Normal development in tests requires a temperature. cremaster muscle contract or relax to move testes toward or away from the body or to maintain the acceptable temperature for testicular. The body temperature regulation is controlled by the autonomic nervous system under the guidance of medulla oblongata which is in the brain system.
The temperature in testicles is controlled by their location and scrotum (its muscle layers)
Explanation:
The testicles in male body is located outside their body. This is so because it regulates the temperature requirement of testicles to produce spermatozoa and male hormone testosterone is sufficient amount. Since testicle is located outside the body, its normal temperature is 4 to 5 degree lesser than the normal body temperature. Also the scrotum covering the testicles also regulate the temperature for optimum spermatozoa development. There are three layers in a scrotum that helps controlling the temperature –
a) Tunica dartos (located inside the scrotum) – This layer is temperature sensitive. It relaxes when hot and contracts when cold
b) Cremaster muscle in the spermatic cord – Based on environmental temperature it regulates proximity of testicle to the body
c) Pampiniform plexus – It is the coil of testicular veins that cools the arterial blood entering the testicle
So an autosomal trait is one that occurs due to a mutation on Chromosomes 1 through 22. Dominant means that you only need one copy of a mutation in order to be effective. Some autosomal dominant traits that individuals may be familiar with are neourofibromitosis Type I, Huntington disease, and Marfan syndrome.
<em>Exposure to such particles can affect both your lungs and your heart. Numerous scientific studies have linked particle pollution exposure to a variety of problems, including: ... decreased lung function. increased respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing.</em>
