Meaning
The kanji 胞 primarily means "cell," "sac," "bladder," or "placenta." It's a key character in biological and medical terminology, referring to small, enclosed biological units or structures.
As a 形声文字 (keisei moji), or phono-semantic compound, 胞 is formed by combining a semantic radical and a phonetic component—a common kanji structure. It consists of two parts: the radical 月 on the left, and the phonetic component 包 on the right.
The radical 月 here is known as 肉月 (niku-zuki), a variant of 肉 (flesh, meat). When 月 appears on the left side of a kanji, it almost always signifies something related to the human body, organs, or biological matter. This connection makes sense, given 胞's meanings like "cell," "sac," or "placenta," all of which are biological structures.
The component on the right, 包, primarily means "to wrap," "to pack," or "to enfold." It also gives 胞 its 音読 (on'yomi), ホウ (HŌ), which comes from Chinese. Together, "flesh/body" (月) and "to wrap/enfold" (包) suggest a small, biological unit that encloses its contents. Think of a cell wrapping what's inside, or a sac holding something, like a fetus within a placenta.
This kanji has 11 strokes. It's not on the 常用漢字 (Jōyō Kanji) list, meaning it isn't taught in elementary school in Japan. This is consistent with its N1 JLPT level.
Readings
On'yomi (音読み) — Chinese-derived readings
胞's primary 音読 (on'yomi) is ホウ (HŌ). You'll find this reading in nearly all significant compound words, especially those in biology, medicine, and other scientific fields. It's derived from the character's original Chinese pronunciation.
- ホウ (HŌ)
This reading is key to understanding 胞's common applications. It appears almost exclusively in compound words, rarely by itself.
- 細胞 (saibō) — This is arguably the most common word using 胞, meaning "cell." It combines 細 (fine, minute) with 胞, essentially meaning "fine sac" or "minute unit."
- 胎胞 (taihō) — Meaning "fetal sac" or "amnion." Here, 胎 means "fetus" or "womb," so the compound translates to "fetus sac."
- 胞子 (hōshi) — Meaning "spore." This word is used in biology for reproductive cells of plants, fungi, and bacteria.
Kun'yomi (訓読み) — Native Japanese readings
The kanji 胞 has no widely recognized 訓読 (kun'yomi) readings that function as standalone words in modern Japanese. While some older dictionaries or specialized texts might suggest a connection to words like ふくろ (fukuro, bag/sac), this isn't a practical or frequently encountered reading for 胞 itself. Its use is almost entirely confined to 音読 compounds, which highlights its specialized, technical nature as a borrowing from Chinese.
Therefore, when you encounter 胞, focus primarily on its 音読 ホウ (HŌ) and its role within compound words.
Common Words & Compounds
You'll almost exclusively find the kanji 胞 within compounds, where it plays a vital role in biological, medical, and scientific contexts. Here are some of the most common and important words to know:
Biology and Anatomy
- 細胞 (saibō) — cell. This is the most fundamental word, central to biology.
- 赤血球 (sekkeikyū) — red blood cell. While this specific compound doesn't use 胞, it's a type of 細胞 (cell), illustrating how fundamental 胞 is to understanding biological cells.
- 卵細胞 (ransaibō) — egg cell, ovum. The female reproductive cell.
- 神経細胞 (shinkeisaibō) — nerve cell, neuron.
- 単細胞 (tansaibō) — unicellular (organism), or metaphorically, simple-minded.
- 多細胞 (tasaibō) — multicellular.
- 胞子 (hōshi) — spore. A reproductive unit for fungi, plants, and bacteria.
- 胞嚢 (hōnō) — cyst, sac. A pathological fluid-filled sac.
- 気胞 (kihō) — air sac, air vesicle. Such as in the lungs.
- 胚胞 (haihō) — blastocyst. An early stage of embryonic development.
Pregnancy and Obstetrics
- 胎胞 (taihō) — fetal sac, amnion. The membrane enclosing the fetus.
- 胞衣 (ena) — afterbirth, placenta. This is a special 熟字訓 (jukujikun) reading, where the reading applies to the compound as a whole rather than individual kanji.
- 羊膜 (yōmaku) — amnion, amniotic membrane (related to 胎胞).
Other Specialized Terms
- 胞膜 (hōmaku) — membrane. A general term for a biological membrane, similar to 膜 (maku).
Learning these compounds is essential for anyone studying biology, medicine, or related fields in Japanese, as 胞 is fundamental to describing biological structures.
Example Sentences
生物の基本は細胞から成り立っている。
Seibutsu no kihon wa saibō kara naritatteiru.
All living things are fundamentally composed of cells.
植物は胞子で増えるものも多い。
Shokubutsu wa hōshi de fueru mono mo ooi.
Many plants reproduce using spores.
この微生物は単細胞で、非常に小さい。
Kono biseibutsu wa tansaibō de, hijō ni chiisai.
This microorganism is unicellular and extremely small.
胎児は胎胞の中で安全に育つ。
Taiji wa taihō no naka de anzen ni sodatsu.
The fetus grows safely within the fetal sac.
専門家が新種の細胞を発見したと発表しました。
Senmonka ga shinshu no saibō wo hakken shita to happyō shimashita.
Experts announced the discovery of a new type of cell.
肺には酸素を交換するための小さな気胞が多数あります。
Hai ni wa sanso wo kōkan suru tame no chiisana kihō ga tasū arimasu.
The lungs have numerous small air sacs for gas exchange.
ガン細胞の増殖を抑制する研究が進められています。
Gan saibō no zōshoku wo yokusei suru kenkyū ga susumerareteimasu.
Research to suppress the proliferation of cancer cells is underway.
受精卵は分裂を繰り返し、胚胞へと発達します。
Juseiran wa bunretsu wo kurikaeshi, haihō e to hattatsu shimasu.
A fertilized egg repeatedly divides and develops into a blastocyst.
多細胞生物は、様々な種類の細胞から構成されています。
Tasaibō seibutsu wa, samazama na shurui no saibō kara kōsei sareteimasu.
Multicellular organisms are composed of various types of cells.
Memory Tip
To remember 胞, consider its components. The left part, 月 (niku-zuki), acts as the "flesh" or "body" radical, signaling a connection to biological matter. The right part, 包 (tsutsumu), means "to wrap" or "to enclose" and also provides the 音読 ホウ (HŌ). So, you can visualize 胞 as a "flesh-filled sac" or a "biological unit that wraps its contents." Imagine a tiny biological "wrap" (包) made of "flesh" (月). This image immediately brings to mind a "cell" or a "sac." This mnemonic helps link the kanji's visual form to its core meanings and reading, making it easier to recall in biological contexts.