Sign: Atrioventricular valve closure, S1

Label: Semilunar valve closed, S2

slow down

fast

atrial systole

Preload = initial length active tension

afterload = contraction tension Active tension—speed/degree/time (inversely proportional)

Cytoplasmic Ca2 concentration

Cross-bridge ATPase activity

Spatial (multi-fiber) sum

Frequency (time) sum

Mechanism: Rapid influx of Na ions

Factors: Sodium inward current (INa), T-type calcium current (ICa-T)

Main transmembrane current: instantaneous outward current (Ito), the main component is K ions

Inward current: L-type calcium current (ICa-L) Na slow deactivation Na-Ca exchange

Outward current: Inward rectifier potassium current (IK1)

It is in a balanced state in the early stage, and then calcium channels gradually become inactivated and potassium ion outflow increases.

Ion current: outward current

Increased activity of sodium pump and Na ion-Ca calcium ion exchanger

sinoatrial node cell action potential

Purkinje cell action potential

Valid refractory period

relative refractory period

supernormal period

Resting potential/maximum repolarizing potential level

threshold potential level

Ion channels that cause phase 0 depolarization

Myocardial c excitation cycle is effective and the refractory period is particularly long

Premature beats (premature/excitable)

compensatory interval

Heart activity is always carried out according to the rhythmic excitement emitted by the most autonomous tissues.

Normal pacemaker: sinoatrial node

Potential pacemaker points: other self-regulatory organizations, which under normal circumstances only serve to transmit excitement

Phase 4 automatic depolarization speed: the faster the speed, the higher the self-discipline.

Maximum repolarization potential level: as the level decreases, automaticity increases

Threshold potential: When it increases, automaticity decreases

Automatic excitement frequency

Slow conduction at the atrioventricular junction: atrioventricular delay

Purkinje cells conduct rapidly

diameter of c

The speed and amplitude of phase 0 depolarization

Membrane potential level (voltage)/resting potential

The excitability of the myocardium in the adjacent unexcited zone

Mainly the resistance of arterioles and arterioles to blood flow

Aortic blood pressure by measuring brachial artery blood pressure

Systolic blood pressure: the blood pressure that reaches its highest value in the middle of ventricular systole, 100-120mmHg

Diastolic blood pressure: The blood pressure at which arterial blood pressure reaches its lowest value at the end of ventricular diastole, 60-80mmHg

Pulse pressure (referred to as pulse pressure): the difference between systolic blood pressure and diastolic blood pressure, 30-40mmHg

Mean arterial pressure: diastolic pressure 1/3 pulse pressure, 100mmHg

Blood pressure increases with age

Men have higher blood pressure than women

genetics

Nutritional pathways, material exchange

The blood flow resistance is small and the flow rate is fast, which promotes blood return to the heart and ensures circulating blood volume.

Often closed, open when temperature rises, often seen on the skin; regulates body temperature

Maximum resistance to blood flow (peripheral resistance)

Blood pressure dropped most significantly

Regulates arterial blood pressure

Main function of regulating organ blood flow

Nerve fibers are less distributed and not subject to neural regulation

Regulated by local metabolites (CO2, H, adenosine), local body fluid regulation, metabolic autoregulation

Capillary blood pressure↑

Interstitial fluid colloid osmotic pressure↑

hypoalbuminemia

Filariasis, cancer patients (lymphatic metastasis-cancer thrombus)

Mechanism: The cell body of the preganglionic neuron of the cardiac sympathetic ganglia (located in the middle and lateral side of the 1st to 5th thoracic spinal cord)

Preganglionic neuron cell bodies (dorsal vagal nucleus and nucleus ambiguus located in the medulla oblongata)

Mechanism: Postganglionic fiber terminals release norepinephrine → vascular smooth muscle cells

Almost all blood vessels in the body are innervated by sympathetic vasoconstrictor nerve fibers

Most blood vessels only receive a single innervation from sympathetic constrictor N fibers (cutaneous blood vessels)

Distribution density

skeletal muscle blood vessels

parasympathetic vasodilatory nerve

Concept: The most basic center that regulates cardiovascular activity (life center)

The ventrolateral area of ​​the rostral medulla oblongata: an important site for generating and maintaining tonic activity of cardiac sympathetic nerves and sympathetic vasoconstrictors

arterial baroreceptor

Features

cardiopulmonary receptors: receptors located in the walls of the atria, ventricles, and large vessels of the pulmonary circulation

Suitable stimulation

physiological significance

Physiological significance: plays a role in hypoxia, suffocation or blood loss to ensure blood supply to important organs

It can hydrolyze angiotensin synthesized and released in the liver or tissues into a decapeptide, which is angiotensin I.

Vasodilation, peripheral resistance decreases

Decreased cardiac output

Enhanced renal drainage and sodium excretion