Blood Pressure,Structure of the heart, Cardiac output

Cardiac Output

• Cardiac output is represented by the equation: CO = SV × HR
• Stroke volume (SV) is affected by the mechanical factor of preload, which is the stretch of the heart muscle prior to contraction

Stroke Volume and Cardiac Output

• The equation for stroke volume is: SV = EDV - ESV
• The equation for cardiac output is: CO = 80 mL × 70 beats/min = 5600 mL/min
• End-diastolic volume (EDV) is the volume of blood in the ventricle at the end of diastole
• An increase in EDV increases stroke volume

Factors Affecting Cardiac Output

• The strength of myocardial contraction can be increased by sympathetic stimulation
• Endocrine responses that affect cardiac output can be triggered by the sympathetic nervous system
• If stroke volume decreases but heart rate increases, cardiac output remains the same or increases slightly
• If stroke volume and heart rate both increase, cardiac output increases significantly

Blood Pressure Regulation

• Blood pressure is directly proportional to cardiac output and peripheral resistance
• Baroreceptors are located in the walls of large arteries, such as the aorta and carotid arteries
• Baroreceptors play a role in regulating blood pressure by detecting changes in blood pressure and sending signals to the brain to make adjustments

Heart Structure and Function

• The outermost layer of the heart wall is called the epicardium
• The myocardium is the layer of the heart wall responsible for the contraction of the heart
• The innermost lining of the heart muscle is called the endocardium
• The structures that project outwards from the endocardium are called trabeculae carneae
• Cardiac output refers to the volume of blood pumped by the heart per minute
• Cardiac output is a critical factor in maintaining blood pressure and delivering oxygen and nutrients to the body's tissues
• Pressorreflexes play a role in regulating blood pressure by increasing sympathetic nervous system activity in response to low blood pressure.