In: Biology
You are babysitting your niece (age 10) and nephew (age 3). You nephew is very upset that you won’t let him eat candy for dinner and throws a temper tantrum, becoming so angry that decides he’s going to hold his breath until you give in to his demands. Your niece is very concerned and wonders why you are so relaxed and confident that he cannot harm himself by holding his breath. For this week’s science communication assignment explain to your niece why respiration is necessary and how the nervous system controls breathing, both under normal conditions and in your nephew’s attempts to blackmail you by holding his breath.
Breathing consistof two phase called inhalation and exhalation .
Inhalation or inspiration :-
It is defined as the process of drawing in air into lungs . It occurs with the help of diagram muscles. The muscle of diaphragm contract due to diaphragm moves in the downward direction due to this the volume of chest cavity increases and it results in decrease of air pressure inside the chest cavity, then oxygenated air present outside the body being at high pressure flow rapidly into the lungs by passing through nasal cavity, pharynx, larynx, trachea, bronchi and bronchioles.
Exhalation or Expiration :-
The diaphragm relaxes and moves up and the relaxation of the intercostal muscles moves the ribs in and down. This has the effect of decreasing the volume within the thoracic cavity and increasing the pressure within the lungs with respect to atmospheric pressure. As a result, air moves out of the lungs down a pressure gradient.
Nervous system cotrolsc breathing:-
The respiratory center that control your rate of breathing are in the brainstem and medulam. The nerve cell live within these centers automatically send singnal to diaphragm and intercostal muscle to contract or relax at regular intervals.
Autonomic nervous system regulate the rate of breathing.
We can hold our breath 1-2 minutes. if we hold our breath for long time then there will be accumulation of CO2 in blood and lungs will not function properly and trigger impuls from respiratory center and led to unconsciousness and may people die also.