The Heart Flashcards
What is Pulmonary Circulation?
The right heart pumps deoxygenated blood to the lungs (lower pressure)
What is the systemic circulation?
Left heart pumps oxygenated blood to the body (higher pressure)
What is the pericardium?
3 layered sac
What is the fibrous pericardium and what is it attached to?
- Protective layer
- Attached to the great vessels
- Attached to the diaphragm
- anchors the heart in place
What are the 2 layers of the serous pericardium?
- Pariteal
- Visceral - epicardium
What are the 4 functions of the perciardium?
- Fixes the heart in the mediastinum and limitis its motion
- Protection from infections coming from other organs
- Prevents excessive dilation of the heart in cases of acute volume overload
- Lubrication
Epicardium
Visceral layer of serous pericardium
Myocardium
cardiac muscle fibres arranged in bundles that squeeze blood out of the heart
Endocardium
continous with endothelium. Lines the inner surface of the walls as well as the valves.
Recieves oxygen and nutrients directly from the chambers of the heart
What makes up the base of the heart?
left atrium, pulmonary veins and small portion of the RA
Where is the base of the heart?
Fixed ppsteriorly to the pericardium at the level of T6(5) - T(9)8 vertebrae
Where does the oblqiue pericardial sinus lie?
posteriorly
Where is the apex of the heart?
Left 5th intercostal space in the midclavicular line
What is on the sternocaostal (anterior) surface of the heart?
- Right ventricle
- Right atrium
- Left ventricle
what is on the diaphragmatic (inferior) surface of the heart
- Left ventricle
- Right ventricle
What separates the diaphragmatic surface of the heart from the base of the heart?
coronary sinus
Right margin of the heart
right atrium
left margin of the heart
left ventricle and left auricle
inferior margin of the heart
right ventricle and left ventricle (between anterior and diaphragmatic surfaces)
What is within the naterior interventricular sulcus?
- Anterior interventricular artery
- Great cardiac vein
- Right of the apex
What runs in the posterior interventricular sulcus
- Posterior interventricular artery
- Middle cardiac vein
What does the coronary sulcus separate and what travels in it?
- Separates atria from ventricles
- Right coronary artery
- Left circumflex artery
Where does the RA recieve blood from?
- Superior Vena Cava
- Inferior Vena Cava
- Coronary sinus
- Smallest cardiac veins
What 2 continuous spaces does the RA consist of?
- Sinus of vena cava
- Right auricle
What is internally bound between the sinus of the vena cava and the right auricle
crista terminalis
Describe the inner surface of the space posterior to crista terminalis
smooth and veins drain into this part
What is fossa ovalis? And where is it?
- On the right side of the IA septum
- Site of foramen ovale in foetus and margin is limbus fossae ovalis (border)
- Remnant of embryologicak orifice
Describe the surface of the right auricle
- Trabeculated (rough) surface
- Formed by pectinate muscles
What is thr function of pectinate muscles?
Provide some force of contraction without significantly thickening the cardiac wall
What blood passes into the RV?
Deoxygenated blood from the RA enters throguh the right AV orifice into the RV
Where does the RV sit?
On the central tendon of the diaphragm
What is the outflow tract of the RV?
is the pulmonary trunk and arises from the infundibulum (conus arterosis)
How does blood flow out of the RV in the pulmonary trunk?
blood flows upwards, backwards and to the left
Describe the surface of the infundibulum
Smooth
What are the irregular musuclar structures in the walls of the RV?
trabeculae carnea
name the 3 types of muscles on the right ventricle wall
- Trabecula carnea
- Septomarginal trabecula (moderator band)
- Papillary muscles
Describe the septomarginal trabecula
- Bridge between IV septum and anterior papillary muscle
- Only in RV
carries right bundle branch of AV bundle of cardiac conduction system
Describe papillary muscles
- 3 muscles
- named relative to their position
- Fibrous cords called chorda tendinea run between their apex and free edges of tricuspid cusps
- Contract before ventricular contraction
What is the function of chorda tendinea
Prevent the eversion of cusps, which stops the regurgitation of blood into the atria during systole
Function of the tricuspid valve
Closes the right AV orifice
What are the names of the cusps of the tricuspid valve?
- anterior
- posterior
- septal
How does blood flow through the tricuspid value?
Forwards and medially (inferior and to the left)
How many cusps does the pulmonary valve have and what are their names?
3
- anterior
- right
- left
What do the cusps of the pulmonary valve form? And what is its function
a pulmonary sinus
helps closure of the pulmonary valves after systole
What does the LA form?
most of the base of the heart
What enters the LA?
Four pulmonary veins (no valves) carry oxygenated blood from the lungs
What is the depressed area on the LA septum?
Falx septi - is caused by the fusion of the valve of foramen ovale
How does blood flow in the LV?
Anteriorly towards the apex
What is closed by the mitral valve?
Left AV orficie
How many cusps does the mitral valve have? And what are their names?
2
- anterior
- posterior
What are the bases of the cusps in the tricuspid valve attached to?
right fibrous ring (anulus fibrosus)
What are the cusps of the mitral valve attached to?
left fibrous ring
Where are the chorda tendinae attached to the mitral valve
Attached to free margins
What is the aortic vestibule?
outflow tract of the LV
Where is blood from the LV ejected to?
The aorta
How does blood flow through the site of the aortic valve?
upwards, backwards and to the right side
Name the 3 cusps in the aortic valve
- right
- left
- posterior
What is between the superior surface of the cusps and the aortic wall
aortic sinuses (sinus valsalvae)
What does the fibrous skeleton provide the heart?
functional and structural support
What does the fibrous skeleton provide for cusps in the heart?
Points of attachment for the cusps
Give the main functions of the fibrous skeleton of the heart
- Maintains the patency and integreity of AV and semi-lunar orificies
- Origin/insertion for atrial and ventricular muscles
- Insulates atria from ventricles
By insulating the atria and ventricles how does the fibrous skeleton help the function of the heart?
- Allow independent atrial and ventricular contraction
- Atrioventricular Bundle of His should be the only conduction between A and V
