---
title: "Organ of Corti – Anatomy, Structure and Clinical Relevance"
description: "Detailed anatomy of the Organ of Corti - basilar membrane, tectorial membrane, cochlear hair cells and supporting cells - for medical students and ENT residents."
source: "The ENT Resident"
author: "Dr. Mausumi Das"
canonical_url: "https://www.theentresident.com/ent-notes-lectures/organ-of-corti"
categories: ["Otology", "Short Questions in ENT"]
video: "https://www.youtube.com/watch?v=7wwj3DCIglw"
image: "https://media.theentresident.com/og-images/organ-of-corti.png"
---

# Organ of Corti – Anatomy, Structure and Clinical Relevance

Detailed anatomy of the Organ of Corti - basilar membrane, tectorial membrane, cochlear hair cells and supporting cells - for medical students and ENT residents. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=7wwj3DCIglw

In this post, we’ll explore the **Organ of Corti**, the **sensory organ of hearing**.

### 📍 Location and General Structure

- The **Organ of Corti** is located **on top of the basilar membrane** within the **scala media** of the cochlea.
- The **basilar membrane** forms the **floor of the scala media** and separates it from the scala tympani.
- The **basilar membrane and Organ of Corti** increase in **width and thickness from the base to the apex** of the cochlea.

---

### 🧱 1. Basilar Membrane

- It is a **sheet of extracellular matrix** composed of:

  - **Collagen (type IV – α1 to α5 chains)**
  - **Fibronectin**
  - **Laminin type 11**

- **Underside** of the basilar membrane faces the **perilymph of scala tympani** and is lined by **tympanic border cells**.

---

### 🧱 2. Tectorial Membrane

- Overlies the Organ of Corti.

- Attached **medially** to the **interdental cells of the spiral limbus**.

- **Not attached** laterally to the organ of Corti.

- Composed of:
  - **Collagen types II, V, and IX**
  - **Autogelin, α and β tectorin**
  - **CEACAM16**

- Contains:
  - **Henson’s stripe** on its underside
  - **Covenant fiber network** on its upper surface

- **Formed only during cochlear development** and **cannot regenerate** – damage leads to **permanent hearing loss**.

---

### 🎧 3. Cochlear Hair Cells

- Convert **sound energy into electrical impulses**.
- Two types:
  - **Inner Hair Cells (IHC)** – ~3,500 cells in 1 row  
  - **Outer Hair Cells (OHC)** – ~12,000 cells in 3–4 rows

>What are the **Differences Between Inner and Outer Hair Cells**?

- **Afferent fibers** mostly innervate **inner hair cells (95%)**.
- **Efferent fibers** originate from the **olivocochlear bundle** in the **superior olivary complex**.

---

### 🧱 4. Supporting Cells

**🔹 Deiters’ Cells**

- Intercalated between outer hair cells.

- Provide mechanical support and rest on the basilar membrane.

**🔹 Pillar Cells**

- **Inner and outer pillar cells** separate IHCs and OHCs.

- Form the **tunnel of Corti**, filled with **cortilymph**.

**🔹 Hensen’s Cells**

- Located **lateral to Deiters’ cells**.

- Contain **lipid droplets**, may add **mass**.

**🔹 Claudius and Boettcher Cells**

- Located on the **outer skirt** of the Organ of Corti.

- Functions:
  - **Mechanical support**
  - **Add mass**
  - **Cochlear homeostasis** – remove **extracellular K⁺** via **gap junctions**

>What is **Stria Vascularis**?
---

### 📌 Summary

- The **Organ of Corti** is essential for hearing and consists of **basilar and tectorial membranes**, **inner and outer hair cells**, and **supporting cells**.
- **Inner hair cells** are crucial for **sound transmission**, while **outer hair cells** help in **modulating** the function of IHCs.
- **Tectorial membrane damage** causes **irreversible hearing loss**.
- **Supporting cells** play both **structural and metabolic roles** in cochlear function.

---

## About This Note

This free ENT note on Organ of Corti – Anatomy, Structure and Clinical Relevance was written by Dr. Mausumi Das and is paired with a corresponding video lecture.

Canonical page of this note: https://www.theentresident.com/ent-notes-lectures/organ-of-corti

When citing or referencing this content, please credit The ENT Resident and link to the canonical page above.

## Related Notes by Category

- Otology: https://www.theentresident.com/ent-notes-lectures/category/otology.md
- Short Questions in ENT: https://www.theentresident.com/ent-notes-lectures/category/short-questions-in-ent.md

## About The ENT Resident

The ENT Resident is an educational website and resource library created by Dr. Mausumi Das (MS ENT) for ENT residents, ENT postgraduates preparing for exams, and MBBS students.

Dr. Mausumi Das writes the notes, draws the diagrams, and records the lectures herself.

Browse all ENT notes and lectures on The ENT Resident: https://www.theentresident.com/ent-notes-lectures.md

## Medical-use Boundary

The ENT Resident provides educational material for medical learning and revision. It does not provide patient-specific medical advice, diagnosis, or emergency care, and it is not a substitute for evaluation by a qualified healthcare professional.

## More Resources

- Learn about the Premium ENT Notes, preview a complete sample, and find purchase options: https://www.theentresident.com/premium.md
- Premium note for this topic, Organ of Corti – Anatomy, Structure and Clinical Relevance: https://theentresident.gumroad.com/l/jekys
- Buy Complete Notes on Anatomy of Ear: https://theentresident.gumroad.com/l/anatomyofear
- Read student testimonials: https://www.theentresident.com/testimonials.md
- Contact The ENT Resident: https://www.theentresident.com/contact.md

---

A complete index of all pages on this site, with descriptions and markdown links can be found here: https://www.theentresident.com/llms.txt