MALE ANATOMY 201_sandbox

MALE ANATOMY 201_sandbox

MALE ANATOMY – TEACHER NOTES 

HOW TO USE THESE TEACHER NOTES

Description of this Class for Parents + Caregivers

Description of this Class for Parents + Caregivers — Español

Teacher notes are designed to supplement the slide deck for lessons throughout That Health Class. The goal of these supplemental notes is twofold: 

  • To offer basic background information on the topic for educators
  • To offer a deeper dive into biology, physiology, and data for educators craving more information

Here’s how the teacher notes are organized:

At the start of each set of notes is a general INTRO FOR EDUCATORS – this information does not have a corresponding slide, but instead sets the stage for why this class is relevant and, in some cases, how the information has changed over time. It also includes an episode from the This Is So Awkward podcast that includes even more information on the topic. 

Then follows a description of every slide in the deck: You will see thumbnail images of each slide, followed by detailed definitions and explanations of the text and/or videos included. 

The LET’S TALK ABOUT IT section concluding each slide deck is meant to start conversations. It can be a jumping off point for wrapping up class discussions or can serve as an exit ticket if needed. 

For more information on any given lesson across the entire That Health Class curriculum, we encourage you to login to the Less Awkward Hub  or search the Resource We Love list.

 

INTRO FOR EDUCATORS: 

This lesson builds on our middle school lesson introducing male anatomy basics. It starts with a review of body parts and their functions, and then moves into more functional content covering erections, ejaculation, testicular self-examination, and tips for promoting hygiene. It’s important for all people to have an in-depth understanding of the male body, regardless of whether or not they have these anatomical parts. When someone has a question – whether it’s from curiosity or concern – communication becomes far more clear when they know the name, location, and function of all organs. 

Traditionally, health education classes have spent more time on female anatomy and physiology compared to male anatomy and physiology. This is driven by a misconception that there is more to teach about female bodies, particularly because of the menstrual cycles. There’s lots to learn about male bodies, though!

And by focusing on both male and female bodies equally, all kids get the message that they are not alone as their bodies and brains mature, and their lived experiences are just as valid as everyone else’s. There are so many benefits associated with learning about all types of bodies: from removing stigma and mystery to identifying online or peer-provided misinformation. Ultimately, understanding anatomy is the first step towards taking care of one’s self and, ultimately, embracing bodily autonomy. 

One specific call out when discussing anatomy: You might get questions about what “intersex” means. This term refers to people who have genitals, chromosomes, or reproductive organs that don’t fit into a male/female sex binary. For more information on intersexuality, check out this link to The Cleveland Clinic. 

Listen to this episode of the This Is So Awkward podcast to learn much more: Penises, Testicles,  and the Internal Reproductive Organs. 

 

ICE BREAKER

How many anatomical parts of the male reproductive system can you name? How many unofficial names do you know?!

Teacher note: Be sure to establish clear boundaries about using anatomical language and keeping comments appropriate throughout this class. That said, these anatomical terms can feel awkward to say out loud. Different educators approach this limit-setting in different ways, but one way that often works well is to get the laughs out early. Then acknowledge the discomfort in saying these words in front of you (their teacher!) and make sure they know the language limits that push the bounds too far.

 

LEARNING OBJECTIVES 

  • Identify parts of male anatomy and their functions. 
  • Learn about the role of erections, sperm, and ejaculation in reproduction.
  • Understand how to perform testicular self-examinations and why it’s important.

 

SIMILARITIES BETWEEN MALE AND FEMALE ANATOMY

Fun fact: the origin of the male and female reproductive systems is the same! In the beginning, male and female embryos are indistinguishable: the very same cells go on to form the internal and external genitalia for both sexes. This is why, when viewed in a line drawing like the one in this lesson (and the one in the female anatomy lesson, too), the two systems take the same general shape.

If you have time, you can show this 5 minute video from AuAu Studios about how male and female anatomy share the same origin (this video is also included in the female anatomy lesson).

Teacher note: To learn more about the science of sex differentiation and development, check out this paper from the Institute of Medicine and the NIH.   

