The reason your balls move up and down is due to a normal and natural physiological response which is mainly a result of the cremaster muscle, contracting in response to stress, temperature changes, fear or pulling of the testicles closer to your body for protection.
Your testicles are attached to a cremaster muscle which is a smooth muscle that covers your testes and connects your scrotum to your perineum.
The dartos muscle also helps the testicles move up and down inside the scrotum.
The reason why balls go up when ejaculating is because of a result of involuntary contractions of your cremaster muscle.
The cremaster muscle is a smooth muscle which surrounds your testicles and pulls them up towards your body.
Your cremaster muscle is also a thin, pouch like muscle which covers your testes or testicles and connects your scrotum to your perineum.
When your cremaster muscle contracts it pulls your testicle up toward your body, which is a reflex known as your cremaster reflex.
The cremaster reflex helps to protect your testicles from injury and helps to regulate their temperature by moving the testicles closer to your body when it's cold or further away when it's warm.
And in some men the cremaster reflex can also be hyperactive and cause the testicles to retract more vigorously than they usually would which can occur especially during physical activity, sexual activity or emotional stress.
After ejaculating it takes on average of 2 months to 2.5 months or 74 days for sperm to build back up fully and mature after you release the previous batch of sperm during ejaculation.
Although you continuously produce sperm and can ejaculate the same day or soon after again it takes longer for full sperm buildup.
The entire process of sperm production which also called spermatogenesis takes between 64 to 72 days, from the time a germ cell begins developing to when it becomes a mature spermatozoon.
Sperm comes from the left and right testicles.
Both of your left and right testicles or testes are responsible for producing sperm and also the male sex hormone.
Your testicles are the primary organs of your male reproductive system that is responsible for producing sperm and they also produce and release testosterone which is a key hormone in male sexual function and development.
For optimal sperm production and over all male reproductive health, both testicles are required for producing sperm.
The sperm is also produced in your seminiferous tubules that are within your testicles and then move to your epididymis, where they mature and are stored.
And during sexual arousal, sperm are then released from your epididymis and travels through your vas deferens to be ejaculated.
And while the prostate does not produce sperm, the prostate does contribute to the production of semen which is the fluid which carries the sperm during ejaculation.
One part of your semen is produced in your prostate and together with your sperm cells from your testicles, the fluid from your seminal vesicle and the secretions are released by another pea sized gland below your prostate which is called the bulbourethral gland and the prostate fluid makes up your semen.
The prostate does many things which includes the production of seminal fluid.
The prostate is a gland which is located in a males reproductive system.
Your prostate produces a fluid which mixes with your sperm from your testicles to form semen.
This fluid also helps to nourish and protect your sperm and makes it easier for the sperm to travel and to fertilize an egg.
A males prostate also regulates ejaculation and contains muscles which contract during ejaculation which force your seminal fluid and sperm out of your urethra.
Your prostate also produces PSA also known as Prostate Specific Antigen which is a protein that plays a role in maintaining the health of your prostate gland.
And having elevated levels of PSA or prostate specific antigens can indicate prostate cancer or other potential prostate problems.
The prostate also supports male fertility by providing a suitable environment for sperm and facilitating the sperms movement.
However the prostate is not essential for life and you can live a long and productive life without a prostate but you won't be fertile and won't be able to get a woman pregnant without a prostate.
The muscles of the prostate also ensure that your semen is pressed into the urethra forcefully and then expelled outwards during ejaculation.