FACT
WATCH:a video
about the anatomy
of a muscle cell:
See video:
SHORTCODEat
http://www.everythingscience.co.za
Learn more about
myosin and actin:
See video:
SHORTCODEat
http://www.everythingscience.co.za
Learn about the role
of sarcoplasmic
reticulum in muscle
cell:
See video:
SHORTCODEat
http://www.everythingscience.co.zaFACT
ATP stands for
adenosine
triphosphate. It is
the energy reserve
of the body.by perimysium. Several of these together make up the fasciculus. Numerous fasciculi are
surrounded by epimysium. These structures combine to form a muscle.
Figure 7.21: Different structural components of the voluntary muscle.Muscle contraction
Each muscle cell (muscle fibre) is made up of manymyofibrils. Myofibrils are responsible for
the muscle contraction. Each myofibril consists of units calledsarcomeres(there are many
sarcomeres joined end to end in each myofibril). Sarcomeres consist of thin actin filaments
and thick myosin filaments. When muscle fibres contract these filaments slide across each
other. The actin filaments shorten, but the length of the myosin filaments do not change.
This causes the sarcomeres to shorten, resulting in the shortening of the whole muscle. The
contraction of the muscle fibres requires energy in the form of ATP. The energy is supplied
by the process of cellular respiration.
Chapter 7. Support systems in animals 213