The Penis – Anatomy, Nerve Supply, Functions

Last updated: February 8, 2026Reviewed date: February 8, 2026Reading time: 6 min read
Patient Tools

Read, save, and share this guide

Use these quick tools to make this medical article easier to read, print, save, or share with a family member.

Article Summary

The Penis is a male organ that is used for reproduction and urination which is located within the urogenital triangle between the perineal membrane superiorly and deep perineal fascia inferiorly. Its composition divides it into 3 parts: the glans, body, and root. Dorsally, it is composed of the paired corpora cavernosa and ventrally the corpus spongiosum which contains the urethra. The anatomical positions of the...

Key Takeaways

  • This article explains Structure and Function of The Penis in simple medical language.
  • This article explains Blood Supply and Lymphatics of The Penis in simple medical language.
  • This article explains Nerves Supply of The Penis in simple medical language.
  • This article explains Muscles of Supply of The Penis in simple medical language.
Educational health guideWritten for patient understanding and clinical awareness.
Reviewed content workflowUse writer and reviewer profiles for stronger trust.
Emergency safety firstUrgent warning signs are highlighted below.

Seek urgent medical care if you notice

These warning signs are general safety guidance. Local emergency numbers and clinical judgment should always come first.

  • Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
  • New weakness, severe pain, high fever, or symptoms after a serious injury.
  • Any symptom that feels urgent, unusual, or unsafe for the patient.
1

Emergency now

Use emergency care for severe, sudden, rapidly worsening, or life-threatening symptoms.

2

See a doctor

Book a professional medical evaluation if symptoms persist, worsen, recur often, affect daily activities, or occur in a high-risk patient.

3

Learn safely

Use this article to understand possible causes, tests, treatment options, prevention, and questions to ask your clinician.

The Penis is a male organ that is used for reproduction and urination which is located within the urogenital triangle between the perineal membrane superiorly and deep perineal fascia inferiorly. Its composition divides it into 3 parts: the glans, body, and root. Dorsally, it is composed of the paired corpora cavernosa and ventrally the corpus spongiosum which contains the urethra. The anatomical positions of the penis are according to the erect penis with the dorsal direction being closer to the head and ventral direction being closer to the feet. The tunica albuginea is a fibrous sheet that encapsulates the cavernous body. Buck’s fascia, also known as the deep fascia of the penis is superficial to the tunica albuginea and is the continuation of the deep perineal fascia which covers the corpora cavernosa and corpus spongiosum together. The spongy urethra is contained within the corpus spongiosum. The crura of the penis are between the 2 corpora cavernosa in the median plane externally. The corpora cavernosa are separated by the septum of the penis internally. The attachment of the penis consists of the bulb, crura, and ischiocavernosus, and bulbospongiosus muscles, which collectively make up the root of the penis. The bulb of the penis and crura contain erectile tissue. The middle portion of the penis is suspended and known as the body of the penis. The body of the penis lacks muscles and consists mostly of corpora cavernosa, corpus spongiosum, and spongy urethra with supporting skin, connective tissue, and blood, lymph, and fascia. The distal part of the penis is known as the glans penis. The proximal portion of the glans is termed the corona. The neck of the corona glans separates it from the body of the penis. The tip of the glans contains the opening to the urethra, known as the meatus. There is the loose connective tissue between the thin skin of the penis and the tunica albuginea. The prepuce or foreskin is the second skin layer that covers the glans penis. The frenulum of the prepuce connects it to the urethral surface of the penis glans. The suspensory ligament of the penis is part of the deep fascia that arises from the anterior surface of the pubic symphysis. The fundiform ligament of the penis descends in the midline from the linea alba anterior to the pubic symphysis and splits to surround the penis and then unites and blends inferiorly with the dartos fascia forming the scrotal septum.

Structure and Function of The Penis

The 2 main functions of the penis are intercourse and urination. For intercourse, the penis must be erect. Erection occurs via parasympathetic innervation which allows engorgement of the corporal bodies. The bulbospongiosus and ischiocavernosus muscle compress the veins to prevent them from draining blood from the corpora cavernosa. The erectile tissue of the cavernosum becomes firm and enlarged when the erection occurs. The emission phase is due to the sympathetic response and occurs when semen exits the vas deferens to the ejaculatory ducts where fluid from the seminal glands are added. They then continue onto the prostatic urethra where the prostatic fluid is added. The ejaculation phase is due to the sympathetic response and is when semen exits from the urethra through the external urethral orifice. After ejaculation, the penis becomes flaccid again due to the sympathetic stimulation and constriction of the coiled helicine arteries and relaxation of the bulbospongiosus and ischiocavernosus muscles allowing blood to drain from the cavernous spaces.

