Question 1

According to an evolutionary scientist, what characteristic of the penis would serve an important function related to sperm competition (when the sperm of two or more men is present in the female reproductive tract)?

Accepted Answer

The coronal ridge, also known as the "cock head," is believed to have evolved as a tool for sperm competition. It is believed that the ridge helps to displace the semen of competitors by trapping it in the female reproductive tract and then removing it during subsequent sexual encounters. This increases the likelihood of a male's sperm to fertilize the female's egg. Factors such as force of ejaculation, sperm count, and penis size may also play a role in sperm competition, but the coronal ridge is believed to be the most important characteristic in this regard.

Question 2

Jay often wakes up with an erection and sometimes experiences erections throughout the night. What is the most likely reason for this?

Accepted Answer

During REM (Rapid Eye Movement) sleep, which is a stage of deep sleep, men often experience erections. These erections can occur multiple times throughout the night, and sometimes continue into the morning upon waking up. It is a natural and normal physiological response and is not necessarily a sign of sexual arousal or desire.

Question 3

What is the primary function of the Cowper's glands?

Accepted Answer

The primary function of Cowper's glands, also known as bulbourethral glands, is to produce fluid to clean and lubricate the urethra before ejaculation. This helps to reduce the acidity of the urethra, protect sperm from damage and facilitate ejaculation. They do not produce seminal fluid or help propel sperm, so options A and B are incorrect.

Question 4

What are the two main functions of the testicles?

Accepted Answer

The testicles have two main functions: production of sperm and production of testosterone.

Question 5

What structure in the male reproductive system adds an alkaline fluid to semen which helps in neutralizing vaginal acidity?

Accepted Answer

The prostate gland adds an alkaline fluid to semen which helps in neutralizing vaginal acidity. The seminal vesicles also add fluids to semen, but they do not have an alkaline pH. The epididymis and Cowper's gland do not add fluids to semen.

Question 6

What part of the male reproductive system contracts and expands to regulate the temperature of the testicles?

Accepted Answer

The cremaster muscle is responsible for regulating the temperature of the testicles by contracting and relaxing to either bring the testicles closer to the body for warmth or away from the body for cooler temperatures.

Question 7

How many sperm per day are commonly produced by the human male?

Accepted Answer

The average human male produces around 300 million sperm per day, which are continually produced throughout their lifetime.

Question 8

According to recent research with college populations what was found related to sperm production?

Accepted Answer

Recent research with college populations found that sperm production was lower during exam periods than at the beginning of the semester. This was attributed to the students' increased stress levels during exams, which can negatively impact sperm production. The other options listed have not been supported by current research.

Question 9

If during semen analysis, a doctor found that Tim's ejaculate contained approximately 15 million sperm per milliliter, what would a probable diagnosis be?

Accepted Answer

The normal sperm count in semen is between 15 and 200 million sperm per milliliter. Therefore, a count of 15 million would be considered low and could indicate infertility. Gynecomastia, prostate cancer, and erectile dysfunction would not necessarily affect sperm count.

Question 10

All of the following statements describe the epididymis EXCEPT:

Accepted Answer

The epididymis does store sperm, but not for several months. Sperm can be stored in the epididymis for a few days to a couple of weeks at most, where they gain motility and mature before being ejaculated.

Question 11

All of the following are true regarding sperm EXCEPT:

Accepted Answer

Options A, B, and D are all true statements about sperm, while option C is false. There are only limited treatment options available to increase sperm quantity and quality, including lifestyle changes, medications, and assisted reproductive technologies, but they are not always effective for everyone.

Question 12

What describes the process of erection?

Accepted Answer

The process of erection occurs when the erectile tissues in the penis fill with blood, causing it to become hard and erect. This is the result of increased blood flow into the corpora cavernosa, which are two sponge-like structures that run along the shaft of the penis. This increased blood flow is usually triggered by sexual stimulation, either through physical touch or mental arousal.

Question 13

If the semen of a man has a bitter taste, one could suspect that he:

Accepted Answer

Coffee consumption can affect the taste of semen, often making it bitter.

Question 14

Ovulation typically produces just one egg per cycle. Why does ejaculate contain more than just one sperm?

Accepted Answer

Ejaculate contains more than one sperm to increase the chances of reaching the ovum and working together to achieve fertilization through combined enzyme production. While only one egg is typically released during ovulation, there are millions of sperm in a single ejaculation, giving a greater chance for successful fertilization.

Question 15

What is 60-70% of semen made up of?

Accepted Answer

The majority of semen, about 60-70%, is made up of fluid from the seminal vesicles, which provides nutrients and energy for the sperm.

Question 16

What is the 18-inch tube that carries sperm away from the testicles and mixes it with other seminal fluids?

Accepted Answer

The vas deferens is the 18-inch long tube that carries sperm away from the testicles and mixes it with other seminal fluids to form semen. The epididymis is a coiled tube on the surface of the testicles where sperm are stored and matured. The ejaculatory duct is formed by the joining of the vas deferens and the seminal vesicle, and it propels semen out of the body through the urethra. The prostate is a gland that produces additional fluids that make up semen.

Question 17

What does the term spermatogenesis refer to?

Accepted Answer

Spermatogenesis refers to the process of production of sperm in the testicles.

Question 18

What happens to faulty sperm and sperm that are not ejaculated?

Accepted Answer

Faulty sperm and sperm that are not ejaculated are typically reabsorbed into the body. This is a natural process and does not typically cause any pain or reduction in sexual arousal. Temporary infertility may occur if there is a significant decrease in the number or quality of sperm produced or ejaculated, but this is not directly related to the fate of faulty or un-ejaculated sperm.

Question 19

Erection is best described as a:

Accepted Answer

Erection is primarily a spinal reflex that involves the parasympathetic nervous system. This response is triggered by sensory stimulation, such as touch or visual stimuli, which sends signals to the spinal cord and causes the release of neurotransmitters that relax smooth muscle and increase blood flow to the penis. While sexual arousal may involve cognitive processes and tactile responses, erection itself is primarily a physiological reflex.

Question 20

What is the primary reason the testicles are located outside of the body?

Accepted Answer

The primary reason the testicles are located outside of the body is to provide temperature regulation for the sperm to survive. Sperm are produced best at a temperature slightly cooler than body temperature, so being outside the body allows them to be kept at the ideal temperature.

Quiz 6: Male Sexual Anatomy and Physiology

According to an evolutionary scientist, what characteristic of the penis would serve an important function related to sperm competition (when the sperm of two or more men is present in the female reproductive tract) ?