 

INTERNAL MALE REPRODUCTIVE SYSTEM

The male reproductive system includes both internal and external parts which work together in a coordinated way. Here’s why it’s important to know the names of these parts, where they are located, and how each contributes to the reproductive system:

  1. Knowledge is power, making students feel more comfortable (many in their own skin)
  2. Communication becomes much clearer when a person can better describe where they are experiencing pain, discomfort, or worry. 

Teacher note: There is plenty of data documenting that knowledge of genital anatomy helps keep kids safe from sexual predators. When a younger child knows their body parts, predators are more likely to leave them alone because this suggests there are adults in that child’s life who talks to them about body safety. When an older child knows their body parts, they are able to more clearly and successfully disclose abusive incidents in a way that can be understood by others.

These are the internal parts of the male reproductive system.

Testicles (AKA testes, much more commonly called balls)

There are typically two testicles. These egg-shaped organs that hang away from the body, inside the scrotum.

The testicles are responsible for making sperm. The testicles are also involved in producing testosterone, which is the primary hormone in male puberty. (Remember that hormones are chemical messengers that travel through the bloodstream to tell distant organs what to do.) Testosterone helps with muscle development, deepening of the voice, and growth of body hair. It also impacts mood. 

The testicles usually hang down, but they can move up towards the abdomen. This generally happens when it’s cold or when something touches the inside of the thigh. 

It’s very common for testicles to be asymmetrical – one usually hangs lower than the other and the two often have slightly different shapes.

Epididymis

There are two of these long tubes, coiled up and sitting behind each testicle. If unraveled, their total length can be up to 20 feet!

This is where sperm matures, and then where it’s stored. Sperm remain inside the epididymis anywhere from a couple of weeks to 2-3 months, until it is released through the vas deferens and out the urethra in a process called ejaculation. If there is no ejaculation (after about 2.5 months) the body breaks sperm down and re-absorbs them. 

Vas Deferens

There are two of these tubes – one on each side emerging out of each epididymis. The vas deferens connects the epididymis and the urethra. It is on the path along which sperm travel from the testicles past the bladder and into the urethra. Along the vas deferens, there are 3 different spots where fluids are pumped into the tube, joining the sperm.

Seminal Vesicles

There are two of them, one on each side, behind the bladder. The seminal vesicles are long, skinny, sac-like glands that make sugar-rich fluid to help nourish the sperm on their long journey. The sperm + fluid mixture is called semen (from the seminal vesicle – get it?).

Prostate Gland

There is one prostate gland. It is located after the vas deferens have joined together to form the urethra, below the bladder.Like the seminal vesicles, the prostate also produces fluid. This fluid helps nourish the sperm and help sperm swim more freely.

In young adulthood, the prostate is about the size of a walnut. But, the prostate grows as men age—by age 60, the prostate may be the size of a lemon! Because the prostate surrounds part of the urethra, this bigger size creates added pressure that can make it harder to get urine out. This is why so many older men describe feeling the need to pee without being able to go, and also why they often have trouble emptying their bladders completely, which causes them to feel the need to urinate more often.

Urethra (internal)

There is one urethra. It runs from the bladder down the middle of the shaft of the penis. It has two jobs: 

  1. To carry urine from the bladder outside of the body. 
  2. To channel semen (sperm mixed with fluid) through the body during ejaculation.

Urine and semen will never go through the urethra at the same time!

 

EXTERNAL MALE REPRODUCTIVE SYSTEM

These are the parts of the male reproductive system outside of the body. 

Penis

There is one penis, but it is made up of two parts:

  1. The shaft (the long narrow part)
  2. The glans (the tip or the head)

The penis is a long, cylindrical organ that hangs outside of the body below the pelvis.

At birth, the glans of the penis is covered with tissue called foreskin. Circumcision is the removal of the foreskin. An uncircumcised penis still has the foreskin on it; a circumcised penis has the foreskin removed. The foreskin of an uncircumcised penis should never be forcibly retracted. Healthcare providers can teach how to properly clean the penis, underneath the foreskin – it never involves forcing the skin back over the head of the penis because the skin can get stuck.  

The urethra runs down the inside of the shaft of the penis, emerging at its tip. Surrounding the urethra (also inside the penis) is spongy tissue that can fill with blood, making the penis stiff or “erect” – there is no bone in the human penis!

