Question

20. Indicate the order of motor unit recruitment based on muscle types (I, IIa, IIx) for the following tasks completed by an average healthy individual.

a)Picking up a pen	1st =	2nd =	3rd =
b)Picking up a heavy weight	1st =	2nd =	3rd =
c)Walking on a treadmill	1st =	2nd =	3rd =
d)Running up a flight of stairs	1st =	2nd =	3rd =

23. The following information is taken from an individual’s respiratory results:

Age = 61

Height = 1.7m

Weight = 75kg

Tidal Volume = 400mL

Breathing Frequency = 17breaths/min

Medical Conditions = Asthma, Diabetes

a) What is the individual’s pulmonary ventilation? Show work.

b) How would the individual’s medical condition/s effect their respiratory system?

Answer 1

a)picking up a pen - Type 2b muscle fibre

b) picking up a heavy weight - Type 2b muscle fibre

c) walking on a treadmill- type 1 muscle fibre

d)Running up a flight of stair- type 1 muscle fibre

Slow-twitch muscle fibers are more efficient at using oxygen to generate fuel for extended muscle contractions over a long time. They fire slower than fast-twitch fibers and they can go a long time before they fatigue. Marathon runners, distance bikers, and endurance athletes have an abundance of slow-twitch muscle fibers which allow them to do their sports for hours.

Low intensity cardio such as walking or jogging promotes the growth of slow-twitch fibers.

Fast-twitch muscle fibers use anaerobic metabolism to create fuel and are much better at generating bursts of strength or speed for a short amount of time than slow-twitch fibers are. Fast-twitch muscle fibers are essential to being a good power athlete such as a powerlifter or a sprinter. These muscles generally produce the same amount of force per contraction as slow-twitch fibers but they are able to fire more rapidly and fatigue much quicker.

2)pulmonary ventilation

minute ventilation = Respiratory rate * Tidal volume

= 400*17 =6800ml/min

3)

With normal breathing, air flows in through the nose or mouth and then into the windpipe (trachea). From there, it passes through the airways (bronchial tubes), into the lungs, and finally back out again.

In people with asthma, the airways are inflamed(swollen) and produce lots of thick mucus. Inflamed airways are also very sensitive, and things like dust or smoke can make the muscles around them tighten up. All these things can narrow the airways and make it harder for a person to breathe.

So, the pulmonary ventilation in asthma patient will be less than normal person