceptors, chemoreceptors. The receptors send impulses (action potentials) to the cardiac control centre (medulla oblongata), which then sends an impulse through the sympathetic nervous system to stimulate the SA node of the heart where the heart rate increases. |
Parasympathetic Nervous System | When exercise stops, the receptors pick up decreases in co2 levels, blood pressure and muscle movement; hence impulses are sent to the cardiac control centre (medulla oblongata). An impulse is sent to the parasympathetic nervous system which stimulates the SA node and heart rate decreases. |
Hormonal Control | Adrenaline and noradrenaline are stress hormones Released by adrenal glands Exercise causes stress induced adrenaline response which results in: Stimulation of SA node, which results in increased speed and force of contraction. Increase in blood pressure due to constriction of blood vessels. Increase in blood glucose levels (glucose is used by muscles for energy) |
Pulmonary circulation | is the portion of the cardiovascular system that carries oxygen-depleted blood away from the heart and to the lungs and then returns it, oxygenated, back to the heart. |
Systematic circulation | is the portion of the cardiovascular system that carries the oxygenated blood away from the heart and delivers it to the body. It also carries the deoxygenated blood after use back to the heart to be re-oxygenated. |
relationship between heart rate, cardiac output and stroke volume at rest and during exercise | cardiac output = stroke volume x heart rate |
Stroke volume- exercise | increases according to how you exercise because your body needs more oxygen and nourishment, which are both received from the blood. increases depending on the type of physical activity your are doing and your training level. during an upright physical activity like jogging, stroke volume increases from about 50 mL at rest to 120 mL at maximal exercise intensity. In a trained Olympic runner, stroke volume can increase from 80 mL at rest to 200 mL during maximal exercise intensity as the heart pumps more efficiently. |
Cardiac Output-- exercise | because stroke volume increases, cardiac output increases simultaniously with the increase in heart rate and the body beings to work harder |
cardiovascular drift | An increase of body temperature results in a lower venous return to the heart, a small decrease in blood volume from sweating. A reduction in stroke volume causes the heart rate to increase to maintain cardiac output. Blood viscosity, if the blood is thinker and more viscous, it makes it more difficult to be returned back (up gravity) to the heart to pick up more oxygen |
Venus Return Mechanism | |
Systolic blood pressure | the force exerted by the blood on the arterial walls during ventricular contraction |
diastolic blood pressure | the force exerted by the blood on the arterial walls during ventricular relaxation |
Static Exercise | Why does Systolic blood pressure increase? Volume of blood + contraction rate a larger amount of blood is being pumped through the arteries with each contraction; Why does Diastolic blood pressure increase? The pressure on the arterial walls is increased even during relaxation The vasoconstriction creates an increase in pressure Muscles squeeze the veins to promote venous return, by doing so increases pressure During static exercise, breathing is more constricted, there is less oxygen and more carbon dioxide, the heart must work harder to pump the blood it does have to supply the muscles with sufficient oxygen to continue the static exercise |
Dynamic Exercise | Why does Systolic blood pressure increase at a lower rate? the breathing frequency is much higher than in static exercise, therefore the pressure is not as high as during static exercise Why does Diastolic blood pressure remain the same? muscles are moving constantly, no added pressure on constant contraction you are constantly breathing, which allows carbon dioxide to be quickly expelled arteries are dilated as vasodilation is occurring |
Distribution of blood at rest and the redistribution of blood during exercise | |
Heart Adaptation | The myocardium (muscular tissue of the heart) increases in thickness - The left ventricles internal dimensions increase |
Stroke Volume | The increase in size of the heart enables the left ventricle to stretch more and thus fill with more blood. - The increase in muscle wall thickness also increases the contractility resulting in increased stroke volume at rest and during exercise, increasing blood supply to the body |
Resting Heart Rate | As the stroke volume increases the cardiac output can remain constant, therefore enabling the resting heart rate to be lower. |
Cardiac Output | - Cardiac output increases exponentially during maximal exercise, because of increases stroke volume. - This results in a greater oxygen supply, waste removal and hence improved endurance performance. |
Muscular Adaptations | - increased capillarization of the trained muscles. - improvements in the vasculature efficiency |
Blood | - resting blood pressure decreases as a result of improved cardiovascular factors. - increase in blood plasma - red blood cell volume and haemoglobin |
maximal oxygen consumption | Fitness can be measured by the volume of oxygen you can consume while exercising at your maximum capacity. VO2 max is the maximum amount of oxygen in milliliters, one can use in one minute per kilogram of body weight. Those who are ‘fitter’ have higher VO2 max values and can exercise more intensely than those who are not as well conditioned. |
the variability of maximal oxygen consumption in selected groups | Numerous studies show that you can increase your VO2 max by working out at an intensity that raises your heart rate to between 65 and 85% of its maximum for at least 20 minutes three to five times a week. |
Factors affecting VO2 max | The physical limitations that restrict the rate at which energy can be released aerobically are dependent upon: the chemical ability of the muscular cellular tissue system to use oxygen in breaking down fuels the combined ability of cardiovascular and pulmonary systems to transport the oxygen to the muscular tissue system |
Ideal VO2 max scores for various sports |
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