The Human Body - Circulatory System Flashcards
The circulatory system is entirely closed, with capillaries connecting ___
Arterioles and venules
Two circuits in the circulatory system
- Systemic circulation in the body
- Pulmonary circulation in the lungs
Function of the systemic circulation
Circuit in the body that carries oxygen-rich blood from the left ventricle through the body and back to the right atrium. Blood passes through the tissues and organs, giving up oxygen and absorbing cellular wastes and carbon dioxide
Function of the pulmonary circulation
Circuit in the lungs that carries oxygen-poor blood from the right ventricle through the lungs and back to the left atrium. Blood passes through the lungs and is refreshed with oxygen and gives up carbon dioxide
Many cellular wastes are eliminated in passages through the ___
Liver and kidneys
Size of the heart
About the size of a clenched fist
The heart is made from ___
Cardiac muscle (myocardium)
The heart works as ___
Two paired pumps
The ___ side of the heart is more muscular
Left
Divides the heart down the middle into right and left sides
Septum
Each side of the heart is divided into ___
An upper chamber (atrium) and a lower chamber (ventricle)
The left side of the heart pumps blood to the ___
Body
The ___ side of the heart is a high-pressure pump
Left
The right side of the heart supplies blood to the ___
Lungs
The ___ side of the heart is a low-pressure pump
Right
The heart muscle is under the control of the ___
Autonomic nervous system
The heart has it’s own ___ and will ___ without its central nervous system control
- Electrical system
- Continue to function
The heart requires ___ and cannot function on ___ metabolism
- A continuous supply of oxygen and nutrients
- Anaerobic
The heart can tolerate a serious interruption of its own blood supply for only a few seconds before the signs of a ___ develop
Heart attack
The heart muscle’s blood supply comes from the ___
Aorta
The aorta has two branches at its base that form the ___
Left and right coronary arteries
These arteries supply the heart muscle with oxygenated blood
Left and right coronary arteries
The right side of the heart receives blood from ___
The veins of the body
The blood from the body into the heart enters from the ___
Superior and inferior venae cavae into the right atrium and then passes through the tricuspid valve to fill the right ventricle
After the right ventricle is filled, the ___ closes to prevent ___
- Tricuspid valve
- Backflow as the right ventricular contracts
Contraction of the right ventricle causes blood to ___
Flow through the pulmonic valve into the pulmonary artery and the pulmonary circulation
The left side of the heart receives oxygenated blood from ___
The lungs through the pulmonary veins into the left atrium
From the left atrium blood passes through the ___
Mitral valve into the left ventricle
Most muscular pumping chamber of the heart
Left ventricle
From the left ventricle blood passes through the ___
Aortic valve into the aorta and then to the arteries of the body
The flow of blood through the four heart chambers is governed by ___
One way valves
The chord tendineae are ___
Thin bands of fibrous tissue that attached to the valves in the heart and prevent them from inverting
When a valve controlling the filling of a heart chamber is open, the other valve allowing it to empty is ___
Shut
Normal adult resting heartbeat
60 to 100 bpm
HR
Heart rate
A well-conditioned athlete may have a normal resting heart rate of ___
45 to 60 bpm
During vigorous physical activity, the heart rate may rise to as fast as ___
180 bpm
At each beat, ___ of blood is ejected from the adult heart
70 to 80 mL
SV
Stroke volume
Stroke volume
The amount of blood moved in one beat
In one minute, the entire blood volume of ___ is circulated through all the vessels
5 to 6 L
Cardiac output
The amount of blood moved in one minute
CO
Cardiac output
Cardiac output calculation
CO = HR x SV
A network of specialized tissue with the capacity to conduct ___ runs through the heart
Electrical current
The flow of electrical current through this network in the heart causes ___
Smooth, coordinated contractions of the heart
These contractions of the heart produce ___
The pumping action of the heart
Each mechanical contraction of the heart is associated with ___
Two electrical processes
Two electrical processes that produce mechanical contraction of the heart
- Depolarization
- Repolarization
The electrical charges on the surface of the muscle cell change from positive to negative
Depolorization
The heart returns to its resting state and the positive charge is restored to the surface
Repolarization
Electrical impulse flow through the heart
- Begins high in the atria at the sinoatrial node
- Travels to the atrioventricular node and bundle of His
- Moves through the Purkinje fibers to the ventricles
The electrical impulse flow through the heart produces a smooth flow of electricity through the heart, which ___
Depolarizes the muscle and produces the coordinated pumping contraction
If areas of the heart’s conduction system are deprived of blood flow and oxygen, ___ can occur
Serious abnormalities of the heart’s rate, rhythm, and coordinated contraction leading to dangerously low blood pressure can occur
Carry blood from the heart to all body tissues
Arteries
Arteries branch into ___
Smaller arteries and then into arterioles
The arterioles branch into ___
The vast network of capillaries
The walls of an artery are made of ___
Fine, circular muscle tissue or fine circular muscle and elastic tissue
Arteries contract to ___
Accommodate loss of blood volume and increase blood pressure
Blood is supplied to tissues as they ___
Need it