Penises come in many different shapes and sizes. There is no “right” or “best” one. 

Teacher note: You might get a question or comment about “showers vs. growers.” These terms refer to the change in penis length from a flaccid to an erect state. A “shower” is a person whose penis does not expand much in length (less than 4 cm) when it becomes erect. Conversely, a “grower” is a person whose penis grows significantly longer (4 cm or more) when erect. There is no correlation with health, and one is not any better or worse than the other. But teenagers often have a lot to say on this topic!

Scrotum

There is one scrotum and it covers both testicles. This scrotal sac is the skin that holds and helps protect the testicles. The scrotum itself includes the muscles and tissues that hold the testicles inside of the sac.

The scrotum is located outside of the body so that the sperm can remain at a slightly lower temperature (lower than 98.6 degrees). Staying cool is very important for sperm production and survival. Fun (physiology) fact! This is why some healthcare providers recommend avoiding using laptop computers resting on the thighs and groin. The heat from the laptop can warm up the scrotum and potentially negatively impact reproductive health. 

Doctors sometimes use a medical device called an orchidometer to measure the volume of the testicles in milliliters. This is useful for monitoring male sexual development and diagnosing certain conditions. Yes, it doubles as an awkward beaded necklace!

Urethral opening 

There is one urethral opening, and it is located at the tip of the penis. The urethral opening marks the end of the long urethra that runs down the middle (inside) of the penis.

This is where urine exits the body during urination and semen exits the body during ejaculation.  Important point, though: despite sharing the same exit tube, either urine or semen comes out, never both at the same time! Signals from the brain tell the body which fluid should be released when.

The tip of the urethra is one of the 2 openings in the area. The other is the anus.

Pubic Hair:

Pubic hair is the hair that grows around the genitals and over time extends to the inner thighs. It begins appearing during adrenarche* across all genders. Compared with the hair on most other parts of the body, pubic hair tends to be thicker, curlier, coarser, and darker. 

The function of pubic hair isn’t entirely agreed upon, but it definitely reduces transmission of bacteria and other organisms between bodies. It also reduces skin-on-skin friction during sex. 

Some people choose to groom or remove their pubic hair by trimming, shaving, waxing, or using chemical creams, while others choose to keep their pubic hair. Peers, partners, and the media can include the choice to keep or remove pubic hair, but it is ultimately a personal decision. It is not medically or hygienically necessary to remove pubic hair. If a person decides to remove their pubic hair, it is important to understand how to do so safely. 

If you’re looking for more information on any of this anatomy, The Cleveland Clinic site is an excellent resource. 

*Teacher note: As a reminder, adrenarche is responsible for two major shifts: (1) new and more hair and (2) more sweat (which leads to acne and body odor). It is governed by the hormones made by the adrenal glands called DHEA and DHEAS, not by the sex hormones. Adrenarche often happens around the same time as puberty, but not always! For more information about adrenarche, check out lessons on Hair Care and Skin Care, or listen to this podcast episode on hair. 

Teacher note: There is a ton of misinformation out there about male anatomy—ever hear the one about big feet?! This is a great opportunity to remind students where to find accurate information about all these parts if they have questions (including healthcare providers, trusted adults, and credible medical outlets). Social media, on the other hand, is NOT a great resource. 

 

ERECTIONS

An erection is when the penis becomes hard and enlarged because it is filled with blood. Even though erections are sometimes called “boners,” there is not actually a bone in the penis!

Penises can become erect no matter a person’s age… in fact, erections even happen in the womb. But it’s also true that erections often become much more frequent during puberty. They can occur when a person experiences sexual arousal or when parts of the body – separate from or including the penis – are touched. They can also occur for no particular reason at all. This last group is called spontaneous erections.

An erection can last anywhere from a few minutes to a couple of hours. Erections typically go away after ejaculation, and they can also go away without ejaculation. Here are some things that impact how long an erection lasts:

  • Age
  • Medications
  • Stress
  • Alcohol or drugs

If an erection lasts longer than four hours, it is important to go to the emergency room. This is a condition known as priapism.

