Answer:
When a person engages in physical activity, he undergoes aerobic situations where the heart muscle is optimally strained and improves its muscle strata.
There are scientific studies that compare the muscular walls of athletes and sedentary people, the walls of athletes are thicker and have more power when it comes to pumping and ejecting blood, that is, they make fewer contractions of the heart muscle but more effectively due to They eject more blood, while in unhealthy or sedentary people their muscles are weak, and they pump less blood into the torrent for each contraction, so they need to compensate for non-ejected blood volume by contracting more times and therefore increasing the heart rate.
Thus, physical activity generates a more effective contraction, which is why the heart rate of athletes is lower.
In the case of blood pressure, blood pressure is lower and there are no atheroma plaques or fatty tissue accumulation as in the case of sedentary patients.
Venous return in athletes is aided by contraction of the skeletal muscles of the lower limb, so cardiac filling is better and the heart has less energy demand (this does not happen with sedentary).
Explanation:
In summary, the heart rate is decreased by the great contractile power of each cardiac pump, the blood pressure is decreased by the low cardiac demand and by the good blood circulation, the venous return is favored by the contraction of the skeletal muscles of the Lower limb and myocardial walls are much thicker or hypertrophic due to good oxygenation and sports activation during physical activity.
Answer:
Spermatogonia , Primary Spermatocyte, Secondary Spermatocyte, Spermatids and Spermatozoa.
Explanation:
Seminiferous tubules are the main site for spermiogenesis. The two main cells included in the seminiferous tubules are germ cells which produce sperms another one is the Sertoli cells which nurture the germ cells throughout the developement process.
There are 3different phases described below:
1. Proliferative Phase: Spermatogonia i the basal region of the tubular epithelium undergo mitosis. Spermatogonia divide to give rise to primary spermatocytes. All descendants of a B spermatogonium remain connected by cytoplasmic bridges, forming a syncytium - like cell clone which undergoes synchronous development.
2. Meiotic Phase:Each primary spermatocyte divides to give rise to two short-lived secondary spermatocytes, which in turn give rise to two spermatids each. The spermatids contain a haploid number of chromosomes (half the number of a somatic cell). Primary spermatocytes are the largest cells in the spermatogenic series and are located approximately midway within the seminiferous epithelium.The process of meiosis occurs over a long period, with prophase of the first meiotic division taking up to three weeks
3. Differentiation phase
This phase is also known as spermiogenesis.
Spermatids undergo transformation into spermatozoa. Many changes occur within the cells, the three major ones being:
i) formation of the acrosome, which covers the cranial part of the head. The acrosome will contain hydrolytic enzymes to allow fusion of sperm and egg for fertilisation.
ii) condensation of nuclear chromatin in the head to form a dark-staining structure
iii) growth of the tail opposite the acrosome, and loss of excess cytoplasmic material which is shed as a residual body. The body is phagoctosed by the Sertoli cells..
Answer:
Primary prevention
Explanation:
Primary prevention is the correct level of prevention to give a healthy person.
