Applied anatomy and physiology Flashcards
Myogenic
the capacity of the heart to generate its own impulse
Sinoatrial node (SAN/ SA node)
a small mas of cardiac muscle found in the wall of the right atrium that generates the heartbeat. Also known as “pacemaker”
Atrioventricular node (AVN/ AV node)
relays the impulse between the upper and lower sections of the heart (delays 0.1 seconds)
Systole
heart contracts
Bundle of His
collection of heart muscle cells that transmit electrical impulses from AVN via bundle branches to ventricles
Purkinje fibres
muscle fibres that conduct impulses in the wall of the ventricle
Sympathetic nervous system
part of autonomic system that speeds up heart rate
Parasympathetic nervous system
part of autonomic nervous system that decreases heart rate
Medulla oblongata
most important part of the brain, it regulates processes that keep us alive such as breathing and heart rate
Chemoreceptors
tiny structures in carotid arteries and aortic arch that detect changes in blood acidity caused by increase/ decrease of carbon dioxide concentration
Baroreceptors
special sensors in tissues in the aortic arch, carotid sinus, heart and pulmonary vessels that respond to changes in blood pressure to increase/ decrease heart rate
Proprioceptors
sensory nerve endings in the muscles, tendons and joints that detect changes in muscle movement
Adrenaline
stress hormone that is released by the sympathetic nerves and cardiac nerve during exercise, causes increased heart rate
Stroke volume
volume of blood pumped out by heart ventricles in each contraction
Diastole phase
heart relaxes
