1.1 The Cardiovascular System Flashcards
Myogenic
The capacity of the heart to generate its own impulses
SAN
Cardiac muscle found in the wall of the right atrium that generates the heartbeat.
AVN
The atrioventricular node relays the impulse between the upper and lower sections of the heart but will delay it 0.1 seconds to allow the ventricles to fill up
Systole
When the heart contracts
Diastole
When the heart relaxes
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
Muscles fibres that conduct impulses in the walls of the ventricles causing them to contract
Adrenaline
A stress hormone that is released by the sympathetic nerves and cardiac nerve during exercise causing an increase in heart rate.
Stroke volume
The volume of blood pumped by the heart ventricles in each contraction
Ejection fraction
The percentage of blood pumped out by the left ventricle per beat
Cardiac output + equation
The volume of blood pumped out by the ventricles per minute.CO=SVxHR
Cardiac hypertrophy
The thickening of the muscular wall of the heart so it becomes bigger and stronger
Bradycardia
A decrease in resting heart rate to below 60 bpm
Sympathetic system
A part of the autonomic nervous system that speeds up heart rate
Parasympathetic system
A part of the autonomic 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
What does the neural control system involve and what do each of them detect?
𝐁𝐚𝐫𝐨𝐫𝐞𝐜𝐩𝐞𝐭𝐨𝐫𝐬 (chemical):
Detect stretch and pressure changes in blood vessels.
𝐏𝐫𝐨𝐩𝐫𝐢𝐨𝐜𝐞𝐩𝐭𝐨𝐫𝐬:
Detect movement and stretch in muscles.
𝐂𝐡𝐞𝐦𝐨𝐫𝐞𝐜𝐞𝐩𝐭𝐨𝐫𝐬:
Detect changes in carbon dioxide
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. Increase in CO2 increase heart rate.
Baroreceptors
Special sensors in tissues in the aortic arch, carotid sinus, heart and pulmonary vessels that respond to changes in blood pressure. Increase blood pressure decrease in heart rate.
Proprioceptors
Sensory nerve endings in the muscles, tendons and joints that detect changes in muscle movement. Increase in muscle movement increase in heart rate.
Plasma
The fluid part of the body that surrounds blood cells and transports them