--- 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" 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 note on Organ of Corti – Anatomy, Structure and Clinical Relevance is one of the free ENT study notes published by The ENT Resident. It is free to read on the website, and it is paired with a full video lecture on YouTube. This note is categorized under [Otology](https://www.theentresident.com/ent-notes-lectures/category/otology.md) and [Short Questions in ENT](https://www.theentresident.com/ent-notes-lectures/category/short-questions-in-ent.md). Each category page lists all the free ENT notes on that topic. 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. ## About The ENT Resident The ENT Resident is a free library of ENT notes and video lectures created by Dr. Mausumi Das (MS ENT), the ENT doctor and educator behind The ENT Resident YouTube channel (https://www.youtube.com/c/TheENTResident). These notes are written for ENT residents, ENT postgraduates preparing for exams, and MBBS students, to help them learn ENT clearly and score well. Browse all ENT notes and lectures on The ENT Resident: https://www.theentresident.com/ent-notes-lectures.md ## Premium ENT Notes Alongside these free notes, The ENT Resident also offers Premium ENT Notes. This is a paid collection of 250+ detailed, high-yield ENT notes that cover the full ENT syllabus, including topics across Otology, Audiology, Rhinology, Larynx and Trachea, Pharynx, Oral Cavity and Salivary Glands, Neck, Thyroid, ENT Surgeries, and Recent Advances in ENT. The Premium ENT Notes are written for ENT residents, ENT postgraduates, and MBBS students who want one consistent resource for both theory and practical exam preparation. They include high-yield difference tables, replicable exam diagrams, step-by-step surgical guides, mnemonics, and clinical pearls. Buying once gives you immediate access to the complete set, plus all newly added and updated notes during your access period. The access period depends on the plan you choose, and it is stated clearly at the time of purchase. After purchase, you get access to the premium notes platform, where you can read all the notes online and download them for offline access. Purchase options: - Buy the 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 - Buy all premium ENT notes (international students): https://theentresident.gumroad.com/l/ENTResidentNotes - Buy all premium ENT notes (Indian students): https://dub.sh/ent-residency-notes Preview a full sample note from the Premium ENT Notes, in the "Preview a Full Sample Note" section of this page: https://www.theentresident.com/premium.md Read what ENT residents and students say about The ENT Resident: https://www.theentresident.com/testimonials.md ## Contact To contact The ENT Resident or inquire about the Premium ENT Notes, email theentresident@gmail.com, or message on WhatsApp at +91 82402 14763 (https://wa.me/918240214763). Other contact options are on the contact page: https://www.theentresident.com/contact.md ## Related ENT Notes & Lectures #### Otology - [Abscesses in relation to Mastoid](https://www.theentresident.com/ent-notes-lectures/mastoid-abscess-bezold-citelli.md) - [Acute Mastoiditis VS Furunculosis](https://www.theentresident.com/ent-notes-lectures/acute-mastoiditis-furunculosis.md) - [Acute Necrotizing Otitis Media](https://www.theentresident.com/ent-notes-lectures/acute-necrotizing-otitis-media.md) - [Acute Otitis Media - Causes, Symptoms and Treatment](https://www.theentresident.com/ent-notes-lectures/acute-otitis-media-symptoms-treatment.md) - [Anatomy