C&b 066 Nervous, Local And Humoral Control Of Vascular Resistance And The Distribution Of Blood Flow

Front 1

What are the three layers of the blood vessels?

Back 1

Intima
Media
Adventitia

Front 2

The 'endothelial lining of the lumen' describes which blood vessel layer?

Back 2

The intima (There is also a thin layer of CT)

Front 3

The 'vascular smooth muscle' describes which blood vessel layer?

Back 3

The media (Smooth muscle contains elastin and collagen)

Front 4

The 'connective tissue with autonomic nerves' describes which blood vessel layer?

Back 4

The adventitia

Front 5

The greatest pressure drop occurs over which vessel?

Back 5

The arterioles

Front 6

What is it about the arterioles that make them have the greatest drop in pressure? (It's a ratio)

Back 6

The arterioles have the highest ratio between vessel wall thickness and vessel diameter

Front 7

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

Back 7

Important concept to understand!

Front 8

Does the sympathetic supply to the blood vessels vasoconstrict or vasodilate them?

Back 8

Increased sympathetic activity will constriction

Front 9

Are arterioles normally under some sympathetic, or parasympathetic tone?

Back 9

Slight sympathetic tone (i.e. slightly constricted)

Front 10

Which catecholamine is released by sympathetic vasoconstrictor fibres to the blood vessels?

Back 10

Noradrenaline (norepinephrine)

Front 11

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?

Back 11

A alpha-1 adrenoceptor receptor blocker (antagonist)

Front 12

What receptors does noradrenaline act on?

Back 12

alpha-1 adrenoceptors (NB use in treating hypertension with agonist)

Front 13

Which substances are released by parasympathetic vasodilator fibres?

Back 13

Acetylcholine and nitric oxide

Front 14

All blood vessels are innervated by sympathetic and parasympathetic fibres T/F

Back 14

F, some are not innervated by sympathetic fibres

Front 15

Give an example of humoral control of blood vessels.

Back 15

Adrenaline released from the adrenal medulla (humoral refers to body fluids)

Front 16

Does adrenaline cause vasoconstriction, or vasodilation? Which receptors does it act on?

Think!

Back 16

Vasodilation! Acts on beta-2 adrenoceptors

Front 17

ACE inhibitors, however, cannot be used to treat hypotension T/F

Back 17

T (They treat hypertension)

Front 18

What is an ACE inhibitor?

Back 18

A group of pharmaceuticals that are used primarily in treatment of hypertension and congestive heart failure.

Front 19

A group of pharmaceuticals that are used primarily in treatment of hypertension and congestive heart failure

Back 19

ACE inhibitors

Front 20

In a blood vessel, where is speed the greatest, and why?

Back 20

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

Front 21

What is the body's (?humoral) response to shear stress in blood vessels

Back 21

Release of NO which causes local relaxation of vascular smooth muscle (constant basal release)

Front 22

What is shear stress? How is this relevant to vessels?

Back 22

A stress which is applied parallel or tangential to a face of a material. This happens in blood vessels (normal stress is perpendicular)

Front 23

A peptide that causes blood vessels to enlarge (dilate), and therefore causes blood pressure to lower

Back 23

Bradykinin

Front 24

What is bradykinin?

Back 24

A peptide that causes blood vessels to enlarge (dilate), and therefore causes blood pressure to lower

Front 25

How do prostaglandins, histamines, bradykinins etc. actually cause inflammation?

Back 25

The stimulate the release of NO resulting in vasodilation (amongst other things, I'm sure)

Front 26

An increase in blood flow in response to an increase in local metabolic demand

Back 26

Functional hyperaemia

Front 27

An increase in blood flow following an interruption of arterial supply above the level that occurred before occlusion.

Back 27

Reactive hyperaemia

Front 28

The muscle of the heart is called the...

Back 28

Myocardium

Front 29

What *is* the myocardium?

Back 29

The muscle of the heart

Front 30

What is the name for the thick sheet that separates the ventricles?

Back 30

The interventricular septum

Front 31

What is the name for the layer that lines the valves and chambers of the heart?

Back 31

The endocardium

Front 32

What does the endocardium line?

Back 32

The chambers and valves, it is the innermost layer

Front 33

Which small layer separates the tunica intima and tunica media?

Back 33

The internal elastic lamina

Front 34

Which layer separates the tunica media from the tunica adventitia?

Back 34

The external elastic lamina

Front 35

What are the two types of arteries? What's the difference between them?

Back 35

Elastic (media contains a high amount of elastin, highly distensible) and muscular arteries

Front 36

Which type of artery is the aorta?

Back 36

It is an elastic artery

Front 37

The principal function of this artery is the efficient distribution of blood to the various vascular beds

Back 37

Muscular arteries

Front 38

In a few tissues, there are some direct connections between arterioles and venules, these are known as...

Back 38

Arteriovenous shunt vessels (or anastomoses)

Plentiful near skin - imagine this is something to do with homoeostasis

Front 39

What is 'perfusion pressure'?

Back 39

The gradient between arterial blood pressure and venous pressure in a comparable location in the vascular tree

Front 40

'The gradient between arterial blood pressure and venous pressure in a comparable location in the vascular tree' is the...

Back 40

Perfusion pressure

Front 41

What are the two broad categories that affect the tone of a blood vessel, and how are they different?

Back 41

Intrinsic: Response of smooth muscle to stretch, temperature and local chemical factors

Extrinsic: Control exerted by ANS and by circulating hormones

Front 42

The major arteries (except the aorta) are mainly under intrinsic/extrinsic/both. The arterioles and small veins are subject to intrinsic/extrinsic/both.

Back 42

Major arteries: Extrinsic

Arterioles and small veins: Both

Front 43

Capillaries and postcapillary venules are normally under intrinsic/extrinsic/both

Back 43

Neither!

Front 44

What is the different effect histamine has in arteries and veins?

Back 44

Vasoconstriction in veins

Vasodilation in arterioles

Front 45

Autonomic nerves that alter the calibre of blood vessels fall into three groups, what are they?

Back 45

Sympathetic vasoconstrictor fibres
Sympathetic vasodilator fibres
Parasympathetic vasodilator fibres

Front 46

What kind of receptors to epinephrine and norepinephrine act on?

Back 46

Adrenoceptors

Front 47

Interaction of catecholamines with alpha-adrenoceptors leads to vasoconstriction/vasodilation

Back 47

Vasoconstriction

Front 48

What is theistic proof?

Back 48

an attempt to prove God's existence through valid, sound arguments

Front 49

Norepinephrine has a much greater affinity for alpha/beta adrenoceptors, and therefore will normally case vasoconstriction/vasodilation

Back 49

Greater affinity for alpha adrenoceptors, therefore will normally cause vasoconstriction

Front 50

Why does norepinephrine normally cause vasoconstriction, rather than vasodilation?

Back 50

Norepinephrine has greater affinity for alpha adrenoceptors, therefore will normally cause vasoconstriction

Front 51

Which catecholamine has a greater affinity for alpha adrenoceptors, and hence tends to cause vasoconstriction?

Back 51

Norephinephrine