muscular system: muscles (chapter 11) lecture materials for amy
TRANSCRIPT
Muscular System: Muscles(Chapter 11)
Lecture Materials
for
Amy Warenda Czura, Ph.D.
Suffolk County Community College
Eastern Campus
Primary Sources for figures and content:
Marieb, E. N. Human Anatomy & Physiology 6th ed. San Francisco: Pearson BenjaminCummings, 2004.
Martini, F. H. Fundamentals of Anatomy & Physiology 6th ed. San Francisco: PearsonBenjamin Cummings, 2004.
Amy Warenda Czura, Ph.D. 1 SCCC BIO130 Chapter 11 Lecture Slides
Muscle Organization-groups of fibers organized into fascicles-fibers in fascicle run parallel to fascicle, but
fascicle can be arranged in 4 differentshapes with respect to tendon:
1. Parallel muscles-fascicles run parallel to length of muscle-most skeletal muscles arranged this way-able to change length extensively-can move load over a great distance
Amy Warenda Czura, Ph.D. 2 SCCC BIO130 Chapter 11 Lecture Slides
2. Convergent muscles-fascicles spread out like fan on one end and
converge to single point on other-produces less tension and distance than
parallel muscle but- independent contraction of fascicles can
produce different movements from same muscle
-provides versatility
Amy Warenda Czura, Ph.D. 3 SCCC BIO130 Chapter 11 Lecture Slides
3. Pennate muscles (“feather like”)-fascicles are arranged at an angle to tendon
A. Unipennate =fascicles angled on one side of tendon
B. Bipennate =tendon in middle with angled fascicles oneither side
C. Multipennate =branched tendon with fascicles organizedaround each branch-pennate muscles produce more tension than
parallel muscles but cannot move as far
Amy Warenda Czura, Ph.D. 4 SCCC BIO130 Chapter 11 Lecture Slides
4. Circular muscles (sphincters)-concentric arrangement of fascicles-function to decrease diameter of openings,
guard entrances and exits
Muscle Terminology
Origin = where the fixed end of the muscleattaches to bone, cartilage, or CT
Insertion = where the moveable end attaches
Action = the specific movement produced bythe muscle during contraction
Amy Warenda Czura, Ph.D. 5 SCCC BIO130 Chapter 11 Lecture Slides
Muscles often work in groups to increasetension or fine tune movement.
Different muscles serve different functions:
Agonist = prime mover, muscle mostresponsible for the specific action
Synergist = a muscle with the same action asthe agonist, assists agonist at thebeginning of contraction when fiberlength is not optimal for agonist
Antagonist = a muscle whose action opposesthe agonist: produces the oppositeaction to fine tune movement by theagonist
Amy Warenda Czura, Ph.D. 6 SCCC BIO130 Chapter 11 Lecture Slides
Names of muscle derived from aspects of theirfeatures:
1. Location: named for part of body wherelocated e.g. Brachii, Abdominis
2. Fascicle organization: named for howfascicles are organized with respect tobody e.g. Rectus = straight
Oblique = angle3. Relative position: named for depth when
layered e.g. Externus/ Superficialis =top, surface
Internus/ Profundus =deep4. Structure, Size and Shape: A. Number of tendons
e.g. triceps, biceps B. Shape of muscle
e.g. trapezius = trapezoid deltoid = triangle soleus = fish
Amy Warenda Czura, Ph.D. 7 SCCC BIO130 Chapter 11 Lecture Slides
C. Size of muscle relative to othersMajor = biggerMaximus = biggestLongus = longVastus = great
5. Origin and Insertion: name for regions ofattachment, origin first, insertion seconde.g. Sternocleidomastoidorigin = manubrium of sternum and
medial clavicleinsertion = mastoid process
6. Action: named for action performed and region acted upone.g. Extensor digitorum
Usually multiple naming schemes arecombined to name the muscle:e.g. flexor carpi ulnaris
*Individual muscles, origins, insertions andactions will be examined in detail in lab!
Amy Warenda Czura, Ph.D. 8 SCCC BIO130 Chapter 11 Lecture Slides