A clinical chart in a gynaecology office. An anatomical-textbook diagram. A specimen-tag in an anatomy lab. The kanji compound 陰核 (inkaku, “the core of the pudendum”) signals an entry into formal medical register, where the same anatomical structure that everyday vocabulary calls kuri or kuritorisu takes its formal-anatomical name.

Inkaku (Japanese formal-anatomical: 陰核, inkaku; Latin: clitoris; English: clitoris) is the formal Japanese anatomical name for the primary sensory-erotic organ of the external female genitalia. The same structure is named in Japanese vernacular and loanword vocabulary as kuritorisu (クリトリス, from English/Latin); the present entry follows the formal-anatomical name and concentrates on the anatomical description, while the dedicated clitoris entry covers the broader sexual-response, cultural, and historical dimensions of the same organ.

Distinction in vocabulary

The Japanese vocabulary distinguishes the formal-anatomical inkaku (陰核) from the vernacular loanword kuritorisu (クリトリス) and the diminutive kuri (クリ). The three terms denote the same anatomical structure but operate in distinct registers: inkaku in clinical, legal, and academic writing; kuritorisu in everyday non-clinical and sex-education writing; kuri in colloquial-and-intimate contexts.

The Japanese five-character compound inkaku-kitō (陰核亀頭, “clitoral glans”) and inkaku-hōhi (陰核包皮, “clitoral hood”) provide sub-component vocabulary, with the parallel English terms glans clitoridis and preputium clitoridis serving the same function in Anglophone medical writing.

The English vocabulary uses clitoris in both formal-anatomical and everyday registers, with the shorter clit in vernacular-and-intimate registers. The five-register Japanese distinction (formal-anatomical / vernacular-loanword / diminutive-loanword / vernacular-affectionate / metaphorical-literary) is somewhat more elaborate than the English three-register distinction.

Overview

The clitoris is, externally, a small projection at the anterior of the vulva — but anatomical research from approximately 1998 onward has clarified that this external projection (the clitoral glans) is only the visible component of a substantially larger sub-surface structure. The total volume of the clitoral structure in the engorged state is comparable to that of an erect penis. The present entry concentrates on the anatomical description; the sexual-response and cultural dimensions are treated in the dedicated clitoris entry.

Etymology

The Latin clitoris descends from the Greek kleitorís (κλειτορίς), with one of the proposed etymological connections being to the Greek verb kleíein (“to close, to enclose”). The Japanese inkaku (陰核) is a Meiji-era medical-translation compound, with in (陰, “yin, hidden, pudendal”) and kaku (核, “core, kernel, central structure”). The compound was developed in the Meiji-period systematic medical-translation work that established the Japanese-language formal anatomical vocabulary from European-medical-Latin source.

Anatomical structure

Components

The clitoris consists of the following anatomical components, ordered from the visible external structure inward:

The clitoral glans (glans clitoridis; Japanese 陰核亀頭, inkaku-kitō) is the external projection at the anterior of the vulva, at the anterior junction of the labia minora. The glans is approximately a few millimetres in diameter, with high-density sensory-nerve-end innervation.

The clitoral body (corpus clitoridis; Japanese 陰核体, inkaku-tai) is the internal erectile-tissue structure extending from the glans approximately 2-4 cm into the body. The body bends sharply at the “knee of the clitoris” and continues into the paired crura.

The clitoral crura (crura clitoridis; Japanese 陰核脚, inkaku-kyaku) are the paired erectile-tissue structures branching from the clitoral body and extending laterally along the inferior pubic rami, approximately 5-9 cm in length.

The vestibular bulbs (bulbi vestibuli; Japanese 前庭球, zenteikyū) are the paired erectile-tissue structures flanking the vaginal opening, approximately 3-7 cm in length. The vestibular bulbs are continuous with the clitoral body and crura, forming part of the broader erectile-tissue complex.

The clitoral hood (preputium clitoridis; Japanese 陰核包皮, inkaku-hōhi) is the skin-fold formed by the anterior fusion of the labia minora, partially covering the clitoral glans.

The clitoral frenulum (frenulum clitoridis; Japanese 陰核小帯, inkaku-shōtai) is the thin tissue fold connecting the medial inner surface of the labia minora to the clitoral glans.

These components function as a continuous, connected sensory-and-erectile-tissue complex. Under sexual arousal, the entire complex engorges and increases in sensitivity, with increased blood-volume distribution across the full structure rather than isolated to the visible glans.

Internal structure

The clitoral body, the paired crura, and the vestibular bulbs are erectile-tissue structures (corpus cavernosum) with internal cavernous-sinusoid lacunae. Under sexual arousal, the cavernous arteries dilate, the intracavernosal pressure rises, and the structures expand. The mechanism is analogous to the male penis erectile mechanism, though the clitoral structure does not produce comparable external protrusion.

