Vessel physiology

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Questions and Answers

Which of the following statements about elastic arteries is true?

They primarily function as distributing arteries.

They contain more smooth muscle than muscular arteries.

They serve as major pressure reservoirs in the circulation. (correct)

They have a thick external elastic lamina.

What is the primary function of muscular arteries?

To distribute blood to various organs and tissues. (correct)

To control systemic blood pressure exclusively.

To completely vasoconstrict and cut off blood flow.

To serve as primary pressure reservoirs.

Which artery is classified as an elastic artery?

Coronary artery

Aorta (correct)

Radial artery

Brachial artery

What role do arterioles play in the circulatory system?

They regulate blood flow into capillary beds via smooth muscle constriction. (D) Signup and view all the answers

What is the function of metarterioles in the circulatory system?

To control blood flow into individual capillaries using precapillary sphincters. (C) Signup and view all the answers

Which pathological condition is least likely to disturb laminar flow and increase turbulence?

Low blood viscosity (C) Signup and view all the answers

What is the effect of increased forward velocity in a blood vessel according to the Bernoulli Principle?

Pressure remains constant (C) Signup and view all the answers

How does the pressure change as blood moves from arteries to capillaries?

Pressure decreases significantly (D) Signup and view all the answers

In which vessel is blood velocity the highest?

Aorta (B) Signup and view all the answers

What happens to blood velocity as it moves from capillaries back to veins?

It increases (C) Signup and view all the answers

Which statement about capillary pressure is correct?

It can drop to around 30 mm Hg or lower (C) Signup and view all the answers

Which of the following factors does NOT contribute to turbulence in blood flow?

Increased blood viscosity (D) Signup and view all the answers

What is the primary reason for the reduction in blood velocity in capillaries?

Increased total cross-sectional area (A) Signup and view all the answers

What is the primary function of valves in veins?

To prevent backflow of blood (C) Signup and view all the answers

Which layer is the thickest in the structure of a typical vein?

Tunica Adventitia (A) Signup and view all the answers

According to Poiseuille’s Law, what is the effect of a smaller vessel radius on resistance?

Higher resistance (D) Signup and view all the answers

What structural feature distinguishes venules from larger veins?

Very few layers of smooth muscle cells (B) Signup and view all the answers

What is the significance of vasa vasorum in the tunica adventitia?

They provide oxygen and nutrients to the vessel walls (D) Signup and view all the answers

What role do postcapillary venules play in inflammatory responses?

Allow white blood cells to exit the bloodstream (B) Signup and view all the answers

How does the volume of blood contained in systemic veins compare to that in arteries?

Systemic veins contain close to 2/3 of total blood volume (C) Signup and view all the answers

What feature typically distinguishes large and medium veins in the body?

Presence of valves (A) Signup and view all the answers

What is the primary function of veins in the circulatory system?

They act as reservoirs to store blood without significant pressure changes. (A) Signup and view all the answers

What effect does standing up have on blood volume distribution?

It causes a shift of blood from central to peripheral compartments due to gravity. (D) Signup and view all the answers

In cases of congestive heart failure (CHF), what risk is associated with administering extra IV fluids?

It can worsen fluid overload and exacerbate the patient's condition. (D) Signup and view all the answers

What role does central blood volume play in the cardiovascular system?

It is critical for optimal ventricular stretch and influence on cardiac output. (C) Signup and view all the answers

Why is it beneficial to constrict arteries and veins during hemorrhage?

It can help maintain blood pressure and direct blood towards vital organs. (C) Signup and view all the answers

What characteristic of veins contributes to their ability to hold more blood without significantly increasing pressure?

High compliance (B) Signup and view all the answers

How does the arrangement of capillaries in the systemic circulation affect cumulative resistance?

It decreases cumulative resistance due to parallel arrangement (C) Signup and view all the answers

What happens to the compliance of blood vessels with age?

It decreases due to calcification and atherosclerosis (B) Signup and view all the answers

What is the main function of low compliance in arteries?

Maintains high blood pressure for efficient organ blood flow (A) Signup and view all the answers

What percentage of total blood volume is typically found in the systemic circulation of an average adult male?

80% (B) Signup and view all the answers

Why do small arteries and capillaries contribute only 20% of blood volume in systemic circulation?

They are a minor component compared to veins (D) Signup and view all the answers

What is the effect of increasing blood volume on venous pressure due to high compliance?

Leads to only minor increases in venous pressure (B) Signup and view all the answers

What is the main reason arteries are characterized by low compliance?

They have thick muscular walls and elastic fibers (A) Signup and view all the answers

What factors contribute to the regulation of blood flow in capillaries?

Local tissue factors and myogenic regulation (D) Signup and view all the answers

Which of the following explains the function of albumin in capillary regulation?

It creates oncotic pressure that retains water in the capillaries. (C) Signup and view all the answers

What role do glycosaminoglycans play in tissue fluid balance?

They act as a sponge absorbing excess water. (A) Signup and view all the answers

What determines the flow of molecules through a membrane according to Fick's law?

Concentration gradient and membrane thickness (A) Signup and view all the answers

How does myogenic regulation respond to increased pressure in the vessel?

It triggers smooth muscle contraction resulting in constriction. (A) Signup and view all the answers

Which statement about the constant 'k' in flow diffusion is correct?

It increases when permeability to the substance rises. (C) Signup and view all the answers

What is the primary consequence of excessive movement of substances across capillary walls?

Edema (C) Signup and view all the answers

What prevents excessive edema in tissues?

Presence of lymphatic vessels and glycosaminoglycans (C) Signup and view all the answers

Study Notes

BMS 200 - Macrocirculatory and Microcirculatory Physiology

Course focusing on the physiology of the macro- and microcirculation.
Objectives include understanding the relationship between venous return, cardiac output, arterial pressure, and systemic vascular resistance.
Objectives also include the characteristics of various blood vessels (elastic arteries, muscular arteries, arterioles, capillaries, venules, and veins) and their roles in physiological function (compliance, elasticity, pressure, and fluid velocity).
The histological structure of these vessels is also a key objective to understand.
Venous return mechanisms and their relationship to cardiac preload are targeted.
Cellular physiology of baroreceptors and the overall function of the baroreceptor reflex are also studied.
Poiseuille's law is applied to blood pressure regulation.
Comparisons between turbulent and laminar blood flow and the situations where each occur are discussed.
Arterioles as the major site of blood pressure regulation is clarified.
Histological structures of the microcirculation and their function are analyzed.
The locations, functions and structures of different capillary types (continuous, fenestrated, and sinusoidal) are contrasted.
Starling forces and their impact on bulk flow across capillary endothelium are explored. This includes filtration, edema, and inflammation.
Autoregulation mechanisms in the microcirculation are detailed.
The role of the autonomic nervous system and the renin-angiotensin-aldosterone system in blood pressure control are discussed.
Blood flow regulation in various vascular beds (cerebral, pulmonary, coronary, renal, skeletal muscle, cutaneous) are compared and contrasted.
Simulating hemorrhage, and its impact on the cardiac system, is part of the course.
Blood vessel histology, including tunica intima, tunica media, and tunica externa, is covered.
Detailed descriptions of different vessel types (elastic arteries, muscular arteries, arterioles, metarterioles, capillaries, venules and medium/large veins) and their roles are included.
Types of capillaries (continuous, fenestrated, sinusoidal) are explained in detail, emphasizing their structure/function, permeability and locations.
Information about venous systems, including structure and function (large, medium and small veins) are presented.
Hemodynamic properties of large vessels, including Poiseuille's Law, laminar and turbulent flow, and Reynolds number, are detailed.
Bernoulli's Principle, and the concept of constant pressure within a system despite velocity changes, are detailed.
Hemodynamic characteristics of different vessels (arteries, capillaries, veins) and the changes in pressure and velocity within them are explored.
Summarizing the changes in pressure and velocity across different vascular segments.
Detailed explanations about arterial and venous pressure.
Different vascular systems in series and parallel are included.
The concept of central versus peripheral blood volume, and its clinical relevance, are outlined.
Definitions of compliance in both arteries and veins are offered.
The impact of compliance and its role in maintaining blood pressure are explained.
Methods of regulating blood flow, including autoregulation (metabolic factors, hormonal factors) are discussed.
This includes an investigation into the role of vasodilation (e.g., histamine, bradykinin, prostaglandins) and vasoconstriction (e.g., epinephrine, norepinephrine, serotonin, thromboxane A2). Analysis of the effects of various factors (e.g., pH, CO2) are presented.
Differences in oxygen extraction and blood flow regulation during rest vs. exercise are analyzed across various vascular beds (skeletal muscle, cerebral, pulmonary, coronary, renal).
Specific hormonal controls over blood flow (e.g., catecholamines).
Role of different vascular beds in regulating blood flow (skeletal muscle, cerebral, pulmonary, coronary, renal, cutaneous).
Simulating hemorrhage using lower body negative pressure (LBNP) methods and its cardiovascular impact are noted.

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Description

Test your knowledge on the types and functions of arteries within the circulatory system. This quiz covers elastic and muscular arteries, arterioles, and metarterioles. Challenge yourself to identify their roles and characteristics.