Anatomy of the Male Reproductive System - Online Tutor, Practice Problems & Exam Prep

The male reproductive system includes key structures such as the scrotum, which regulates temperature for sperm production, and the testes, where sperm are produced in seminiferous tubules. Sperm mature in the epididymis before traveling through the vas deferens during ejaculation. Accessory organs like the seminal vesicles and prostate contribute to semen volume, with seminal fluid aiding sperm motility. The penis, composed of erectile tissue, facilitates copulation, highlighting the interconnectedness of these anatomical components in male reproduction.

The Scrotum

Okay. So we're going to begin our section on male reproductive anatomy by talking about the scrotum. The scrotum is an external sac that contains the testes. It hangs outside of the abdominopelvic cavity right around the root of the penis, and this allows it to provide the ideal temperature for sperm production, which is approximately 93 to 96 degrees—a bit cooler than the human body. Two muscles play an important role in maintaining that: the cremaster and the dartos muscles. They work together to adjust the scrotum based on temperature. If we look down at our image here, just to kind of orient you to what you're looking at, the correct anatomical position for a penis is a fully erect penis, so that is what we are seeing here. We are basically inferior to the penis, so lower than it, looking straight up, if that makes sense. The bladder is right behind the penis right there, and then this structure is the scrotum. We see we have the testes would be located here and here. So we'll go ahead and label that as a testis step.

You can see, this skeletal muscle right there, that is the cremaster muscle. What it does is basically when it contracts, it will draw the scrotum up closer to the body, closer to the root of the penis, and that will, of course, keep it warmer. It can also contract due to sexual arousal as well. So it will contract if the scrotum gets too cold and it will relax if the scrotum is getting too hot. Next to that, we have the dartos muscle, which is a little harder to see here, but it's basically this whitish-gray, sheet-like muscle right there. The dartos muscle is comprised of smooth muscle and what it does is basically when it contracts, it tightens the scrotum and causes it to wrinkle, which causes the testes to move closer together, decreasing their surface area, which prevents heat loss. So working together, they can provide the ideal temperature for sperm production. So those are our cremaster and dartos muscles.

Our next major structure is the spermatic cord. The spermatic cord is a connective tissue sheet that will basically contain blood vessels, nerves, as well as the vas deferens, which we will get to in a later video. If you look at our image here, you can see, the spermatic cord really nicely right there. And over here, you can see what it would look like if we peeled back that cord, and you can see all those blood vessels and nerves running through where that cord would be. So we'll label that as our spermatic cord. It's basically just like the sheath that will be encapsulating everything that's coming into the scrotum or leaving the scrotum.

Then we have one last structure, and that is this structure right here on the midline there, and that is called the septum. The septum basically just divides the scrotum, which creates two compartments, one for each testis, of course.

Alright. So that is the scrotum, and I'll see you guys in our next video. Bye-bye.

Anatomy of the Male Reproductive System Example 1

Okay, so what is the primary function of the dartos muscle? Remember, the dartos muscle is a sheet of smooth muscle inside the scrotum, and when the temperature outside gets cold, that muscle will contract. This action will kind of wrinkle the scrotum and pull the testes closer together, which will decrease their surface area and allow them to conserve heat. So, our answer is going to be a) the temperature regulation of the testes.

So, just looking quickly at options b and c, the contraction of the vas deferens and to eject sperm from the testes—both of these actions happen through smooth muscle contractions of the vas deferens itself. So, the dartos muscle is not really helping with that at all. Then, option c can be a little bit tricky. It says the relaxation of the scrotum, and the dartos muscle, of course, can relax just like any other muscle. However, its main function is not to relax. Its function is to help regulate the temperature within the scrotum, so our answer here is going to be a.

The Testes

In this video, we're going to be talking about the anatomy of the testes. Now the testes are paired organs that are enclosed within the scrotum, and these, of course, are the primary sex organs for males or the gonads for males and they're going to be producing the male reproductive cells which, of course, are sperm.

