---
title: "Lacrimal Bone | Anatomy and Physiology I"
description: "Lacrimal bone is the tiny facial bone in the medial orbit that helps form the lacrimal fossa and supports tear drainage in Anatomy and Physiology I."
canonical: "https://fiveable.me/anatomy-physiology/key-terms/lacrimal-bone"
type: "key-term"
subject: "Anatomy and Physiology I"
unit: "Unit 7"
---

# Lacrimal Bone | Anatomy and Physiology I

## Definition

The lacrimal bone is a small bone in the medial wall of the orbit that helps form the lacrimal fossa for tear drainage. In Anatomy and Physiology I, you study it as part of the skull and the lacrimal system.

## What It Is

The lacrimal bone is a very small, thin facial bone that sits in the front inner corner of each eye socket. In Anatomy and Physiology I, you usually meet it when you study the orbit, the skull, and the path tears take after they leave the eye.

Its main job is not to move or bear weight. Instead, it helps build the medial wall of the orbit and forms part of the bony space that protects the eyeball. Because it is so slender, it is easy to overlook on a skull model, but it matters because small orbital bones fit together to make a stable, protective cavity.

A useful landmark on the lacrimal bone is the lacrimal fossa, a shallow depression that houses the lacrimal sac. The lacrimal sac collects tears that drain from the eye surface. From there, tears continue into the nasolacrimal duct and then into the nasal cavity, which is why your nose runs when you cry. The bone is part of the route, even though the fluid itself is carried by soft tissue structures.

The lacrimal bone also articulates with nearby bones, especially the maxilla, ethmoid, and frontal bone. Those joints help complete the orbital wall. If you are labeling a skull, this bone is usually found near the bridge of the nose and the medial corner of the eye, right where the tear drainage pathway begins.

In lab, a common mistake is confusing the lacrimal bone with the lacrimal system itself. The bone is the hard structure. The lacrimal sac and nasolacrimal duct are the soft tissues that move tears. If a fracture or swelling in this area blocks drainage, tears can back up and irritate the eye, which shows how a tiny bone can affect a visible body function.

## Why It Matters

The lacrimal bone matters because it ties together two big Anatomy and Physiology I ideas: skeletal structure and organ support. You are not just memorizing a skull label here. You are seeing how a bone creates a protected space for the eye and helps shape the route tears follow from the eye to the nose.

That connection shows up when you study the orbit as a functional unit. The orbit is made from several bones, and each one contributes a wall, edge, or notch that supports the eyeball and nearby structures. The lacrimal bone is one of the pieces that makes the medial orbit work as a real anatomical space instead of just a hole in the skull.

It also helps you connect bone anatomy with the respiratory and digestive entry area of the face, since tear drainage ends in the nasal cavity. That is why a small change in the bone or the surrounding tissues can affect eye watering, drainage, or irritation. In lab practicals and skull ID questions, being able to spot the lacrimal bone helps you distinguish the orbit from the nasal and maxillary regions.

If your instructor asks about facial trauma, sinus pressure, or tear drainage, the lacrimal bone gives you a precise place to anchor your answer. It is a small bone, but it sits at the intersection of protection, drainage, and bone articulation.

## Connections

### Lacrimal System

The lacrimal bone is part of the bony framework that supports the lacrimal system. The system includes the structures that collect and drain tears, while the bone helps house the lacrimal sac in the medial orbit. When you trace tear flow, the bone marks the place where drainage begins in the skull, even though the actual fluid pathway is in soft tissue.

### Orbital Cavity

The lacrimal bone is one of the small bones that help form the orbital cavity, the socket that holds and protects the eye. On a skull model, it sits on the medial side of the orbit. Knowing this relationship helps you identify how several facial bones combine to create a strong, protective space around the eyeball.

### Tear Duct

The tear duct, or nasolacrimal duct, carries tears away after they collect in the lacrimal sac. The lacrimal bone is close to this pathway because its lacrimal fossa houses the sac. If you are tracing tear drainage in lab or on a diagram, the bone is the landmark that points you to the start of the duct system.

### [Ethmoid Bone](/anatomy-physiology/key-terms/ethmoid-bone)

The ethmoid bone joins with the lacrimal bone along the medial orbit. These bones work together to shape the inner wall of the eye socket, so they are often studied together in skull anatomy. If you are labeling bones of the orbit, the ethmoid helps define the same crowded region where the lacrimal bone sits.

## On the AP Exam

A lab practical may ask you to identify the lacrimal bone on a skull or model, especially in the medial wall of the orbit near the nose. A diagram question may connect it to tear drainage and ask which structure houses the lacrimal sac. In a short-answer or case prompt, you might explain why swelling or fracture near the inner corner of the eye can lead to blocked tear drainage. If your class uses bone articulation questions, you should know that it joins with the maxilla, ethmoid, and frontal bone.

## lacrimal bone vs Lacrimal System

The lacrimal bone is a bone, while the lacrimal system is the set of structures that produce, collect, and drain tears. People mix them up because they are in the same area and share the same root word. If the question asks about a skull landmark, think bone. If it asks about tear flow, think system.

## Key Takeaways

- The lacrimal bone is a tiny bone on the medial side of the orbit, right near the inner corner of the eye.
- Its lacrimal fossa helps house the lacrimal sac, which is part of tear drainage.
- The bone helps build the orbit, so it contributes to protecting the eyeball even though it is very small.
- It articulates with the maxilla, ethmoid, and frontal bone, which is why it shows up in skull ID and orbit anatomy.
- If tear drainage is blocked or the area is injured, the lacrimal bone region can become part of the problem.

## FAQs

### What is the lacrimal bone in Anatomy and Physiology I?

The lacrimal bone is a small facial bone that forms part of the medial wall of the orbit. It contains the lacrimal fossa, which helps house the lacrimal sac for tear drainage. In A&P I, you usually study it as part of skull anatomy and the lacrimal system.

### Where is the lacrimal bone located?

It is located in the front inner corner of the eye socket, on the medial side of the orbit. On a skull, it sits near the bridge of the nose and helps form the bony space around the eye. That position makes it easy to link to tear drainage structures.

### Is the lacrimal bone the same thing as the tear duct?

No. The lacrimal bone is a bone, but the tear duct is a soft tissue channel that carries tears into the nasal cavity. The bone helps create the space where the lacrimal sac sits, but it does not carry the tears itself.

### Why does the lacrimal bone matter in skull anatomy?

It matters because it is part of the orbital wall and part of the pathway tears use to drain from the eye. In lab, it can help you identify the medial orbit and distinguish the lacrimal region from nearby bones like the maxilla and ethmoid.

## Related Study Guides

- [7.2 The Skull ](/anatomy-physiology/unit-7/2-skull/study-guide/UlZ8y25gzC1E8srV)

## About This Document

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