pe neuromuscular system and respiratory system Flashcards
what is wave summation?
the process that involves the increasing force of contraction because muscle fibres have insufficient time to go through the relaxation phase after muscular contractions.
The strength of a muscle contraction if directly related to…
the frequency of the action potential generated.
What is spatial summation?
The process of relaxing and resting some motor units while others contract.
what does LOST stand for?
Large surface area
One cell thick
Short diffusion pathway
Tons of cappillaries
what is minute ventilation:
volume of air that enters the lungs per minute.
what happens during inspiration?
Diaphragm flattens, external intercostal muscles contracts.
These 2 processes increases the size of the thoracic cavity, reducing the pressure in the lungs.
Air enters the lungs from high to low concentration.
What happens during expiration?
Diaphragm relaxes to a dome shape, external intercostal muscles move down and in.
These 2 processes decreases the size of the thoracic cavity, increasing the pressure in the lungs.
Air enters the lungs from high to low concentration.
what muscles contract during inspiration?
pectoralis minor
scalenes
stermocleidomastoid
external intercostals
diaphragm
what muscles contract during expiration?
internal intercostals
abdominals
what happens to the breathing rate during inspiration in excersies?
CO2, vagus nerve, sympathetic ns, muscles.
-increased CO2, detected by chemoreceptors in the carotid artery and the aortic arch.
-they send impulses through the vagus nerve up to the respiratory centre in the medulla.
-The inspiratory centre sends impulses through the sympathetic nervous system via the phrenic nerve.
-This message reaches the sternocleidomastoid, scalenes, pectorals minor to contract faster to increase the rate of breathing.
What happens to our breathing rate during expiration in excersies?
depth of breathing, stretched, intercosta nerve, muscles.
-increased depth of breathing rate, so he lungs are stretched out more. this prevents the overinflation of lungs.
-send impulses to the respiratory centre.
-the respiratory centre send impulses via the intercostal nerve to the internal intercostals and abdomen to increase rate of contraction.
What happens to our breathing rate during rest?
Rest is a passive process.
The inspiratory centre sends impulses through the sympathetic nervous system vie the phrenic nerve.
These messages reach the external intercostals and diaphragm to contract.
After 2 second these muscles stoop and passive expiration occurs, the lungs naturally recoil.
What happens if inflammation caused by nicotine constricts the bronchioles?
Less O2 in, less CO2 out.
What happens if smoking damages the cilia in the cells of the trachea, bronchi and bronchioles?
mucus cant be trapped so constant coughs and colds.
what happens if smoke breaks down the alveoli walls making them join together?
less surface area so less diffusion.
