Ch.1 physiology quiz again

What is the basic unit of contraction in skeletal muscle

• sarcomere
• actin filament
• muscle fiber
• myofibril

The light bands in a sarcomere are known as

• I bands
• M lines
• Z lines
• A bands

The dark bands in a sarcomere are known as

• A bands
• H zones
• Z lines
• I bands

The structures that carry action potentials deep into all regions of a muscle fiber are known as

• Sarcoplasmic reticulum
• Myofibrils
• Neuromuscular junction
• T-tubules

The primary role of the sarcoplasmic reticulum (SR) is to

• transport oxygen in the blood
• store and release calcium ions
• produce energy through glycolysis
• synthesize proteins in muscle cells

A-bands appear as a dark region of the sarcomere and are created when

• A-bands appear as a light region of the sarcomere.
• A-bands are formed only by thick filaments.
• A-bands appear as a dark region of the sarcomere when thick and thin filaments overlap.
• A-bands are created when muscle fibers contract.

What region of a myosin molecule is the only part of the molecule that will interact with actin to create a cross-bridge

• Myosin head
• Myosin neck
• Actin binding site
• Myosin tail

An α-motor neuron and all the muscle fibers it innervates are collectively called a

• neuromuscular junction
• motor unit
• muscle fiber bundle
• axon terminal

the series of events that begins with excitation of a motor nerve and results in muscle contraction is called

• Nerve impulse transmission
• Muscle fiber activation
• Neuromuscular junction signaling
• Excitation-contraction coupling

what type of motor units typically contain fewer muscle fibers

• Fast-twitch motor units
• Large motor units
• Type II motor units
• Small motor units