Anatomy Of The Heart Flashcards
What is the shape and primary function of the heart?
Cone-shaped, muscular pump
The heart functions to pump blood throughout the body.
Where is the heart located?
In the thorax between the lungs (region of mediastinum)
It is protected by the ribs and sternum.
What is the apex of the heart?
Lies in the 5th intercostal space in the midclavicular line
The apex indicates the lower tip of the heart.
What is the fibrous pericardium?
Inelastic, made of dense connective tissue (network of capillary fibres)
It fuses inferiorly with the diaphragm and superiorly with great vessels, preventing overfilling of the heart and anchoring it in position
What are the two layers of the serous pericardium?
Parietal layer (outer layer) and visceral layer (inner layer)
The visceral layer is also known as the epicardium.
What is the function of the pericardial cavity?
Contains pericardial fluid, prevents friction & allows heart to move smoothly
overproduction can cause inflammation
The pericardial cavity is a potential space between the parietal and visceral layers.
What are the three layers of the heart wall?
- Endocardium: inner layer - endothelium (simple squamous epithelium)
- Myocardium: middle layer - cardiac muscle (main layer, forms atria and ventricles)
- Epicardium: outer layer - visceral pericardium
What chambers make up the heart?
- Right atrium (RA)
- Left atrium (LA)
- Right ventricle (RV)
- Left ventricle (LV)
These chambers are responsible for receiving and pumping blood.
What are the great vessels connected to the heart?
- Superior vena cava - delivers blood to RA from head, neck and upper limbs
- Inferior vena cava - carries blood to RA from trunk, viscera and lower limbs
- Pulmonary trunk & arteries
- Pulmonary veins (4 of them)
- Aorta
These vessels are essential for blood circulation to and from the heart.
What is the function of heart valves?
Prevent backflow of blood
There are 4 heart valves:
- 2x Atrioventricular valves
- 2x Semilunar valves
Heart valves ensure unidirectional blood flow through the heart chambers.
Name the two types of atrioventricular (AV) valves.
- Tricuspid (right AV valve) = has 3 cusps
- Bicuspid/mitral (left AV valve) = has 2 cusps
These valves separate the atria from the ventricles.
What are the semilunar valves?
- Pulmonary valve
- Aortic valve
These valves guard the entrances to the aorta and pulmonary trunk.
What is the role of chordae tendineae and papillary muscles?
Anchors AV valves and prevents backflow
Chordae tendineae connect the valves to the papillary muscles.
What is the cardiac conducting system responsible for?
Coordinating effective heart contraction
It consists of non-contractile cells that initiate electrical impulses.
What are the shortcuts in fetal circulation?
- Foramen ovale (window) = connects the right to the left atria, bypassing the right ventricle and pulmonary system
- Ductus arteriosus = connects the pulmonary trunk to the arch of the aorta, bypassing the pulmonary system and left side of heart (goes to aorta instead of lungs)
- Ductus venosus = connects the umbilical vein to the inferior vena cava (as processed by the mother), bypasses the liver