Flashcards in 1.1 The Cardiovascular System Deck (68)
A state of complete physical, mental and social well being and not merely the absence of disease and injury.
The ability to meet and cope with the demands of a environment.
Define the septum?
The muscular wall that divides the heart into two parts.
What are the two chambers that each part of the heart contains?
An atrium and ventricle.
Which chamber (Atrium and Ventricle) is larger?
The atria are smaller than the ventricles as all they do is push the blood down into the ventricles.
The ventricles have much thicker muscular walls as they need to contract with greater force in order to push blood out of the heart.
Which side of the heart is larger?
The left side of the heart is larger as it needs to pump blood all around the body, whereas the right side pumps deoxygenated blood to the lungs.
Function of the blood vessels attached to the heart?
The vena cava brings deoxygenated blood back to the right atrium and the pulmonary vein delivers oxygenated blood to the left atrium.
The pulmonary artery leaves the right ventricle with deoxygenated blood to go to the lungs and the aorta leaves the left ventricle with oxygenated blood leading to the body.
What is the function of the valves in the heart?
The valves regulate blood flow by ensuring it flows in one direction.
What are the 4 main valves in the heart?
The tricuspid valve
The bicuspid valve
The semi lunar valves
Where is the tricuspid valve located?
The tricuspid valve is located between the right atrium and right ventricle.
Where is the bicuspid valve located?
Located between the left atrium and left ventricle.
Where is the semi lunar valves located?
The semi lunar valves can be located between the right and left ventricles and the pulmonary artery and aorta.
The capacity of the heart to generate its own impulses.
Define the sinoatrial node (SAN)?
A small mass of cardiac muscle found in the wall of the right atrium that generates the heartbeat. More commonly called the pacemaker.
Define the atrioventricular node?
This node relays the impulse between the upper and lower sections of the heart.
Define the bundle of his?
A collection of heart muscle cells that transmit electrical impulses from the AVN via the bundle branches to the ventricles.
Define the purkanje fibres?
Muscle fibres that conduct impulses in the walls of the ventricles.
Name the correct order that the impulses in the conduction system travel?
Sally (Sinoatrial node SAN)
Always (Atrial Systole)
Aims (Atrioventricular node AVN)
Big (Bundle of his)
Balls (Bundle Branches)
Past (Purkanje Fibres)
Vicky (Ventricular systole)
Define the sympathetic system?
A part of the autonomic nervous system that speeds up the heart rate.
Define the parasympathetic system?
A part of the autonomic nervous system that decreases heart rate.
Define the medulla oblongata?
The most important part of the brain as it regulates processes that keep us alive such as breathing and heart rate.
What mechanisms control what rate cardiac impulses are fired at?
Neural control mechanism.
Hormonal control mechanism.
Explain the Neural Control Mechanism?
This involves the sympathetic nervous system which stimulates the heart to beat faster, and the parasympathetic system which returns the heart to its resting level.
The nervous system is made of two parts the Central Nervous System (CNS) and the Peripheral Nervous system.
These two systems are coordinated by the Cardiac Control Centre located in the Medulla Oblongata in the brain. Sympathetic nervous impulses are sent to the SAN and there is a decrease in parasympathetic nerve impulses so that heart rate increases. The Cardiac Control Centre is stimulated by the three receptors.
Explain the Hormonal Control Mechanism?
Hormones can have an effect on HR. The release of adrenaline during exercise is known as hormonal control. Adrenaline is a stress hormone that is released by the sympathetic nerves and cardiac nerve during exercise. It stimulates the SAN (pacemaker) which results in increase in both the speed and force of contraction, thereby increasing cardiac output. This results in more blood being pumped to the working muscles so they can revive more oxygen for the energy they need.
What are the two parts of the nervous system and what do they consist of?
The central nervous system (CNS) which consist of the brain and spinal cord
Peripheral Nervous system consists of nerve cells that transmit information to and from the CNS.
Tiny structures in the carotid arteries and aortic arch that detect changes in blood acidity caused by a increase or decrease in the concentration of Carbon Dioxide (CO2)
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.
A stress hormone that is released by the sympathetic nerves and cardiac nerve during exercise which causes a increase in heart rate.
Sensory nerve endings in the muscles, tendons and joints that detect changes in muscle movement.