Skip to main content

Anatomy & Physiology 2e: 4.4 Muscle Tissue

Anatomy & Physiology 2e
4.4 Muscle Tissue
    • Notifications
    • Privacy
  • Project HomeNatural Sciences Collection: Anatomy, Biology, and Chemistry
  • Projects
  • Learn more about Manifold

Notes

Show the following:

  • Annotations
  • Resources
Search within:

Adjust appearance:

  • font
    Font style
  • color scheme
  • Margins
table of contents
  1. Cover
  2. Title Page
  3. Copyright
  4. Table Of Contents
  5. Chapter 1. An Introduction to the Human Body
    1. 1.0 Introduction
    2. 1.1 How Structure Determines Function
    3. 1.2 Structural Organization of the Human Body
    4. 1.3 Homeostasis
    5. 1.4 Anatomical Terminology
    6. 1.5 Medical Imaging
  6. Chapter 2. The Chemical Level of Organization
    1. 2.0 Introduction
    2. 2.1 Elements and Atoms: The Building Blocks of Matter
    3. 2.2 Chemical Bonds
    4. 2.3 Chemical Reactions
    5. 2.4 Inorganic Compounds Essential to Human Functioning
    6. 2.5 Organic Compounds Essential to Human Functioning
  7. Chapter 3. The Cellular Level of Organization
    1. 3.0 Introduction
    2. 3.1 The Cell Membrane
    3. 3.2 The Cytoplasm and Cellular Organelles
    4. 3.3 The Nucleus and DNA Replication
    5. 3.4 Protein Synthesis
    6. 3.5 Cell Growth and Division
    7. 3.6 Cellular Differentiation
  8. Chapter 4. The Tissue Level of Organization
    1. 4.0 Introduction
    2. 4.1 Types of Tissues
    3. 4.2 Epithelial Tissue
    4. 4.3 Connective Tissue Supports and Protects
    5. 4.4 Muscle Tissue
    6. 4.5 Nervous Tissue
    7. 4.6 Tissue Injury and Aging
  9. Chapter 5. The Integumentary System
    1. 5.0 Introduction
    2. 5.1 Layers of the Skin
    3. 5.2 Accessory Structures of the Skin
    4. 5.3 Functions of the Integumentary System
    5. 5.4 Diseases, Disorders, and Injuries of the Integumentary System
  10. Chapter 6. Bone Tissue and the Skeletal System
    1. 6.0 Introduction
    2. 6.1 The Functions of the Skeletal System
    3. 6.2 Bone Classification
    4. 6.3 Bone Structure
    5. 6.4 Bone Formation and Development
    6. 6.5 Fractures: Bone Repair
    7. 6.6 Exercise, Nutrition, Hormones, and Bone Tissue
    8. 6.7 Calcium Homeostasis: Interactions of the Skeletal System and Other Organ Systems
  11. Chapter 7. Axial Skeleton
    1. 7.0 Introduction
    2. 7.1 Divisions of the Skeletal System
    3. 7.2 Bone Markings
    4. 7.3 The Skull
    5. 7.4 The Vertebral Column
    6. 7.5 The Thoracic Cage
    7. 7.6 Embryonic Development of the Axial Skeleton
  12. Chapter 8. The Appendicular Skeleton
    1. 8.0 Introduction
    2. 8.1 The Pectoral Girdle
    3. 8.2 Bones of the Upper Limb
    4. 8.3 The Pelvic Girdle and Pelvis
    5. 8.4 Bones of the Lower Limb
    6. 8.5 Development of the Appendicular Skeleton
  13. Chapter 9. Joints
    1. 9.0 Introduction
    2. 9.1 Classification of Joints
    3. 9.2 Fibrous Joints
    4. 9.3 Cartilaginous Joints
    5. 9.4 Synovial Joints
    6. 9.5 Types of Body Movements
    7. 9.6 Anatomy of Selected Synovial Joints
    8. 9.7 Development of Joints
  14. Chapter 10. Muscle Tissue
    1. 10.0 Introduction
    2. 10.1 Overview of Muscle Tissues
    3. 10.2 Skeletal Muscle
    4. 10.3 Muscle Fiber Excitation, Contraction, and Relaxation
    5. 10.4 Nervous System Control of Muscle Tension
