Studied by 0 people
Exam 2
Function of the Circulatory System
maintains blood flow and supply to the body
Function of the Circulatory System
is to transport oxygen, nutrients, and hormones to cells while removing waste products.
Atrioventricular Valves
are valves located between the atria and ventricles, preventing back-flow of blood into the atria during heart contraction.
Bicuspid Valves
The LEFT AV valve consists of two flaps, or cusps, of the endocardium that regulates blood flow from the left atrium to the left ventricle.
AKA: mitral valve
Tricuspid Valve
The RIGHT AV valve, located between the right atrium and right ventricle, also consists of three flaps that prevent backflow of blood during contraction.
Semilunar Valve
Guards the bases of the two large arteries leaving the ventricular chambers
Pulmonary and Aortic Valves
Phases of the Cardiac Cycle
Atriole Systole
Ventricular Systole first phase
Ventricular Systole second phase
Ventricular Diastole early
Ventricular Diastole late
Atriole Systole
The phase of the cardiac cycle where the atria contract, pushing blood into the ventricles.
Ventricular Systole first phase
Ventricular contraction pushes AV valves closed
Ventricular Systole second phase
Semilunar valves open and blood is ejected
Ventricular Diastole early
Semilunar valves close and blood flows into atria
Ventricular Diastole late
Chambers relax and blood fills ventricles passively
Cardiac Output
the amount of blood the heart pumps/ejects per minute
Stroke Volume
the amount of blood pumped by the ventricles with each heartbeat
Preload
Stretching
Left Ventricular End Diastolic Pressure or Preload
the pressure in the left ventricle at the end of diastole, reflecting the volume of blood returning to the heart.
Frank Starling’s Law
the principle that the heart will contract more forcefully when it is filled with more blood due to increased stretch of the cardiac muscle fibers.
Afterload
the amount of resistance the heart must pump against when ejecting blood
Afterload
think hose kink
When afterload is low
the heart can eject blood more easily, leading to better stroke volume and cardiac output.
When afterload is high
the heart must work harder to eject blood, leading to increased workload and potential heart failure.
High afterload
hypertension
vasoconstiction
Contractility
the ability of the heart muscle to contract forcefully, affecting stroke volume and cardiac output.
Positive inotropy
increased force of contraction
Negative inotropy
decreased force of contraction
Ejection fraction
stroke volume/preload
Normal: 55-65%
below 40% is abnormal
left Ventricular
Beta 1 Receoptors
kidney, heart, adipose tissue
Beta 2 Receptor
smooth muscle, blood vessels, liver
Aldosterone
A hormone produced by the adrenal glands that regulates sodium and potassium levels, influencing blood pressure and fluid balance.
Hypertension
A chronic condition characterized by elevated blood pressure in the arteries, which can lead to serious health issues such as heart disease and stroke.
Regulation of Blood Pressure
Maintain tissue perfusion and/or blood to the capillary beds
Regulation of Blood pressure
Arterial pressure is determined by cardiac output and systemic vascular resistance, affecting overall blood flow.
Normal BP
120mm/80mm
Pulse Pressure
Difference between systolic and diastolic
120-80=40
Mean Arterial Pressure
Average pressure during ventricular contraction and relaxation
Systolic Blood Pressure
The pressure in the arteries during ventricular contraction, typically the higher number in a blood pressure reading.
Diastolic Blood Pressure
The pressure in the arteries during ventricular relaxation, typically the lower number in a blood pressure reading.
Hypertension
Primary: no known cause
Secondary: Caused by another disease or factor
Isolated systolic HTN: elevated systolic BP
Metabolic Syndrome Characteristics
Hypertension, Obesity, Abnormal cholesterol levels, chronic inflammation, insulin resistance
Insulin Resistance
A condition where cells in the body do not respond effectively to insulin, leading to elevated blood sugar levels.
Insulin Resistance
Insulin is not able to reduce blood sugar, the compensatory insulin fails as well and the person remains hyperglycemic
Angina
A type of chest pain caused by reduced blood flow to the heart muscles, often triggered by physical exertion or stress.
Cardiac Cycle
The sequence of events in one heartbeat, including diastole and systole, during which the heart chambers fill with blood and pump it out.
One complete heartbeat
Frank-Starlings law
The more the heart muscles stretch during diastole the more forcefully it will contract at systole
Note 
Flashcard (49)