module 5 - 13.9 voluntary and involuntary muscles Flashcards
1
Q
what are the 3 types of muscles in humans?
A
- skeletal muscle
- cardiac muscle
- smooth muscle
2
Q
what are skeletal muscles?
A
- attached to tendons to the skeleton
- voluntary muscles controlled by somatic nervous system
3
Q
what are cardiac muscles?
A
- only found in the heart
- involuntary muscle and is controlled by autonomic nervous system
4
Q
what are smooth muscles?
A
- found in the walls of hollow organs, in blood vessels, in the respiratory system, in eyes, in the skin
- involuntary muscle and controlled by autonomic nervous system
5
Q
what are features of skeletal muscles?
A
- striated appearance (looks stripy, stripes at right angles to length of cell)
- under conscious control of somatic nervous system
- muscle cells are called muscle fibres
- fibres are multicellular in origin and multinucleate (multi nucleus)
- fibres arranged to allow muscle to contact in one direction
- rapid contraction for short length of time
6
Q
what are features of cardiac muscle cells?
A
- striated appearance but less pronounced
- under involuntary control of autonomic nervous system
- muscle cells are called muscle fibres/cadriomyocytes
- fibres arranged in branching pattern connected by intercalated discs
- intermediate contraction and length of time
7
Q
what are features of smooth muscle?
A
- non-striated appearance
- involuntary control of autonomic nervous system
- muscle cells are called muscle fibres and are spindle shaped, with a wide middle and tapering ends
- fibres arranged in non-regular pattern
- slow contraction speed but can contract for long length of time
8
Q
what is the structure of a skeletal muscle?
A
- extremely long, made from embryonic muscle cells fusing together to make a muscle fibre
- multinucleate
- has a sarcoplasm
- bundles of muscle fibres are covered by sarcolemma
- sarcolemma folds to form t-tubules
- many mitochondria to provide ATP for contraction
- ER is modified to form sarcoplasmic reticulum
- each muscle contains many myofibrils
9
Q
what is a sarcolemma?
A
additional plasma membrane covering muscle fibres
10
Q
what is a sarcoplasm?
A
cytoplasm in muscle fibre
11
Q
what do t-tubules help with?
A
help spread electrical impulses throughout the muscle to allow it to contract as a whol
12
Q
what does sarcoplasmic reticulum contain?
A
many Ca2+ ions for the muscle fibre to contract
13
Q
what are myofibrils?
A
specialised organelles that allow the muscle fibre to contract longitudinally
14
Q
A