    6. 10.5 Types of Muscle Fibers
    7. 10.6 Exercise and Muscle Performance
    8. 10.7 Smooth Muscle Tissue
    9. 10.8 Development and Regeneration of Muscle Tissue
  15. Chapter 11. The Muscular System
    1. 11.0 Introduction
    2. 11.1 Describe the roles of agonists, antagonists and synergists
    3. 11.2 Explain the organization of muscle fascicles and their role in generating force
    4. 11.3 Explain the criteria used to name skeletal muscles
    5. 11.4 Axial Muscles of the Head Neck and Back
    6. 11.5 Axial muscles of the abdominal wall and thorax
    7. 11.6 Muscles of the Pectoral Girdle and Upper Limbs
    8. 11.7 Appendicular Muscles of the Pelvic Girdle and Lower Limbs
  16. Chapter 12. The Nervous System and Nervous Tissue
    1. 12.0 Introduction
    2. 12.1 Structure and Function of the Nervous System
    3. 12.2 Nervous Tissue
    4. 12.3 The Function of Nervous Tissue
    5. 12.4 Communication Between Neurons
    6. 12.5 The Action Potential
  17. Chapter 13. The Peripheral Nervous System
    1. 13.0 Introduction
    2. 13.1 Sensory Receptors
    3. 13.2 Ganglia and Nerves
    4. 13.3 Spinal and Cranial Nerves
    5. 13.4 Relationship of the PNS to the Spinal Cord of the CNS
    6. 13.5 Ventral Horn Output and Reflexes
    7. 13.6 Testing the Spinal Nerves (Sensory and Motor Exams)
    8. 13.7 The Cranial Nerve Exam
  18. Chapter 14. The Central Nervous System
    1. 14.0 Introduction
    2. 14.1 Embryonic Development
    3. 14.2 Blood Flow the meninges and Cerebrospinal Fluid Production and Circulation
    4. 14.3 The Brain and Spinal Cord
    5. 14.4 The Spinal Cord
    6. 14.5 Sensory and Motor Pathways
  19. Chapter 15. The Special Senses
    1. 15.0 Introduction
    2. 15.1 Taste
    3. 15.2 Smell
    4. 15.3 Hearing
    5. 15.4 Equilibrium
    6. 15.5 Vision
  20. Chapter 16. The Autonomic Nervous System
    1. 16.0 Introduction
    2. 16.1 Divisions of the Autonomic Nervous System
    3. 16.2 Autonomic Reflexes and Homeostasis
    4. 16.3 Central Control
    5. 16.4 Drugs that Affect the Autonomic System
  21. Chapter 17. The Endocrine System
    1. 17.0 Introduction
    2. 17.1 An Overview of the Endocrine System
    3. 17.2 Hormones
    4. 17.3 The Pituitary Gland and Hypothalamus
    5. 17.4 The Thyroid Gland
    6. 17.5 The Parathyroid Glands
    7. 17.6 The Adrenal Glands
    8. 17.7 The Pineal Gland
    9. 17.8 Gonadal and Placental Hormones
    10. 17.9 The Pancreas
    11. 17.10 Organs with Secondary Endocrine Functions
    12. 17.11 Development and Aging of the Endocrine System
  22. Chapter 18. The Cardiovascular System: Blood
    1. 18.0 Introduction
    2. 18.1 Functions of Blood
    3. 18.2 Production of the Formed Elements
    4. 18.3 Erythrocytes
    5. 18.4 Leukocytes and Platelets
    6. 18.5 Hemostasis
    7. 18.6 Blood Typing
  23. Chapter 19. The Cardiovascular System: The Heart
    1. 19.0 Introduction
    2. 19.1 Heart Anatomy
    3. 19.2 Cardiac Muscle and Electrical Activity
    4. 19.3 Cardiac Cycle
    5. 19.4 Cardiac Physiology
    6. 19.5 Development of the Heart
  24. Chapter 20. The Cardiovascular System: Blood Vessels and Circulation
    1. 20.0 Introduction
    2. 20.1 Structure and Function of Blood Vessels
    3. 20.2 Blood Flow, Blood Pressure, and Resistance
    4. 20.3 Capillary Exchange
