Cardiovascular System Flashcards
What does the cardiovascular include?
The heart and a system of vessels that distributes blood to the tissues of the body and to the lungs for exchange of gases
What is the term to describe the heart and lung combination portion of the cardiovascular system?
Pulmonary circulation
What are arteries?
Vessels that carry blood away from the heart and are highly oxygenated
What are veins?
Vessels that carry blood to the heart and are low in oxygenation
What is the term for circulation to everywhere in the body except the lungs?
Systemic circulation
How do pulmonary and systemic circulation relate?
Pulmonary circulation is functionally and anatomically separate from systemic circulation
In terms of pumps, how can the heart be visualized, and what does each of the pumps do?
The heart can be thought of as two pumps in one organ
One pump is low in pressure and directs blood returning from the body to the lungs
The other pump is high in pressure and distributes blood to the systemic circulation
What is the heart’s overall shape?
A cone-shaped, hollow, muscular structure
What is the base of the heart?
The dorsally-oriented part that is attached to thoracic structures via large arteries, veins, and the pericardial sac
What is the apex of the heart?
The ventrally-oriented part that is free within the pericardial sac
How is the heart angled?
So the left and right sides are somewhat cranial and caudal to each other
What is the pericardium?
A serous membrane that partially surrounds the heart and allows for movement with little friction
What is the pericardial space?
A closed cavity formed by the pericardium that contains a small amount of fluid which allows for frictionless beating of the heart
What are the two layers of the pericardium?
Visceral pericardium (epicardium) and the parietal pericardium
What is the visceral pericardium?
The inner layer of the pericardium that is adherent to the outer parts of the heart
What is the parietal pericardium?
The outer layer of the pericardium that is consistent with the visceral pericardium at the base (top) of the heart
What is the fibrous pericardium?
A superficial fibrous layer that reinforces the parietal pericardium
What makes up the pericardial sac?
The parietal pericardium, the fibrous pericardium, and the mediastinal pleura
What is the pericardial sac?
A thin and tough tissue surrounding the heart
What are the three layers of the heart wall?
The epicardium, the endocardium, and the myocardium
What is the epicardium?
A thin, outer, serous covering of the heart
What is the endocardium?
A thin, inner endothelial covering of the heart
What are endothelial cells?
A single cell layer that lines all blood vessels and regulates exchanges between the bloodstream and surrounding tissues
What is the myocardium?
A think muscular layer of the heart
What is the epicardium the same as?
It’s the same thing as the visceral layer of pericardium
What is the endocardium?
A layer of simple squamous endothelial cells
Where can endocardium be found?
Lining the chambers of the heart, covering heart valves, and being continuous with the lining of blood vessels
What is the myocardium made of?
Cardiac muscle
What are the left and right divisions of the heart associated with?
Right- low-pressure and pulmonary circulation
Left- high-pressure and systemic circulation
What are the two chambers located in each side of the heart?
Atrium and ventricle
What does the atrium do?
Receives blood via a large vein and contracts to fill itself
What does the ventrical do?
Pumps blood from the heart through a large artery
What type of animals have 4 chambered hearts and what type differs?
Mammalians have 4 chambered hearts, this can differ with avians
What is an auricle?
An appendage within the thin-walled chambers of the atrium
Where is the myocardium thickest?
a. atrium or ventricle
b. left or right
a. ventricle
b. left
Why is the left ventricle’s myocardium thicker than the right ventricle’s?
Because blood is ejected at a higher pressure from the left ventricle than it is from the right ventricle
Which ventricle entirely forms the apex?
The left ventricle, which is more muscular. The right ventricle doesn’t quite reach the apex
What is the ventricular septum?
Myocardium between the two ventricle chambers
There is also a version for the atriums
What is the atrioventricular (A-V) valve?
A one-way operating valve that is between the atrium and the ventricle on each side
What is the bicuspid valve?
It’s another name for the left A-V valve since it has 2 flaps/cusps in humans
What is the mitral valve?
A synonym for the A-V valve
What is the tricuspid valve?
Another name for the right A-V valve since it has 3 flaps/cusps in humans
Where are the flaps of the valves connected?
The inner wall of the ventricle where the atrium and ventricle meet
What is the semilunar valve?
A valve in the ventricle that ensures blood only flows from the ventricle into the artery and not vice versa
What way is the semilunar valve situated?
With the convex side of the three flaps facing toward the ventricle
What is the aortic valve?
A valve at the junction of the left ventricle and the aorta
What is the pulmonary valve?
A valve at the junction of the right ventricle and the pulmonary trunk
What does blood returning to the heart from systemic circulation enter through and what part of the heart does it go to?
It enters through the cranial and caudal vena cava and goes into the right atrium before it moves through the right A-V valve into the right ventricle
What is the conus arteriosus?
The origin of the pulmonary trunk, which it is split away from by the pulmonary valve
What does the pulmonary trunk divide into?
The left and right pulmonary arteries
What do the pulmonary arteries do?
Carry deoxygenated blood to each of the lungs
What do pulmonary veins do?
Carry blood back to the lungs into the left atrium
After blood is pumped from the left atrium to the left ventricle, where is it pumped next?
Past the aortic valve and into the aorta
What does the aorta do?
It branches and carries oxygenated blood to all the parts of the body
What do the septum and myocardium look like when the atrium contracts?
They’re in a relaxed state
What do the septum and myocardium look like when the ventricle contracts?
They contract with them and are no longer relaxed
How are arteries structured?
They begin as large vessels and divide into smaller and smaller branches to carry blood to the body
What is an arteriole?
The smallest artery, which is continuous with capillaries, which are the smallest blood vessels
What are venules?
The structures formed when capillaries begin to come together
What are veins?
Large blood vessels formed from venules coming together that carry blood to the heart
What are the largest veins and where do they lead?
The cranial and caudal venae cava that lead to the atrium
What tissue layers both arteries and veins?
Smooth muscle
Why are capillaries important?
They have a high level of diffusion and are located close to tissues, so oxygen is taken from the blood at the capillaries and distributed to the tissues