Structure of the Heart Flashcards
Right side of the heart
Received DE-OXYGENATED blood from the body tissues via the vena cava into the right atrium.
This de-oxygenated blood is forced through the tricuspid valve into the right ventricle.
This blood is then pumped/ forced under high pressure out of the right ventricle into the lungs vis the pulmonary artery
Left side of the Heart
The left side receives OXYGENATED BLOOD from the lungs via the pulmonary veins into the left atrium.
This oxygen passed through the bicuspid valve into the left ventricle. It is then pumped to the aorta under greater pressure.
This higher pressure ensures that the oxygenated blood leaving the heart via the aorta is effectively delivered to other parts of the body via the arteries, arterioles and capillaries.
Circuits of Blood
Your body has about 5L of blood continually travelling through the heart by way of the CARDIAC CYCLE.
The heart, lungs and blood vessels work together to form the PULMONARY CIRCUIT of the circulatory system.
The left ventricle pumping of the heart forced the blood on its journey through the SYSTEMIC CIRCUIT, taking oxygen to every body cell.
3 Main Body Circulatory Systems
Pulmonary circulation = the lungs
Coronary, cardiac circulation = the heart
Systematic Circulation = the rest of the system
Heart Beat - Muscle Actions
The left and right atrium contract by an electric pulse in the SINOATRIAL NODE (Sa node)
The ATRIOVENTRICULAR NODE (AV node) sends a message down the septum to tell the ventricles to contract.
Terminologies
Systole = the contraction of the heart
Diastole = the relaxation of the heart
SV = stroke volume of blood pumped from the left ventricle per beat
Heart Rate and Regulation
The cardiovascular centre is a perfect if the human brain responsible for the regulation of the rate at which the heart beats through the nervous and endocrine system. It is found in the medulla, the brain stem part of the brain.
Hormones Involved
Heart rate is controlled by both, the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS)
The sympathetic nervous system releases the hormones to accelerate the heart rate
The parasympathetic nervous system releases hormones to decrease the heart rate.
SUMMARY
The right side of the heart takes blood and pumps it up to the lungs to pick up oxygen
The left side then pumps it to the rest of the body at great pressure
The brain medulla senses the level carbon dioxide and releases hormones to regulate the heart beat
In times of need, the heart rate can be sped up in adrenalin flight or flight reaction