Erectile dysfunction (commonly called by its initials: ED) happens when a person can’t get an erection, or they can’t keep an erection long enough or hard enough for sexual intercourse. There are lots of causes of ED – the ones most relevant to teenagers include tobacco, alcohol, other drugs, and pornography. For more information, here’s a great link to the Mayo Clinic. ED can be treated with medications like (some of the most well known include Viagra, Cialis, and Levitra), but these are almost never recommended for people under 18. 

Teacher note: ED used to be exceedingly rare in teenagers and young adults, but now it is surprisingly common: a 2024 paper found a 31x increase in ED diagnoses in this population in the 10 year span between 2014-2024. This Cleveland Clinic article lists the wide-ranging reasons why younger men experience ED, though it leaves off one of the most talked-about: porn. Watch this 6 minute video from How to Medicate to learn more about the relationship between porn and ED. 

An involuntary or spontaneous erection is one that happens for no reason. During certain stages of puberty, spontaneous erections can happen as often as every 45-90 minutes. This can be quite embarrassing, especially if it happens in public (at school, for example). Here are some tips for what to do if an involuntary erection occurs: 

  • Sit down
  • Put hands in pockets to pull the pants away from the body, hiding the erection 
  • Tense up the quad muscles in the thigh to redirect blood flow
  • Concentrate on something else in front of you
  • Try wearing longer and/or looser shirts that will cover erection if they happen
  • Remember these are completely normal! – some people get them often (even every 90 minutes) and some almost never get them… again both normal!

It is common to have an erection when waking up in the morning. This is called nocturnal penile tumescence, but it is often called “morning wood.” This happens because the parasympathetic nervous system is active when you’re asleep, and the sacral nerve (part of the parasympathetic nervous system) controls erections. In fact, people with penises generally experience between 3-6 spontaneous erections while asleep! 

If you have an extra couple of minutes, watch this short video from WikiHow to learn some strategies for hiding an erection, or watch this 2 minute video from ASAP Science to learn about nocturnal penile tumescence (aka “morning wood”). Both of these are also linked in the slide. 

 

 SPERM

Sperm are male reproductive cells – these cells contain half the DNA of a typical cell, so they are called haploid cells. They are also called gametes. They carry half of the genetic material that might one day be used to make a baby.

A sperm is the male equivalent of an egg – they are 2 different types of gametes. But unlike females, who have all their eggs present at birth and release them one at a time with each menstrual cycle, a sexually mature male makes 200-300 million sperm per day (1,500 per second!), and about 50–100 million of them (¼ - ⅓) become viable.

Sperm are microscopic cells with “tails.” They’re often compared to tadpoles, although they are much tinier. 

Spermatogenesis is the biological process of production of sperm cells in the testicles. It. The sperm regeneration cycle – where the body produces and replenishes sperm – takes around 64-72 days to produce a new sperm from start to finish. Here’s how it works:

    • The pituitary gland in the brain secretes luteinizing hormone (LH), which travels through the blood to the testes to stimulate the production of testosterone and sperm. 
    • Newly-formed sperm develop over 50-60 days in the testicles
    • Then they move to the epididymis, where they stay for at least 14 days, until they’re fully mature, or longer if there’s no ejaculation. 
    • Mature sperm are stored in the epididymis – after about 2.5 months, if there’s no ejaculation, the body breaks sperm down and reabsorbs them. 
    • Because sperm production is constant, the supply never runs out—this is true even if someone ejaculates once or several times a day. 

Watch this video 2 minute from Today’s Parent to learn more surprising facts about sperm

If you have an extra 4 minutes, watch this video from Dandelion Medical Animation to learn about the parts of an individual sperm.

Teacher note: The sperm quiz below offers some fun facts about sperm. You may lead this quiz verbally, having students raise their hands to vote for the answer they think is correct. 

Open the PDF document below for a quick activity testing students' knowledge of sperm

Male Anatomy 201 - Sperm Quiz

 

EJACULATION

Male ejaculation refers to the release of semen (sperm + fluid) through the penis. Here’s how it works:

  • Sperm production happens in the testicles, and maturation + storage in the epididymis.
  • During ejaculation, muscle contractions propel sperm from each epididymis through the vas deferens..
  • As they pass through the vas deferens, the sperm mix with sugary fluids produced by the seminal vesicles and the prostate gland to make semen – this mix is also called seminal fluid. 
  • The same muscle contractions that propel the sperm from the epididymis through the vas deferens also move the semen out the urethra at the tip of the penis. About 100,000,000 sperm are released in semen during ejaculation!

