Gynecomastia is an increase in the size of the mammary gland in men. The condition can occur in one or both breasts. It starts as a small mass under the nipple, which can be sensitive. One breast can be bigger than the other. Its cause is an imbalance between the stimulatory effects of estrogen (female sex hormones) and the inhibitory effects of androgens (male sex hormones) in the breast tissue, when the first ones increase, or the second ones descend.
Gynecomastia is a problem relatively common in the population, and there are three prevalence peaks throughout life:
Newborns: Between 60 and 90% of newborns have gynecomastia, produced by the passage of maternal estrogens through the placenta. It is a transient gynecomastia that disappears in about 2-3 weeks.
Puberty: Gynecomastia in puberty affects mainly young people aged between 10 and 14 years, and is due to the transient and physiological increase in estrogen that occurs at this age.
Elderly: Is due to an increase in fatty tissue with a greater peripheral aromatization ( a process that occurs in adipose tissue and that involves the conversion of androgens into estrogens), a decrease in the production of testosterone by the testes and the use of drugs.
<span>It is process through which plants and other photoautotrophs generate carbohydrate and oxygen from carbon dioxide, water and light energy in chloroplast. It is two stage reaction-
1.Light dependent reaction- in this sunlight is absorbed by chlorophyll and converted into chemical energy and stored in the form of NADPH and ATP. It takes place in thylakoid membrane in chloroplast.
2.Light Independent Reaction- in this energized electrons from the light dependent reaction provides the energy to form carbohydrate from carbon dioxide molecules. It is known as Calvin cycle.</span>
Answer:
The cell organelles are the functional structures present inside the cell. Some of the organelles such as nucleus, mitochondria, chloroplast, Endoplasmic Reticulum, Golgi Complex etc are membrane-bound. Each organelle inside the cell has a different function to carry out. For example, the nucleus is the organelles which stores and protects the genetic material. Ribosomes are the organelles where a protein is formed. The Golgi- complex is the site where the proteins are modified and packaged.
A medical researcher measured the diastolic wall thicknesses of the arteries in a young, healthy test subject. The test subject came back 20 years later to have the measurements repeated. The measurements revealed that the subject's artery walls were half as thick as they were originally. Which of the following is the most likely long-term effect if the measured trend continues?
b) Arteries will be unable to withstand the pressure exerted by the heart, causing an aneurysm
