Muscular Study Guide Flashcards
Define myofiber
A muscle cell
Define sarcoplasmic reticulum
The smooth endoplasmic reticulum of a muscle cell
Define sarcoplasm
The cytoplasm of skeletal muscle cells
Define sarcolemma
The cell membrane of a muscle
Define sarcomere
1 contractile unit. Makes up muscle cells
What is excitability?
The ability to receive and respond to a stimulus
What is contractility?
The ability to shorten forcibly
What is extensibility?
The ability to be stretched/ extended
What is elasticity?
The ability to recook to resting length
What are the 4 main functions of the muscular system?
Producing movement, maintaining posture and position, stabilizing joints, and generating heat
What are 4 other functions of the muscular system?
Protect viscera, form valves, dilate pupils, and form the arrector pili
What are the characteristics of skeletal muscle?
Striated, multi-nucleated, and voluntary
What are the characteristics of cardiac muscle?
Striated, branched, uni-nucleated, and involuntary
What are the characteristics of smooth muscle?
Not striated, uni-nucleated, involuntary, and visceral.
What tissue does a muscle have?
Contractile and connective tissues
What does it mean that each muscle is an organ?
It’s served by one nerve and an artery, and one or more veins.
Why is blood supply important to a muscle?
So it can have enough oxygen and nutrients to continue aerobic respiration
What is the A band?
The part of the sarcomere where the myosin is
What is the I band?
In a sarcomere, it’s the space between where it’s only actin
What is the Z line?
The line between two sarcomeres
What’s a motor unit?
A motor neuron and all the fibers it supplies
What’s muscle tension?
The force exerted by contracting muscle
What’s load?
The force opposing muscle contraction
Define isometric
When the load is greater than the tension