Textbook Question
Which of the following is greater?
(a) The osmotic pressure of the interstitial fluid during inflammation
(b) The osmotic pressure of the interstitial fluid during normal conditions
(c) Neither is greater
1
views
Ch. 21 Blood Vessels and Circulation
Martini, Nath, Bartholomew12th EditionFundamentals of Anatomy and PhysiologyISBN: 9780137854011
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 An Introduction to Anatomy and Physiology25
- Ch. 2 The Chemical Level of Organization34
- Ch. 3 The Cellular Level of Organization29
- Ch. 4 The Tissue Level of Organization24
- Ch. 5 The Integumentary System17
- Ch. 6 Bones and Bone Structure33
- Ch. 7 The Axial Skeleton11
- Ch. 8 The Appendicular Skeleton17
- Ch. 9 Joints13
- Ch. 10 Muscle Tissue12
- Ch. 11 The Muscular System28
- Ch. 12 Nervous Tissue18
- Ch. 13 The Spinal Cord, Spinal Nerves, and Spinal Reflexes22
- Ch. 14 The Brain and Cranial Nerves20
- Ch. 15 Sensory Pathways and the Somatic Nervous System17
- Ch. 16 The Autonomic Nervous System and Higher-Order Functions30
- Ch. 17 The Special Senses15
- Ch. 18 The Endocrine System21
- Ch. 19 Blood31
- Ch. 20 The Heart31
- Ch. 21 Blood Vessels and Circulation26
- Ch. 22 The Lymphatic System and Immunity25
- Ch. 23 The Respiratory System4
- Ch. 24 The Digestive System18
- Ch. 26 The Urinary System31
- Ch. 27 Fluids & Electrolytes30
- Ch. 28 The Reproductive System12
- Ch. 29 Development and Inheritance17
Martini, Nath, Bartholomew12th EditionFundamentals of Anatomy and PhysiologyISBN: 9780137854011Not the one you use?Change textbook
Chapter 21, Problem 20
Which of the following conditions would have the greatest effect on peripheral resistance?
(a) Doubling the length of a vessel
(b) Doubling the diameter of a vessel
(c) Doubling the viscosity of the blood
(d) Doubling the turbulence of the blood
(e) Doubling the number of white cells in the blood
Verified step by step guidance1
Understand that peripheral resistance in blood vessels is primarily influenced by vessel length, vessel diameter (radius), blood viscosity, and blood flow characteristics such as turbulence.
Recall the formula for resistance in a blood vessel based on Poiseuille's law: \(R = \frac{8 \eta L}{\pi r^{4}}\), where \(R\) is resistance, \(\eta\) is blood viscosity, \(L\) is vessel length, and \(r\) is the radius of the vessel.
Analyze how each condition affects the variables in the formula: (a) Doubling length \(L\) will double resistance linearly; (b) Doubling diameter means doubling radius \(r\), which affects resistance to the fourth power, so resistance changes by a factor of \(2^{4} = 16\); (c) Doubling viscosity \(\eta\) doubles resistance linearly; (d) Doubling turbulence increases resistance but is not directly in Poiseuille's formula and generally has a less predictable effect; (e) Doubling white blood cells has minimal effect on viscosity or flow properties.
Compare the magnitude of changes: since resistance is inversely proportional to the fourth power of radius, changes in diameter have a much greater effect than changes in length or viscosity, which are linear.
Conclude that doubling the diameter of a vessel (option b) would have the greatest effect on peripheral resistance due to the exponential relationship between radius and resistance.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Peripheral Resistance
Peripheral resistance refers to the resistance to blood flow offered by the blood vessels, primarily the arterioles. It is influenced by factors such as vessel diameter, length, blood viscosity, and flow characteristics. Understanding peripheral resistance is essential to grasp how changes in these factors affect blood pressure and circulation.
Recommended video:
3:33
Peripheral Nervous System
Effect of Vessel Diameter on Resistance
Vessel diameter has a powerful inverse effect on resistance; according to Poiseuille’s law, resistance is proportional to the fourth power of the radius. This means even small changes in diameter cause large changes in resistance, making diameter the most significant factor in controlling blood flow.
Recommended video:
8:32Altering Resistance in Blood Vessels
Blood Viscosity and Turbulence
Blood viscosity is the thickness of blood, affecting how easily it flows through vessels; higher viscosity increases resistance. Turbulence refers to chaotic blood flow, which also raises resistance by disrupting smooth laminar flow. Both factors influence peripheral resistance but generally less dramatically than vessel diameter.
Recommended video:
6:11Functions of Blood
Related Practice
Textbook Question
The vein that drains the dural sinuses of the brain is the
(a) Cephalic vein
(b) Great saphenous vein
(c) Internal jugular vein
(d) Superior vena cava
1
views
Textbook Question
How is blood pressure maintained in veins to counter the force of gravity?
1
views
Textbook Question
Why do capillaries permit the diffusion of materials, whereas arteries and veins do not?
1
views
Textbook Question
What are the primary forces that cause fluid to move?
(a) Out of a capillary at its arterial end and into the interstitial fluid
(b) Into a capillary at its venous end from the interstitial fluid?
1
views
Textbook Question
What cardiovascular changes occur at birth?
2
views