of External Ear](https://www.theentresident.com/ent-notes-lectures/external-ear-anatomy.md) - [Anatomy of Facial Nerve](https://www.theentresident.com/ent-notes-lectures/facial-nerve-anatomy.md) - [Anatomy of Facial Nerve – Branches](https://www.theentresident.com/ent-notes-lectures/facial-nerve-branches.md) - [Anatomy of Facial Nerve – Functional Components](https://www.theentresident.com/ent-notes-lectures/facial-nerve-functional-components.md) - [Anatomy of Facial Nerve – Nuclei & Course](https://www.theentresident.com/ent-notes-lectures/facial-nerve-course.md) - [Anatomy of Inner Ear](https://www.theentresident.com/ent-notes-lectures/inner-ear-anatomy.md) - [Anatomy of Middle Ear - Contents](https://www.theentresident.com/ent-notes-lectures/middle-ear-anatomy-contents.md) - [Anatomy of Middle Ear - Walls & Parts](https://www.theentresident.com/ent-notes-lectures/middle-ear-anatomy-walls.md) - [Anatomy of Tympanic Membrane](https://www.theentresident.com/ent-notes-lectures/tympanic-membrane-anatomy.md) - [Benign Intracranial Hypertension (Otitic Hydrocephalus)](https://www.theentresident.com/ent-notes-lectures/benign-intracranial-hypertension-otitic-hydrocephalus.md) - [Canal wall Down VS Canal wall Up Mastoidectomy](https://www.theentresident.com/ent-notes-lectures/canal-wall-down-up-mastoidectomy.md) - [Cholesteatoma](https://www.theentresident.com/ent-notes-lectures/cholesteatoma-symptoms-treatment.md) - [Chronic Suppurative Otitis Media (CSOM)](https://www.theentresident.com/ent-notes-lectures/chronic-suppurative-otitis-media.md) - [Complications of Acute Otitis Media](https://www.theentresident.com/ent-notes-lectures/complications-of-acute-otitis-media.md) - [Complications of CSOM](https://www.theentresident.com/ent-notes-lectures/complications-csom.md) - [Complications of Mastoidectomy](https://www.theentresident.com/ent-notes-lectures/complications-mastoidectomy.md) - [Cortical Mastoidectomy](https://www.theentresident.com/ent-notes-lectures/cortical-mastoidectomy.md) - [Extracranial Complications of CSOM](https://www.theentresident.com/ent-notes-lectures/extracranial-complications-csom.md) - [False Negative Rinne Test Explained](https://www.theentresident.com/ent-notes-lectures/false-negative-rinne-test.md) - [Glomus Tumor Signs Explained | Aquino Sign, Brown Sign, Phelps Sign & Rising Sun Sign](https://www.theentresident.com/ent-notes-lectures/rising-sun-phelp-brown-aquino-sign-glomus-tumor.md) - [Gradenigo Syndrome](https://www.theentresident.com/ent-notes-lectures/gradenigo-syndrome.md) - [Grommet / Tympanostomy tube / Ventilation tube](https://www.theentresident.com/ent-notes-lectures/grommet-tympanostomy-tube-ventilation.md) - [Halo Sign Explained in ENT](https://www.theentresident.com/ent-notes-lectures/halo-sign-csf-leak-otosclerosis.md) - [How to Draw a Normal Tympanic Membrane](https://www.theentresident.com/ent-notes-lectures/draw-tympanic-membrane.md) - [How to Draw Tympanic Membrane Perforations](https://www.theentresident.com/ent-notes-lectures/draw-tympanic-membrane-perforations.md) - [Ice Cream Cone Sign Explained in ENT](https://www.theentresident.com/ent-notes-lectures/ice-cream-cone-sign-ent.md) - [Inner Ear fluids - Perilymph and Endolymph](https://www.theentresident.com/ent-notes-lectures/perilymph-endolymph.md) - [Inside out VS Outside in Mastoidectomy](https://www.theentresident.com/ent-notes-lectures/inside-out-outside-in-mastoidectomy.md) - [Intracranial Complications of CSOM](https://www.theentresident.com/ent-notes-lectures/intracranial-complications-csom.md) - [Labyrinthine