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Penis

Anatomy and Physiology · NLM MeSH · updated 2026-10-31 · version 1

Citations verified against PubMedNot yet clinician-reviewed9 referencesApproximately 3 min read

The external reproductive organ of males.

Table of Contents

1. Definition2. Research landscape3. Reading the evidence4. Open-access studies5. Key reviews6. References7. About this article

Definition and research guide

This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.

Content available: 3 complete abstracts (572 words), 9 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.

Definition

The external reproductive organ of males. It is composed of a mass of erectile tissue enclosed in three cylindrical fibrous compartments. Two of the three compartments, the corpus cavernosa, are placed side-by-side along the upper part of the organ. The third compartment below, the corpus spongiosum, houses the urethra.

Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.

Also known as: Glans Penis; Penis, Glans.

Where it fits in the MeSH classification

Broader topics
Genitalia, Male
Narrower topics
Foreskin; Urethra

Research landscape

PubMed indexes 47,881 records tagged with the MeSH heading “Penis” (counts retrieved 2026-10-31). 6,045 of them (12.6%) were published from 2020 onward, and the busiest period so far is through 1999 with 23,445 records.

Reviews account for 4,201 records (8.8%) and meta-analyses for 206. Randomized controlled trials number 804 (1.7%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.

PubMed records by publication periodthrough 1999: 23,445 records; 2000-2009: 8,613 records; 2010-2019: 9,778 records; 2020 onward: 6,045 records23,445through 19998,6132000-20099,7782010-20196,0452020 onward
Records in PubMed indexed with this heading, by publication period. Real counts from NCBI E-utilities; the final period covers only part of the current year. Volume reflects how much has been published, not how strong the evidence is.
Show the data
PeriodRecords
through 199923,445
2000-20098,613
2010-20199,778
2020 onward6,045
Share of records by publication typeReviews: 8.8 percent; Meta-analyses: 0.4 percent; Randomized controlled trials: 1.7 percentReviews8.8% (4,201)Meta-analyses0.4% (206)Randomized controlled trials1.7% (804)
Share of all PubMed records on this heading that carry each publication type. Types overlap with other records, so the shares do not sum to 100%.
Publication-type chart data
Publication types among 47,881 PubMed records
TypeRecordsShare
Reviews4,2018.8%
Meta-analyses2060.4%
Randomized controlled trials8041.7%

Method: PubMed query "Penis"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.

Reading the evidence in anatomy and physiology

Anatomy describes how body structures are built and physiology describes how they normally work, so most findings here are descriptive or mechanistic rather than evidence about treatment. Much of what is known comes from dissection, imaging, tissue studies and experiments in animals, and measurements in healthy volunteers can differ from those in people with disease or at different ages. Normal ranges vary between individuals and populations. Check whether a result was measured in people or in another species, the age and health of the participants, and the method used.

Evidence from open-access studies

These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.

Study comparison — selected abstracts, not a systematic review
Study / authorsYearSource label / designEurope PMC citationsLicence / source
HIV-associated penile anaerobes disrupt epithelial barrier integrity
Buchanan LB, Shao Z, Galiwango RM, Constable S, Zuanazzi D, Biribawa VM, et al.
2025Research article
Design not recorded in structured metadata
9cc by
PMID 40245064 · DOI · PMC12040277
MT-100, a human Tie2-agonistic antibody, improves penile neurovasculature in diabetic mice via the novel target Srpx2
Liu FY, Cho YL, Fridayana FR, Niloofar L, Vo MN, Huang Y, et al.
2025Research article
Design not recorded in structured metadata
7cc by
PMID 39741183 · DOI · PMC11799434
The role of the urologist in managing high flow priapism
Dursun M, Kalkanlı A, Tantekin SA, Sevinç AH, Kaçan T, Ercan CC, et al.
2026Review article
Design not recorded in structured metadata
5cc by
PMID 39910241 · DOI · PMC13581607

HIV-associated penile anaerobes disrupt epithelial barrier integrity [1]

Research article Buchanan LB, Shao Z, Galiwango RM, Constable S, Zuanazzi D, Biribawa VM, et al. · · 2025 · cited 9 times (Europe PMC)

Abstract reading summary — source excerpts
Opening excerpt
Specific anaerobic taxa within the penile microbiome-the Bacteria Associated with Seroconversion, Inflammation and Immune Cells (BASIC) species-enhance HIV-1 susceptibility, in part by recruiting susceptible cells to the inner foreskin.
Closing excerpt
Therefore, BASIC species may enhance penile HIV susceptibility by directly disrupting epithelial integrity, in addition to previously described target cell recruitment.
Interpretation limits
Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (202 words)

