Vascular Resistance, Flow, and Mean Arterial Pressure

Blood flows through the heart, arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries, capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries, and veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular resistance is directly related to the diameter of the vessel (smaller vessels have higher resistance). Mean arterial pressure (MAP) is the average systemic arterial pressure and is directly related to cardiac output (CO) and systemic vascular resistance (SVR). The SVR and MAP are affected by the vascular anatomy as well as a number of local and neurohumoral factors.

Last update:

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Table of Contents

Share this concept:

Share on facebook
Share on twitter
Share on linkedin
Share on reddit
Share on email
Share on whatsapp

Flow, Pressure, and Resistance in Blood Vessels

Overview

  • Blood flows through the heart, arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries, capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries, and veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins in a closed, continuous circuit.
  • Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute).
  • Hemodynamics refer to the physical principles governing blood flow, which are:
    • The pressure gradient between 1 point and another
    • Resistance of the vessel

Ohm’s law

Ohm’s law is an important basic formula in physics. A derivation of Ohm’s law can be used to calculate blood flow.

  • Ohm’s law: I = V / R:
    • Current (I) = flow of charged particles
    • Voltage (V) = the difference in concentration of charged particles at 2 different points
    • Resistance (R) = opposition to current flow
  • The current (flow of electrons) in a closed system is directly proportional to voltage and inversely proportional to resistance within the system.
$$I= \frac{V}{R}$$
  • Ohm’s law applied to the cardiovascular system: F = ΔP / R:
    • Flow (F) = blood flow through a vessel 
    • Pressure gradient (ΔP) = change in pressure between 2 different points (i.e., ΔP = P1 ‒ P2
    • Resistance (R) = opposition to blood flow
$$F= \frac{\Delta P}{R}$$

Flow

Flow: the volume of fluid passing a point per unit of time:

  • Caused by a ΔP between 2 points (there is no flow without a ΔP)
  • 2 types of flow: laminar and turbulent
  • Laminar flow:
    • Smooth-walled vessels allow for smooth flow through the tube
    • Flow is fastest in the center of the vessel (less friction) and slowest against the walls (more friction).
    • Results in cylindrical “layers” of different flow rates
    • Characteristic of healthy vessels
  • Turbulent flow:
    • Irregular swirling or turnover of fluid in the vessel
    • Results in ↑ contact with vessel walls → ↑ friction → ↑ resistance 
    • → ↓ Flow at a given ΔP (compared to laminar flow)
    • Occurs when there is:
      • Too much pressure for a given vessel
      • An occlusion in the vessel
    • An atherosclerotic vessel causes turbulent flow.

Resistance

Resistance: forces opposing flow:

  • Arises from the friction between the moving blood and vessel walls
  • Equation for resistance against laminar flow: R = (8 x viscosity x length) / πr4
    • R = resistance
    • Viscosity = thickness of the blood
    • Length = length of the vessel
    • r = radius of the vessel
  • Viscosity:
    • The thickness of the blood
    • Due primarily to:
      • Number of erythrocytes Erythrocytes Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes
      • Albumin levels
      • Hydration status
    • ↑ Viscosity: due to polycythemia, hyperalbuminemia, and dehydration
    • ↓ Viscosity: due to anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview, hypoalbuminemia, and adequate hydration
    • Relatively stable within individuals: The body is unable to quickly regulate flow by adjusting viscosity.
  • Length of the vessel: 
    • The longer the vessel, the greater the cumulative friction encountered
    • Each vessel has a fairly fixed length (no ability for regulation).
  • Radius of the vessel:
    • Significant impact on resistance
    • Highly regulated by smooth muscle within the vessel walls
    • = ↑ Radius of vessel → ↓ blood in contact with the vessel wall → ↓ friction → ↓ overall resistance → ↑ blood flow through the vessel
    • Vasoconstriction: ↓ radius 
    • Vasodilation: ↑ radius

Pressure gradient (ΔP)

