UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
CHAPTER 7
3 types of muscles
- The main function of the muscular system is movement.
- There are three types of muscle tissue: skeletal, cardiac, and smooth.
Skeletal
Voluntary, striated, multiple nuclei, parallel
- Skeletal muscle is voluntary.
- These muscles are attached to bones and are responsible for their movement.
- Skeletal muscle consists of long fibers and is striated due to the repeating patterns of the
myofilaments (made of the protein actin and myosin) that make up the fibers.
Cardiac
Involuntary, striated, intercalated disc (made of
desmosomes and gap junctions) branched
- Cardiac muscle is found in the heart.
- Cardiac muscle is striated like skeletal muscle, but differs in that the plasma membrane of the
cardiac muscle causes the muscle to beat even when away from the heart.
- The action potentials of cardiac and skeletal muscles also differ.
Smooth
UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
, UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
- Smooth muscle is involuntary.
- It is found in organs and enables functions such as digestion and respiration.
- Unlike skeletal and cardiac muscle, smooth muscle is not striated.
- Smooth muscle has less myosin and does not generate as much tension as skeletal
muscle.
Involuntary, NO STRIATIONS, spindle shaped, found in hollow organs
Muscle is electrically excitable
Action potentials (AP) will cause a release of a NT
(neurotransmitter), the NT will bind to receptors on
muscle cells causing them to be “turned on”
Muscle characteristics
• excitability.
• contractility.
• extensibility - they can be stretched.
• elasticity - they return to normal length after stretching.
UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
, UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
Skeletal Muscle Arrangement:
Skeletal muscles vary considerably in size, shape, and arrangement of fibers
..................................................................................................................An individual
skeletal
muscle may be made up of hundreds, or even thousands, of muscle fibers
bundled together and wrapped in a connective tissue covering. Each muscle
is surrounded by a connective tissue sheath called the epimysium.
A bunch of sarcomeres make up a
myofibril Myofibrils are contractile
organelles of a muscle cell
A bunch of myofibrils make up a muscle cell/fiber and it is surrounded
by endomysium
A bunch of muscle cells/fibers make up a fascicle and a fascicle
is surrounded by perimysium A bunch of fascicles make up a
muscle and a muscle is surrounded by epimysium
The arrangement of fascicles is what causes the striped
appearance of muscles Muscles can be joined to bone directly or
indirectly by tendons
Myoglobin
UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
2022
CHAPTER 7
3 types of muscles
- The main function of the muscular system is movement.
- There are three types of muscle tissue: skeletal, cardiac, and smooth.
Skeletal
Voluntary, striated, multiple nuclei, parallel
- Skeletal muscle is voluntary.
- These muscles are attached to bones and are responsible for their movement.
- Skeletal muscle consists of long fibers and is striated due to the repeating patterns of the
myofilaments (made of the protein actin and myosin) that make up the fibers.
Cardiac
Involuntary, striated, intercalated disc (made of
desmosomes and gap junctions) branched
- Cardiac muscle is found in the heart.
- Cardiac muscle is striated like skeletal muscle, but differs in that the plasma membrane of the
cardiac muscle causes the muscle to beat even when away from the heart.
- The action potentials of cardiac and skeletal muscles also differ.
Smooth
UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
, UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
- Smooth muscle is involuntary.
- It is found in organs and enables functions such as digestion and respiration.
- Unlike skeletal and cardiac muscle, smooth muscle is not striated.
- Smooth muscle has less myosin and does not generate as much tension as skeletal
muscle.
Involuntary, NO STRIATIONS, spindle shaped, found in hollow organs
Muscle is electrically excitable
Action potentials (AP) will cause a release of a NT
(neurotransmitter), the NT will bind to receptors on
muscle cells causing them to be “turned on”
Muscle characteristics
• excitability.
• contractility.
• extensibility - they can be stretched.
• elasticity - they return to normal length after stretching.
UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
, UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
Skeletal Muscle Arrangement:
Skeletal muscles vary considerably in size, shape, and arrangement of fibers
..................................................................................................................An individual
skeletal
muscle may be made up of hundreds, or even thousands, of muscle fibers
bundled together and wrapped in a connective tissue covering. Each muscle
is surrounded by a connective tissue sheath called the epimysium.
A bunch of sarcomeres make up a
myofibril Myofibrils are contractile
organelles of a muscle cell
A bunch of myofibrils make up a muscle cell/fiber and it is surrounded
by endomysium
A bunch of muscle cells/fibers make up a fascicle and a fascicle
is surrounded by perimysium A bunch of fascicles make up a
muscle and a muscle is surrounded by epimysium
The arrangement of fascicles is what causes the striped
appearance of muscles Muscles can be joined to bone directly or
indirectly by tendons
Myoglobin
UNIT 3 EXAM HELP GUARANTEED SUCCESS NEW UPDATE
2022