So within each testis, there are 4 major regions that we need to know and these will basically just be a series of tubes and ducts that sperm are going to be moving through. So first up are the seminiferous tubules. These are tightly coiled tubules. They are highly, highly convoluted. You can see those here in purple, and this is where sperm are actually being produced. And I always remember that because to me, seminiferous just sounds kind of like semen, and when I think of semen, I think of sperm. So that's how I kind of keep in my head that this is the location where sperm are actually being created. And so sperm are going to be produced here, but they're not going to mature here.

So the sperm are going to immediately begin to move out, so the immature sperm are going to go out of these purple seminiferous tubules and they're going to enter the straight tubules. And you can see those here in green and they are literally just much more straight and much less convoluted compared to those seminiferous tubules. Those straight tubules will convey sperm to the rete testis. So that is our next structure. And so you can see those right here, and this is just a tubular network on the posterior side of the testis that sperm are going to be passing through as well.

The rete testis will convey sperm to the efferent ductule. Alright. So you can see that efferent ductule right there. And, of course, efferent always means exit. Right? So this is the exit duct for sperm that are going to the epididymis, which is the structure right outside of the testis right here. Alright. And that will be the location where sperm are going to be maturing. I know that this is a whole bunch of just tubes and ducts, but to help you remember the journey that sperm are going to be taking, we have a little memory tool here. So you can think of the sentence 'speedy sperm rush excitedly', where the first letter of each of those words will match up to the first letter of the anatomy in the order that sperm move through. So they're going to begin with those seminiferous tubules, enter the straight tubules, enter the rete testis, and then enter that efferent ductule which will convey them to the epididymis.

Alright, so that is the anatomy of the testes and I'll see you guys in our next video. Bye bye.

Anatomy of the Male Reproductive System Example 2

Okay, so we're going to be determining the order in which sperm move through the testis to the epididymis. There's a whole bunch of tubes in here, so you guys remember our little memory tool for how we keep track of the order that this goes. We think of the phrase "speedy, sperm, rush, excitedly," and then the first letter is going to be the first letter of each of those tubes. So, we are going to begin with our seminiferous tubule, remember, because "seminiferous" kind of sounds like semen. You think semen, you think sperm, and that is where sperm are going to be produced.

So we're going to be starting in our seminiferous tubule and based on that our answer choices are down to b and c. We have our seminiferous tubule and then we have our straight tubule and then we're going to move into our rete testis and then from there we will go to the efferent ductule. Based on that, it looks like our answer is going to be b. We're going to start producing sperm in that seminiferous tubule. The sperm will move into the straight tubule, into the rete testis, into the efferent ductule, and then from there they would move on to the epididymis. And there you have it.

Which of the following structures might be referred to as a ‘sperm factory’?

• A. Straight tubules.
• B. Seminiferous tubules.
• C. Rete testis.
• D. Spermatic cord.

The Ducts

In this video, we're going to be talking about the duct system of the male anatomy, and we're going to begin with the epididymis. So as I alluded to in our last video, this is the location where sperm mature. And this structure kind of arches over the lateral side of the testis. You can see that nicely here, this purple epididymis is hanging on the side of the testis there. And sperm can actually be stored in this location for several months. So, to kind of put everything together, sperm are being created in the seminiferous tubules within the testes. They're being conveyed to the straight tubules, to the rete testis, to the efferent ductule, and then into the epididymis where they can then be stored for weeks or even months, and then they can mature during that time as well. So that is the epididymis.

