Chemical factors: This is due to internal stimuli. Changes in the blood such as decrease in O2, increase in CO2 and decrease in PH cause impulse in the carotid artery which stimulates the respiratory centers in the medulla and cause breathing.
Mechanical factors: also called external stimuli. Compression of the fetal chest during delivery forces small amount of lung fluid out of the lungs. This increase in pressure in the chest draws air into the lungs.
Answer:
<h2>Genetic abnormality</h2>
Explanation:
The genetic disease in which (i) the 23rd pair of chromosomes is always involved, (ii) there are always two chromosomes that comprise the 23rd pair, and (iii) there is always something wrong with one or both of the chromosomes is called a Genetic abnormality.
A genetic abnormality is happens by one or more abnormalities in the genome. It can be occurred by a mutation in a single gene or multiple genes or by a chromosomal abnormality.
Answer:
The bones of the skull are highly irregular. Most of the bones of the skull are held together by firm, immovable fibrous joints called sutures or synarthroses. These joints allow the developing skull to grow both pre- and postnatally.
Explanation:
