week 1 (heart) Flashcards
how big is the heart?
about the size of a clenched fist
Where is the heart found?
In the thoracic cavity, midway between the sternum and vertebrae
What portion of the heart sits on the right and left?
1/3 on the right, 2/3 on the left
which interspace is the apex found?
left 5th intercostal interspace
what is anterior to the heart?
Sternum
Costal cartliages
medial ends of 3rd- 5th ribs on the left side
What sac encloses the heart?
The pericardial sac
what are the two parts of the pericardium
fiborous and serous
What is the fiborous pericardium?
Part of the layers of the heart, attached to the central tendon of the diaphragm and the great vessels, it is lined by serous membrane
anchors the heart so it remains in position in the mediastinum
What is the serous pericardium/
it is a double layered membrane of the heart, has a film between its layers which reduces the friction between heart and the fiborous pericardium.
its parietal and visceral layers are continuous with each other.
It also forms the hearts outer layer known as the epicardium
do the left and right sides of the heart work together or individually?
the left and right work as two different pumps
what does the superior vena cava drain?
blood from the head, neck thorax and arms
What does the inferior vena cava drain
blood from the parts of the body below the diaphragm
What pathway does blood flow through the heart?
SVC/IVC - Right atrium - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - left ventricle - aorta - around the body
what do the left and right sides of the heart pump into?
Right side = pulmonary circulation
Left side = systemic circulation
What are the valves of the heart?
tricuspid, mitral, pulmonary and aortic
What shape is the heart?
A tipped over pyramid
- base
- Apex
- 4 sides
- Diaphragmatic surface
- Sternocostal surface
- Rt pulmonary surface
What makes up the anterior/sternocostal surface?
Mainly by the right ventricle
What makes up the diapghragmatic/ inferior surface
The left ventricle and right ventricle
What makes up the pulmonary surfaces?
left formed by the left ventricle
right is mainly formed by the right atrium
What forms the right border?
The right atrium
What forms the inferior border?
formed mainly by the right ventricle and slightly by the left ventricle
What forms the left border?
formed by the left ventricle and slightly by the left auricle
What forms the superior border?
formed by the right and left atria and auricles
What are the tendinous chords?
they are string like processes that attach the margins of the mitral and tricuspid valves to the walls of the ventricles, preventing backflow of blood in the heart, hence preventing the vavles from opening in the wrong direction
What are the tendinous chords?
they are string like processes that attach the margins of the mitral and tricuspid valves to the walls of the ventricles, preventing backflow of blood in the heart, hence preventing the vavles from opening in the wrong direction
What are the papillary muscles?
are conical projections of muscle attached to the ventricular walls.
Prevent the cusps from turning inside out!
the right ventricle has 3 and the lef ventricle has 2 (due to the tricuspid valve)
They contract at the same time as the ventricles
What is the endocardium?
the thin, internal lining of the heart that covers its valves
What is the epicardium?
thin, external layer formed by the visceral layer of the pericardium
What is the vasculature of the heart?
made up of;
- coronary arteries
- cardiac veins
What is the vasculature of the heart?
made up of;
- coronary arteries
- cardiac veins
What are the coronary arteries
Are the first branches of the aorta and arise off the aortic sinus (the left coronary artery arises off the left aoritc sinus, likewise does the right) and these supply the atria and ventricles
What are the branches of the right coronary artery?
- sinoatrial nodal branch
- Rt marginal branch
- AV nodal branch
- Posterior interventricular artery
What does the Right coronary artery supply?
Right atrium Right ventricle part of left ventricle part of I/V septum SA node AV node
What are the branches of the left coronary artery
anterior interventricular branch
lateral branch
circumflex artery
left marginal artery
What does the left coronary artery supply?
left atrium most of left ventricle part of right ventricle most of IV septum SA node AV node
What is the arterial supply to the heart?
Right coronary artery Anteriorly; sinuatrial branch rt marginal branch Posteriorly: atrioventricular nodal branch posterior interventricular branch
Left coronary artery: Anteriorly: Anterior interventricular branch Posteriorly amd laterally: circumflex branch left marginal branch
What is the venous drainage of the heart?
Coronary sinus Great cardiac vein posterior interventricular vein small cardiac vein anterior cardiac vein smallest cardiac vein
nerve supply to the heart
sympathetic:
T1-T5/6 by cardiopulmonary splanchnic nerves
Parasympathetic:
Vagus nerve (CN X)
what is the nerve supply to the heart
sympathetic:
T1-T5/6 by cardiopulmonary splanchnic nerves
Parasympathetic:
Vagus nerve (CN X)