Bluegrass Technical 10 - Blair High Schoolblairschools.org/gen/blair_generated_bin/documents/basic_module/...1/16/17 1 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Human Anatomy & Physiology SEVENTH EDITION

Elaine N. Marieb Katja Hoehn

PowerPoint® Lecture Slides prepared by Vince Austin, Bluegrass Technical and Community College

C H

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10 The Muscular System

P A R T A


I. Interactions of Skeletal Muscles

A. Skeletal muscles work together or in opposition

B. Muscles only pull (never push)

C. As muscles shorten, the insertion generally moves toward the origin Insertion = ??? Origin = ???? Insertion = Attachment on moveable bone Origin = attachment to fixed/immovable bone

D. Whatever a muscle (or group of muscles) does, another muscle (or group) “undoes”


E. Muscle Classification: Functional Groups

1. Prime Movers / Agonists Agonist = “leader”

a. provide the major force for producing a specific movement

2. Antagonists a. oppose or reverse a particular movement

•  Opposite side of joint •  Triceps is antagonist to biceps •  Relaxed or stretched when the agonist is moving •  Can provide resistance to control movements


3. Synergists syn=“together erg=“work”

a. Add force to a movement b. Reduce undesirable or unnecessary movement

§  Joint stabilizers (finger flexors)

4. Fixators a. synergists that immobilize a bone or muscle’s origin (scapula)


II. Naming Skeletal Muscles A. Location of muscle 1. bone or body region associated with the muscle (temporalis / temporal bone)

B. Shape of muscle 1. deltoid muscle (deltoid = triangle)

C. Relative size 1. maximus – largest (gluteus maximus) 2. minimus - smallest (gluteus minimus) 3. longus – long 4. brevis - short


D. Direction of fibers (imaginary axis)

1. rectus – fibers run straight up & down

2. Transversus – fibers run at 90º

3. Oblique – fibers run at 45º

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E. Number of origins 1. biceps (two origins) 2. triceps (three origins)

F. Location of attachments 1. named according to point of origin or insertion (sternocleidomastoid = dual origin on sternum and clavicle / insertion on mastoid process)

G. Action 1. flexor, extensor, or adductor (as in the names of muscles that flex or extend, respectively)


A. Arrangement of Fascicles 1. Parallel a. fascicles run parallel to the long axis of the muscle b. Example - Sartorius c. “strap-like”

2. Fusiform a. spindle-shaped muscles b. Example - biceps brachii c. “spindle-like”


3. Pennate penna = “feather” a. short fascicles that attach obliquely to a central tendon running the length of the muscle b. rectus femoris


4. Convergent a. fascicles converge from a broad origin to a single tendon insertion b. pectoralis major

5. Circular a. fascicles are arranged in concentric rings b. orbicularis oris


B. Lever Systems: Bone-Muscle Relationships 1. Lever a. rigid bar (lever/bones) that moves on a fulcrum (joints), or fixed point

2. Effort a. force applied to a lever (muscle contraction)

3. Load a. resistance moved by the effort (actual bone)


B. Lever Systems: Bone-Muscle Relationships

Mechanical Advantage Mechanical Disadvantage

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C. Lever Systems: Classes 1. First class a. fulcrum is between the load and the effort (can be mechanical advantage or disadvantage) b. Lifting your head off your chest


C. Lever Systems: Classes 2. Second class a. load is between the fulcrum and the effort (uncommon in body / mechanical advantage) b. Standing on your toes


C. Lever Systems: Classes 3. Third class a. effort is applied between the fulcrum and the load (great speed / mechanical disadvantage) b. Most skeletal


A. Muscles: Name, Action, and Innervation

1. Name and description of the muscle

a. be alert to information given in the name

2. Origin and insertion

a. Origin - attachment to the immovable bone

b. Insertion - attachment to the movable bone

c. there is always a joint between the origin and insertion


3. Action a. best learned by acting out a muscle’s movement on one’s own body

4. Nerve supply a. name of major nerve that innervates the muscle


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A. Muscles of the Scalp

1. Epicranius (occipitofrontalis)

a. bipartite muscle consisting of the:

1) Frontalis

2) Occipitalis

Bipartate = “2 parties”


2. Galea aponeurotica

a. cranial aponeurosis connecting above muscles

3. These two muscles have alternate actions of pulling the scalp forward and backward


1. Eleven muscles are involved in lifting the eyebrows, flaring the nostrils, opening and closing the eyes and mouth, and smiling

B. Muscles of the Face


2. All are innervated by cranial nerve VII (facial nerve)

3. Usually insert in skin (rather than bone), and adjacent muscles often fuse

B. Muscles of the Face


C. Muscles of Mastication 1. There are four pairs of muscles involved in mastication

a. Prime movers 1. Temporalis 2. Masseter


b. Grinding movements 1. Pterygoids 2. Buccinators

2. All are innervated by cranial nerve V (trigeminal nerve)

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D. Extrinsic Tongue Muscles 1. Three major muscles that anchor and move the

tongue

2. All are innervated by cranial nerve XII (hypoglossal nerve)


E. Muscles of the Anterior Neck and Throat: Suprahyoid

1.  Four deep throat muscles

2.  Form the floor of the oral cavity

3.  Anchor the tongue

4.  Elevate the hyoid

5.  Move the larynx superiorly during swallowing


F. Muscles of the Anterior Neck and Throat: Infrahyoid 1. Straplike muscles that depress the hyoid and

larynx during swallowing and speaking


G. Muscles of the Neck: Head Movements

1. Major head flexor is the sternocleidomastoid

2. Synergists to head flexion are the suprahyoid and infrahyoid


G. Muscles of the Neck: Head Movements 3. Lateral head movements are accomplished by the

sternocleidomastoid and scalene muscles


G. Muscles of the Neck: Head Movements 4. Head extension is accomplished by the deep

splenius muscles and aided by the superficial trapezius

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Documents

Bluegrass Technical 10 - Blair High Schoolblairschools.org/gen/blair_generated_bin/documents/basic_module/...1/16/17 1 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin