Heart I Flashcards
heart location
- located in the mediastinum
- posterior to the sternum
position of the heart
- 45° rotation to the left
- caudal lift
mediastinum
-central space between the lungs
base of the heart
- broad superior region
- where major vessels enter and exit the heart
apex of the heart
- cone-shaped end at the inferolateral aspect of organ
- lies at level of nipple (T4)
chambers of the heart
- two atria (superior)
- two ventricles (inferior)
pericardium
- double-walled sac
- encloses the heart and the roots of great vessels
parts of the pericardial sac
- fibrous pericardium
- serous pericardium
fibrous pericardium
- outer sac
- tough/dense CT
- attaches heart to diaphragm and base of vessels
serous pericardium components
- parietal pericardium
- visceral pericardium
serous pericardium
-thin, double layer with two portions
parietal pericardium
-outer membrane attached to fibrous portion
visceral pericardium
- aka epicardium
- inner membrane to the heart surface
pericardial cavity composition
- space contains serous fluid
- thing layer of watery fluid that lubricates membrane
pericardial cavity function
-decreases friction between the layer of the pericardium as heart beats (since it contracts and relaxes)
what is located within the grooves of the heart?
-coronary blood vessels
external anatomy components
- atrioventricular(AV) sulcus
- anterior and posterior interventricular sulci
atrioventricular(AV) sulcus
- separates atria from ventricles
- contains right and left coronary arteries and circumflex artery (goes around ‘circumference’ of heart)
- arteries are imbedded in fat pad
anterior and posterior interventricular sulci
- separates right and left ventricles
- contains interventricular arteries (anterior and posterior)
layers of the wall of the heart components
- epicardium
- myocardium
- endocardium
epicardium
- same as visceral pericardium
- outermost layer
- composed of fibrous CT and fat in sulci
- major coronary vessels found here
myocardium
- middle layer
- composed of cardiac muscle
- has special conduction capillaries
endocardium
- innermost layer
- composed of simple squamous epithelium
- continuous w/ endothelial lining in blood vessel
- values are also covered w/ endocardium
what vessels carry blood into the heart?
- superior vena cava
- inferior vena cava
- coronary sinus
- pulmonary veins
superior vena cava
-carries deoxygenated blood returned to right atrium from upper body and head
inferior vena cava
-carries deoxygenated blood which is returned to right atrium from lower body
coronary sinus
- contains venous blood returning from the heart’s coronary circulation
- enters posterior right atrium
pulmonary veins
- four pulmonary veins: 2 from right and 2 from left
- transports oxygenated blood from lungs to the posterior left atrium
which veins are the only set of oxygen rich veins in an adult body?
-pulmonary veins
what vessels carry blood away from the heart?
- pulmonary trunk
- aorta
pulmonary trunk
- divides into right and left pulmonary arteries
- transports deoxygenated blood from right ventricle to the lungs
aorta
-transports oxygenated blood from left ventricles to body
which side of the heart receives oxygenated blood?
-left receives this blood from lungs and is pumped throughout body
which side of the heart receives deoxygenated blood?
-right receives this blood from tissues and is sent to lungs where CO2 is exchanged for O2
what are the superior receiving chambers of the heart?
- right atrium
- left atrium
what does the right atrium receive?
-receives oxygen poor blood from the body
what does the left atrium receive?
-receives oxygen rich blood from lungs
what separates the atria from one another?
-interatrial (IA) septum
what are the inferior pumping chambers of the heart?
- right ventricle
- left ventricle
what does the right ventricle pump?
-pumps oxygen poor blood to lungs
what does the left ventricle pump?
-pumps oxygen rich blood to the body
what separates the ventricles from one another?
-interventricular (IV) septum
what are some specializations of the chambers?
- trabeculae carneae
- valves
trabeculae carnae
- muscular ridges that project from inner surface of ventricle
- prevents suction that would’ve occurred with a flat surface membrane
valves
- acts as gates within the heart ensuring that blood flows in one direction
- opens/closes in response to volume and pressure in heart
- covered in endothelium
valve types
- atrioventricular valves
- semilunar valves
atrioventricular(AV) valve
- acts as gates that open/close due to pressure gradients
- ensures that blood flows only in one direction
atrioventricular valve components
- tricuspid valve
- bicuspid valve
- papillary muscles
- chordae tendineae
atrioventricular tricuspid valve
- aka right AV valve
- has three cusps
- blood passes from right atrium through this valve to right ventricle
atrioventricular bicuspid valve
- aka left AV valve or mitral valve
- has two cusps
- blood passes from left atrium through this valve to left ventricle
what is the importance of the structures in the ventricles?
-helps stabilize the valves and prevents backflow
atrioventricular papillary muscles
- finger-like projections from the wall of the heart
- prevents prolapse
- stabilizes the valve**
what is prolapse?
-valve inversion
atrioventricular chordae tendineae
- tendinous cords which attach papillary muscles to cusps of valves
- looks like strings on a guitar
semilunar(SLV) valve
-three cup like valves covered in endothelium which open and close according to pressure gradients
semilunar valve components
- pulmonary SLV
- aortic SLV
pulmonary semilunar valve
-blood passes from right ventricle through this valve on its way to the lungs
aortic SLV
-blood passes from left ventricle through this valve on its way to the body
what closes at birth that separates the right and left atria? and what results from this?
-foramen ovale closes at birth and results in the formation of the fossa ovale
what happens if the foramen ovale doesn’t close at birth?
- allows for mixing of oxygenated blood with deoxygenated blood
- causes the infant to have a decrease in normal blood oxygen saturation being pumped out systematically
- they’ll appear cyanotic (“blue baby”)
what happens if there’s defects in the formation of the valves in an infant?
-may allow blood to flow backwards that produces heart murmurs