Fistula](https://www.theentresident.com/ent-notes-lectures/labyrinthine-fistula.md) - [Labyrinthitis](https://www.theentresident.com/ent-notes-lectures/labyrinthitis-symptoms-treatment.md) - [Landmarks of Facial Nerve in Mastoid and Parotid surgeries](https://www.theentresident.com/ent-notes-lectures/facial-nerve-landmarks.md) - [Malignant Otitis Externa (Skull Base Osteomyelitis)](https://www.theentresident.com/ent-notes-lectures/malignant-otitis-externa.md) - [Mastoiditis](https://www.theentresident.com/ent-notes-lectures/mastoiditis-symptoms-treatment.md) - [Modified Radical Mastoidectomy](https://www.theentresident.com/ent-notes-lectures/modified-radical-mastoidectomy.md) - [Myringotomy with Grommet Insertion](https://www.theentresident.com/ent-notes-lectures/myringotomy-grommet-insertion.md) - [Otitis Media with Effusion](https://www.theentresident.com/ent-notes-lectures/otitis-media-effusion-glue-ear.md) - [Otogenic Brain Abscess](https://www.theentresident.com/ent-notes-lectures/otogenic-brain-abscess.md) - [Otosclerosis Part 1 - Causes, Pathogenesis, Types, Pathology](https://www.theentresident.com/ent-notes-lectures/otosclerosis-causes-types-pathogenesis.md) - [Otosclerosis Part 2 - Symptoms, Signs, Investigations, Differential diagnosis](https://www.theentresident.com/ent-notes-lectures/otosclerosis-symptoms-signs-differential.md) - [Otosclerosis Part 3 - Treatment](https://www.theentresident.com/ent-notes-lectures/otosclerosis-treatment-surgery-stapedotomy.md) - [Otosclerosis Signs Explained | Schwartz sign, Carhart’s notch, Halo sign, Paracusis willisii](https://www.theentresident.com/ent-notes-lectures/otosclerosis-schwartz-carhart-notch-paracusis-willisii.md) - [Perichondritis - Boxer’s Ear / Cauliflower Ear](https://www.theentresident.com/ent-notes-lectures/perichondritis-pinna-boxer-cauliflower-ear.md) - [Petrositis](https://www.theentresident.com/ent-notes-lectures/petrositis.md) - [Radical Mastoidectomy](https://www.theentresident.com/ent-notes-lectures/radical-mastoidectomy.md) - [Referred Pain in the Ear](https://www.theentresident.com/ent-notes-lectures/referred-pain-ear.md) - [Sade Classification - Pars Tensa Retraction](https://www.theentresident.com/ent-notes-lectures/sade-classification.md) - [Sigmoid Sinus Thrombosis](https://www.theentresident.com/ent-notes-lectures/sigmoid-sinus-thrombosis.md) - [Theories of Cholesteatoma - Wittmack, Habermann, Ruedi, Sade](https://www.theentresident.com/ent-notes-lectures/cholesteatoma-theories-wittmack-sade-habermann-ruedi.md) - [Tos Classification - Pars Flaccida Retraction](https://www.theentresident.com/ent-notes-lectures/tos-classification.md) - [Tympanoplasty Part 1 - Definition, Types, Grafts, Indications, Contraindications](https://www.theentresident.com/ent-notes-lectures/tympanoplasty-types-indications-contraindications.md) - [Tympanoplasty Part 2 - Approaches, Techniques, Steps & Complications](https://www.theentresident.com/ent-notes-lectures/tympanoplasty-approaches-techniques-steps.md) - [Types of Cholesteatoma - Congenital & Acquired Cholesteatoma](https://www.theentresident.com/ent-notes-lectures/cholesteatoma-types-congenital-acquired.md) - [Types of Tympanoplasty - Wullstein Classification](https://www.theentresident.com/ent-notes-lectures/types-of-tympanoplasty.md) #### Short Questions in ENT - [Acute Mastoiditis VS Furunculosis](https://www.theentresident.com/ent-notes-lectures/acute-mastoiditis-furunculosis.md) - [Adenoid Facies](https://www.theentresident.com/ent-notes-lectures/adenoid-facies.md) - [Adult