systolic reserve

diastolic reserve

The difference between ventricular end-diastolic and end-systolic volumes.

Preload brings skeletal muscles to a certain initial length before contraction

Ventricular end-diastolic volume is equivalent to ventricular preload

The amount of venous return to the heart is the main factor that determines the size of ventricular preload.

Definition: The regulation of changes in myocardial contractility by changing the initial length of the myocardium.

Anti-overextension properties of normal ventricular myocardium

Physiological significance: Finely adjust small changes in stroke volume to maintain a balance between ventricular ejection volume and venous return blood volume, thereby maintaining ventricular end-diastolic volume and pressure within the normal range.

Aortic blood pressure is the afterload experienced by the ventricles during contraction

High arterial blood pressure (hypertension) leads to left ventricular hypertrophy, dilation and even left heart failure

Enhancement can shift the ventricular function curve to the upper left

Isometric adjustment

period

Issue 0

Issue 3

Issue 4

Issue 0, 1, 2, 3, 4

longest duration

Phase 4 depolarization relies on the enhancement of If

Subtopic 1

Valid refractory period

relative refractory period

supernormal period

Myocardium does not undergo complete tetanic contraction

Pre-term excitement

Ensures that ventricular contraction occurs after atrium contraction is completed, which is conducive to ventricular filling and ejection

Action potential phase zero depolarization speed and amplitude

membrane point level

Excitability of membranes adjacent to unexcited areas

normal pacemaker

sinus rhythm

potential pacemaker

ectopic pacemaker

4-stage automatic depolarization speed

maximum repolarization potential level

threshold potential level

Innervates the sinoatrial node, atrioventricular junction, atrioventricular bundle, atrial myocardium, ventricular myocardium

posterior cardiac sympathetic fibers

Innervates the sinus node, atrioventricular junction, atrioventricular bundle and its branches

retrovagal fibers

nervous

Norepinephrine

acetylcholine

Activity is mainly controlled by the activity of high cardiovascular centers

The most basic center that regulates cardiovascular activity

When neurons in the nucleus of the solitary tract (NTS) of the medulla oblongata are excited, the vagus nerve activity is enhanced and the sympathetic nerve activity is inhibited.

The frequency of incoming impulses is directly proportional to the degree of vasodilation

Baroreceptor reflex set point 100mmHg

physiological significance

Sensitive to rapid blood pressure changes but insensitive to slow blood pressure changes

Feel the stimulation of decreased oxygen partial pressure, increased carbon dioxide partial pressure and increased hydrogen ion concentration in arterial blood

Not obvious, it only plays a regulatory role in situations such as hypoxia, asphyxia, blood loss, hypotension, and acidosis.

mechanical stretch stimulation

Chemicals - prostaglandins, adenosine and bradykinin

Increased heart rate, increased cardiac contractility, increased cardiac output

Extensive contraction of blood vessels throughout the body, increased peripheral resistance, and increased blood pressure

cause vasoconstriction

Promote water reabsorption

Average filling pressure 7mmHg

100～120mmHg

60~80mmHg

The difference between the two is 30~40mmHg