Download Muscular System ppt

Chapter 10 p278
Chapter 11 p 312
Is this what
you guys want
to look like?
…or you girls?
…this is a little more realistic…
…and
this is
more
like
what
we
have to
learn!!
What is the difference between a typical animal
cell and a MUSCLE CELL?
Why are muscle cells called MUSCLE FIBERS?
What do you think a MYOFIBER is?
Muscle fiber:
Cytoplasm: SARCOPLASM
Cell membrane: SARCOLEMMA
ER: SARCOPLASMIC RETICULUM
Nucleus
A muscle cell is a MUSCLE FIBER !!
One MUSCLE FIBER is wrapped in connective tissue called ENDOMYSIUM
A bunch of muscle fibers are wrapped
in connective tissue called
PERIMYSIUM
and the whole thing is called a FASCICLE.
All the fascicles are wrapped in
connective tissue called the
EPIMYSIUM
Muscle fiber or one muscle cell
Let’s COLOR…
Page 142A…….numbers 1-2-3-4-5 only…
Right now…….
Remember, one muscle cell/muscle fiber is made of
a thousand or more myofibrils … and each of them
is made of thousands of myofilaments !!
One Muscle fiber
is made of
One-thousand myofibrils
each of which contains
Thousands of myofilaments
Thin – actin
Thick -- myosin
UH OH .. more new terms:
Sarcomere – basic contractile unit of a myofibril;
thin myofilaments –made of proteins called actin,
tropomyosin, and troponin;
thick myofilaments – made entirely of myosin;
T tubules – inward extensions of sarcolemma at a right angle
to the long axis of the cell;
Z disk or Z line – separates one sarcomere from the next and
also serves as an anchor for the myofibrils;
Let’s color!!!!
Page 142A….numbers 6-7-8-9-10
Right now….. 
Neuromuscular junction
Impulse travels down the AXON of the motor nerve to the terminal end
plate. There, the NEUROTRANSMITTER Acetylcholine (Ach) is released
to cross the SYNAPSE and stimulate the sarcolemma of the muscle cell:
Are you absolutely, positively, guaranteed, for sure
that you know what each of these things are?????????
terminal end plate
calcium
Ach
sarcolemma
T tubules
SR
sarcoplasm
sarcomere
troponin
tropomyosin
ATP
Sliding filament theory
Terminal end plate of neuron
Calcium is required to trigger the
release of Ach
Ach diffuses rapidly across synapse
Ach receptors initiate an impulse that
travels along the sarcolemma, along T
tubules to the SR
Ca is released from SR into the
sarcoplasm where it binds to troponin
molecules in the thin myofilaments
Tropomyosin molecules in those thin
filaments shift, exposing actin’s active
sites
Energized myosin cross bridges bind
to actin and pull the thin myofilament
toward the center of the sarcomere
This continues several times a second
as long as there is ATP available
As the thin filaments slide past the
thick filaments, the entire muscle
shortens
Relaxation
Immediately after the
Calcium is released into the
sarcoplasm, it is pumped
back into the SR. The Ca is
stripped off the troponin
molecules…troponin without
Calcium allows the
tropomyosin to block the
active sites on actin.
The contraction is over.
Disuse atrophy: prolonged inactivity results in decreased muscle mass;
Hypertrophy: exercise results in increased muscle mass;
Strength training: exercise increasing resistance, isometric exercises, and
weight lifting results in increased numbers of myofilaments (protein strands)
Endurance training: (aerobic training) increases a muscle’s ability to sustain
moderate exercise over a long period—results in increase vascular presence
which increases supply of oxygen and glucose;
Muscle fibers must continually
resynthesize ATP– energy is
also supplied by the
breakdown of creatine
phosphate which is present in
small amounts in muscle
fibers.
Lactic acid accumulates in muscle
tissue and causes a burning
sensation. Some of it is carried
back to the liver where it is
converted back into glucose…this
takes time…time to work the
soreness out.
ASSIGNMENT: one minute verbal report or description of one of these:
1. 3 types of muscle fibers—slow, fast, intermediate
2. Myography
13. myalgia
3. Twitch
14. contusion
4. Treppe
15. poliomyelitis
5. Tetanus
16. Duchene Muscular Dystrophy
6. Muscle tone
17. Myasthenia Gravis
7. Graded strength principle
18. Hernia
8. Isotonic contractions
19. Origin/Insertion
9. Isometric contrctions
20. Prime mover/agonist
10. Cramps
21. Antagonist
11. Convulsions
22. Synergist
12. Fibrillation
23. fixator muscle
TEST
Wednesday,
January 28
Naming muscles
Location -- brachialis in arm; gluteus in buttocks
Function – flexor carpi radialis
Shape -- deltoid (triangular)
Direction of fibers – rectus (straight) abdominus
Number of heads – biceps brachii, triceps brachii
Points of attachment – sternocleidomastoid
Size of muscle – gluteus maximus, gluteus medius, and
gluteus minimus
Table on page 285-287 in your textbook
LEARN THESE!!