The clitoral erectile tissue is enveloped by a strong fibrous tunica albuginea, parallel to the corresponding structure in the penile corpora cavernosa. Under arousal, the increased intracavernosal pressure produces erection-like firmness and volume increase in the structure as a whole.

Innervation

The dorsal nerve of the clitoris (nervus dorsalis clitoridis), a terminal branch of the pudendal nerve (nervus pudendus), is the principal sensory innervation of the clitoral surface. The nerve distributes in a network pattern across the glans, body, and hood.

The 2022 Peters et al. tissue-quantification study produced the first direct measurement of human clitoral nerve-fibre count. The study found approximately 5,140 fibres per side and a bilateral total of more than 10,000 fibres in the clitoral structure. The figure substantially exceeds the dorsal penile-nerve fibre count (~4,000 fibres) and supports the clitoral structure’s status as one of the highest nerve-fibre-density-per-area structures in the human body.

Embryology

In embryonic development, the male and female external genitalia derive from a common genital-tubercle primordium. Under androgenic (principally dihydrotestosterone) signalling at approximately 8-12 weeks gestation, the genital tubercle differentiates into the penis, with the genital swellings fusing to form the scrotum. In the absence of androgenic signalling, the same primordium differentiates into the clitoris, with the genital folds differentiating into the labia minora and the genital swellings remaining bilaterally separated to form the labia majora.

The embryological homology between the clitoris and the penis is reflected anatomically in the shared erectile-tissue structure, the glans-and-hood configuration, the innervation pattern, and the erectile physiology. The two structures are variant differentiations of a single primordium rather than opposing organs.

The further embryological connection between the clitoral structure and the vestibular bulbs is increasingly treated in contemporary anatomical writing as part of the unified clitoral-erectile-complex description rather than as a separate adjacent structure.

The history of anatomical re-description

Twentieth-century medical-textbook description of the clitoris substantially under-represented the sub-surface anatomical structure, with the majority of mid-twentieth-century textbooks treating the clitoris as a near-superficial structure (the visible glans) without adequate description of the body, crura, and vestibular bulbs.

The systematic re-description that produced the contemporary anatomical account is associated with Helen O’Connell and colleagues’ work from the late 1990s onward. O’Connell et al.’s Anatomy of the Clitoris (Journal of Urology, 1998) provided systematic re-examination of the structure, including the body, crura, vestibular-bulb continuity, and innervation pattern. The work prompted substantial revision of medical-textbook description through the 2000s and 2010s, with contemporary major anatomical references (Gray’s Anatomy 42nd edition, 2020; Williams Gynecology, 2020) incorporating the systematic-anatomical updated description.

The history of the under-description and subsequent re-description has become a recurring case in the gender-and-medicine literature, treated as illustrative of the way medical knowledge is constructed within social-and-cultural conditions rather than as pure objective description.

Pathologies and clinical issues

Major medical issues relating to the clitoris include:

Clitoral hypertrophy (clitoral hypertrophy): substantial size variation outside the typical population range. The condition appears in certain endocrine conditions, including congenital adrenal hyperplasia (CAH), and is medically a separate category from the cosmetic-aesthetic preference for larger clitoral size in adult-content vocabulary.

Clitoral hood adhesion: chronic inflammation can produce adhesion between the clitoral hood and the glans, with consequences for hygiene maintenance and sensitivity.

Female genital cutting (FGC): the cultural practice (in a number of jurisdictions) of partial or total clitoral excision. The World Health Organization (WHO) and the major human-rights bodies explicitly oppose the practice as a violation of bodily integrity and a human-rights violation. This entry treats FGC as a recognised pathology-and-rights-violation category rather than as a normalised cultural variant.

Adult-content representation

In adult-content production, references to the clitoris use the vernacular kuritorisu substantially more frequently than the formal-anatomical inkaku. The formal inkaku term appears predominantly in medical-and-educational contexts and in literary-and-critical contexts where the formal register is appropriate.

Cunnilingus, manual stimulation, vibrator-and-toy stimulation, and other principal female-pleasure stimulation techniques operate directly or indirectly on the clitoral structure. Accurate understanding of the full clitoral anatomy — including the sub-surface body, crura, and vestibular bulbs — provides relevant grounding for accurate representation of the structure’s functional role.

Related Terms

• Clitoris (loanword) — same organ, everyday loanword name
• Vagina (chitsu) — adjacent internal anatomy
• G-spot — anterior vaginal-wall region, continuous with clitoral sub-surface structure
• Cunnilingus — oral-tongue stimulation of the clitoral region
• Shiofuki (female ejaculation) — associated sexual-response phenomenon
• Labia minora (sho-inshin)
• Labia majora (dai-inshin)
• Penis (inkei) — embryologically homologous organ