Question

question 4
1 pts
the minimal level of stimulation required to cause a fiber to contract is called the
all - or - none principle.
summation.
tetanus.
threshold stimulus.
question 5
1 pts
repeated stimulation of muscle in time lessens its excitability and contractibility and may result in
tetanus.
summation.
twitch contraction.
fatigue.
question 6
1 pts
the joint present during the growth years between the epiphyses of a long bone and its diaphysis is the
symphysis.
synchondrosis.
syndesmoses.
suture.

Explanation:

• Question 4: The threshold stimulus is the minimum level of stimulation needed to make a fiber contract. The all - or - none principle states that a muscle fiber either contracts completely or not at all. Summation is the adding together of individual muscle twitches. Tetanus is a sustained contraction.
• Question 5: Repeated stimulation of muscle reducing its excitability and contractibility leads to fatigue. Tetanus is a sustained contraction, summation is the combination of twitches, and twitch contraction is a single, brief muscle contraction.
• Question 6: The synchrondrosis is the joint between the epiphyses of a long bone and its diaphysis during growth years. A symphysis is a cartilaginous joint, syndesmoses are fibrous joints, and a suture is a fibrous joint mainly found in the skull.

Answer:

Question 4: threshold stimulus.
Question 5: fatigue.
Question 6: synchrondrosis.