1 / 116

Understanding the Muscular System: Types, Functions, and Structures

Learn about the three types of muscles and their characteristics, muscle attachments like tendons and aponeuroses, and muscle actions like prime movers and antagonists. Explore muscle naming conventions and the functions of head and neck muscles.

michaelsessions
Download Presentation

Understanding the Muscular System: Types, Functions, and Structures

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Muscular System

  2. Learning Objectives List the 3 types of muscles and describe the characteristics of each. Describe the structure and function of tendons, aponeuroses, and ligaments. Differentiate between prime mover, antagonist, synergist, and fixator muscles. List the locations and actions of the muscles of the head and neck, abdomen, thoracic limb, pelvic limb, and the muscles of respiration.

  3. Muscle • One of the four basic tissues of the body • Made up of cells that can shorten or contract • Three different types of muscle • skeletal muscle – moves the bones of the skeleton • Voluntary striated muscle • cardiac muscle • smooth muscle –eyes, air passageways in lungs, stomach, intestines, urinary bladder, blood vessels, reproductive tract

  4. Striated means stripes (light and dark colored bands) Skeletal Muscle

  5. Skeletal muscle- multiple nuclei Smooth muscle cells Cardiac muscle cells (intercalated discs)

  6. Questions • What is muscle? • What are the three types of muscle and some characteristics of each?

  7. Muscle Attachments : • Are well defined groups of skeletal muscle cells surrounded by a layer of fibrous (collagen)connective tissue called fascia • Surrounds, binds together • Sliding and gliding • Are attached to bones by tendons (fibrous connective tissue) • https://www.youtube.com/watch?v=PdJ5QDkqG2g • Are attached to bones or other muscles by broad sheets of fibrous connective tissue called aponeuroses • Linea Alba-abdominal muscles come together at the linea alba • Common surgical incision site abdominally (ventral midline) • https://www.youtube.com/watch?v=dvJzxg1y2rs

  8. Aponeurosis (in human)

  9. Muscle fascia

  10. Muscle Attachment sites • Origin: the more stable of a muscle's attachment sites • The bone does not move much when the muscle contracts • Insertion: site that undergoes most of the movement when a muscle contracts • Undergoes most movement when a muscle contracts

  11. Belly of a muscle- the bulging central part of a muscle. (Pretty much between tendon and tendon) • Important to know for intramuscular injections purpose of depositing drug

  12. Questions • What is the difference between a tendon, fascia and an aponeurosis? • What is the origin of a muscle? • What is the insertion of a muscle?

  13. Muscle Actions • Muscles contract/ relax…they do not push or stretch by their own • Prime mover (agonist): a muscle or muscle group that directly produces a desired movement • Antagonist: a muscle or muscle group that directly opposes the action of a prime mover

  14. Muscle Actions Synergist: a muscle that contracts at the same time as a prime mover and assists it in carrying out its action Fixator: muscles that stabilize joints to allow other movements to take place

  15. example • Bicep Curl movement • Prime mover is the biceps • Antagonist is triceps • Fixator is deltoid • Synergist is brachialis

  16. Muscle-Naming Conventions Action: flexor muscles; extensor muscles levatator, depressor, rotator, supinator, pronator Shape: deltoid means “triangular shaped” Quadratus Rhomboideus Scalenus Serratus Teres

  17. Location: • Biceps brachii muscle is located in the brachial region • Pectoral = chest • Epaxial= above pelvic axis • Intercostal=between ribs • Infraspinatus=beneath spine of scapula • Supraspinatus=above spine of scapula • Inferior=below, medius=middle, superior=above • Externus=outer, internus=inner • Orbicularis=surrounding another structure

  18. Direction of fibers: • rectus means “straight” • Oblique means slanted (outward away from midline • Transverse means crosswise (to midline)

  19. Muscle-Naming Conventions • Number of heads or divisions: -cep means “head”; • biceps brachii muscle has two heads • Attachment sites: • origin of the sternocephalicus muscle is the sternum and insertion is the back of the head

  20. Cutaneous Muscles • Thin, broad, superficial muscles • Found in the fascia just beneath the skin • Little or no attachment to bones • Serve to twitch the skin

  21. Cutaneous Muscles • Cutaneous Trunci • Platysma

  22. Head and Neck Muscles Functions Control facial expressions Enable mastication Move structures such as eyes and ears Support the head Allow the head and neck to flex, extend, and move laterally