Next up, we have the ductus deferens or the vas deferens. I'm going to mostly be calling it the vas deferens because it's a much more common name, but it is technically called the ductus deferens. And this is the structure that actually transports sperm during ejaculation. And so it's going to extend from the epididymis all the way up through the pelvic cavity. You can see nicely here where it's connected to that epididymis, and it will extend all the way through the pelvic cavity, arch over the posterior side of the bladder, and then it will empty into this little duct called the ejaculatory duct right there. I'm going to label that on our image for us. And we're going to talk about this duct a bit in our next video, coming up as well. Alright. So that is the vas deferens. So basically, that's going to be carrying the sperm once an ejaculation is taking place. So the sperm are being stored in the epididymis, and then once an ejaculation is taking place, they will get carried up through this vas deferens.

And then finally, we have the urethra, and this is the terminal portion of the male duct system. Okay? And this will be the structure that is transporting both urine and semen, though not at the same time. So we can see our urethra going here all the way down the penis to the outside world. So we'll label that as the urethra. Alright. So that is the male duct system, and I will see you guys in our next video. Bye bye.

Anatomy of the Male Reproductive System Example 3

Alright. So which structure is responsible for the transport of sperm between the epididymis and the ejaculatory duct? So if you can kind of picture this in your head, remember the epididymis is going to be kind of arching over the lateral side of the testis. So that is located all the way down in the scrotum. So what we are talking about here is the structure that would connect the epididymis all the way down there, kind of come through the pelvic cavity and connect to that ejaculatory duct. And that structure is going to be our vas deferens or the ductus deferens. Right? So our answer is b. So the vas deferens will be extending from the epididymis in the scrotum all the way up through the pelvic cavity. It will kind of arch over the posterior side of the bladder and it will empty into that ejaculatory duct. Looking at these other answer choices, I see seminal glands and seminal glands actually do not contribute to the transport of sperm at all. Those are glands located on the posterior surface of the bladder, and they produce seminal fluid. So those are definitely out. These straight tubules are located within the testes, so those are going to be basically handling the transport of sperm before they ever get to the epididymis. And then finally, we have the urethra which will be transporting sperm after the ejaculatory duct. So we'll be ejaculating into the urethra and then, of course, to the exterior world. So our answer here is b, the vas deferens will be transporting sperm between the epididymis and the ejaculatory duct.

What is the primary function of the epididymis?

• A. Production of sperm.
• B. Secretion of seminal fluid.
• C. Storage and maturation of sperm.
• D. Anchor the testis to the cremaster muscle.

Accessory Organs

In this video, we're going to be talking about the male accessory organs, and we're going to start with the seminal glands, also known as seminal vesicles. These are 2 glands that lie on the posterior bladder surface. You can see those in this kind of grayish blue color here and here, so I'm going to label those as 1. The seminal glands produce something called seminal fluid, and this accounts for about 70% of semen volume. The seminal fluid makes up the bulk of the semen volume, and the seminal fluid will empty into the ejaculatory duct, which you guys remember is right about here, and that is where the sperm and the seminal fluid will mix. We're going to have sperm coming in from the vas deferens, and we'll have seminal fluid coming in from that seminal gland, and they will mix right there in the ejaculatory duct. The seminal fluid will essentially provide a transport for the sperm as well as aid in sperm motility. Alright, so that is our summary.

Next, we have the prostate. The prostate is located inferior to the bladder and is a gland that essentially encircles the urethra. We can see the prostate right here. I'm going to label that as 2. The prostate produces something called prostatic secretion and that accounts for approximately 30% of semen volume.

Finally, we have the bulbourethral glands, also known as the Cowper's gland, and these are two glands that are located inferior to the prostate. You can see those here and here. I'm going to label that as 3. These glands produce a thick mucus that will drain into the urethra, and this mucus is going to drain into the urethra usually before ejaculation takes place; it will neutralize traces of acidic urine and will also lubricate the head of the penis or the glans of the penis. This is commonly known as pre-ejaculate fluid. There can also be some of that fluid left over in the urethra when ejaculation takes place. Thus, all of these fluids in combination with sperm will make up semen.

