Human Physiology: Cardiac Output, Blood Flow & Blood Pressure

Flashcards covering key terms and concepts related to cardiac output, blood flow, and blood pressure as described in the lecture notes.

Cardiac Output

Volume of blood pumped each minute by each ventricle, calculated as stroke volume X heart rate.

Stroke Volume

The amount of blood ejected by the ventricles per heartbeat, typically around 70-80 ml/beat.

Heart Rate (HR)

The number of beats of the heart per minute, with an average of 70 bpm.

End Diastolic Volume (EDV)

Blood volume in ventricles at the end of diastole; also known as preload.

Afterload

Total peripheral resistance that the heart must work against to eject blood; inversely related to stroke volume.

Contractility

Strength of ventricular contraction; can increase stroke volume.

Frank-Starling Law

Increased EDV leads to increased contractility and thus increased stroke volume.

Ejection Fraction

Percentage of EDV that is ejected with each heartbeat; normally about 60%.

Pacemaker Potential

Spontaneous depolarization at the SA node, leading to heart rhythm control.

Atrial Natriuretic Peptide (ANP)

Hormone produced by the atria that promotes salt and water excretion when blood volume is high.

Antidiuretic Hormone (ADH)

Hormone that stimulates water reabsorption in kidneys, released when plasma osmolality is high.

Hypertension

High blood pressure; can lead to increased risk of cardiovascular diseases.

Sympathetic Nervous System

Part of the autonomic nervous system that increases heart rate and contractility through norepinephrine.

Parasympathetic Nervous System

Part of the autonomic nervous system that decreases heart rate through acetylcholine.

Venous Return

The flow of blood back to the heart; affected by total blood volume and venous pressure.

Edema

Excessive accumulation of interstitial fluid caused by high blood pressure, venous obstruction, or low plasma protein concentration.

Sphygmomanometer

Device used to measure blood pressure.

Aldosterone

Hormone secreted by adrenal cortex that stimulates reabsorption of sodium and water when blood volume is low.

Metabolic Vasodilation

Widening of blood vessels in response to increased metabolism, particularly during physical activity.

Total Peripheral Resistance

Resistance that must be overcome to push blood through the circulatory system; affects blood pressure.