The Heart Flashcards
What is the same of the serous sac that surrounds the heart?
Pericardium
Where does the heart lie?
The mediastinum
What is the mediastinum?
The space that separates the two pleural cavities of the thorax
What divides the heart into right and left parts?
The septum
Which side of the heart pumps blood into the pulmonary circulation?
Right
Which side of the heart pumps blood into the systemic circulation?
Left
What is the name of the upper chambers of the heart?
Atria / atrium
What is the name of the lower chambers of the heart?
Ventricles
Which parts of the heart has the thickest muscle?
The walls of the ventricles
Which ventricle has the thickest myocardium?
Left ventricle
What are the layers of the wall of the heart?
Endocardium
Myocardium
Epicardium
What is the name of the valves within the chambers of the heart?
Atrioventricular valves (AV)
What is the name of the atrioventricular valve in the right side of the heart?
Tricuspid
What is the name of the atrioventricular valve in the left side of the heart?
Bicuspid or Mitral
What is the name of the fibrous threads that attach the free edge of the AV valves to the papillary muscles of the walls of the ventricles?
Chordae tendineae
What is the name of the valves at the base of the major vessels leaving the ventricles?
The semilunar valves
What is the function of the semilunar valves?
prevent the flow of blood from the vessels back into the ventricle
What is the name of the valve located at the base of the pulmonary artery?
Pulmonary valve
What is the name of the valve located at the major vessel leaving the right ventricle?
Pulmonary valve
What is the name of the valve located at the base of the aorta?
Aortic valve
What is the name of the valve located at the major vessel leaving the left ventricle?
Aortic valve
Which side of the heart contains deoxygenated blood?
The Right side
Which side of the heart contains oxygenated blood?
The left side
What is the name of the major veins that carry deoxygenated blood back to the heart?
cranial vena cava and caudal vena cava
When the heart contracts where does the blood from the right atrium go?
The Right ventricle
When the heart contracts where does the blood from the right ventricle go?
out of the heart via the pulmonary artery
Where does blood from the pulmonary artery go?
the the lungs
Where does oxygenated blood from the lungs go?
to the left atrium via the pulmonary veins
When the heart contracts where does blood from the left atrium go?
the left ventricle
When the heart contracts where does blood from the left ventricle go?
the aorta
What is the term for the period of contraction within the cardiac cycle?
systole
What is the term for the period of relaxation within the cardiac cycle?
diastole
What is the name of the mechanism responsible for initiating and coordinating the heart beat?
The conduction system
What does inherent contractibility mean?
The heart is able to contract rhythmically and automatically without nervous input.
Where does the heart beat begin?
the sinoatrial node (pacemaker)
Where is the sinoatrial node located?
the wall of the right atrium, near its junction with the cranial vena cava
What is the sinoatrial node?
an area of modified cardiac muscle cells
Where does the nerve impulse travel after the sinoatrial node?
to the AV node
Where is the AV node located?
at the top of the interventricular septum
What is the bundle of his?
specialised nerve fibres that run down the interventricular septum and divide into right and left branches at the bottom of the interventricular septum and spread into the two ventricles.
What is the name of the neurons that spread out through the ventricular muscles?
Purkinje Fibres
On an ECG reading what does the P wave indicate?
Atrial Systole - SA node sinds signal to both atria causing muscle to contract.
On an ECG reading what does the QRS wave indicate?
Ventricular systole - SA node sends signal to AV node which enters the bundle of his to the bundle branches to the purkinje fibres which causes the ventricles to contract.
On an EGA reading what does the T wave indicate?
Ventricular diastole - Relaxation
