W8 - Blood Vessels Flashcards
Name the five types of blood vessels
Arteries (conducting and distributing)
Arterioles (resistance vessels)
Capillaries (exchange vessels)
Venules (collecting vessels)
Veins (capacitance vessels)
What’s the equation for blood pressure?
Blood pressure = cardiac output x peripheral resistance
Name the four layers of walls that all vessels have
Tunica intima (inner)
Tunica media
Túnica externa (outer)
Name the properties of an artery
Tunica intima = thick, muscular and elastic
Tunica externa = elastic and made up of collagen fibres for strength and recoil
Tunica media = smooth muscle for regulating flow
Name some properties of an arteriole
Smallest brunch of an artery
Leads into capillaries
Resistance vessels : regulate arterial blood pressure and distribute blood (more smooth muscle)
Less elastic in collagen fibres due to blood being evened out
Name some properties of a vein
Regulate and return blood to the heart
Thinner walls
Cannot withstand high pressure
Needs skeletal muscle pump to assist Venous return
Warm wave valves
What’s a normal blood pressure?
Systolic 120 or less / diastolic 80 or less
What is a pre-high blood pressure?
121-139 / 81-89
What is a hypertension blood pressure?
140 or above / 90 or above
Name two long-term consequences of hypertension
Artereosclerosis = hardening & loss of elasticity
Atherosclerosis = hardening of the arteries
Name three phases in hematosis that prevent blood loss
Vascular phase
Step 1 = immediate vasospasm
Step 2 = endothelial cells on the damaged membrane are exposed, releasing chemicals and hormones to stimulate more contraction
Step 3 = endothelial cells become sticky
Platelet phase
Step 1 = plate let adhesion: in the first 15 seconds after injury platelet attached to endothelial surface and expose collagen fibres
Step 2 = platelet aggregation is where everything sticks together
Coagulation phase
Extrinsic pathway , intrinsic pathway and common pathway