The body knows the difference between peeing and ejaculating – this is why these two things never occur at the same time: either semen comes out of the penis or urine but not both together.

A nocturnal emission or “wet dream” describes ejaculation that happens during sleep. This is not pee, it's semen! It’s normal to have wet dreams. It’s also normal NOT to have them. While they can sometimes be caused by sexual dreams, they are not necessarily sexual and can happen for no reason at all. 

If you have an extra 4 minutes, watch this video from FreeMedEducation to learn how the parts of male reproductive system work together during ejaculation. 

Open the PDF below for directions for a class activity:

Male Anatomy 201 - HS Activity Handout

 

PENIS + TESTICLE TRIVIA

Have you ever wondered why it hurts so much to get kicked in the balls? Or if “blue balls” are a real thing? Here are some fun facts about male genitalia that are – the real answers to some of the most popular urban myths:

1. Does shoe size correlate with penis length?

No! There is no scientific evidence to suggest that a person’s shoe size is correlated with the length of their penis. 

2. Is a circumcised penis cleaner than an uncircumcised penis? 

Nope, circumcision has nothing to do with penile cleanliness. Hygiene is all about regular washing. Bathing daily is important, which means using soap + water. But no soap right at the tip of the penis (it can be irritating) and uncircumcised guys should never forcibly retract the foreskin, even to clean because the skin can get stuck. Have a question? Ask your healthcare provider!

3. Is it normal to have uneven testicles?

Yes, it is common to have one testicle hang slightly lower or be a different shape than the other. Examining the testicles once a month can help you figure out what is normal for you. Watch this 30 second video about uneven testicles.

4. Why does it hurt so much to get kicked in the balls?

It is because the testicles contain a lot of nerve endings, making them extra sensitive and susceptible to pain. After a hit, nerves in the testicles transmit information about tissue damage to the brain. Because the testicles develop in the abdominal cavity during fetal development, the abdomen and the testicles have overlapping nerve pathways. As a result, the brain can’t always tell where the pain originated, explaining why some people feel a blow to the testicles all the way up in their stomach. 

5. Are “blue balls” a real thing?

Yes! “Blue balls” are scientifically known as epididymal hypertension. This term describes pain in the scrotum following heightened sexual arousal that didn’t result in orgasm. Females can feel similar discomfort when they are sexually aroused but don’t orgasm. “Blue balls” can actually look a little bit blue: without ejaculation, drainage of blood from the genitals can go slowly and the deoxygenated blood under the scrotal skin sometimes appears blueish. Yes, there can be some mild discomfort, but no, it’s not associated with any long-term negative health outcomes. It resolves on its own usually within a few minutes.

Sometimes people use blue balls as an excuse to coerce sexual activity, arguing that not having an orgasm will hurt them. Remember that you never have to engage in sexual activity that you don’t want to participate in. For more information on blue balls and sexual coercion, check out this study published in Sexual Medicine.

 

TESTICULAR SELF-EXAMINATION

A testicular self-exam helps people get to know their body’s normal lumps and bumps — it’s an important way to learn what’s “normal” for them and to identify potential problems early on. In the same way that women are taught to do self-breast exams once a month, men should get in the habit of testicular exams once a month, too. This exam is also usually part of a regular check-up, so don’t be surprised by it!

Self-exams involve 2 steps: inspection (looking) and examination (touching):

  1. INSPECT: Lift your penis out of the way and visually inspect your scrotum, looking for any changes such as swelling, lumps, or other changes in size or shape.
  2. EXAMINE: You want to do this when the scrotum is most relaxed because the testicles hang at their lowest that way — after taking a bath or shower is usually great timing. You’ll examine one testicle at a time

Start by gently gripping the top of the scrotum, with the thumb on top and fingers underneath so the testicle won’t move. Between the fingers, the spermatic cord (which contains the blood vessels and nerves running to the testicles) feels ropey. 

