AS PE Anatomy & Physiology Key Words


Myogenic: The capacity of the heart to generate its own impulses.

Sinoatrial node (SA node): A small mass of cardiac muscle found in the wall of the right atrium that generates the heartbeat. 

Atrioventricular node (AV node): This node relays the impulse between the upper and lower sections of the heart.

Systole: When the heart contracts.

Bundle of His: A collection of heart muscle cells that transmit electrical impulses from the AVN via the bundle branches to the ventricles.

Purkinje fibres: Muscle fibres that conduct impulses in the walls of the ventricles.

Sympathetic system: A part of the autonomic nervous system that speeds up heart rate.

Parasympathetic system: A part of the autonomic nervous system that decreases heart rate.

Medulla oblongata: The most important part of the brain as it regulates processes that keep us alive such as breathing and heart rate.

Chemoreceptors: Tiny structures in the carotid arteries and aortic arch that detect changes in blood acidity caused by an increase or decrease in the concentration of carbon dioxide.

Baroreceptors: Special sensors in tissues in the aortic arch, carotid sinus, heart and pulmonary vessels that respond to changes in blood pressure to either increase or decrease heart rate.

Proprioceptors: Sensory nerve endings in the muscles, tendons and joints that detect changes in muscle movement.

Adrenaline: A stress hormone that is released by the sympathetic nerves and cardiac nerve during exercise which causes an increase in heart rate.

Stroke volume: The volume of blood pumped out by the heart ventricles in each contraction.

Diastole phase: When the heart relaxes to fill with blood.

Ejection fraction: The percentage of blood pumped out by the left ventricle per beat.

Cardiac output: The volume of blood pumped out by…


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