    5. 20.4 Homeostatic Regulation of the Vascular System
    6. 20.5 Circulatory Pathways
    7. 20.6 Development of Blood Vessels and Fetal Circulation
  25. Chapter 21. The Lymphatic and Immune System
    1. 21.0 Introduction
    2. 21.1 Anatomy of the Lymphatic and Immune Systems
    3. 21.2 Barrier Defenses and the Innate Immune Response
    4. 21.3 The Adaptive Immune Response: T lymphocytes and Their Functional Types
    5. 21.4 The Adaptive Immune Response: B-lymphocytes and Antibodies
    6. 21.5 The Immune Response against Pathogens
    7. 21.6 Diseases Associated with Depressed or Overactive Immune Responses
    8. 21.7 Transplantation and Cancer Immunology
  26. Chapter 22. The Respiratory System
    1. 22.0 Introduction
    2. 22.1 Organs and Structures of the Respiratory System
    3. 22.2 The Lungs
    4. 22.3 The Process of Breathing
    5. 22.4 Gas Exchange
    6. 22.5 Transport of Gases
    7. 22.6 Modifications in Respiratory Functions
    8. 22.7 Embryonic Development of the Respiratory System
  27. Chapter 23. The Digestive System
    1. 23.0 Introduction
    2. 23.1 Overview of the Digestive System
    3. 23.2 Digestive System Processes and Regulation
    4. 23.3 The Mouth, Pharynx, and Esophagus
    5. 23.4 The Stomach
    6. 23.5 Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder
    7. 23.6 The Small and Large Intestines
    8. 23.7 Chemical Digestion and Absorption: A Closer Look
  28. Chapter 24. Metabolism and Nutrition
    1. 24.0 Introduction
    2. 24.1 Overview of Metabolic Reactions
    3. 24.2 Carbohydrate Metabolism
    4. 24.3 Lipid Metabolism
    5. 24.4 Protein Metabolism
    6. 24.5 Metabolic States of the Body
    7. 24.6 Energy and Heat Balance
    8. 24.7 Nutrition and Diet
  29. Chapter 25. The Urinary System
    1. 25.0 Introduction
    2. 25.1 Internal and External Anatomy of the Kidney
    3. 25.2 Microscopic Anatomy of the Kidney: Anatomy of the Nephron
    4. 25.3 Physiology of Urine Formation: Overview
    5. 25.4 Physiology of Urine Formation: Glomerular Filtration
    6. 25.5 Physiology of Urine Formation: Tubular Reabsorption and Secretion
    7. 25.6 Physiology of Urine Formation: Medullary Concentration Gradient
    8. 25.7 Physiology of Urine Formation: Regulation of Fluid Volume and Composition
    9. 25.8 Urine Transport and Elimination
    10. 25.9 The Urinary System and Homeostasis
  30. Chapter 26. Fluid, Electrolyte, and Acid-Base Balance
    1. 26.0 Introduction
    2. 26.1 Body Fluids and Fluid Compartments
    3. 26.2 Water Balance
    4. 26.3 Electrolyte Balance
    5. 26.4 Acid-Base Balance
    6. 26.5 Disorders of Acid-Base Balance
  31. Chapter 27. The Sexual Systems
    1. 27.0 Introduction
    2. 27.1 Anatomy of Sexual Systems
    3. 27.2 Development of Sexual Anatomy
    4. 27.3 Physiology of the Female Sexual System
    5. 27.4 Physiology of the Male Sexual System
    6. 27.5 Physiology of Arousal and Orgasm
  32. Chapter 28. Development and Inheritance
    1. 28.0 Introduction
    2. 28.1 Fertilization
    3. 28.2 Embryonic Development
    4. 28.3 Fetal Development
    5. 28.4 Maternal Changes During Pregnancy, Labor, and Birth
    6. 28.5 Adjustments of the Infant at Birth and Postnatal Stages
    7. 28.6 Lactation
    8. 28.7 Patterns of Inheritance
  33. Creative Commons License
  34. Recommended Citations
  35. Versioning

