Muscles Flashcards
What percentage of body weight does muscle account for?
40%
What is a myofibril?
The contractile threads (basic rod-like organelle) of a muscle that extend from one end of muscle fibre to the other.
What is a sarcomere?
The basic structural unit of a muscle, consisting of a dark and light bands and long fibrous proteins that slide past each other.
What is the Hydrolysis Process?
Food eaten is synthesized into glucose, which mitochondria then convert to ATP.
Interactions between actin and myosin filaments in sarcomeres are responsible for
Muscle contraction
What is the strength of muscle contraction related too?
To the amount of muscle fibers activated.
What is a twitch?
Sudden rapid stimulation of many fibers
What is the primary role of muscle tissue/fibre?
Contraction
What process is used to convert food molecules into ATP?
Hydrolysis process
Without ____ , cells wouldn’t have the fuel or power to perform necessary functions
Adenosine Triphosphate (ATP)
What 2 factors result in muscle fatigue?
Lack of nutrients and oxygen
Build up of product waste (lactic acid)
In health what is the normal temperature range?
35.8-36.9 centigrade
How many times can a muscle be stretched before rupturing?
3 times the contracted length
Muscle Extensibility definition
The ability for a muscle to be stretched
Muscle Excitability definition
The ability to respond to a stimulus from motor neurone or hormone
Muscle contractility definition
Ability of a muscle to forcefully shorten
Muscle elasticity definition
The ability for the muscle to recoil or bounce back to its original length after being stretched
Opposite partners to prime movers
Antagonist
The state of sustained partial contraction of a muscle
Muscle tone
Properties of muscle tissue
Contractility
Excitability
Extensibility
Elasticity
Location of skeletal muscle
Attached to the bone by tendons and skin
Functions of skeletal muscle
Voluntary movements such as; locomotion, facial expressions and other body movements
Skeletal muscle structure
Numerous nucleus placed away from centre
Striations present
Has blood vessels and nerves associated with it
Very long cylindrical cell shape
40mm – 35 cm mm in length
0.02 – 0.08mm in diameter
Location of cardiac muscle
Only found in the wall of the heart (myocardium)
Function of the cardiac muscle
Involuntary pumps blood and exhibits rhythmic contractions
Structure of the cardiac muscle
Cylindrical and branched
Single, centrally located nucleus
Intercalated discs
Striations present but not clear
Location of smooth muscle
Viscera
Walls of hollow organs, blood and lymphatic vessels, eyes, glands and skin
Function of smooth muscle
Involuntary used for;
Opening and closing airways
Digestion
Urination
Structure of smooth muscle
One centrally placed nucleus
Fusiform
Long and narrow spindle shaped
0.03mm-0.2mm in length
0.005-0.01mm in diameter
What can alter the rate of muscle contractions under the autonomic nervous system?
Nerve impulses
Hormones
Chemicals
What are the 3 main muscle groups?
Striated/Skeletal muscle
Cardiac muscle
Smooth/Visceral muscle
