Transcript The Muscular System

Biology 2121
Chapter 10
Introduction to Muscles

are found in many areas of the body
Skeletal muscles only “ ”
 Work
 (1).
in pairs - opposition
Prime movers
 (2). Antagonists
 (3). Synergists
 (4). Fixators
Opposition
Agonists
Antagonists
Naming of Skeletal Muscles

(1).

(2).

(3).

(4).

(5).

(6).

(7).
(“intercostal”)
(“deltoid”)
(“longus” “brevis”)
of
of
(“oblique” “rectus”)
(“bicep” “tricep”)
(sterno cleido mastoid)
(“extensor” “flexor”)
Fasicle Arrangement

(1).

(2).

(3).

(4).
 A.
– sphincters; orbicularis oris
- pectoralis major
– sartorius
unipennate
 B. bipennate
 C. multi-pennate
Fasicle Arrangement
Range of motion and Power
 More
parallel – more shortening
 Longer fibers – more shortening
 >number
; >power
Circular
Convergent and Multipennate
Parallel
Bipennate
BicepsFusiform
Bones and Muscles

Skeletal muscles operate via a “
 Mechanical
 Types
 1st
of
class
 2nd class
 3rd class
advantage
” system
Examples of Lever Systems

Attachments of muscles to bones are made in two
places.
and

As a muscle contracts the
(moveable bone)
moves towards the (less moveable bone)
.
:
 Origin
lies proximal to the insertion
You Are Responsible for:

All of the muscles listed on the next couple of pages.
 Origin
and Insertions
 Action(s)

Identification or general description of any muscle you
are responsible for in the lab.
 M/C
questions
 Diagram identification
Origins and Insertions/Action(s)
Neck
Sternocleidomastoid; Sternohyoid
Abdominals
Muscles of the Back
Trapezius and Latissimus Dorsi
External Thorax – Upper arms; Shoulder
?
?
Shoulder Muscles
?
Upper Arms
Pelvic Muscles
Levator Ani and Coccygeus
Upper Leg
Long Head
Short Head
Hamstring Group
Biceps Femoris
Lower Leg