Blood Supply and Lymphatics of The Penis

The branches of the internal pudendal arteries are the main supplier of blood to the penis. The dorsal arteries of the penis run along the dorsal vein between the corpora cavernosa to supply the fibrous tissue surrounding the corpora cavernosa, corpus spongiosum, spongy urethra, and penile skin. The deep arteries of the penis run in the center of each corpora cavernosa to supply the erectile tissue of the penis. The helicine arteries of the penis are branches of the deep arteries of the penis which are coiled when the penis is flaccid. The arteries of the bulb of the penis supply the bulbous part of the corpus spongiosum, urethra, and bulbourethral gland. The superficial and deep branches of the external pudendal arteries supply the penile skin.

The deep dorsal vein of the penis receives blood from the venous plexus which receives drained blood from the cavernous spaces. The superficial dorsal vein drains blood from the skin and subcutaneous tissue of the penis.

The skin of the penis and all of the perineum excluding the glans penis drain lymph to the superficial inguinal nodes. The lymphatics of the intermediate and proximal parts of the urethra and cavernous bodies drain into the internal iliac lymph nodes. The distal spongy urethra and glans penis drain to the deep inguinal nodes.

Nerves Supply of The Penis

The penis innervation is from spinal cord segments of the S2 to S4.  These cord segments pass through the pelvic splanchnic nerves.  The spinal ganglia of S2 to S4 passes through the pudendal nerves.  The dorsal nerve provides sympathetic plus sensory innervation to the penis.  The pudendal nerve branches to become the dorsal nerve of the penis.  The nerve runs next to the dorsal artery and supplies the skin and glans penis also.  The glans penis has a copious amount of sensory nerve endings.  The root of the penis has innervation from the ilioinguinal nerve.  The cavernous nerves have parasympathetic fibers that innervate the helicine arteries which supply erectile tissue.

Muscles of Supply of The Penis

The bulbospongiosus muscles cross the pelvic outlet intersecting with the superficial transverse perineal muscles. These structures support the perineal body and pelvic viscera. The bulbospongiosus muscles compress the bulb of the penis and the corpus spongiosum which can aid in emptying the spongy urethra. The anterior fibers of the muscle surround the proximal part of the body of the penis. These fibers can increase the pressure on the erectile tissue in the root of the penis for erections. The bulbospongiosus muscle can compress the deep dorsal veins to prevent drainage of the cavernous spaces and help promote erection of the penis. The root of the penis contains the crura which is encircled by the ischiocavernosus muscle. The muscle can push blood to the distal parts of the corpora cavernosa and help with erections. The muscle can also lead to compression of the deep dorsal vein of the penis as it is leaving the crus of the penis and restrict venous outflow to help with erections.

Functions of The Penis

The other function of the penis is to drain urine from the body. Urine starts draining from the bladder into the bladder neck where the internal urethral sphincter will relax to allow urine to pass via involuntary control of the parasympathetic system. Urine will then pass into the prostatic urethra and the membranous urethra. The external sphincter will relax to allow urine to pass from the membranous urethra into the spongy penile urethra, then into the navicular fossa and out of the urethra through the external urethral orifice.

References

Patient safety assistant

Check your symptom safely

Hi, I am RX Symptom Navigator. I can help you understand what to read next and what warning signs need care.
Warning: Do not use this in emergencies, pregnancy, severe illness, or as a substitute for a doctor. For children or teens, use with a parent/guardian and clinician.
A rural-friendly guide: warning signs, when to see a doctor, related articles, tests to discuss, and OTC safety education.
1 Symptom 2 Severity 3 Safe guidance
First safety question

Is there chest pain, breathing trouble, fainting, confusion, severe bleeding, stroke-like weakness, severe injury, or pregnancy danger sign?

Choose quickly

Browse by body area
Start here: Write or select a symptom. The guide will show warning signs, doctor guidance, diagnostic tests to discuss, OTC safety education, and related RX articles.

Important: This tool is educational only. It cannot diagnose, treat, or replace a doctor. OTC information is not a prescription. In an emergency, contact local emergency services or go to the nearest hospital.

Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Rest, drink safe water, and observe symptoms carefully.
  • Keep a written note of symptoms, duration, temperature, medicines already taken, and allergy history.
  • Seek medical care quickly if symptoms are severe, worsening, or unusual for the patient.

OTC medicine safety

  • For mild pain or fever, ask a registered pharmacist or doctor before using common over-the-counter pain/fever medicines.
  • Do not combine multiple pain medicines without advice, especially if you have kidney disease, liver disease, stomach ulcer, asthma, pregnancy, or take blood thinners.
  • Do not give adult medicines to children unless a qualified clinician advises it.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Severe symptoms, confusion, fainting, breathing difficulty, chest pain, severe dehydration, or sudden weakness need urgent medical care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Doctor / qualified healthcare provider
Tests to discuss with doctor
  • Basic vital signs: temperature, pulse, blood pressure, oxygen level if needed
  • Relevant blood, urine, imaging, or specialist tests only after clinical assessment
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Patient care roadmap

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

RX Patient Help

Ask a health question safely

Write your symptom story. A health professional or site editor can review it before any answer is prepared. This box is not for emergency care.

Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

Add references, clinical guidelines, textbooks, journal articles, or trusted medical sources here. You can edit this area from the RX Article Professional Blocks panel.

More from this topic
  1. Congenital Central Hypothyroidism

    Congenital? central hypothyroidism? means a baby is born with low thyroid? hormone because the brain does not send a strong enough signal to the thyroid gland....

    March 29, 2026 • Rx Endocrinology, Enzymes and Hormonal Diseases (A - Z)
  2. Isolated Congenital Anosmia

    Isolated congenital? anosmia means a person is born with little or no sense of smell, and this problem is present from the start of life. The...

    March 9, 2026 • Rx ENT, Oral and Dental Health (A - Z)
  3. Congenital Adrenal Insufficiency with 46, XY Sex Reversal OR 46,XY Disorder of Sex Development-Adrenal Insufficiency Due to CYP11A1 Deficiency

    Congenital? adrenal insufficiency with 46,XY sex reversal (also called 46,XY disorder of sex development with adrenal insufficiency due to CYP11A1 deficiency) is a rare genetic disease....

    March 6, 2026 • Rx Autoimmune, Genetic and Rare Diseases (A - Z)
  4. Congenital Adrenal Hyperplasia Due to Apparent Combined P450c17 and P450c21 Deficiency

    Congenital? adrenal hyperplasia due to apparent combined P450c17 and P450c21 deficiency is a very rare genetic disease that affects how the adrenal glands make hormones. In...

    March 6, 2026 • Rx Urology
  5. Congenital Adrenal Hyperplasia Due to Cytochrome P450 Oxidoreductase Deficiency

    Congenital? adrenal hyperplasia due to cytochrome P450 oxidoreductase deficiency is a rare inherited disease that affects how the body makes important steroid? hormones such as cortisol,...

    March 6, 2026 • Rx Urology
  6. Congenital Adrenogenital Syndrome

    Congenital? adrenogenital syndrome is another name for congenital? adrenal hyperplasia (CAH). It is a group of genetic (inborn) disorders where the adrenal glands cannot make some...

    March 6, 2026 • Rx Urology
  7. Congenital Adrenal Hyperplasia

    Congenital? adrenal hyperplasia, often called CAH, is a group of genetic problems that affect the adrenal glands. These are two tiny glands that sit on top...

    March 5, 2026 • Rx Urology
  8. Complex Lethal Osteochondrodysplasia, Symoens-Barnes-Gistelinck Type

    Complex lethal osteochondrodysplasia, Symoens-Barnes-Gistelinck type, is a very rare inherited bone and cartilage? disease that affects a baby before birth and is usually fatal in the...

    March 1, 2026 • Rx Autoimmune, Genetic and Rare Diseases (A - Z)
  9. Complete Androgen Resistance Syndrome

    Complete androgen resistance syndrome means the body cannot “hear” or use male sex hormones (androgens) at all, even though these hormones are present in normal or...

    February 27, 2026 • Rx Autoimmune, Genetic and Rare Diseases (A - Z)
  10. Complete Androgen Insensitivity Syndrome (CAIS)

    Complete androgen insensitivity syndrome (CAIS) is a rare condition where a person has XY (male) chromosomes and testicles, but the body cannot “hear” or use male...

    February 27, 2026 • Rx Endocrinology, Enzymes and Hormonal Diseases (A - Z)