If you're looking at these numbers and wondering how it adds up, since 70% and 30% already make 100%, and what about the mucus? To give you context, these numbers are approximations, but usually, sperm makes up a very small amount of semen. It’s usually approximately between 1% to 5%, and that can vary across males and also vary within the same male across different ejaculations. Keep in mind that these are approximations, but what you should know is that the majority of the volume of semen comes from the seminal glands, and the next highest percentage will come from the prostate. Alright, those are the male accessory organs, and I'll see you guys in our next video. Bye-bye.

Anatomy of the Male Reproductive System Example 4

Alrighty, so this one is asking us, the majority of the contents of semen come from which of these structures? And that is going to be the seminal glands. Right? Seminal just sounds like semen and seminal glands produce seminal fluid which makes up about 70% of semen volume. Looking quickly at the other answer choices here, we see we have the prostate and the prostate does create prostatic secretion which makes up about 30% of semen volume. So not insignificant by any means, but not the majority either. The epididymis does, of course, store sperm, which contributes to semen volume in that sense, but the epididymis itself is not producing the contents of semen at all. And then finally, we have the bulbourethral glands and those do produce a thick mucus that's often secreted before ejaculation takes place and that can get mixed up into the semen but it's not going to be contributing any significant amount to semen volume. So our answer here is the seminal glands.

The Penis

In this video, we're going to be talking about the penis. The penis, as you may recall, is the male organ of copulation. That just means that this is the organ that delivers sperm to the female reproductive tract. We divide the penis into three major anatomical regions. First, we have the root or the base of the penis; in the middle, we have the body; and then at the tip, we have the head, also known as the glans penis. I will show you that on our image in one moment. The penis is comprised mainly of erectile tissue, which is connective tissue and smooth muscle that is filled with vascular spaces. During sexual arousal or excitement, those vascular spaces can fill with blood, causing the penis to become enlarged and rigid, which we call an erection. An erection allows the penis to act as the organ of copulation. A very fun fact about the penis is that it is actually homologous with the female clitoris. Homologous structures are structures that have common evolutionary origins and are composed of similar tissues. Early in embryonic development, these would basically be the exact same tissue, and then throughout embryonic and fetal development, it would become differentiated into a penis for a male fetus or a clitoris for a female fetus. We have outlined our main homologous structures with a little blue outline there, and you will see those in our video on the clitoris as well. You can see which structures are direct homologues between those two organs. So here is our penis, and like I mentioned, we have the root of the penis here at the base. We have the body of the penis in the middle. That's going to be the majority of the organ. And then we have the head of the penis, also known as the gland, at the tip. We're going to start by labeling structures, starting at the root with these kind of little wing-shaped triangular structures there at the base, and that is called the crus of the penis. The crus is surrounded by muscles that help to attach the penis to the pelvic floor and that helps to stabilize the organ and give it some integrity. Next up, we have these two bulbous structures right here on the root, and those are known as the bulbs of the penis. The bulbs are composed of erectile tissue, so they will fill with blood during sexual arousal. These are also going to be surrounded by muscles that help to anchor the penis to the pelvic floor. Moving down here, we have our corpus cavernosa. The corpus cavernosa, which we have here in this kind of light pink color, is on the outside of the penis. These are paired erectile bodies that will extend from the roots basically all the way down through the body of the penis. Cavernosa literally means cavernous. These have that characteristic vascular structure where there's plenty of room for them to become engorged with blood. When the corpus cavernosa becomes erect, they become extremely rigid. These are going to give the erection a lot of its structure and rigidity. Moving down here, we have our corpus spongiosum. The corpus spongiosum, drawn here in this magenta color, surrounds the urethra. These extend all the way from the root to the glans or the head of the penis. The bulb of the penis is made up of the same tissue as that corpus spongiosum. Spongiosum literally means spongy. When the corpus spongiosum becomes erect and filled with blood, it does not become rigid. It maintains a spongy texture, preventing the urethra from closing, which is important. If we were to have tissue like the corpus cavernosa next to the urethra, when it filled with blood it could shut the urethra, preventing ejaculate fluid from leaving the penis, which we don't want. The corpus spongiosum stays nice and spongy and soft, allowing the urethra to stay open, but it does add a little bit of compression to the urethra, which helps with the velocity of the ejaculate as it exits the penis. That is the main difference between the corpus cavernosa and the corpus spongiosum. One becomes very rigid when it's erect, the other stays kind of spongy and soft. Last but not least, we have our prepuce or the foreskin of the penis, and you can see that really nicely right here. This is just skin that extends around the glans or the head of the penis. That is penile anatomy, and I will see you guys in the next one. Bye bye.