ΔP: the difference in pressure between 1 point and another 

  • Influences the direction of blood flow (blood flows from high pressure → low pressure)
  • If the flow is constant (which the body tries to maintain), vessel resistance ↑ (e.g., vasoconstriction) and leads to ΔP ↑.
  • Clinical relevance: narrow vessels from atherosclerotic disease = ↑ blood pressure
  • Types of physiologic ΔP:
    • Systemic: arterial pressure > venous pressure
    • Local: proximal vessel pressure > distal vessel pressure
Pressure as a function of flow and resistance

Pressure as a function of flow and resistance:
Pressure is directly related to both flow and resistance. As either flow or resistance increases, pressure increases proportionally.
ΔP (pressure gradient) = R (resistance) x F (flow)

Image by Lecturio.

Capacitance

Capacitance: the amount a vessel can stretch without significantly increasing pressure:

  • Capacitance: C = ΔV / ΔP:
    • C: capacitance
    • ΔV: change in volume
    • ΔP: change in pressure
  • Venous capacitance > arterial capacitance
  • 60%–80% of total blood volume is in the venous circulation.

Velocity

  • The speed blood is traveling.
  • Velocity is inversely related to the radius of the blood vessel (i.e., velocity increases when diameter decreases).
  • Velocity is different from flow:
    • Velocity is a unit of distance per unit of time.
    • Flow is a unit of volume per unit time.
    • Clinical relevance: The velocity of blood moving across the valve will increase with a stenotic valve (smaller diameter), but the flow will not.
  • Relationship between flow and velocity:
    • Flow = velocity x the area of the vessel or pathway available to blood
    • Flow = velocity x (πr2)
Relationship between flow and velocity

The relationship between flow and velocity:
Velocity is inversely related to area. If the radius of the cylinder (r) is halved, the velocity increases 4-fold.
F: flow
V: velocity
A: area
r: radius

Image by Lecturio.

Mean Arterial Pressure (MAP)

Mean arterial pressure equations

Mean arterial pressure is the average systemic arterial pressure.

  • MAP = (CO x SVR) + CVP:
    • CO: cardiac output (stroke volume x heart rate)
    • SVR: systemic vascular resistance
    • CVP: central venous pressure (close to 0; often disregarded)
  • Approximate using systolic blood pressure (SBP) and diastolic blood pressure (DBP):
    • Because the heart spends more time in diastole than systole, DBP contributes more to the MAP than SBP.
    • Equation: MAP ≅ [⅓ (SBP ‒ DBP)] + DBP
Map cycle

Mean arterial intravascular pressure throughout the cardiac cycle
MAP: mean arterial pressure
P: pressure
Sys: systolic
Dias: diastolic

Image by Lecturio.

Factors affecting the MAP

Mean arterial pressure is primarily affected by the CO and SVR:

CO = heart rate x stroke volume:

  • Heart rate is determined by:
    • The autonomic nervous system Autonomic nervous system The ANS is a component of the peripheral nervous system that uses both afferent (sensory) and efferent (effector) neurons, which control the functioning of the internal organs and involuntary processes via connections with the CNS. The ANS consists of the sympathetic and parasympathetic nervous systems. Autonomic Nervous System (primary regulator)
    • Other factors: 
      • Thyroid hormones Thyroid hormones The 2 primary thyroid hormones are triiodothyronine (T3) and thyroxine (T4). These hormones are synthesized and secreted by the thyroid, and they are responsible for stimulating metabolism in most cells of the body. Their secretion is regulated primarily by thyroid-stimulating hormone (TSH), which is produced by the pituitary gland. Thyroid Hormones 
      • Circulating catecholamines
      • K+ levels
      • Ischemia
  • Stroke volume is determined primarily by:
    • Inotropy: the contractile strength of each heartbeat
    • Afterload: the pressure the left ventricle needs to overcome to eject blood into the aorta
    • Preload: the amount the ventricles have stretched or filled with blood by the end of diastole, which is affected by:
      • Venous compliance (the amount of blood the veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins can hold)
      • Blood volume (primarily affected by renal Na+ and H2O handling)

Systemic vascular resistance is primarily affected by:

  • Vascular anatomy:
    • Arrangement of vessels in series or parallel
    • Anatomy of the vessel walls
  • Local factors secreted by vessel walls
  • Multiple neurohumoral factors
Actors that affect mean arterial pressure

Factors affecting mean arterial pressure
MAP: mean arterial pressure
CO: cardiac output
SVR: systemic vascular resistance
SV: stroke volume
HR: heart rate

Image by Lecturio.

