Textbook Question
Differentiate between stroke volume and cardiac output. How is cardiac output calculated?
1302
views
Ch. 20 The Heart
Martini, Nath, Bartholomew11th EditionFundamentals of Anatomy & PhysiologyISBN: 9780136874089
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 An Introduction to Anatomy and Physiology26
- Ch. 2 The Chemical Level of Organization34
- Ch. 3 The Cellular Level of Organization30
- Ch. 4 The Tissue Level of Organization24
- Ch. 5 The Integumentary System17
- Ch. 6 Bones and Bone Structure36
- 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 Senses16
- Ch. 18 The Endocrine System20
- Ch. 19 Blood31
- Ch. 20 The Heart31
- Ch. 21 Blood Vessels and Circulation29
- Ch. 22 The Lymphatic System and Immunity31
- Ch. 23 The Respiratory System12
- Ch. 24 The Digestive System18
- Ch. 26 The Urinary System31
- Ch. 27 Fluids & Electrolytes32
- Ch. 28 The Reproductive System12
- Ch. 29 Development and Inheritance23
Martini, Nath, Bartholomew11th EditionFundamentals of Anatomy & PhysiologyISBN: 9780136874089Not the one you use?Change textbook
Chapter 20, Problem 26
What effect does sympathetic stimulation have on the heart? What effect does parasympathetic stimulation have on the heart?
Verified step by step guidance1
Step 1: Understand the autonomic nervous system's role in regulating heart function. The sympathetic and parasympathetic divisions have opposite effects on the heart to maintain homeostasis.
Step 2: Recognize that sympathetic stimulation increases heart rate and force of contraction. This occurs because sympathetic nerves release norepinephrine, which binds to beta-1 adrenergic receptors on cardiac muscle cells.
Step 3: Note that sympathetic stimulation also increases the speed of electrical conduction through the heart, particularly at the sinoatrial (SA) node and atrioventricular (AV) node, leading to a faster heartbeat.
Step 4: Understand that parasympathetic stimulation decreases heart rate by releasing acetylcholine, which acts on muscarinic receptors in the SA and AV nodes, slowing the rate of depolarization and conduction.
Step 5: Summarize that parasympathetic stimulation primarily reduces heart rate without significantly affecting the force of contraction, promoting a state of rest and energy conservation.
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.
Sympathetic Nervous System and Cardiac Function
The sympathetic nervous system increases heart rate and force of contraction by releasing norepinephrine, which binds to beta-1 adrenergic receptors on cardiac cells. This prepares the body for 'fight or flight' responses by enhancing cardiac output and blood flow to muscles.
Recommended video:
2:52
Function of the Sympathetic Nervous System
Parasympathetic Nervous System and Cardiac Function
The parasympathetic nervous system decreases heart rate by releasing acetylcholine, which acts on muscarinic receptors in the heart, primarily the sinoatrial node. This promotes 'rest and digest' activities by slowing the heart rate and conserving energy.
Recommended video:
1:56Function of the Parasympathetic Nervous System
Autonomic Regulation of Heart Rate
Heart rate is regulated by the balance between sympathetic and parasympathetic inputs to the sinoatrial node. Sympathetic stimulation accelerates heart rate, while parasympathetic stimulation slows it, allowing the body to adapt to varying physiological demands.
Recommended video:
Guided course
6:13Control of Heart Rate
Related Practice
Textbook Question
Describe the effects of epinephrine, norepinephrine, glucagon, and thyroid hormones on the contractility of the heart.
891
views
Textbook Question
What factors influence cardiac output?
1180
views
Textbook Question
Vern is suffering from cardiac arrhythmias and is brought into the emergency room of a hospital. In the emergency room he begins to exhibit tachycardia and as a result loses consciousness. Explain why Vern lost consciousness.
865
views
1
rank
Textbook Question
Harvey has a heart murmur in his left ventricle that produces a loud 'gurgling' sound at the beginning of systole. Which valve is probably faulty?
940
views
Textbook Question
What are the sources and significance of the four heart sounds?
733
views