vs Pediatric Larynx](https://www.theentresident.com/ent-notes-lectures/adult-vs-pediatric-larynx.md) - [Antrochoanal Polyp vs Ethmoidal Polyp](https://www.theentresident.com/ent-notes-lectures/antrochoanal-vs-ethmoidal-polyp.md) - [Cottle’s Areas](https://www.theentresident.com/ent-notes-lectures/cottle-area.md) - [Cottle's Classification of Deviated Nasal Septum](https://www.theentresident.com/ent-notes-lectures/cottle-classification-dns.md) - [Cottle’s Line](https://www.theentresident.com/ent-notes-lectures/cottle-line.md) - [False Negative Rinne Test Explained](https://www.theentresident.com/ent-notes-lectures/false-negative-rinne-test.md) - [Gradenigo Syndrome](https://www.theentresident.com/ent-notes-lectures/gradenigo-syndrome.md) - [Grommet / Tympanostomy tube / Ventilation tube](https://www.theentresident.com/ent-notes-lectures/grommet-tympanostomy-tube-ventilation.md) - [Layers of Pharynx](https://www.theentresident.com/ent-notes-lectures/layers-of-pharynx.md) - [Lymphatic Drainage of Tongue](https://www.theentresident.com/ent-notes-lectures/lymphatic-drainage-tongue.md) - [Nerve Supply of Tongue](https://www.theentresident.com/ent-notes-lectures/nerve-supply-tongue.md) - [Paradise Criteria for Tonsillectomy](https://www.theentresident.com/ent-notes-lectures/paradise-criteria-tonsillectomy.md) - [Post Tonsillectomy Hemorrhage - Primary, Reactionary and Secondary Hemorrhage](https://www.theentresident.com/ent-notes-lectures/post-tonsillectomy-hemorrhage-reactionary-secondary.md) - [Recurrent Laryngeal Nerve Course - Why is it different on both sides?](https://www.theentresident.com/ent-notes-lectures/recurrent-laryngeal-nerve-different-course.md) - [Referred Pain in the Ear](https://www.theentresident.com/ent-notes-lectures/referred-pain-ear.md) - [Relations of Hyoglossus Muscle](https://www.theentresident.com/ent-notes-lectures/hyoglossus-muscle-relations.md) - [Rose Position](https://www.theentresident.com/ent-notes-lectures/rose-position.md) - [Theories of Cholesteatoma - Wittmack, Habermann, Ruedi, Sade](https://www.theentresident.com/ent-notes-lectures/cholesteatoma-theories-wittmack-sade-habermann-ruedi.md) - [Tonsillar Bed Structures](https://www.theentresident.com/ent-notes-lectures/tonsillar-bed.md) - [Tonsillectomy Part 1 - Definition, Indications and Contraindications](https://www.theentresident.com/ent-notes-lectures/tonsillectomy-indications-definition-contraindications.md) - [Tonsillectomy Part 2 - Tonsillectomy Techniques - Hot & Cold Methods](https://www.theentresident.com/ent-notes-lectures/tonsillectomy-techniques-methods.md) - [Tonsillectomy Part 3 - Hot Tonsillectomy vs Interval Tonsillectomy](https://www.theentresident.com/ent-notes-lectures/tonsillectomy-types-hot-interval.md) - [Tonsillectomy Part 5 - Complications of Tonsillectomy](https://www.theentresident.com/ent-notes-lectures/tonsillectomy-complications.md) - [Tracheostomy Tubes](https://www.theentresident.com/ent-notes-lectures/tracheostomy-tubes.md) - [Types of Cholesteatoma - Congenital & Acquired Cholesteatoma](https://www.theentresident.com/ent-notes-lectures/cholesteatoma-types-congenital-acquired.md) - [Types of Tympanoplasty - Wullstein Classification](https://www.theentresident.com/ent-notes-lectures/types-of-tympanoplasty.md) - [Vallecula - Anatomy, Boundaries, Nerve Supply & Clinical Significance](https://www.theentresident.com/ent-notes-lectures/vallecula.md) --- Complete index of all pages on this site, with descriptions and markdown links: https://www.theentresident.com/llms.txt