The main arteries supplying blood to the penis are the three terminal branches of the internal pudendal artery: the bulbourethral artery, the dorsal artery, and the cavernosal (deep) artery, each serving a specific physiological role in nutrition or erection.

While all three vessels transport oxygenated blood to the organ, they perform drastically different functions. One branch is responsible for keeping the skin alive, another maintains the health of the urethra, and the third acts as the high-pressure line that physically drives the hydraulic expansion of an erection.

This guide provides a detailed anatomical map of the penile arterial system, tracing the flow from the pelvis to the specific branches and explaining the micro-vascular mechanisms that regulate inflow.

What Is the Origin of the Main Arteries Supplying the Penis?

The arterial supply to the penis originates from the anterior division of the Internal Iliac Artery, which gives rise to the Internal Pudendal Artery, the primary vessel for the entire perineal region. This vascular path ensures that blood flow is channeled securely from the deep pelvis before reaching external structures.

The “Internal Pudendal” Pipeline

The “Internal Pudendal Pipeline” describes the specific route the artery takes as it travels out of the pelvis, through the gluteal region, and into the perineum via Alcock’s canal.

Upon exiting the canal and reaching the perineum, the vessel transitions into the Common Penile Artery. It then terminates by trifurcating (splitting into three) into the specific penile branches that service the organ. This trifurcation is the critical transition point where general pelvic blood flow becomes specialized penile circulation.

Source: StatPearls – Internal Pudendal Artery

What Are the Three Terminal Branches of the Penile Artery?

The Common Penile Artery divides into three distinct terminal branches: the Bulbourethral Artery, the Dorsal Artery, and the Cavernosal (Deep) Artery, each targeting a specific tissue compartment.

The arterial walls themselves are anchored by surrounding structures, including the supportive layers of the tunica albuginea . This fibrous envelope compresses venous channels against the sub-tunical plane, creating the pressure trap necessary for a rigid erection. Even minor asymmetry in this layer can produce uneven arterial expansion.

The Bulbourethral Artery (The “Primer”)

The Bulbourethral Artery enters the bulb of the penis to supply oxygenated blood to the corpus spongiosum and the urethra. Its primary role is metabolic rather than mechanical. It ensures the urethra remains viable and contributes to the engorgement of the glans (head) during arousal. Without this steady supply, the tissues surrounding the urinary tract would lack necessary oxygenation.

The Dorsal Artery (The “Sustainer”)

The Dorsal Artery runs along the top (dorsum) of the penis, positioned between the dorsal nerve and the deep dorsal vein, superficial to the tunica albuginea.

This artery targets the outer layers. It provides nutritional blood flow to the shaft skin and engorgement to the head, but contributes minimally to shaft rigidity. It is the vessel responsible for maintaining the health of the penile fascia and the integumentary system of the penis.

On the surface, arterial responsiveness can be influenced by the configuration of the glans penis , which receives blood via the dorsal network rather than the cavernosal system. In contrast, the proximal inflow is stabilized by the musculature around the pelvic base, especially the perineal base muscles , which enhance intracavernosal pressure through rhythmic contraction.

Pathologies add an important layer of complexity. In Peyronie’s disease , plaque formation along the tunica disrupts normal arterial curvature and can create areas of restricted inflow. Similarly, early stages of arteriogenic erectile dysfunction often manifest as reduced responsiveness in the penile arterial tree , long before total occlusion appears on imaging.

The Cavernosal (Deep) Artery (The “Engine”)

The Cavernosal Artery, also known as the Deep Artery, pierces the crus and runs through the center of each Corpus Cavernosum.

This vessel targets the erectile tissue (sinusoids). Anatomically and functionally, the deep cavernosal artery serves as the primary inflow channel during arousal, driving the hydraulic pressure needed for erection. It is the central component of the erectile mechanism.

The hemodynamic behavior of the penile arteries depends heavily on the integrity of the corpora cavernosa , since these paired chambers receive the majority of inflow during tumescence. Any disruption to their smooth muscle or endothelial lining alters expansion capacity and arterial responsiveness.

If fibrosis develops in the cavernosal tissue, arterial inflow may be preserved but expansion becomes impaired. The reduced compliance limits how effectively blood pressure can build within the cavernosal drainage system , producing a condition clinically similar to venous leak despite normal upstream arterial supply.

How Do the Helicine Arteries Regulate Flow?

The Helicine Arteries regulate flow by acting as microscopic valves; they are tiny, coiled branches of the Cavernosal Artery that open directly into the lacunar spaces (sinusoids).

The initial surge of blood enters through branches of the internal pudendal system, especially the helicine arteries . These microscopic vessels straighten under parasympathetic signaling, allowing unrestricted flow toward the deep cavernosal vascular pathway , which transitions the penis from a low-pressure to a high-pressure system within seconds.

The “Valve” Mechanism

The “Valve” mechanism of the Helicine Arteries is controlled by the autonomic nervous system, determining whether the penis is flaccid or erect.

The term “helicine” refers to their spiral or corkscrew-shaped structure. In the flaccid state, these arteries are coiled and constricted (high sympathetic tone), limiting inflow to a nutritional baseline. During the erect state, they uncoil and dilate (driven by parasympathetic release of Nitric Oxide), dumping blood directly into the lacunar spaces. This rapid dilation allows arterial blood to fill the spongy tissue, expanding the penis.

The neural drive controlling these arterial transitions arises from both somatic and autonomic pathways. Sensory feedback from the dorsal nerve of the penis integrates with parasympathetic fibers that coordinate vasodilation and sinusoidal filling. Any impairment in these pathways affects arterial tone and cavernosal expansion.

Source: NCBI – Physiology of Erection

These relationships demonstrate that penile hemodynamics depend on the coordinated function of the spongiosal-urethral complex , the cavernosal bodies, the tunical envelope, and the neuromuscular inputs sustaining pressure. When any part of this system becomes compromised — anatomically or pathologically — the arterial waveform reflects the underlying disorder.