Lexture 10- Anatomy Of The Heart Flashcards
What does the right side of the heart do?
receives deoxygenated blood returning from body tissues and pumps it to the lungs to release CO2 and pick up O2.
This is called the pulmonary circuit.
What does left side of the heart do?
receives oxygenated blood from the lungs and pumps it out to the body to supply oxygen to tissues.
This is called the systemic circuit.
Where is the heart situated?
In the mediastium ( space between the lungs) and two thirds is left of the midsternal line
Fibrous pericardium
Outside wall
protects the heart, anchors it to surrounding structures, and prevents the heart from overfilling.
Serous pericardium
double-walled serous membrane, consisting of a parietal layer that lines the inside of the pericardium, and a visceral layer (epicardium) that covers the surface of the heart.
Pericardial cavity
Between visceral and parietal layers
containing a film of serous fluid that lubricates their movement against each other.
What is the Myocardium composed of?
mainly of cardiac muscle and forms bulk of heart
Endocardium
Epithelial tissue that lines chambers of the heart
Continuous with the endothelial linings of the vascular system
Right and left atria
Recieving chambers of heart
Minimally contract to propel blood into ventricles
What are the three veins that enter the right atrium?
Superior vena cava and inferior vena cava which return blood from body
Coronary sinus which return blood from myocardium
Ventricles
Pump blood out of heart
Right ventricle
Pumps blood to pulmonary trunk which branches to pulmonary arteries to take blood to lungs
Left ventricle
Pumps blood into aorta with many branches to carry blood throughout body
Interstitial septum
Divides atria
Interventricular septum
Divides ventricles
Why is left ventricle wall thicker?
Allowing it to generate a much higher pressure, so that the force can overcome the much greater resistance in the systemic circulation.
Initially it works harder
What are the two atrioventricular valves?
Tricuspid (right) and bicuspid (left)
When heart relaxed, hang loosely
When contracted, blood forced upward against valves pushing them closed
Chordate tendonae
Attach atrioventricular ventricles to papillary muscles
Prevent Eversion of valves into atria
Aortic and pulmonary semilunar valves
located at base of the arteries exiting the heart and prevent backflow of blood into the ventricles.
When ventricular pressure rises, the semilunar valves are forced open allowing blood to be ejected from the heart.
When the ventricles relax, blood flows backward toward heart, filling the cusps of the semilunar valves, forcing them closed
Where are there no valves in the heart?
Entrances of vena cava or pulmonary veins
Flow of blood through heart
Deoxygenated blood In through superior vena cava/inferior vena cava to right atrium
Pass through tricuspid valve to right ventricle to pulmonary trunk To lungs
Oxygenated blood Enters in through pulmonary veins into left atrium
Pass through bicuspid valve to left ventricle through aortic semilunar valve and exit through aorta to rest of body
What is the function of coronary circulation or coronary vessels?
Supply blood and nutrients to heart itself
Myocardial infarction (heart attack)
blockage of blood flow to the coronary blood vessels.
Because cardiac muscle does not regenerate, any damage caused by a temporary lack of oxygen results in fibrosis (scarring) and a permanent reduction in heart function.
