Skip to content
Quick Guides

Anatomy and Physiology - The Muscular System

Preview 10 of 39 pages

See the first 10 pages exactly as they appear in the document.

  1. Page 1
    Read page 1 as text

    Study Guide Anatomy and Physiology – The Muscular System 1. Quiz: Skeletal Muscle Actions 1. Question The origin is the point of muscle attachment that is __________. Answer Choices • stationary • moveable • synergistic Correct Answer stationary Why This Is Correct The origin is the attachment point that stays more fixed (stationary) when a muscle contracts. It is usually located closer to the center of the body. 2. Question The insertion is the point of muscle attachment that is __________. Answer Choices • stationary • moveable • synergistic

  2. Page 2
    Read page 2 as text

    Study Guide Correct Answer moveable Why This Is Correct The insertion is the attachment point that moves when the muscle contracts. It is usually located farther from the center of the body. 3. Question Which muscle would be antagonistic to the biceps brachii? Answer Choices • brachialis • palmaris longus • triceps brachii Correct Answer triceps brachii Why This Is Correct The biceps brachii flexes the elbow (bends the arm). The triceps brachii extends the elbow (straightens the arm), doing the opposite action. So the triceps is the antagonist . 4. Question If muscle A causes movement, muscle B helps A, and muscle C does the opposite of A, then muscle A is a(n) __________, muscle B is a __________, and muscle C is a(n) __________.

  3. Page 3
    Read page 3 as text

    Study Guide Answer Choices • antagonist; synergist; prime mover • prime mover; synergist; antagonist • synergist; prime mover; antagonist Correct Answer prime mover; synergist; antagonist Why This Is Correct • Prime mover (agonist) = main muscle causing the movement • Synergist = helps the prime mover • Antagonist = opposes the movement So A = prime mover, B = synergist, C = antagonist. 2. Names of Skeletal Muscles Skeletal muscles often have names that give clues about their structure, location, size, or function . Learning these naming rules makes it much easier to understand and remember muscle names. 2.1 Common Ways Skeletal Muscles Are Named 1. Number of Origins Some muscles are named based on how many starting points ( origins ) they have. • Biceps = 2 origins • Triceps = 3 origins • Quadriceps = 4 origins

  4. Page 4
    Read page 4 as text

    Study Guide 2. Location of Origin or Insertion A muscle may be named using the bones it attaches to. Example: Sternocleidomastoid • sterno = sternum (origin) • cleido = clavicle (origin) • mastoid = mastoid process of the temporal bone (insertion) So the name tells you exactly where it begins and ends. 3. Location (Body Region or Nearby Bone) Some muscle names describe the body area or nearby bone where the muscle is found. Example: Temporalis • covers the temporal bone area 4. Shape Some muscles are named based on their shape. Examples: • Deltoid = triangular • Trapezius = trapezoid shape • Serratus = saw - toothed edge • Rhomboideus major = rhomboid shape 5. Direction of Muscle Fibers Some muscle names tell the direction of fibers compared to the body’s midline: • Rectus = fibers run parallel to the midline • Transverse = fibers run perpendicular to the midline • Oblique = fibers run at an angle

  5. Page 5
    Read page 5 as text

    Study Guide 6. Size Muscles may also be named based on size. Common terms include: • Maximus = largest • Minimus = smallest • Longus = longest • Brevis = shortest 7. Action (Movement Produced) Many muscles are named for what they do — how they move a body part. Examples: • Flexor = bends a joint (flexes) • Extensor = straightens a joint (extends) • Abductor = moves a limb away from the body • Adductor = moves a limb back toward the body 3. Quiz: Names of Skeletal Muscles 1. Question Which of the following terms do NOT describe the shape of a muscle? Answer Choices • rhomboid • rectus • deltoid

  6. Page 6
    Read page 6 as text

    Study Guide Correct Answer rectus Why This Is Correct • Rhomboid describes a diamond - shaped muscle. • Deltoid describes a triangular - shaped muscle. • Rectus does not describe shape — it means straight (direction of muscle fibers). 2. Question Which of the following muscles are named according to both the insertion and origin? Answer Choices • rectus femoris • tibialis anterior • coracobrachialis Correct Answer coracobrachialis Why This Is Correct Coracobrachialis is named for: • origin: coracoid process (scapula) • insertion: brachium (arm/humerus region) So it includes both origin and insertion in its name.

