A ligamentous connection, such as that between the bones of the lower leg, is called a __________.

• synostosis

• synchondroses

• symphysis

• syndesmosis

Answer explanation

In the syndesmosis at the distal tibiofibular joint, the fibrous tissue connecting the bone is longer than that in the sutures, and slight to considerable movement is possible.

A synovial joint is an example of a(n) __________.

• amphiarthrosis

• diarthrosis

• synarthrosis

• syndesmosis

Answer explanation

Synovial joints are those in which the articulating bones are separated by a fluid-containing joint cavity. This arrangement permits substantial freedom of movement, and all synovial joints are freely movable diarthroses.

An entire skeletal muscle is surrounded by

• sarcolemma

• tendon sheath

• endomysium

• epimysium

Answer explanation

Perimysium surrounds bundles of fibers (fasciculi), and endomysium surrounds each fiber. The entire muscle is surrounded by epimysium.

a motor neuron along with all the muscles fibers it supllies is called a(n)

• synaptic cleft

• motor end plate

• motor unit

• axon terminal

Answer explanation

A motor unit is a nerve-muscle functional unit, with a motor neuron supplying all the muscle fibers within the motor unit.

Which of the following muscle types is/are both voluntary and striated?

• cardiac muscle only

• skeletal muscel only

• cardiac muscle and skeletal muscle

• smooth muscle

Muscle cells initiate nerve impulses

• True

• False

The final "go" signal for skeletal muscle contraction is __________.

• a decrease in extracellular calcium ion levels

• an increase in extracellular calcium ion levels

• an increase in intracellular calcium ion levels

• a decrease in intracellular calcium ion levels

Acetylcholinesterase __________.

• breaks down acetylcholine

• helps acetylcholine bind to its receptor

• activates acetylcholine

• is another name for acetylcholine

When an action potential arrives at the neuromuscular junction, the most immediate result is __________.

• the depolarization of the sarcolemma

• a rise in intracellular Ca2+ levels in the muscle fiber

• the release of acetylcholine from the motor neuron

• the formation of actin-myosin cross bridges

What would occur if a contracting muscle became totally depleted of ATP?

• The muscle would remain in a contracted state because of an inability to break actin-myosin cross bridges.

• The muscle would relax and lengthen because of an inability to sustain actin-myosin cross bridges.

• The muscle would exhibit isotonic contraction.

• The muscle would exhibit isometric contraction.