characteristics of muscle (5)
- responsiveness
- conductive
- contractility
- extensibility
- elasticity
(also have lots of cells, highly innervated [nerves], highly vascular [blood flow])
muscle energy conversion steps
chemical energy>electrical energy>mechanical energy
Name the muscle contractile proteins
Actin- Thin filaments
Myosin - Thick filaments
List the muscle organelles specific to the muscle cells
- sarcolema: plasma membrane
- sarcoplasmic reticulum: like endoplasmic reticulum
- sarcoplasm: endoplasm
which type of muscles can generate spontaneous contraction?
-cardiac and smooth muscle
Main differences in skeletal, cardiac and smooth muscle
Skeletal: striated, multinucleate, “voluntary”
Smooth: uninucleate, no striations, involuntary
Cardiac: uninucleate, some striations, intercalated disks, involuntary
What determines striations in a muscle?
the arrangement of the myofilaments
What do intercalated discs do?
coordinate contraction (electrical conduction) in the cardiac muscle cells
Describe peristalsis
movement in smooth muscled where the muscularis layers (longitudinal and circular) do alternating contractions
Main functions of muscle (4)
- Movement
- Posture
- Stabilize joint
- generate heat
Tone (definition)
shape of the muscle, the amount a muscle is contracted
Parts of the Sarcomere
- Z line
- H band
- I band
- A band
Actin: think filaments
Myosin: thick filaments
where in the muscle is calcium stored?
sarcoplasmic reticulum
Organization level (big to small)
Muscle>fasiculi>myofiblils>sarcomeres>myofilaments
Can muscle cells push?
No, they can only shorten (pull)
Sliding Filament Theory
the contraction itself, think filaments (actin) slide past the thick filaments (myosin), bringing the z-lines together.
Isotonic contractions
length changes, tone does not
ie: bicep curl
Isometric contractions
length does not change, tone does
“tensing muscle”
ie: holding up a book
“any disease of muscle” called…
Myopathy