4.4 Muscle Tissue

Learning Objectives

Describe the characteristics of muscle tissue and how these dictate muscle function.

By the end of this section, you will be able to:

  • Identify the three types of muscle tissue
  • Compare and contrast the functions of each muscle tissue type

Muscle tissue is characterized by properties that allow movement. Muscle cells are excitable; they respond to a stimulus. They are contractile, meaning they can shorten and generate a pulling force. When attached between two movable objects, such as two bones, contraction of the muscles cause the bones to move. Some muscle movement is voluntary, which means it is under conscious control. For example, a person decides to open a book and read a chapter on anatomy. Other movements are involuntary, meaning they are not under conscious control, such as the contraction of your pupil in bright light. Muscle tissue is classified into three types according to structure and function: skeletal, cardiac, and smooth (Table 4.2).

Table 4.2 Comparison of Structure and Properties of Muscle Tissue Types
Muscle typeStructural elementsFunctionLocation
SkeletalLong cylindrical fiber, striated, many peripherally located nucleiVoluntary movement, produces heat, protects organsAttached to bones and around entry & exit sites of body (e.g., mouth, anus)
CardiacShort, branched, striated, single central nucleusContracts to pump bloodHeart
SmoothShort, spindle-shaped, no evident striation, single nucleus in each fiberInvoluntary movement, moves food, involuntary control of respiration, moves secretions, regulates flow of blood in arteries by contractionWalls of major organs and passageways

Skeletal muscle is attached to bones and its contraction makes possible locomotion, facial expressions, posture, and other voluntary movements of the body. Forty percent of your body mass is made up of skeletal muscle. Skeletal muscles generate heat as a byproduct of their contraction and thus participate in thermal homeostasis. Shivering is an involuntary contraction of skeletal muscles in response to lower than normal body temperature. The muscle cell, or myocyte, develops from myoblasts derived from the mesoderm. Myocytes and their numbers remain relatively constant throughout life. Skeletal muscle tissue is arranged in bundles surrounded by connective tissue. Under the light microscope, muscle cells appear striated with many nuclei squeezed along the membranes. The striation is due to the regular alternation of the contractile proteins actin and myosin, along with the structural proteins that couple the contractile proteins to connective tissues. The cells are multinucleated as a result of the fusion of the many myoblasts that fuse to form each long muscle fiber.

Cardiac muscle forms the contractile walls of the heart. The cells of cardiac muscle, known as cardiomyocytes, also appear striated under the microscope. Unlike skeletal muscle fibers, cardiomyocytes are single cells with a single centrally located nucleus. A principal characteristic of cardiomyocytes is that they contract on their own intrinsic rhythm without external stimulation. Cardiomyocytes attach to one another with specialized cell junctions called intercalated discs. Intercalated discs have both anchoring junctions and gap junctions. Attached cells form long, branching cardiac muscle fibers that act as a syncytium, allowing the cells to synchronize their actions. The cardiac muscle pumps blood through the body and is under involuntary control.

Smooth muscle tissue contraction is responsible for involuntary movements in the internal organs. It forms the contractile component of the digestive, urinary, and reproductive systems as well as the airways and blood vessels. Each cell is spindle shaped with a single nucleus and no visible striations (Figure 4.4.1 – Muscle Tissue).

