Cardiac Output

Factors that contribute to the regulation of heart rate

Autonomic Nervous System and Hormones released by the adrenal medullae.

Three Factors that Regulate SV

1. Preload - ° of stretch before contraction. 2. Contractility- forcefulness of contraction 3. After load - pressure before ejection of blood from ventricles

Typical Total Blood Volume

5 L

Cardiac reserve

Difference between a person's maximum cardiac Output and cardiac Output at rest.

Cardiac Output

Volume of blood ejected from the left ventricle (or the right ventricle) into the aorta (or pulmonary trunk) each minute.

Positive Inotropic Agents

substances that increase contractility

Preload is proportional to

the EDV (end diastolic volume)

Afterload

the pressure that must be overcome before a semilunar valve can open

Two Key factors that determine EDV

1. Duration of ventricular diastole 2. Venous return- volume of blood returning to the right ventricle.

What makes your heart rate go faster during physical activity?

Proprioceptors that send nerve impulses.

Preload

Strech that increases the force of contraction (like rubber band) the greater blood flow in diastole : greater in systole

Contractility

Strength of contraction at any given preload

Cardiac Output Equation

Stroke Volume (SV in mL/beat) * Heart Rate (HR in beats/min)

What are the receptors that monitor the stretching of major arteries and veins?

baroreceptors

What are the receptors that monitor chemical changes in the blood?

chemoreceptors

What are some conditions that can increase afterload?

hypertension and artherosclerosis

Where in the brain is the HR regulated?

in the cardiovascular center in the medulla oblongata

The Frank-Starling law of the heart

keeps the same volume of blood flowing in both the systemic and pulmonary circulations

Congestive Heart Failure

loss of pumping efficiency by the heart