Heart Flashcards
Location of Heart
from the second rib to the 5th intercostal space. 60% on the left side of the chest. Sits in the mediastinal cavity.
3 chambers of thoracic cavity
two pleural chambers with lungs and the mediastinal cavity
weight of the heart
300g
where is the apex of the heart and why
Apex of the heart is at the bottom left, has to do with how the heart is form
where is the base of the heart
posterior side of heart is the base
pericardium
serous membrane surrounding the heart
fibrous pericardium
not part of serous membrane, made of dense connective tissue
two layers of serous pericardium and their location
a. Parietal—the layer that lines the cavity
b. Viscera—the layer that lines the heart itself
what is pericardial fluid where does it hang out and how much of it is there
serous fluid between the parietal and visceral layers, 50ml
cardiac tamponade
- Excess fluid or blood in the pericardial sac prevents the heart from expanding fully, so it cannot adequately fill and pump blood
3 layers of the heart
epicardium
myocardium
endocardium
epicardium
Epicardium: outer layer. The same thing as the visceral pericardium
myocardium
middle layer, the cardiac muscle
endocardium
inner layer, made from simple squamous epithelium (endothelium)
auricles
right and left, purple fleshy structures at the top of the heart. Extra spaces for blood. The atria are deep to the auricles
Fossa Ovalis and PFO: function in utero, what happens when baby is born, what can happen when disease processes affect this on adults
When baby is still in uterus, lungs are filled with amniotic fluid which creates a lot of resistance. There is a hole between right and left article called Patent Foramen Ovale (PFO) where blood can move between RA and LA. Patent means open. When baby is born, pressure changes causes a “door” to shut across the PFO, this is referred to as the Fossa Ovalis. In 75% of people the fossa ovalis is sealed shut, but in 25% it is only closed, and being kept closed by the relatively higher pressure in the left atrium. Disease processes may cause the pressure to be higher in the right atrium, which may cause the fossa ovalis to leak which could lead to a stroke.
pectinate muscles
only in the right atrium. “Shaggy carpet” at the top left right atrium. Function unknown.
crista terminalis
C-shaped structure that divides atrium into posterior and anterior
Flow of blood through the heart
- Deoxygenated blood from the body enters the heart on the right side in the RA, exits through RV to go to the lungs, comes back from the lungs through the LA, exits from the LV through the aorta to the body.
atrioventricular (AV) valves location
between the atria and ventricles
tricuspid valve location and number of cusps
has three cusps, is on the right side b/w RA and RV
bicuspid valve location, number of cusps, common name
has two cusps, b/w LA and LV. Also commonly known as mitral valve
AV valves function
the atrioventricular valves are open most of the time, they only close as the ventricles contract.
stenosis
when an atrioventricular valve is too narrow, making it hard for blood to drain into the ventricle, making the heart have to work harder.