Guyton Flashcards
What are the 4 phases of the cardiac cycle
1- Filling
2- Isometric contraction
3- Ejection
4- Isometric relaxation
What are the 3 steps of phase 1
A- Rapid filling
B- Slow (from atria trough ventricle)
C- Atrial contraction (Additional 20% filling)
Main nutrient for myocytes is ___
Fatty acids
Regulation of heart pumping results from those 2 main concept:
1- Changes in volume
(extra blood = stretch = increased force of contraction)
2- Autonomic nervous system
Sympathetic system in regards to heart function results in ____
Increased output and HR
The parasympathetic nervous system innerve mainly ___ of the heart, whereas the sympathetic system innerve mainly the ____
Atria
Ventricle
The sinoatrial node is located ___
In the right atrium, near the vena cava
The impulse in the AV node is ___ to give ______. This is caused mainly by ___ gap junction
delayed
time for atria to empty
deminished number of
If the sinus node do not function well, which 2 location can results in discharge and at which rate
AV node (40-60 bpm) Purkinje fibers (15-40)
Parasymthetic system of the heart results in release of ____ which ____. The sympathetic system results in release of ____ which ___
Ach; increase permeability to K+ (resting potential more negative; slow rhythm and conduction)
Norepinephrine: stimulate B1 receptors
In bundle brache block, if the lead in III is negative, this means that this is a ___ BBB
Left
The colloid pressure includes the presence of ___, ___ and ____
albumin, globulin and fibrinogen
The baroreceptor signal goes from by the ____ or ___ nerve before going to the nucleus tractus solitary
Glossopharyngeal
Vagus
Name the 3 rapid pressure feedback mechanism, the 3 moderate timely response and the one that is delayed response
- Baroreceptors, CNS and chemoreceptors
- RASS, stretch-relaxation vascular mechanism and capillary fluid shift
- Renal
What are the 3 main features of the tetralogie de fallot?
- Aorta originates from right ventricle
-VSD - PS
Results in cyanosis