Anatomy of the Male Reproductive System Example 5

This question asks us, the removal of the prepuce through a surgical procedure is known as what? Keep in mind that prepuce is just a fancy way to say foreskin of the penis, and so if we are removing the foreskin that, of course, would be a circumcision. Looking through our other answer choices here, an orchidectomy would be the removal of the testes, priapism is a disorder of the penis where it maintains prolonged erections in the absence of stimulation, and then a salpingectomy would be the removal of the uterine tube. So, our answer here is going to be b, circumcision.

The corpus spongiosum surrounds which structure in the male reproductive system?

• A. The urethra.
• B. The bulb of the penis.
• C. The bulb of the vestibule.
• D. The corpus cavernosa.

Here’s what students ask on this topic:

What is the function of the scrotum in the male reproductive system?

The scrotum is an external sac that houses the testes and plays a crucial role in regulating the temperature for optimal sperm production. It maintains a temperature of approximately 93 to 96 degrees Fahrenheit, which is slightly cooler than the body's core temperature. This is achieved through the action of two muscles: the cremaster muscle, which contracts to draw the scrotum closer to the body when it is cold, and the dartos muscle, which wrinkles the scrotal skin to reduce surface area and heat loss. Together, these mechanisms ensure the testes remain at an ideal temperature for sperm production.

What are the main structures within the testes and their functions?

The testes contain several key structures involved in sperm production and maturation. The seminiferous tubules are tightly coiled tubes where sperm are produced. Immature sperm then move to the straight tubules, followed by the rete testis, and finally the efferent ductules, which transport them to the epididymis. The epididymis is where sperm mature and are stored until ejaculation. This sequence ensures that sperm are produced, transported, and matured efficiently within the testes.

What is the role of the vas deferens in the male reproductive system?

The vas deferens, also known as the ductus deferens, is a crucial component of the male reproductive duct system. It transports mature sperm from the epididymis to the ejaculatory ducts during ejaculation. The vas deferens extends from the epididymis, travels through the pelvic cavity, arches over the bladder, and empties into the ejaculatory duct. This pathway ensures that sperm are efficiently delivered from their storage site to the urethra, where they can be expelled during ejaculation.

What are the functions of the male accessory glands in semen production?

The male accessory glands, including the seminal vesicles, prostate gland, and bulbourethral glands, play vital roles in semen production. The seminal vesicles produce seminal fluid, which makes up about 70% of semen volume and aids in sperm motility. The prostate gland contributes prostatic secretion, accounting for approximately 30% of semen volume, which helps nourish and protect sperm. The bulbourethral glands produce a thick mucus that neutralizes acidic urine traces in the urethra and lubricates the penis, facilitating sperm transport. Together, these secretions form semen, which supports and protects sperm during ejaculation.

How does the structure of the penis facilitate its function in the male reproductive system?

The penis is composed mainly of erectile tissue, which includes the corpus cavernosa and corpus spongiosum. During sexual arousal, these tissues fill with blood, causing the penis to become erect. The corpus cavernosa provides rigidity, while the corpus spongiosum remains spongy to keep the urethra open for semen to pass through. The penis is divided into three regions: the root, body, and glans (head). This structure allows the penis to deliver sperm effectively to the female reproductive tract during copulation.