10. Muscular System

Muscle Action

Muscle contraction around joints

 Agonists are muscles that serve as the primary movers. Antagonists are muscles that oppose or reverse a particular movement. Synergists help prime movers (agonists) by adding a little extra force to the movement. When synergists act as stabilizers by immobilizing a bone or a muscle's origin, they are called fixators. 

 __________ are muscles that oppose or reverse a particular movement. 

Lever systems in the human body

The Muscular System

 Most skeletal muscles of the body act as third-class lever systems. 

 The most common lever systems in the body are those that have the applied force between the fulcrum and the resistance. These are called __________ levers. 

 Second-class levers have a wide range of motion. 

 Second-class levers sacrifice their range of motion for greater strength. 

 Second-class levers have great strength but are slow and have little range of motion.   

 Second-class levers sacrifice their speed for greater strength. 

 Second-class levers work at a mechanical disadvantage. 

 All second-class levers work at a mechanical advantage. 

 Which of the following statements about second-class levers is correct? 

 <i>Synergists</i> are muscles that help the prime mover by contracting at the same time to add more force or stabilize a part so the movement is more effective. 

 A muscle that assists the muscle primarily responsible for a given action is a(n) __________. 

 The deltoid is a large, thick, triangular muscle forming a rounded mass over the shoulder and upper humerus that abducts the arm. 

 The major abductor muscle of the upper arm is the __________. 

Joints and levers in the human body

 The gastrocnemius plantar flexes the foot. 

 The popliteus flexes and rotates the leg medially but does not cause dorsiflexion of the foot. 

 The __________ is the prime mover of dorsiflexion of the foot. 

 The erector spinae muscles are the prime movers of back extension. The head is moved by muscles that originate from the axial skeleton. The major head flexor muscles are the sternocleidomastoid muscles. The scalene muscles elevate the first two ribs and flex and rotate the neck. The latissimus dorsi is the prime mover of arm extension. 

 The prime movers of back extension are the __________. 

 The extensor digitorum muscle is an example of a pennate muscle. 

 The extensor digitorum muscle is an example of a __________ muscle. 

 Standing on your toes is an example of a second-class lever. Second-class levers sacrifice speed and range of motion in favor of strength. Most skeletal muscles of the body act as third-class levers. Although third-class levers are speedy, they operate at a mechanical disadvantage. Third-class lever systems allow a muscle to be inserted close to the joint across which movement occurs. 

 Standing on your toes is an example of a __________. 

 The brachialis is a flexor of the forearm. 

 The palmaris longus is a weak synergist for elbow flexion. 

 The pronator teres is a weak flexor of the elbow. 

 The __________ assists the triceps brachii in forearm extension. 

Muscle Identification and Action

 The prime mover for flexion of the thigh is the iliopsoas muscle. 

 The prime mover for flexion of the thigh is the __________ muscle. 

 The pectoralis major adducts and medially rotates the arm against resistance. The latissimus dorsi is the prime mover of arm extension. The deltoid is the prime mover of arm abduction. The quadriceps femoris is a powerful knee extensor. 

 The prime mover of arm extension is the __________. 

Learn the toughest concepts covered in Anatomy & Physiology 1&2 with step-by-step video tutorials and practice problems by world-class tutors



Anatomy & Physiology

https://static.studychannel-prd.pearsonprd.tech/courses/anp/thumbnails/anp

#FFFFFF

Professor Dave Explains

Bifrost

Human Anatomy Education

Medic Tutorials - Medicine and Language

CV Biology

1. Introduction to A&P

2. Chemistry

3. Cells

4. Tissues

5. Integumentary System

6. Bones + Skeletal Tissues

7. Skeletal System

8. Joints

9. Muscles and Muscle Tissue

11. Nervous Tissue

12. Central Nervous System

13. Peripheral Nervous System

14. Autonomic Nervous System

15. Special Senses

16. Endocrine System

17. Blood

18. Cardiovascular System: the Heart

19. Cardiovascular System: Blood Vessels

20. Lymphatic System

21. Immune System

22. Respiratory System

23. Digestive System

24. Nutrition, Metabolism, Energy Balance

25. Urinary System

26. Fluid and Electrolyte Balance, Acid Base Balance

27. Reproductive System

28. Pregnancy and Human Development

29. Heredity

undefined - Channels

Muscle Naming

Chapter Practice

Practice

Muscle Shape

Muscle Action, Origin, and Insertion

General Chemistry

Jules

Study the key concepts of Physics with descriptive videos, questions, and more

Physics

Patrick

General Biology

Jason

Financial Accounting

Brian

Dive deep into Psychology with videos, practice problems, and more.

Psychology

Microeconomics

The first in a two-course sequence introduces the basic structure and functions of the human body

College Algebra covers algebraic topics and skills necessary to succeed in college-level math

College Algebra

Organic Chemistry

Johnny

Genetics

Kylia

GOB Chemistry

Microbiology

Cell Biology

Analytical Chemistry

Study topics incliding trogonometric functions, identities and equations, solutions of triangles, complex numbers, and other topics as time permits

Trigonometry

Learn the toughest concepts covered in Precalculus with step-by-step video tutorials and practice problems by world-class tutors

Precalculus

Biochemistry

Macroeconomics

Chemistry

Biology

Math

Business

Social Sciences

Michelle Barry Franco

Building Great Presentations

Eric Zackrison, PhD

Critical Thinking And Problem Solving

Sam Bennett

Embracing Times Of Uncertainty

Nicole Tetreault, PhD

Emotional Intelligence Basics

Eugene Choi, PharmD

Enhancing Your Critical Thinking Skills

Jason Richardson, PsyD

Habits To Win Every Day

Alyssa Lowery, PhD

Having Powerful Advanced Conversations

Don Gilman, EdD

How To Influence & Persuade

Amy Matthews

Leadership Skills For Rising Stars

Listening To Lead

Michael Shermer, PhD

Making Decisions Under Uncertainty

Lynne Hurdle

Mistakes To Avoid When Resolving Conflict

Michael Veltri

Overcoming Decision Making Traps

Mike Vardy

Prioritizing Effectively

Secrets Of Effective Prioritization

Strategies To Build Up Your Creativity

Tools For Decision Making

Tutti Taygerly

Unleash And Advance Your Creativity

Winning Collaboration: How To Work More Effectively With Different Personalities

Writing Emails People Want To Read

Critical Thinking

Self Management

Digital Literacy

Collaboration

Communication

Analytical Thinking

Leadership

Flexibility/Adaptability

Innovation

Eric Zackrison

Nicole Tetreault

Dive deep into Python with videos and more.

Introduction to Python

Arianne Dee

Agile Project and Product Management

Agile & Product Management

Mariya Breyther 

Introduction to Microsoft Power BI

Microsoft Power BI

Chris Sorensen

Data Analysis Fundamentals with Excel

Data Analysis - Excel

Chris Sorensen & Ammul Shergill

Getting Started with  and Cryptocurrency

Introduction to Blockchain

George Levy

Learn Enough HTML, CSS and Layout to be Dangerous

HTML, CSS & Layout

Lee Donahoe & Michael Hartl

Learn Enough JavaScript to be Dangerous: A Tutorial Introduction to Programming with JavaScript