With the free hand, glide the thumb and fingers along both sides of the testicle, from top to bottom. Feel for any lumps or bumps.

Glide the fingers over the front and back of the testicle. The epididymis is palpable at the top back. This normal lump sometimes feels tender to the touch.

Repeat these steps with the other testicle. 

Don’t be surprised by lumps and bumps! The epididymis sits towards the top of the testicle, and is often easy to feel. 

Detect a lump? If a new lump appears that’s never been felt before, it’s a good idea to have a healthcare provider check it out. What’s the worst that happens? Confirmation that it’s the epididymis… and a lifetime of reassurance that this lump is supposed to be there every time it is palpated on a testicular self-exam.

Watch this two-minute video from the National Health Service (UK) to learn what to look for during a testicular self-exam. 

 

BODY CARE

Teacher note: In this quiz, you will prompt students by providing a tip for optimizing health and hygiene and why it works. This exercise is all about the why! Students are asked to identify whether the reason for the tip working is TRUE or FALSE. They can either raise their hands or, to get kids moving, you can assign one side of the room the TRUE side and the other the FALSE side, and students can move to the side corresponding to their answer for each prompt. Some of the prompts are humorous, so feel free to have fun with it! 

There are lots of things you can do to optimize health and hygiene. Here are some top tips:

TIP 1: Practice good hygiene 

Reason: Because a popular influencer says it will make you more attractive

FALSE: Good hygiene might make a person look better, but the real reason to do it is this: cleaning the genital area every day helps avoid accumulation of dirt and bacteria that can cause irritation or infection.

TIP 2: Perform monthly testicular self-examinations.

Reason: This replaces regular exams from a healthcare provider.

FALSE: Healthcare providers will still likely perform testicular exams during check ups. The real reason to perform monthly self-exams is to help you get to know your body and catch any abnormalities early on. It doesn’t replace your doctor visit… but it might get you into the doctor’s office a little sooner than anticipated.

TIP 3: Wear protective gear

Reason: Wearing an athletic cup or jockstrap during contact sports helps reduce the risk of injury to the testicles and surrounding area. 

TRUE: Any fast moving kick, ball, or helmet that hits the groin area can cause serious pain and sometimes serious damage like testicular torsion or rupture. Wearing protective gear helps protect against injury.

TIP 4: Avoid alcohol, cigarettes, and other drugs.

Reason: Substance use can impact sperm count and fertility

TRUE: Drugs and alcohol cause a host of health issues, including impacting reproductive health.

Teacher note: Even though substance use can impact reproductive health, substance use is NOT a recommended or reliable strategy to avoid pregnancy. 

TIP 5: Stay cool

Reason: Wearing loose fitting underwear and pants looks cool

FALSE: Maybe… but the real reason to wear loose bottoms is for temperature control! If the scrotum gets too warm, it can impact the body’s ability to make sperm effectively. As a bonus, increased airflow also helps keep you smelling better. You don’t have to walk around in loosey-goosey bottoms all the time, but definitely air out the body at the end of the day. 

Teacher note: Explain to students that even though it is recommended to keep the scrotum cool, applying heat is NOT a recommended or reliable method of contraception.

TIP 6: Contact a healthcare provider if you have questions or concerns about your body

Reason: They are experts and can answer questions, diagnose potential problems, and help get you what you need. 

TRUE: Healthcare providers will help you navigate any changes in the look or feel of your body that you’re confused or worried about.

Teacher note: STI prevention is also part of penile + testicular health – for more on that go to our lesson on STIs and STDs.

If you have an extra 14 minutes, watch this video from SciShow to learn if the underwear your wear impacts sperm count. 

 

SUMMARY

Understanding anatomy helps demystify bodies. Plus., it’s much easier to communicate effectively when we use accurate terminology and we actually know how different parts work together. And then there’s getting into the habit of good long-term self-care – this is where regular testicular self-examinations come in. When we are educated about our bodies, we can take a more active role in managing our health.  

 

 

LET'S TALK ABOUT IT

What’s something you have heard about the penis or testicles that you’re still unsure about? How can you find an answer that’s accurate?