This shows three micrographs, each depicting one of the three muscle tissues. Picture A shows skeletal muscle tissue, which is dense strips of pink tissue that somewhat resemble bacon in appearance. Many small nuclei are dispersed throughout the tissues. The nuclei are flat and elongated, with multiple nuclei clustered into each cell. Picture B shows smooth muscle, which is densely packed and looks similar to skeletal muscle except that each cell only has one oval-shaped nucleus. Picture C shows cardiac muscle. Unlike skeletal and smooth muscle cells, cardiac muscle cells are not densely packed. The cardiac cells are branched, creating a large amount of space between each muscle cell.
Figure 4.4.1 – Muscle Tissue: (a) Skeletal muscle cells have prominent striation and nuclei on their periphery. (b) Smooth muscle cells have a single nucleus and no visible striations. (c) Cardiac muscle cells appear striated and have a single nucleus. From top, LM × 1600, LM × 1600, LM × 1600. (Micrographs provided by the Regents of University of Michigan Medical School © 2012)

External Website

musctissue

Watch this video to learn more about muscle tissue. In looking through a microscope how could you distinguish skeletal muscle tissue from smooth muscle?

Chapter Review

The three types of muscle cells are skeletal, cardiac, and smooth. Their morphologies match their specific functions in the body. Skeletal muscle is voluntary and responds to conscious stimuli. The cells are striated and multinucleated appearing as long, unbranched cylinders. Cardiac muscle is involuntary and found only in the heart. Each cell is striated with a single nucleus and they attach to one another to form long fibers. Cells are attached to one another at intercalated disks. The cells are interconnected physically and electrochemically to act as a syncytium. Cardiac muscle cells contract autonomously and involuntarily. Smooth muscle is involuntary. Each cell is a spindle-shaped fiber and contains a single nucleus. No striations are evident because the actin and myosin filaments do not align in the cytoplasm.

Interactive Link Questions

Watch this video to learn more about muscle tissue. In looking through a microscope how could you distinguish skeletal muscle tissue from smooth muscle?

Skeletal muscle cells are striated.

Review Questions

An interactive H5P element has been excluded from this version of the text. You can view it online here:
https://open.oregonstate.education/aandp/?p=182#h5p-82

An interactive H5P element has been excluded from this version of the text. You can view it online here:
https://open.oregonstate.education/aandp/?p=182#h5p-83

An interactive H5P element has been excluded from this version of the text. You can view it online here:
https://open.oregonstate.education/aandp/?p=182#h5p-84

Critical Thinking Questions

You are watching cells in a dish spontaneously contract. They are all contracting at different rates, some fast, some slow. After a while, several cells link up and they begin contracting in synchrony. Discuss what is going on and what type of cells you are looking at.

The cells in the dish are cardiomyocytes, cardiac muscle cells. They have an intrinsic ability to contract. When they link up, they form intercalating discs that allow the cells to communicate with each other and begin contracting in synchrony.

Why does skeletal muscle look striated?

Under the light microscope, cells appear striated due to the arrangement of the contractile proteins actin and myosin.

Annotate

Next chapter
4.5 Nervous Tissue
PreviousNext
Anatomy and Physiology
Copyright © 2019 by Lindsay M. Biga, Sierra Dawson, Amy Harwell, Robin Hopkins, Joel Kaufmann, Mike LeMaster, Philip Matern, Katie Morrison-Graham, Devon Quick & Jon Runyeon

Anatomy & Physiology by Lindsay M. Biga, Sierra Dawson, Amy Harwell, Robin Hopkins, Joel Kaufmann, Mike LeMaster, Philip Matern, Katie Morrison-Graham, Devon Quick & Jon Runyeon is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, except where otherwise noted.

Powered by Manifold Scholarship. Learn more at
Opens in new tab or windowmanifoldapp.org