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51 Cards in this Set

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What are the three layers of the blood vessels?
Intima
Media
Adventitia
The 'endothelial lining of the lumen' describes which blood vessel layer?
The intima (There is also a thin layer of CT)
The 'vascular smooth muscle' describes which blood vessel layer?
The media (Smooth muscle contains elastin and collagen)
The 'connective tissue with autonomic nerves' describes which blood vessel layer?
The adventitia
The greatest pressure drop occurs over which vessel?
The arterioles
What is it about the arterioles that make them have the greatest drop in pressure? (It's a ratio)
The arterioles have the highest ratio between vessel wall thickness and vessel diameter
Since resistance is proportional to 1/radius^4, small changes in vessel radius by contraction or relaxation of the vascular smooth muscle in arterioles results in a LARGE changes in vascular resistance and blood flow
Important concept to understand!
Does the sympathetic supply to the blood vessels vasoconstrict or vasodilate them?
Increased sympathetic activity will constriction
Are arterioles normally under some sympathetic, or parasympathetic tone?
Slight sympathetic tone (i.e. slightly constricted)
Which catecholamine is released by sympathetic vasoconstrictor fibres to the blood vessels?
Noradrenaline (norepinephrine)
Sympathetic vasoconstrictor fibres have a tone on arterioles to keep them slightly constricted. They release noradrenaline which acts on alpha-1 adrenoceptors. What do you think could be used to treat hypertenson?
A alpha-1 adrenoceptor receptor blocker (antagonist)
What receptors does noradrenaline act on?
alpha-1 adrenoceptors (NB use in treating hypertension with agonist)
Which substances are released by parasympathetic vasodilator fibres?
Acetylcholine and nitric oxide
All blood vessels are innervated by sympathetic and parasympathetic fibres T/F
F, some are not innervated by sympathetic fibres
Give an example of humoral control of blood vessels.
Adrenaline released from the adrenal medulla (humoral refers to body fluids)
Does adrenaline cause vasoconstriction, or vasodilation? Which receptors does it act on?

Think!
Vasodilation! Acts on beta-2 adrenoceptors
ACE inhibitors, however, cannot be used to treat hypotension T/F
T (They treat hypertension)
What is an ACE inhibitor?
A group of pharmaceuticals that are used primarily in treatment of hypertension and congestive heart failure.
A group of pharmaceuticals that are used primarily in treatment of hypertension and congestive heart failure
ACE inhibitors
In a blood vessel, where is speed the greatest, and why?
In the centre, because there is less 'friction' of the different layers (laminae) - most friction next to endothelium, then gradually decreasing

NB This is where 'laminar flow' comes from
What is the body's (?humoral) response to shear stress in blood vessels
Release of NO which causes local relaxation of vascular smooth muscle (constant basal release)
What is shear stress? How is this relevant to vessels?
A stress which is applied parallel or tangential to a face of a material. This happens in blood vessels (normal stress is perpendicular)
A peptide that causes blood vessels to enlarge (dilate), and therefore causes blood pressure to lower
Bradykinin
What is bradykinin?
A peptide that causes blood vessels to enlarge (dilate), and therefore causes blood pressure to lower
How do prostaglandins, histamines, bradykinins etc. actually cause inflammation?
The stimulate the release of NO resulting in vasodilation (amongst other things, I'm sure)
An increase in blood flow in response to an increase in local metabolic demand
Functional hyperaemia
An increase in blood flow following an interruption of arterial supply above the level that occurred before occlusion.
Reactive hyperaemia
The muscle of the heart is called the...
Myocardium
What *is* the myocardium?
The muscle of the heart
What is the name for the thick sheet that separates the ventricles?
The interventricular septum
What is the name for the layer that lines the valves and chambers of the heart?
The endocardium
What does the endocardium line?
The chambers and valves, it is the innermost layer
Which small layer separates the tunica intima and tunica media?
The internal elastic lamina
Which layer separates the tunica media from the tunica adventitia?
The external elastic lamina
What are the two types of arteries? What's the difference between them?
Elastic (media contains a high amount of elastin, highly distensible) and muscular arteries
Which type of artery is the aorta?
It is an elastic artery
The principal function of this artery is the efficient distribution of blood to the various vascular beds
Muscular arteries
In a few tissues, there are some direct connections between arterioles and venules, these are known as...
Arteriovenous shunt vessels (or anastomoses)

Plentiful near skin - imagine this is something to do with homoeostasis
What is 'perfusion pressure'?
The gradient between arterial blood pressure and venous pressure in a comparable location in the vascular tree
'The gradient between arterial blood pressure and venous pressure in a comparable location in the vascular tree' is the...
Perfusion pressure
What are the two broad categories that affect the tone of a blood vessel, and how are they different?
Intrinsic: Response of smooth muscle to stretch, temperature and local chemical factors

Extrinsic: Control exerted by ANS and by circulating hormones
The major arteries (except the aorta) are mainly under intrinsic/extrinsic/both. The arterioles and small veins are subject to intrinsic/extrinsic/both.
Major arteries: Extrinsic

Arterioles and small veins: Both
Capillaries and postcapillary venules are normally under intrinsic/extrinsic/both
Neither!
What is the different effect histamine has in arteries and veins?
Vasoconstriction in veins

Vasodilation in arterioles
Autonomic nerves that alter the calibre of blood vessels fall into three groups, what are they?
Sympathetic vasoconstrictor fibres
Sympathetic vasodilator fibres
Parasympathetic vasodilator fibres
What kind of receptors to epinephrine and norepinephrine act on?
Adrenoceptors
Interaction of catecholamines with alpha-adrenoceptors leads to vasoconstriction/vasodilation
Vasoconstriction
What is theistic proof?
an attempt to prove God's existence through valid, sound arguments
Norepinephrine has a much greater affinity for alpha/beta adrenoceptors, and therefore will normally case vasoconstriction/vasodilation
Greater affinity for alpha adrenoceptors, therefore will normally cause vasoconstriction
Why does norepinephrine normally cause vasoconstriction, rather than vasodilation?
Norepinephrine has greater affinity for alpha adrenoceptors, therefore will normally cause vasoconstriction
Which catecholamine has a greater affinity for alpha adrenoceptors, and hence tends to cause vasoconstriction?
Norephinephrine