Specific anaerobic taxa within the penile microbiome-the Bacteria Associated with Seroconversion, Inflammation and Immune Cells (BASIC) species-enhance HIV-1 susceptibility, in part by recruiting susceptible cells to the inner foreskin. However, their effect on epithelial barrier integrity has not been described. Using foreskin tissues and penile swabs from 116 males undergoing voluntary medical male circumcision, we assessed the relationship between BASIC species and foreskin epithelial thickness, junction protein expression, and cellular proliferation. The absolute abundance of BASIC species was associated with reduced tissue expression of the epithelial junction proteins claudin-1 and E-cadherin, and with elevated soluble E-cadherin in penile secretions, suggesting proteolytic cleavage. These effects were not seen in participants with a high abundance of control taxa without high levels of BASIC species. The BASIC species Prevotella bivia, but not Peptostreptococcus anaerobius or Dialister micraerophilus, was shown to directly degrade recombinant human E-cadherin and to increase the release of soluble E-cadherin from foreskin epithelial cells in vitro. In vivo BASIC species absolute abundance was also linked to a thicker nucleated epithelium and increased keratinocyte proliferation, with no change in stratum corneum thickness. Therefore, BASIC species may enhance penile HIV susceptibility by directly disrupting epithelial integrity, in addition to previously described target cell recruitment.

Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40245064 · DOI · PMC12040277

MT-100, a human Tie2-agonistic antibody, improves penile neurovasculature in diabetic mice via the novel target Srpx2 [2]

Research article Liu FY, Cho YL, Fridayana FR, Niloofar L, Vo MN, Huang Y, et al. · · 2025 · cited 7 times (Europe PMC)

Abstract reading summary — source excerpts
Opening excerpt
Diabetes is an incurable, chronic disease that can lead to many complications, including angiopathy, peripheral neuropathy, and erectile dysfunction (ED).
Closing excerpt
Our findings not only provide conclusive evidence that MT-100 is a promising therapeutic strategy for the treatment of diabetic ED but also suggest it has substantial clinical applications for other complications associated with diabetes.
Interpretation limits
Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (159 words)

Diabetes is an incurable, chronic disease that can lead to many complications, including angiopathy, peripheral neuropathy, and erectile dysfunction (ED). The angiopoietin-Tie2 signaling pathway plays a critical role in blood vessel development, formation, remodeling, and peripheral nerve regeneration. Therefore, strategies for activating the Tie2 signaling pathway have been developed as potential therapies for neurovascular diseases. Here, we developed a human Tie2-agonistic antibody (MT-100) that not only resists Ang-2 antagonism and activates Tie2 signaling but also regulates a novel target, sushi repeat-containing protein X-linked 2 (Srpx2). This regulation led to the survival of vascular and neuronal cells, a reduction in the production of reactive oxygen species (ROS), activation of the PI3K/AKT/eNOS signaling pathway, increased expression of neurotrophic factors, and ultimately alleviation of ED in diabetic mice. Our findings not only provide conclusive evidence that MT-100 is a promising therapeutic strategy for the treatment of diabetic ED but also suggest it has substantial clinical applications for other complications associated with diabetes.

Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 39741183 · DOI · PMC11799434

The role of the urologist in managing high flow priapism [3]

Review article Dursun M, Kalkanlı A, Tantekin SA, Sevinç AH, Kaçan T, Ercan CC, et al. · · 2026 · cited 5 times (Europe PMC)

Abstract reading summary — source excerpts
Opening excerpt
High-flow priapism (arterial) is a prolonged erection caused by irregular cavernous arterial flow, often resulting from blunt perineal or penile trauma, or iatrogenic needle injury.
Closing excerpt
By ensuring timely and appropriate management, urologists can minimize complications and preserve erectile function.
Interpretation limits
Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (211 words)

High-flow priapism (arterial) is a prolonged erection caused by irregular cavernous arterial flow, often resulting from blunt perineal or penile trauma, or iatrogenic needle injury. This condition leads to the formation of an arteriolacunar fistula, causing unregulated arterial blood flow into the sinusoidal spaces of the penis. Unlike low-flow priapism, high-flow priapism typically presents with a partially erect, non-painful penis. The diagnosis is confirmed through characteristic findings on color Doppler ultrasound, which reveals turbulent high-velocity flow pinpointing the fistula's location. Blood gas analysis typically reflects arterial values, helping to differentiate high-flow priapism from its low-flow counterpart. Although high-flow priapism was historically considered non-urgent, recent evidence suggests that delayed treatment may increase the risk of erectile dysfunction. Therefore, prompt intervention by urologists is crucial. The primary goal is to close the fistula, and the treatment plan should be individualized based on the severity and duration of the condition. Urologists play a critical role in managing this condition, offering a range of therapeutic options. These include conservative approaches, such as observation and compression, medical therapy, arterial embolization, and, in some cases, surgical intervention. The choice of treatment depends on the patient's condition, the fistula's location, and the resources available. By ensuring timely and appropriate management, urologists can minimize complications and preserve erectile function.

Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 39910241 · DOI · PMC13581607

Key reviews and meta-analyses

The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.

  • Research article A Comprehensive Review of Overactive Bladder Pathophysiology: On the Way to Tailored Treatment [4]
    Peyronnet B, Mironska E, Chapple C, Cardozo L, Oelke M, Dmochowski R, et al. · Eur Urol · 2019 · cited 319 times (Europe PMC)
  • Research article Preoperative Membranous Urethral Length Measurement and Continence Recovery Following Radical Prostatectomy: A Systematic Review and Meta-analysis [5]
    Mungovan SF, Sandhu JS, Akin O, Smart NA, Graham PL, Patel MI · Eur Urol · 2017 · cited 182 times (Europe PMC)
  • Research article Penile Fracture: A Meta-Analysis [6]
    Amer T, Wilson R, Chlosta P, AlBuheissi S, Qazi H, Fraser M, et al. · Urol Int · 2016 · cited 106 times (Europe PMC)
  • Research article Urethral reconstruction using buccal mucosa or penile skin grafts: systematic review and meta-analysis [7]
    Lumen N, Oosterlinck W, Hoebeke P · Urol Int · 2012 · cited 78 times (Europe PMC)
  • Research article Meta-analysis of complication rates of the tubularized incised plate (TIP) repair [8]
    Pfistermuller KL, McArdle AJ, Cuckow PM · J Pediatr Urol · 2015 · cited 77 times (Europe PMC)
  • Research article Tissue Engineering of the Urethra: A Systematic Review and Meta-analysis of Preclinical and Clinical Studies [9]
    Versteegden LRM, de Jonge PKJD, IntHout J, van Kuppevelt TH, Oosterwijk E, Feitz WFJ, et al. · Eur Urol · 2017 · cited 71 times (Europe PMC)

References

  1. Buchanan LB, Shao Z, Galiwango RM, Constable S, Zuanazzi D, Biribawa VM, et al.. HIV-associated penile anaerobes disrupt epithelial barrier integrity. . 2025. PMID 40245064 · DOI · PMC12040277
  2. Liu FY, Cho YL, Fridayana FR, Niloofar L, Vo MN, Huang Y, et al.. MT-100, a human Tie2-agonistic antibody, improves penile neurovasculature in diabetic mice via the novel target Srpx2. . 2025. PMID 39741183 · DOI · PMC11799434
  3. Dursun M, Kalkanlı A, Tantekin SA, Sevinç AH, Kaçan T, Ercan CC, et al.. The role of the urologist in managing high flow priapism. . 2026. PMID 39910241 · DOI · PMC13581607
  4. Peyronnet B, Mironska E, Chapple C, Cardozo L, Oelke M, Dmochowski R, et al.. A Comprehensive Review of Overactive Bladder Pathophysiology: On the Way to Tailored Treatment. Eur Urol. 2019. PMID 30922690 · DOI
  5. Mungovan SF, Sandhu JS, Akin O, Smart NA, Graham PL, Patel MI. Preoperative Membranous Urethral Length Measurement and Continence Recovery Following Radical Prostatectomy: A Systematic Review and Meta-analysis. Eur Urol. 2017. PMID 27394644 · DOI · PMC5600894
  6. Amer T, Wilson R, Chlosta P, AlBuheissi S, Qazi H, Fraser M, et al.. Penile Fracture: A Meta-Analysis. Urol Int. 2016. PMID 26953932 · DOI
  7. Lumen N, Oosterlinck W, Hoebeke P. Urethral reconstruction using buccal mucosa or penile skin grafts: systematic review and meta-analysis. Urol Int. 2012. PMID 22889835 · DOI
  8. Pfistermuller KL, McArdle AJ, Cuckow PM. Meta-analysis of complication rates of the tubularized incised plate (TIP) repair. J Pediatr Urol. 2015. PMID 25819601 · DOI
  9. Versteegden LRM, de Jonge PKJD, IntHout J, van Kuppevelt TH, Oosterwijk E, Feitz WFJ, et al.. Tissue Engineering of the Urethra: A Systematic Review and Meta-analysis of Preclinical and Clinical Studies. Eur Urol. 2017. PMID 28385451 · DOI

About this article

Sources
NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
Verification
Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
Review state
automated source verified; no human expert review has been recorded yet.
Version
1, last updated 2026-10-31.

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At a glance

47,881
PubMed records on this heading
13%
published since 2020
4,201
review articles
804
randomized trials
9
verified references below

Counts come from PubMed on 2026-10-31; they show how much has been written, not how strong the evidence is.

Related topics See all →

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