Bellwork 9/22/14
REMINDERS:
Skull Model due Wed
PA Guest Speaker ??!
1.) Which type (s) of muscle is voluntary?
2.) Which type (s) of muscle is involuntary?
3.) Which type is usually attached to bones?
4.) Which type is found in the heart?
5.) Which type is found in walls of organs?
6.) Which has intercalated discs?
7.) Which muscle tissue (s) is striated?
8.) Which muscle tissue is multinucleated?
Learning
Targets:
*I can ID major
muscles
location and
fxn.
*I can describe
steps of muscle
contraction and
relate it to
exercise.
Bellwork 9/23/14
REMINDERS:
Skull Model due Wed
PA Guest Speaker ??!
Bellwork: compare 3 types of muscle
(complete as much as possible)
Classwork: labeling muscles and primary function
Intro of sarcomere
Learning
Targets:
*I can ID major
muscles
location and
fxn.
*I can describe
steps of muscle
contraction and
relate it to
exercise.
Bellwork 9/24/14
REMINDERS:
Skull Model due MONDAY
(NO LATER)
PA Guest Speaker ??!
Bellwork: label and color skeletal muscle cell
(on back of sarcomere sheet from yesterday)
Classwork: sliding filament theory
Learning
Targets:
*I can ID major
muscles
location and
fxn.
*I can describe
steps of muscle
contraction and
relate it to
exercise.
Bellwork 9/29/14
Bellwork:
1. Sit with your partner, have skull and Self-evaluation
completed!
2. review skeletal muscle structure and fxn
Classwork: label and color skeletal muscle cell; I.D.
fxns of all muscles.
Learning
Targets:
*I can ID major
muscles
location and
fxn.
*I can describe
steps of muscle
contraction and
relate it to
exercise.
Muscular System
FUNCTIONS
 Produce skeletal movement
 Maintain posture and body position
 Support soft tissues
 Guard entrances and exits
 Heat Generation body temp.
Types of Muscle Tissue
 Skeletal
 Cardiac
 Smooth
SKELETAL MUSCLES
 Includes all of the skeletal
muscles that can be controlled voluntarily
 Approx. 700 have been
identified in the human body
 Shape indicates function
Functional Characteristics of Muscle
Tissue
 Excitability: receive and response to stimuli
 Contractibility: shorten forcibly when stimulated
 Extensibility: stretch and extension
 Elasticity: bounce back to original length after being
shortened or lengthened.
TYPES OF MOVEMENTS BY MUSCLE
CONTRACTIONS
Each muscle begins at an origin, ends at an
insertion, and contracts to produce an
action.
Origin: immovable (anchored end)
Insertion: movable end of a muscle
** When a muscle contracts and shortens,
its insertion is pulled toward its origin.
Types of Movement
 Actions Include:
 Flexion - a movement that reduces the angle between 2 bones;





Opposite = Extension
Abduction - moving a part away from midline of body;
Opposite = Adduction
Dorsiflexion - elevates top of foot and tilts it up;
Opposite = Plantar flexion
Eversion – sole of foot out
Opposite= Inversion
Supination - turn palm to anterior position;
Opposite = Pronation
Rotation - movement around a longitudinal axis
Extension
Flexion
Dorsiflexion
Extension
Adduction
Abduction
Plantar
Flexion
Flexion
Supination
Eversion
Inversion
Pronation
Rotation
Muscle Organization
Muscles are grouped according to their primary action:
 Agonist - produces a particular movement (triceps)
 Synergist - assists in producing movement
 Antagonist - opposes agonist; relaxes during the prime
movement
Figure 9.2
Connective Tissue Coverings
 Epimysium: connective
tissue that surrounds a
skeletal muscle.
 Perimysium: connective
tissue that extends inward
from the epimysium and
separates the muscle into
bundles of muscle fibers
called fascicles.
 Endomysium: Connective
tissue that surrounds each
fascicle.
Skeletal Muscle Structure
 A muscle is composed of skeletal muscle tissue, nervous
tissue, blood, and connective tissue.
 Individual muscles are held in place by fascia, dense
connective tissue.
 Tendons are extensions of the fascia and intertwine with
the fibers in the periosteum of the bone.
 Muscles are connected to muscles by sheets of
connective tissue called aponeuroses.
Organization of Muscle Fibers
 Parallel - fascicles are parallel to the long axis of muscle
(most muscles); strength
 Convergent - fibers are based over a broad area, but all
fibers come together at a common attachment site
(pectoralis); more versatile in movement
 Pennate - fascicles form a common angle with the tendon;
uni, bi, multipennate; produces high tension
 Circular/spinchter - fibers are concentrically arranged
around an opening (orbicularis oris)
Skeletal Muscle Fibers
 A muscle fiber is a multinucleated cell that attaches to
connective tissue.
 Sarcolemma is the muscle cell membrane.
 Sarcoplasm is the cytoplasm containing nuclei,
mitochondria, and myofibrils.
 Myofibrils are composed of protein filaments, myosin
and actin.
Protein Filaments
 Myosin: Thick filament of twisted protein
strands with globular ends called crossbridges.
 Actin: Thin filament protein, also contains
tropomyosin and troponin. (movable)
 Organization of filaments leads to light and
dark striations seen in skeletal muscle.
Sarcomere Structure
 Sarcomere: The fundamental Unit of a muscle; contains
repeating patterns of striations
 Striations: repeating light and dark regions
Sarcomere Structure
 I bands (light bands) are composed of actin filaments
attached to Z lines.
 A bands (dark bands) are composed of myosin
overlapping actin attached to Z lines by titin.
 A central region (H zone) consists of myosin only with a
thick line, the M line.
Microscopic structure
 Sarcoplasmic reticulum: network of membranous sacs
surrounding myofibrils.
 Transverse tubules (T-tubules) extend into the
sarcoplasm and contain extracellular fluid.
Microscopic structure
 Cisternae: enlarged portions of the sarcoplasmic
reticulum.
 These three structures form a triad where the actin and
myosin overlap.
• http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter10/ani
mation__action_potentials_and_muscle_contraction.html
• http://www.getbodysmart.com/ap/muscletissue/contractio
n/coupling/tutorial.html
• http://www.getbodysmart.com/ap/muscletissue/contractio
n/multipleheads/tutorial.html
Muscle Contraction Quiz
1. Name of the fundamental unit of a muscle.
2. What are the two globular proteins (myofibrils) found in
muscle?
3. What two proteins are associated with the thin filament?
4. What neurotransmitter cause stimulation of SRsarcoplasmic reticulum?
5. What molecule is necessary for cross bridge formation?
6. When this molecule is released from the SR-sarcoplasmic
reticulum, what does it bind to?
7. When a muscle contracts the length of the muscle
___________.
8. Describe a resting sarcomere.