Elastic reservoir blood vessels: the main trunk of the aorta, pulmonary artery and their largest branches; it converts the intermittent ejection of blood from the ventricles into the continuous flow of blood in the blood vessels, and at the same time reduces the fluctuation amplitude of blood pressure during the cardiac cycle.

Distribution blood vessels: middle arteries; transports blood to various organs and tissues

Precapillary resistance vessels: arterioles and arterioles; their systolic and systolic activities change the blood volume and caliber, thereby changing the resistance to blood flow and the blood flow of the organs and tissues where they are located.

Precapillary sphincter: Smooth muscle surrounding the origin of true capillaries; controls the opening or closing of capillaries

Exchange vessels: true capillaries, composed only of a single layer of endothelial cells; the main site for material exchange

Postcapillary resistance vessels: refers to venules; changes capillary blood pressure, blood volume and filtration, affecting the distribution of body fluids inside and outside blood vessels.

Capacitive vessels: the venous system; serves as a reservoir for blood

Short-circuiting vessel: a direct anastomosis between arterioles and venules in a vascular bed; involved in thermoregulation

Endothelial cells: vasodilator active substances are NO, hydrogen sulfide, and prostacyclin; vasoconstrictor active substances are endothelin and TXA2

Smooth muscle cells: regulate the tone and blood flow of local blood vessels

Other cells: protect, support and nourish blood vessels

forming conditions

Pulse pressure = systolic blood pressure - diastolic blood pressure; mean arterial pressure = diastolic blood pressure 1/3 pulse pressure

Factors affecting arterial blood pressure

Classification

venous blood return volume

As a place where the body exchanges substances and gases with the external environment, it plays an important role in maintaining the metabolism of tissue cells and the homeostasis of the internal environment.

Blood circulation between arterioles and venules; including arterioles (general gate), posterior arterioles, precapillary sphincter (branch gates), true capillaries, blood-operating capillaries, arteriovenous anastomosis branches and venules ( rear gate) etc.

Blood flow pathways: circuitous pathways, direct pathways and arteriovenous short circuits

The force of capillary blood pressure and interstitial fluid colloid osmotic pressure to promote fluid filtration from the inside to the outside of capillaries, the force of interstitial fluid hydrostatic pressure and plasma colloid osmotic pressure of outward to inward reabsorption; effective filtration pressure = (capillary blood pressure, interstitial fluid colloid osmotic pressure) - (Tissue fluid hydrostatic pressure, plasma colloid osmotic pressure)

Factors affecting tissue fluid production

Auxiliary system for the return of tissue fluid to blood

Recycle proteins and absorb nutrients; remove red blood cells, bacteria, and foreign matter from tissues; balance the production and absorption of tissue fluid

Sympathetic nerve-NE-β1 receptor ( )

Vagus nerve-ACh-M receptor (-)

innervation of blood vessels

Spinal cord, medulla oblongata, hypothalamus, other

Carotid sinus and aortic arch baroreflex (hypertensive response)

Carotid and aortic body chemoreceptive reflexes: regulate respiration, thereby affecting RP

Cardiovascular reflexes caused by cardiopulmonary receptors: regulate circulating blood volume and extracellular fluid volume

Renin is an acid protease synthesized and secreted by juxtaglomerular cells

The function of Ang II is vasoconstriction, increased release of transmitters from sympathetic nerves, increased central nervousness of sympathetic vasoconstrictors, and increased aldosterone production.

Factors that stimulate renin secretion: reduced resting potential; reduced circulating blood volume; enhanced sympathetic nerve excitation

Synthesized by neurons in the supraoptic and paraventricular nuclei of the hypothalamus, stored and released by the neurohypophysis

Antidiuretic effect occurs under physiological conditions; when the concentration increases significantly, vasoconstriction causes an increase in blood pressure

Maintain constant extracellular fluid volume and arterial blood pressure

Increased ADH production: increased plasma crystal osmotic pressure; decreased blood volume and resting potential; pain, excitement, and hypoxia

Influencing factors: vasopressin VP; atrial natriuretic peptide ANP; RAS system, aldosterone; sympathetic nervous system activity