Vessels and BP regulation Flashcards
What is the vascular system?
A complete circuit of blood vessels that distributes blood to different organs and tissues and allows the return of blood following material exchange.
What are the two parallel loops of circulation?
- Systemic circulation
- Pulmonary circulation
What is the function of pulmonary circulation?
Supplies blood to lungs for exchange of O2 and CO2.
What does systemic circulation do?
Supplies blood to all organs to provide O2 and nutrients.
What is the direction of blood flow in arteries?
Away from the heart.
What is the pressure in veins compared to arteries?
Low.
Describe the wall thickness of arteries.
Thick.
What is the oxygen concentration in arteries?
High (low in pulmonary circulation).
Do veins have valves?
Present most commonly in limbs and in veins inferior to the heart.
What is the tunica intima?
Innermost layer of blood vessels formed by endothelial lining and underlying connective tissue with elastic membrane.
What is the tunica media composed of?
Concentric sheets of smooth muscle in loose connective tissue with external elastic membrane (arteries only).
What is the tunica externa?
Outermost layer; connective tissue sheath that anchors vessel to adjacent tissues.
Define blood flow.
Movement of blood through the vessels, tissues, or organs, denoted in terms of volume of blood flowing in unit time.
How is blood pressure (BP) defined?
The force per unit area exerted on the wall of a blood vessel by its contained blood.
What are the two values BP is expressed as?
- Systolic pressure
- Diastolic pressure
What does systolic BP represent?
Pressure exerted on blood vessels when the ventricle of the heart contracts.
What is the normal systolic BP?
Less than 120 mmHg.
What does diastolic BP represent?
Pressure on blood vessels when the heart is at rest between contractions.
What is the normal diastolic BP?
Less than 80 mmHg.
What is pulse pressure?
The difference between systolic and diastolic pressure readings.
How is mean arterial pressure (MAP) approximated?
MAP = 2/3 Diastolic BP + 1/3 Systolic BP.
What is Poiseuille’s equation used for?
To describe blood flow in relation to pressure difference, radius, viscosity, and length of the vessel.
What is vascular resistance?
Impedance to blood flow in the vessel.
What factors affect blood flow and resistance?
- Blood vessel length and diameter
- Viscosity of blood
