Transcript Skeletal Muscle Tissue

Skeletal Muscle Tissue
ACCESS HE
Human Biology.
Clare Hargreaves-Norris
Muscle Tissue Characteristics
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Muscles are made up of tiny elastic fibres
that have the ability to:
Shorten or contract.
Spring back to the original form after
contraction - like elastic.
Stretch when relaxed.
Respond to stimuli provided by nerve
impulses.
Clare Hargreaves-Norris
Skeletal (Voluntary) Muscle Tissue
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Skeletal muscle tissue is controlled voluntarily by the brain
and nervous system.
When viewed under a microscope, it has visible stripes and is
therefore called striated.
Each muscle tissue consists of bundles of parallel muscle fibres.
Each muscle fibre also has a rich blood and nerve supply.
The blood brings fresh oxygen, nutrients, and adrenalin and
removes waste products such as lactic acid and carbon dioxide.
The nerves carry impulses that stimulate the muscle to contract
or relax.
Clare Hargreaves-Norris
Actin and myosin fibres
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Running the length of the
muscle tissue are two kinds of
protein filaments:
Actin filaments: the thinner
filaments.
Myosin: the thicker
filaments.
Actin and Myosin filaments
are arranged in alternating
bands resulting in a striated
appearance.
Clare Hargreaves-Norris
Structure of a muscle fibre
Clare Hargreaves-Norris
How a voluntary muscle contracts
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Muscle must receive a stimulus
from the motor nerve attached
to the muscle fibre.
Muscle must have a sufficient
energy supply.
Energy comes from Adenosine
triphosphate (ATP), which is rich
in glucose and oxygen.
Nerve stimulus and ATP results
in the actin filaments sliding
further in-between the myosin
filaments, therefore shortening
the muscle fibres.
This is the sliding filament
theory of muscle contraction.
Actin
filament
Myosin
filament
Clare Hargreaves-Norris