Heart Physiology Flashcards
mean arterial pressure
(systolic+diastolic) /2
Pulse Pressure
Systolic - diastolic
flow
pressure/resistance
Cardiac output (L/min)
Stroke Volume (ml/min) x HR (BPM)
Stroke Volume
end diastolic volume - end systolic volume
Sympathetic Cardiac Stimulation
2nd Messenger System (Adrenergic Receptor)
- Opens Na+ ligand gated channel
- allows for a quicker depolarization
Cardiac Control Center is located where? consists of what 3 parts?
Medulla Oblangata
- Cardiac Accellatroy
- Cardiac Inhibitory
- Vasomotor
Parasympathetic Cardiac Stimulation
-Direct Messenger
-Direct Chemical opening of K+ channel
-makes it harder to depolarize
-Cholinergic Receptor
_Beta Nicatinic Receptor
Hormonal Mechanisms of Cardiac Control (3)
Glucagon
-increase HR to increase flow of glucose to cells
Thyroid Hormone
-Increase HR to increase blood flow to support increase metabolism
Epinephrine
-increase HR due to sympathetic response
=adrenaline
Ionic Mechanisms of Cardiac Control (4)
Hyperkalemia (k surplus) -prevents/inhibits re-polarization Hypokalemia (K deficiency) -causes over repolarization, making hard to repolarize Hypercalcemia (Ca+ surplus) -Increase contraction strength Hypocalcemia (Ca+ deficient) -Will NOT "platue) = short contraction -releases PTH
3 Tunics of Vessels
Tunica Externa -Dense CT (collagen) Tunica Media -Smooth Muscle -elastic Fibers Tunica Interna -Endothelium
3 Main Differences Between Arteries & Veins
Arteries
- Thicker muscle layer
- NO valves
- more elastic fibers
Veins
- Thinner muscle layer
- Valves
- Less elastic fibers
Vasa vasorum
feeeds the aorta with blood supply
-“Vessel of the vessels”
A small change in resistance = ?
A LARGE change in flow
How does vasomotor control vessel diameter?
Via stimulus
high frequency = constricting muscle = decrease diameter