  7. Page 7
    Read page 7 as text

    Study Guide 4. Muscle Size and Arrangement of Muscle Fascicles The size and shape of a muscle help decide what that muscle can do best — whether it is built more for movement range or for strength . 4.1 How Muscle Size Affects Movement and Strength 1. Muscle Fiber Length = Range of Movement When a muscle fiber (muscle cell) contracts, it can shorten to almost half its resting length . Longer muscle fibers can shorten over a longer distance, so they produce: • a greater range of movement 2. Number of Muscle Fibers = Strength If a muscle has more muscle fibers , it can generate a stronger contraction. So, more fibers = more strength Fascicles and Muscle Organization Muscle fibers are grouped in bundles called fascicles . Then, fascicles are grouped together to form a whole muscle . The length and number of fascicles help determine: • muscle strength • range of movement Common Fascicle Patterns 1. Parallel Fascicles In this pattern, the fascicles run parallel (side - by - side) in the same direction. Parallel muscles may be: • flat or straplike • fusiform (spindle - shaped) → thick in the middle and thinner at the ends Parallel fascicles usually allow a wide range of movement .

  8. Page 8
    Read page 8 as text

    Study Guide 2. Circular Fascicles Circular fascicles form concentric rings , like circles around an opening. These muscles usually form sphincters , which control the: • opening and closing of orifices (body openings) 3. Pennate Fascicles Pennate fascicles are short and attach at an angle (obliquely) to a long tendon that runs through the muscle. This arrangement packs more fibers into the muscle, which increases strength . Types of Pennate Patterns Unipennate • looks like half a feather • fascicles attach on one side of the tendon Bipennate • looks like a full feather • fascicles attach on both sides of a central tendon Multipennate • looks like three or more feathers • fascicles attach in multiple sections, creating a very strong muscle Pennate muscles are designed mainly for power and strength . 5. Quiz: Muscle Size and Arrangement of Muscle Fascicles 1. Question Sphincter muscles consist of which arrangement of fascicles?

  9. Page 9
    Read page 9 as text

    Study Guide Answer Choices • parallel • circular • pennate Correct Answer circular Why This Is Correct Sphincter muscles form ring - like bands that open and close body openings (like the anus). Ring - shaped muscles have circular fascicles . 2. Question When the arm is flexed, the biceps brachii bulges in the middle. This type of muscle consists of __________ fascicles. Answer Choices • parallel • circular • pennate Correct Answer parallel Why This Is Correct The biceps brachii is an example of a muscle with parallel fascicles . Parallel muscles often create a bulging belly when they contract, like the biceps.

  10. Page 10
    Read page 10 as text

    Study Guide 6. Major Skeletal Muscles Skeletal muscles are the muscles that attach to bones and help the body move. These muscles are mainly voluntary , meaning you can control them consciously (like walking, lifting, and writing). To learn the human muscular system clearly, it is helpful to study muscles in: • front (anterior) view • back (posterior) view • superficial (outer) muscles • deep (inner) muscles The following figures and tables help you identify the major muscles of the body and understand their actions. 6.1 Full - Body Major Skeletal Muscles (Superficial Views) These diagrams show the major muscles you can see on the surface of the body.

29 more pages in the full document

Unlock it once and it stays in your library, ready to chat with or turn into flashcards.

Unlock the full document

More Anatomy and Physiology study materials

See all

Study this document with CramX

Once it is in your library, every tool can work from it.