Vascular Anatomy Affecting Mean Arterial Pressure

Vascular anatomy has significant effects on SVR, which directly affects MAP.

Arrangement of vessels in series or parallel

  • Series circuits: 
    • Blood runs through the vessels sequentially; therefore, resistance is additive along the length of the entire vessel.
    • Example: a measure of the resistance along a single path from aorta → large artery → arteriole → a single capillary
    • Total resistance (RT) = R1 + R2 + R3
  • Parallel circuits: 
    • Multiple paths are available to the blood when vessels divide.
    • The total area through which blood can flow is increased, even if the individual vessels have a smaller diameter.
    • Resistance decreases with each available path for blood to follow.
    • Example: Resistance changes as blood moves farther from the heart:
      • Blood flows from the aorta (a single vessel) → all the capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries in the systemic circulation (millions of pathways)
      • The cross-sectional area of the aorta: approximately 3–5 cm2
      • The cross-sectional area of all capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries combined: approximately 4,500–6,000 cm2 
    • Total resistance for vessels in parallel: 1/RT = 1/R1 + 1/R2 + 1/R3
  • Mathematical example:
    • Assume: a circuit with 3 points of resistance, all equal to 10 arbitrary units
    • In series: RT = 10 + 10 + 10 = 30 
    • In parallel: 1/RT = 1/10 + 1/10 + 1/10 → 1/RT = 3/10 → RT = 3.3 
    • If a 4th circuit is added, resistance increases to 40 in series and drops to 2.5 in parallel.
Vascular circuit

Left: a vascular circuit in series with 3 different points of resistance
Right: a vascular circuit in parallel

Image by Lecturio.

Anatomy of vessel walls

Vessels have:

  • Different functions at different points in the circuit. For example:
    • Pulse dampening: aorta
    • Distribution of blood to the body: aorta, large arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries
    • Resistance (regulates pressure and flow): small arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries and arterioles
    • Gas, nutrient, and waste exchange: capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries
    • Collection: venules
    • Capacitance (holding blood volume): venules, veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins, and vena cava
  • Different amounts of smooth muscle in the wall depending on the function
  • Different diameters

Distribution of pressure:

  • As the blood leaves the heart and moves through the body, pressure continually decreases until the blood returns to the heart → ΔP is always causing forward flow of blood through the circuit
  • In arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: walls are thicker/more smooth muscle:
    • Protect against higher pressures 
    • Ability to control flow
  • In capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries
    • Capillary beds serve as parallel circuits.
    • Minimal resistance is created, allowing for lower pressures.
    • Thicker wall muscles are not needed to protect against high pressures.
    • Thin walls allow for gas exchange Gas exchange Human cells are primarily reliant on aerobic metabolism. The respiratory system is involved in pulmonary ventilation and external respiration, while the circulatory system is responsible for transport and internal respiration. Pulmonary ventilation (breathing) represents movement of air into and out of the lungs. External respiration, or gas exchange, is represented by the O2 and CO2 exchange between the lungs and the blood. Gas Exchange.
    • Pressure is higher at the arteriole end of the capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries than at the venules → pushes blood through capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries
  • In veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: 
    • Thinner walls allow veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins to stretch (capacitance) 
    • Lowest pressures
Respective intraluminal pressures

Respective intraluminal pressures: Intraluminal pressure decreases as blood moves from the arterial to the venous system.

Image by Lecturio.

Local Factors Affecting Mean Arterial Pressure

Endothelial cells lining blood vessels can secrete a number of factors causing vasodilation or vasoconstriction. Changing the radius of the vessel changes the SVR, which changes MAP.

