Blood Vessels Flashcards
What are the 3 layers of blood vessels?
Tunica intima, Tunica media, Tunica externa
Reduces friction between the vessel walls and blood
Tunica Intima
Controls vasoconstriction and vasofilation of the vessel
Tunica Media
Protects, reinforces, and anchors the vessel to surrounding structures
Tunica Externa
Contain large amounts of elastic which enable the vessels to withstand smooth out pressure fluctuations due to heart action
Elastic arteries
Deliver blood to specific body organs and have the greatest proportion of tunica mesia of all vessels making them more active in vasoconstriction
Muscular arteries
The smallest arteries and regulate blood flow into capillary beds through vasoconstriction and vasodilation
Arterioles
Smallest vessels and allow for exchange of substances between the blood and interstitial fluid
Capillaries
Most common capillaries and allow passage of fluids and small solutes
Continuous capillaries
Capillaries that are more permeable to fluids and solutes that continuous capillaries
Fenestrated capillaries
Capillaries that allow large molecles to pass between the blood and surrounding tissues
Sinusoidal capillaries
Microcirculatory networks consisting of a vascular shunt and true capillaries, which function as the exchange vessels
Capillary beds
Surrounds each capillary at the metarteriole and acts as a valve to regulate blood flow into the capillary
Percapillary Sphincter
Difference between diastolic and systolic pressure
Pulse Pressure
Cluster of sympathetic neurons in the medulla that controls the changes in the diameter of blood vessels
Vasomotor Center
Detect, stretch, and send impulses to the vasomotor center, inhibiting its activity and promoting vasodilation of arterioles and veins
Baroreceptors
Detect a rise in carbon dioxide levels of the blood, and stimulate the cardioacceleratory and vasomotor centers
Chemoreceptors
Automatic adjustment of blood flow to each tissue in proportion to its needs and is controlled intrinsically by modifying the diameter of local arterioles
Autoregulation
Force of fluid against a membrane
Hydrostatic pressure (HP)
The force of opposing hydrostatic pressure, is created by the presence of large, nondiffusible molecules that are prevented from moving through the capillary membrane
Colloid osmotic pressure (OP)
Any condition in which blood volume is inadequate and cannot circulate normally, resulting in blood flow that cannot meet the needs of a tissue
Circulatory shock
Results from a large-scale loss of blood, and may be characterized by an elevated heart rate and intense vasoconstriction
Hypovolemic shock
Normal blood volume, but extreme vasodilation, often related to a loss of vasomotor tone, resulting in poor circulation and a rapid drop in blood pressure
Vascular shock
Due to prolonged exposure to heat, resulting in vasodilation of cutaneous blood vessels
Transient vascular shock
When the heart is too inefficient to sustain normal blood flow and is usually related to myocardial damage
Cardiogenic shock
