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BSC 2085, Chapter 9A Class Notes – Fall 2010
Powerful Skeletal muscles are attached to _____________ or _____________, are
___________________, ___________-nucleate, and under ____________________ control.
Cardiac muscles found only in the _____________ have _______________ chains of cells, have _______
or _______ nuclei per cell, and are under ______________________ control.
Smooth muscles are not ________________, have ___________ nucleus and are under
_________________ control.
(Slide #6) What are the 4 main characteristics of Muscle Tissue?
What are 4 functions of muscles?
Each Muscle is served by one __________________, one _____________ and one or more
_______________.
(Slide #9) Each skeletal muscle _________________ or muscle ________________is supplied with a
________________ that controls its activity.
Skeletal muscle has a rich _____________ supply, as contracting muscle fibers use huge amounts of
__________ and require almost continuous delivery of _____________.
(Slide #10) What are the 3 connective skeletal muscle sheaths and what do they surround?
(Slide #12) Please describe 4 types of muscle attachments:
(Slide #14) A muscle cell is a cylindrical cell that is ____ to _____ microns in diameter, and up to
__________ long.
_________________ of embryonic cells have previously fused to produce one mature muscle cell.
The plasma membrane of the muscle cell is called the _____________________ and the cytoplasm is
called the __________________. The muscle cell has many _________________________ for making
___________ (energy molecules).
_____________________ store glycogen in the muscle.
_________________ a red pigment, is used for oxygen storage in the muscle.
What are three unique elements of the muscle fiber?
80% of the volume of the muscle fiber (cell) is comprised of ______________________.
(Slide #18) What comprises the dark A bands and the light I bands of the myofibril?
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What is the role of elastic titin?
Please Label these Figures: Slide #20
Slide # 28
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(Slide #21) Myofibrils may contain hundreds of _________________ packed end to end. A
_____________ is the smallest contractile unit of a muscle fiber (cell) and it is the functional unit of
skeletal muscle.
The Sacromere consists of one _________
flanked by one half of an ____________.
(Slide #22) A Sarcomere is the region of a myofibril that is between two successive ____________. A
Sarcomere is composed of __________ and ________ myofilaments made of contractile proteins.
(Slide #25) Thick filaments run the entire length of an ____________. Thin filaments run the length of
the _____________ and partway into the A band. ___________ is coin-shaped sheet of proteins that
anchors the thin filaments and connects myofibrils to one another.
The _________________ (stands for “helle” = bright) is the lighter mid-region where filaments do not
overlap. The _____________ (stands for middle) is a line of protein myomesin that holds adjacent thick
filaments together. The myofilaments are connected to the sarcolemma and held in perfect alignment at
the __________ and ___________.
Please Label the Figure above (shown on Slide #28).
(Slides 29-30) The thick filament called _______________ has a _______________ and two
__________________________.
Myosin Heads contain 2 smaller, light polypeptide chains that act as ___________________during
contraction, and also have these three things:
(Slide #31) Actin has a twisted double strand of fibrous protein called _______________ that consists of
___________________ that bear active sites for _________________ head attachment during
contraction.
____________________ and ____________________ are regulatory proteins bound to Actin.
(Slide #36) The ______________________________ is a network of smooth endoplasmic reticulum
surrounding each myofibril. The SR has pairs ______________________ that form perpendicular cross
channels. The __________________________ (SR) functions in the regulation of
______________________________________________.
(Slid #37) The ___________________ are continuous with the sarcolemma, and penetrate the cell’s
interior at each A band–I band junction. The T tubule is associated with one pair of
_______________________ of the Sarcoplasmic Reticulum; together these form _____________ that
encircle each sarcomere.
(Slide #39) Muscle contraction is ultimately controlled by _____________________________________
travelling along the sarcolemma. _______________________ conduct impulses deep into muscle fiber.
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(Slide #40) At the Triad, integral proteins of the _______________________ and the SR
__________________ protrude into the space between the T tubule and SR cisternae. These integral
proteins interact to play an important role in ____________________________.
(Slide #41) T tubule integral proteins are ____________________________. Sarcoplasmic Reticulum
integral proteins called _________________________________ are gated channels that regulate
_____________________________ from the SR’s cisternae.
(Slide #42) The T tubule, SR cisternae and Sarcomeres work together to “couple” electrical impulses and
Ca 2+ release to muscle contraction. This is called ____________________________________.
(Slide #43) The generation of force does not necessarily cause shortening of the fiber. Shortening occurs
when tension generated by cross bridges on the thin filaments ____________ forces opposing shortening.
(Slide #44) In the ________________________________ Model of Contraction, in the relaxed state, thin
and thick filaments overlap ________________. During contraction, myosin heads bind to
___________________, detach, and ______________________________ to propel the thin filaments
toward the M line.
(Slide #45) As H zones _________________ and _____________________, sarcomeres shorten, muscle
cells shorten, and the whole muscle shortens.
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