Vasoconstriction

  • Primarily occurs by increasing intracellular calcium (Ca2+) levels, which is required for myofilament (actin and myosin) contraction within muscle cells.
  • Factors causing ↑ intracellular Ca2+ include:
    • Endothelins
    • Thromboxanes
    • Angiotensin II 
    • Trauma

Vasodilation

  • Ultimately occurs due to:
    • ↓ Intracellular Ca2+ levels
    • ↑ Myosin light chain (MLC) phosphatase activity → leads to ↑ dephosphorylation of contracted actin → relaxation
  • Production of NO:
    • Synthesized by:
      • Endothelial NO synthase (eNOS) in endothelial cells (primary mode of synthesis)
      • Neuronal NO synthase (nNOS) in parasympathetic neurons
    • NO stimulates guanylyl cyclase (GC)
    • GC converts guanosine triphosphate (GTP) → cyclic guanosine monophosphate (cGMP)
    • cGMP → ↓ intracellular Ca2+ and ↑ MLC phosphatase activity → vasodilation
  • Production of prostacyclin:
    • Synthesized by cyclooxygenase (COX) enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body's constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes
    • ↑ Levels of cAMP
    • cAMP → ↓ intracellular Ca2+ and ↑ MLC phosphatase activity → vasodilation
  • Factors stimulating the production of NO and/or prostacyclin:
    • Acetylcholine
    • ATP
    • Substance P
    • Bradykinin
    • Thrombin
    • Histamine
    • Bacterial endotoxins
    • Shearing forces
Chemical pathways lead to production of nitric oxide

Chemical pathways lead to the production of nitric oxide, which ultimately causes smooth muscle relaxation and vasodilation.
GTP: guanosine triphosphate
Gq: gq protein
GC: guanylyl cyclase
cGMP: cyclic guanosine monophosphate
Ca2+: calcium

Image by Lecturio.

Overview of Neurohumoral Factors Affecting Mean Arterial Pressure

Effects on the arterial system

Neurohumoral factors can affect both CO and SVR and include:

  • Stimulation from the ANS:
    • Sympathetic stimulation: ↑ CO and SVR → ↑ MAP
    • Parasympathetic stimulation: ↓ CO and SVR → ↓ MAP
  • Arterial baroreceptor reflex: senses pressures and adjusts CO to maintain blood pressure homeostasis
  • Circulating catecholamines:
    • Secreted by the adrenal medulla into the blood
    • Similar effect as sympathetic stimulation: ↑ CO and SVR → ↑ MAP
    • Hormones:
      • Epinephrine
      • Norepinephrine
  • RAAS: 
    • The primary mechanism to control Na+ and level of body water
    • Activation of the RAAS → ↑ Na+ and water retention by the kidneys Kidneys The kidneys are a pair of bean-shaped organs located retroperitoneally against the posterior wall of the abdomen on either side of the spine. As part of the urinary tract, the kidneys are responsible for blood filtration and excretion of water-soluble waste in the urine. Kidneys → ↑ blood volume → ↑ preload → ↑ CO → ↑ MAP
  • Antidiuretic hormone (ADH):
    • Opposes the RAAS by stimulating the excretion of water into the urine
    • Secretion of ADH from the posterior pituitary → ↑ water excretion → ↓ blood volume → ↓ preload → ↓ CO → ↓ MAP
  • Natriuretic peptides:
    • Hormones secreted by the heart inhibit the RAAS.
    • ↓ Na+ and water retention by the kidneys Kidneys The kidneys are a pair of bean-shaped organs located retroperitoneally against the posterior wall of the abdomen on either side of the spine. As part of the urinary tract, the kidneys are responsible for blood filtration and excretion of water-soluble waste in the urine. Kidneys → ↓ blood volume → ↓ preload → ↓ CO → ↓ MAP
    • Hormones:
      • Atrial natriuretic peptide: secreted by atrial myocytes
      • Brain natriuretic peptide: secreted by ventricular myocytes

Effects on the venous system

Neurohumoral factors (primarily via the ANS) can affect venous capacitance, which can affect preload and, as a result, CO and MAP:

  • Venoconstriction → ↓ venous capacitance → ↑ venous return to the heart → ↑ preload → ↑ CO → ↑ MAP
  • Venodilation → ↑ venous capacitance → ↓ venous return to the heart → ↓ preload → ↓ CO → ↓ MAP
Changes in venous tone and the effect of capacitance

Changes in venous tone and the effect on capacitance
VSMC: vascular smooth muscle cell

Image by Lecturio.

