Cardiovascular unit 2 Flashcards
pulmonary circuit
transports blood to and from the lungs, where it picks up oxygen and delivers carbon dioxide for exhalation
systole
The period of contraction that the heart undergoes while it pumps blood into circulation
diastole
The period of relaxation that occurs as the chambers fill with blood
Cardiac Output (CO)
The amount of blood (ml/min) pumped by the heart per minute (this equals blood flow through the entire body). Calculated by: heart rate X stroke volume. CO = HR x SV
Stroke volume (SV)
The volume of blood ejected by the left (or right) ventricle per beat (ml/beat)
Heart Rate (HR)
The number of times the heart contracts per minute (beats/min)
Blood Pressure
The force exerted on a vessel wall by the enclosed blood (mm Hg); unless otherwise stated, “blood pressure” usually refers to pressure in large systemic arteries near heart; blood pressure gradients create the driving force for blood flow
Total Peripheral Resistance
The amount friction encountered by blood as it flows through all of the blood vessels in the body; affected mostly by vessel diameter; the higher the resistance, the more difficult it is to move blood through the vessel
Systole
Contraction of the heart; can be used to describe atria or ventricles
Diastole
Relaxation of the heart; can be used to describe atria or ventricles
Systolic Pressure
Maximum pressure in the arteries during a heart cycle; occurs during ventricular systole (mmHg)
Diastolic Pressure
Minimum pressure in the arteries; occurs just before aortic semi-lunar valve opens (mmHg)
Pulse
The throbbing caused by the regular expansion and recoil of the arteries as the ventricles eject blood (or not) into the arteries. Can be felt through the skin in several places on the body. Counting the number of pulses/minute is a non-invasive way of determining heart rate.
Pulse pressure
The difference in blood pressure between systolic and diastolic pressure
Mean arterial pressure
The mean diastolic pressure plus one third of the pulse pressure; the mean force driving blood flow
Baroreceptors
Special cells that monitor pressure in the walls of the carotid arteries and aorta; associated with afferent neuron; respond to changes in mean arterial pressure
Baroreceptor reflex
A reflex initiated by stimulation of baroreceptors which has the purpose of maintaining a stable level of mean arterial pressure
What ventricle has thicker myocardium
left
Which ventricles pumps to which system?
Right: Pulmonary
Left: Systemic
During the time of early ventricular filling, which has the lowest pressure in the cardiovascular system?
right ventricle
Which of the following is essential to the proper coordination of a single heart beat?
Gap junctions between adjacent cardiac muscle cells
Does the heart need lots of nutrients to cause contraction? Where does the heart receive this nutrients?
Your body uses potassium and sodium as electrolytes to help conduct electrical signals in the heart. Without an appropriate balance of these, contractions become abnormal, with the potential of heart being increased because of it.
The coronary arteries
Where does the healthy cardiac muscle obtain most of its ATP (through aerobic or anaerobic
metabolism)? What anatomical clues are highly suggestive of this?
mostly aerobic
because of the proximity to the lungs, and the supply of oxygen that allows for aerobic respiration
Pericardium and functions
Your pericardium is a protective, fluid-filled sac that surrounds your heart and helps it function properly.
Function: Keeps heart in place, prevents heart from stretching to much and overfilling with blood, prevents friction
