CV Flashcards
(135 cards)
Neural control centers for the heart are located here:
Medulla oblongata
What type of innervation stimulates the heart?
Sympathetic
What receptors respond to norepinephrine?
Beta1-adrenergic
What innervation generally inhibits the heart?
Parasympathetic
What receptors respond to acetylcholine?
Muscarinic
What is the pattern of electrical transmission?
SA node > preferred pathways > AV node > bundle of His> R/L bundle branches > purkinje fibers
Systole is further divided into:
Isovolumetric ventricular contraction and ventricular ejection
Diastole is further divided into:
Isovolumetric ventricular relaxation and ventricular filling
Stroke volume equals:
EDV -ESV
Cardiac output equals:
HR x SV
Ejection fraction
SV/ EDV
The most important variable of resistance is
The radius of the blood vessel
Structure of the blood vessel walls includes these 3 structures:
- Tunica intima- endothelium
- Tunica media- smooth muscle
- Tunica externa- connective tissue
These are low-resistance vessels that serve as conduits for blood flow.
Arteries
Arteries function as pressure reservoirs that maintain blood flow during
Diastole
Elastic arteries are closer to this and easily distend.
Heart
Muscular arteries are closer to these and have more smooth muscle.
Arterioles
These regulate blood flow and distribution by changing the radius from signals that may be extrinsic/systemic or intrinsic/local.
Arterioles
Mechanisms of intrinsic control of arterioles are:
- Active hyperemia
- Flow autoregulation
- Reactive hyperemia
- Response to injury
Mechanisms of extrinsic control include these:
- ANS
2. Hormones
The most important control signals for the arterioles include:
- SNS
- Epi
- Angiotensin II/ ADH
- ANP
- Prostacyclin
- EDRF
What does epi do?
It vasodilator skeletal muscle vessels and vasoconstricts peripheral blood vessels.
What does angiotensin II/ ADH do?
Vasodilator
What does prostacyclin do?
Vasodilator