Term
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Definition
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Term
| The four chambers of the heart |
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Definition
| Right Atrium, Right Ventricle, Left Atrium and Left Ventricle |
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Term
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Definition
| carries blood to the lungs from the heart |
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Term
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Definition
| carries blood from the lungs to the heart |
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Term
| The wall of the left ventricle is thicker than the right |
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Definition
| because the left ventricle pumps blood all around the body whereas the right ventricle pumps blood to the lungs |
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Term
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Definition
| prevent blood flow of blood from ventricles to atria |
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Term
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Definition
| prevent back flow of blood into the ventricles from the pulmonary and aorta arteries |
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Term
| These valves close during ventricular contraction |
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Definition
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Term
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Definition
| The volume of blood expelled by each ventricle per contraction |
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Term
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Definition
| Heart rate x Stroke Volume |
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Term
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Definition
| The period of contraction of the heart during one complete heart beat |
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Term
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Definition
| The period of relaxation of the heart during on complete heart beat |
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Term
| During Atrial contraction and Ventricular diastole |
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Definition
| the atrio-ventricular valves open and the semi-lunar valves close |
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Term
| During ventricular systole and atrial diastole |
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Definition
| the atrio-ventricular valves close and the semi-lunar valves open |
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Term
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Definition
| also called the pacemaker, sets the rate at which the heart contracts |
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Term
| Auto-rhythmic cells of the SAN are found |
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Definition
| in the wall of the right atrium |
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Term
| Impulses from the SAN spreads through the muscles cells of |
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Definition
| the two atria, making them contract simultaneously (atrial systole) |
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Term
| Atrio-ventricular node (AVN) is located |
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Definition
| near the base of the atria |
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Term
| Impulses received by the AVN pass into |
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Definition
| a bundle of conducting fibres which divide into left and right branches into each ventricular wall causing ventricular systole |
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Term
| Ventricular systole occurs slightly later than atrial systole |
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Definition
| allowing for the ventricles to fill completely before they contract |
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Term
| An Electrocardiogram (ECG |
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Definition
| detects electrical currents which have been produced by impulses from the SAN which spread through the ventricle |
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Term
| Heart beat is regulated by |
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Definition
| both nervous and hormonal control |
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Term
| Control centres in the medulla regulate |
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Definition
| the rate of the SAN through the antagonistic action of the autonomic nervous system |
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Term
| The Cardio-accelerator centre of the brain |
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Definition
| sends its nerve impulses via sympathetic nerves to the heart |
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Term
| The Cardio-inhibitor centre of the brain |
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Definition
| sends its nerve impulses via a parasympathetic nerve to the heart |
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Term
| Impulses from the sympathetic nerve to the SAN leads to |
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Definition
| an increase in heart rate due to the sympathetic accelerator nerves releasing nor-epinephrine (noradrenaline) |
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Term
| Impulses from the parasympathetic nerve to the SAN leads to |
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Definition
| a decrease in heart rate due to the slowing parasympathetic accelerator nerves releasing acetylcholine |
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Term
| During exercise or stress |
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Definition
| epinephrine (adrenaline) is released from the adrenalin glands which increases heart rate |
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Term
| Normal ECG patterns consist of three waves |
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Definition
| P wave, QRS wave and T Wave |
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Term
| Blood pressure is highest |
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Definition
| in the aorta and pulmonary artery |
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Term
| Blood pressure in the aorta is lowest during |
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Definition
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Term
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Definition
| The prolonged elevation of blood pressure when at rest eg. above 140/90 mmHg |
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Term
| The prolonged elevation of blood pressure when at rest eg. above 140/90 mmHg |
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Definition
| high fat diet, continuous stress, not enough exercise, eating too much salt, overweight |
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