Clinical relevance

The information presented below explains factors that determine blood pressure and how blood moves throughout the body. The foundational topics are critical to understanding how and why the body adjusts to different situations in order to maintain appropriate perfusion.

  • Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension: chronically increased pressure in the arterial system. The increased pressures are due to narrower vessels (i.e., smaller radius). The pressures can cause damage to more delicate capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries, which is especially problematic in the kidneys Kidneys The kidneys are a pair of bean-shaped organs located retroperitoneally against the posterior wall of the abdomen on either side of the spine. As part of the urinary tract, the kidneys are responsible for blood filtration and excretion of water-soluble waste in the urine. Kidneys and eyes. In addition, hypertension is a state of persistently increased afterload, requiring the heart to pump harder to eject the same volume of blood to maintain flow rates. Therefore, hypertension is a major risk factor for both heart disease and peripheral vascular disease.
  • Hemorrhage: excessive blood loss, which results in decreased blood volume and leads to ↓ preload, ↓ stroke volume, ↓ cardiac output, ↓ MAP, and, as a result, ↓ perfusion to vital organs. To maintain perfusion, the body attempts to increase MAP by boosting CO through increases in heart rate and contractility, and by vasoconstriction to increase SVR. Intravenous fluids Intravenous Fluids Intravenous fluids are one of the most common interventions administered in medicine to approximate physiologic bodily fluids. Intravenous fluids are divided into 2 categories: crystalloid and colloid solutions. Intravenous fluids have a wide variety of indications, including intravascular volume expansion, electrolyte manipulation, and maintenance fluids. Intravenous Fluids and/or blood transfusions can help to restore blood volume.

References

  1. Mohrman, D. E., & Heller, L. J. (2018). Overview of the cardiovascular system. Cardiovascular physiology, 9e (). New York, NY: McGraw-Hill Education. Retrieved from accessmedicine.mhmedical.com/content.aspx?aid=1153946098
  2. Mohrman, D. E., & Heller, L. J. (2018). Vascular control. Cardiovascular physiology, (9e). New York, NY: McGraw-Hill Education. Retrieved from accessmedicine.mhmedical.com/content.aspx?aid=1153946722
  3. Mohrman, D. E., & Heller, L. J. (2018). Regulation of arterial pressure. Cardiovascular physiology, 9e (). New York, NY: McGraw-Hill Education. Retrieved from accessmedicine.mhmedical.com/content.aspx?aid=1153946898
  4. Baumann, B. M. (2016). Systemic hypertension. In J. E. Tintinalli, J. S. Stapczynski, O. J. Ma, D. M. Yealy, G. D. Meckler & D. M. Cline (Eds.), Tintinalli’s emergency medicine: A comprehensive study guide, 8e (). New York, NY: McGraw-Hill Education. Retrieved from accessmedicine.mhmedical.com/content.aspx?aid=1121496251
  5. Klabunde R. E. (2021). Cardiovascular Physiology Concepts. Retrieved 10 June 2021, from https://www.cvphysiology.com/
  6. Saladin, K. S., Miller, L. (2004). Anatomy and physiology. (3rd Ed. Pp. 753–760).

Study on the Go

Lecturio Medical complements your studies with evidence-based learning strategies, video lectures, quiz questions, and more – all combined in one easy-to-use resource.

Learn even more with Lecturio:

Complement your med school studies with Lecturio’s all-in-one study companion, delivered with evidence-based learning strategies.

User Reviews

0.0

()

¡Hola!

Esta página está disponible en Español.

🍪 Lecturio is using cookies to improve your user experience. By continuing use of our service you agree upon our Data Privacy Statement.

Details