Circulation and Short-Term Blood Pressure Regulation

These flashcards cover key concepts related to the circulation system and the regulation of blood pressure, as discussed in the lecture.

Who was William Harvey and what did he contribute to the understanding of blood circulation?

William Harvey was a British physician who first explained blood circulation, demonstrating that blood circulates in a complete loop beginning and ending in the heart.

What is the definition of blood flow (F)?

Blood flow (F) is the volume of blood moving through a vessel, tissue, organ, or entire circulation per unit of time.

What does blood pressure (BP) measure?

Blood pressure (BP) measures the force exerted onto a given area of the vessel wall by the blood contained within it, measured in mm Hg.

What are the three variables that influence blood flow resistance (R)?

1. Blood viscosity, 2. Blood vessel length, and 3. Blood vessel radius.

Describe systolic and diastolic pressures.

Systolic pressure (SP) is the pressure in vessels during ventricular systole, while diastolic pressure (DP) is the pressure in vessels during ventricular diastole.

What is mean arterial pressure (MAP) and how is it calculated?

Mean arterial pressure (MAP) is the average arterial pressure throughout one cardiac cycle, calculated as MAP = DP + 1/3(SP – DP).

What are the layers of blood vessels?

1. Tunica intima, 2. Tunica media, and 3. Tunica externa.

What type of arteries have thicker walls and smaller lumens than veins?

Arteries, which handle larger amounts of pressure from the heart.

What regulates blood flow into capillary beds?

The diameter of arterioles regulates blood flow into capillary beds.

What is the primary function of capillaries?

Capillaries are the site of gas and nutrient exchange due to their permeability and structure.

What happens when hydrostatic pressure exceeds osmotic pressure at capillaries?

Fluid and dissolved molecules will leave the capillaries to go to their intended tissues.

What is angiogenesis?

Angiogenesis is the creation of new blood vessels, often in response to tissue demands or injury.

How does aging affect circulation?

Aging causes blood vessels to stiffen and narrow due to loss of elasticity and accumulation of fatty deposits, increasing the risk of cardiovascular diseases.

What are common causes of hypotension?

Hypotension can result from dehydration, standing up too quickly, pregnancy, and certain medical conditions or medications.

What is the treatment for hypertension?

Treatment for hypertension may include lifestyle changes, medications like ACE inhibitors, and other drugs to relax blood vessels or decrease blood pressure.

What types of veins help ensure the unidirectional flow of blood?

Veins contain valves, which prevent backflow and maintain unidirectional blood flow toward the heart.