Muscular System Flashcards
What are the three types of muscle tissue?
Skeletal muscle
Cardiac muscle
Smooth muscle
Describe the structural characteristics of skeletal muscle
Voluntary - stimulated by nerves
Striated
Multinucleated
Describe the physiology of skeletal muscle.
These muscles form the flesh of the body, and as they contract, they pull on the bones or skin, causing body movements.
Describe the structural characteristics of cardiac muscle.
Involuntary - auto rhythmic
Striated
Single nucleus
Describe the physiology of cardiac muscle.
Found only in the walls of the heart, its contractions help propel blood through the blood vessels to all parts of the body.
Describe the structural characteristics of smooth muscle.
Involuntary - auto rhythmic
Non-striated
Single nucleus
Describe the physiology of smooth muscle.
Except for the heart, the muscles in the walls of body’s hollow organs is almost entirely smooth muscle.
Lacks coarse connective tissue sheaths but does have a fine connective tissue containing blood vessels and nerves.
What are the functions of muscles?
Movement Posture Regulating organ volume Moving substances in the body Heat production
What are the structural characteristics of a muscle?
Excitability (ability to response to a stimulus)
Contractility
Extensibility (ability to be stretched or extended)
Elasticity (ability to return to original length after stretching)
Describe the structural characteristics of a muscle attachment
One end of the muscle is attached to a structure that remains stationary (this is the origin)
The opposite end of the muscle that is moved by the contraction is known as the insertion
What is movement?
Movement occurs when a muscle contracts and results from several muscles working together.
Most skeletal muscles are arranged in opposing pairs called antagonistic pairs.
What are the 4 terms used when referring to movement?
Agonist - prime mover, contracts to cause action
Antagonist - stretches and yields to the action of the agonist
Synergist - contracts to stabilise intermediate joints
Fixator - stabilise the origin of the agonist
What tissue surrounds the whole muscle?
Epimysium
What tissue surrounds bundles of fibres?
Perimysium
What tissue surrounds individual muscle fibres?
Endomysium
What are muscle fibres made up of?
Myofibrils
What are myofibrils made up of?
actin and myosin
myofilaments
What gives muscles their striated appearance?
Overlapping of the thin actin and the thick myosin filaments
Where does ATP come from?
Aerobic and anaerobic respiration
What are the 3 stages of aerobic respiration?
- Glycolysis
- Krebs cycle
- Oxidative phosphorylation
Where does aerobic respiration get its energy from?
Glucose
Free fatty acids from adipose tissue
Amino acids
Does aerobic respiration require oxygen?
Yes
Does anaerobic respiration require oxygen?
No
How long is the duration of energy provision from aerobic respiration?
Hours
How long is the duration of energy provision from aerobic respiration?
60 seconds, or slightly more
Where does anaerobic respiration get its energy from?
Glucose
What are the 2 stages of anaerobic respiration?
Glycolysis
Lactic acid formation
What is creatine phosphate?
Stored in the muscles, part of ATP production
Does creatine phosphate oxygen?
No
Where does creatine phosphate get its energy from?
creatine phosphate
How long is the duration of energy provision from creatine phosphate?
15 seconds
When would someone respire anaerobically?
If ATP demand exceeds that available
What physiological changes take place during exercise?
Increase in CO2 and lactic acid. pH becomes more acidic.
Increase in muscle movement and increases in respiration.
Increased return of blood to the heart.
Which receptors detect changes during exercise?
Chemoreceptors detect CO2 and pH
Proprioceptors detect increased muscle movement
Baroreceptors detect increase blood return to the heart
What are the outcomes of the physiological changes during exercise?
Increase in ventilation and cardiac output
Vasodilation and vasoconstriction