  23. Head and Neck Muscles Masseter muscle - closes the jaw Splenius and Trapezius muscles - extend the head and neck Brachiocephalicus muscle - extends the head and neck; also pulls the front leg forward Sternocephalicus muscle - flexes (LOWER) the head and neck

  24. Head muscles • Masseter O=zygomatic arch I=mandible A= elevates mandible to close mouth • Temporal O=temporal fossa I=coronoid process (of the mandible) A=elevate mandible, moves lower jaw backward FYI: Digastric Muscle opens the mouth

  25. Muscles of the Head and Neck • These muscles move the head and neck

  26. Sternocephalicus Origin - manubrium (sternum) Insertion – 2 points of insertion mastoid nuchal crest of occipital boneAction –depresses the head and neck, draws the head and neck to side

  27. Sternocephalicus head and neck • The sternocephalicus, runs along side the braciocepalicus (thoracic limb muscle) • Forms the jugular groove

  28. Brachiocephalicus is a complex muscle! • Dorsal part of Neck : • Cleidocervicalis – from clavicle remnant to dorsal part of neck • Mastoid Process: Cleidomastoidus – from clavicle remnant to mastoid process

  29. Brachiocephalicus Cleidocervicalis – from clavicle remnant to dorsal part of neck • From clavicle remnant to distal end of humerus: Cleidobrachialis

  30. Human Clavicle

  31. Brachiocephalicus Origin Cleidocervicalis – clavicle remnantCleidomastoid –clavicle remnant Cleidobrachialis-clavicle remnant Insertion Cleidocervicalis – dorsal neck Cleidomastoid – mastoid process (behind external acoustic meatus) Cleidobrachialis-humerusAction – Pulls leg forward, neck and head down, neck and head side to side.

  32. Brachiocephalicus

  33. Trapezius • Origin – Dorsal aspect of neck • Insertion – scapula spine • Action – elevates and abducts forelimb • (Holds shoulder against body)

  34. Trapezius

  35. Rhomboideus This muscle lies beneath the Trapezius and has three parts Origin – Nuchal Crest of Occipital bone Dorsal neck T1- T7Insertion – dorsal border of the scapulaAction - pulls top of shoulder up forwards and towards the body. Elevates forelimbWhen shoulder is still it can lift the neck.

  36. Rhomboideus

  37. Thoracic Limb Muscles • Superficial muscles of the shoulder region • Latissimusdorsi muscle - flexes the shoulder • Pectoral muscles - one superficial and one deep; adduct the front leg • Deltoid muscle - abducts and flexes the shoulder joint

  38. Thoracic Limb Muscles • Brachial muscles • Biceps brachii muscle - flexes the elbow joint • Triceps brachii muscle - extends the elbow joint • Carpal and digital muscles • Extensor carpi radialis muscle - extends the carpus • Deep digital flexor muscle - flexes the digit

  39. Supraspinatus • Origin – supraspinatus fossaInsertion - greater tubericle of humerusAction - Extends and stabilizes shoulder joint

  40. Supraspinatus

  41. Infraspinatus • Origin – infraspinous fossa.Insertion - greater tubericle of the humerus.Action – flexes the shoulder joint, abducts the limb at the shoulder stabilize the shoulder joint.

  42. Infraspinatus

  43. Serratus Ventralis Origin – 2 points of origin Neck – transverse process of C3-C7 Chest –Ribs 1 - 7Insertion – scapula Action –supports the trunk, depresses the scapula

  44. Serratus Ventralis

  45. Latissimus Dorsi Origin - On the top of the spines, muscles starting at the top of the shoulder to the tips of the lumbarvertebrae as well as from the last two or three ribs. Spinous process of the lumbar and thoracic vertebrae (T7 / T8) including ribsInsertion – tuberosity of the humerusAction - pulls leg backwards, flexes shoulder joint

  46. Latissimus Dorsi

  47. Deltoid Origin – Acromial- Acromion at the bottom end of the spine of the scapulaSpinal – spine of the scapulaInsertion - humerusAction – flexes shoulder joint, pulls the foreleg away from the dog’s body

  48. Deltoid

  49. Biceps Brachii • Origin – supraglenoid tubercle (distal scapula)Insertion – proximal medial radius/ ulnaAction - Flexes elbow joint and extends shoulder joint

More Related