Which sequence best describes a normal route for the flow of tears from the eyes into the nasal cavity? a. lacrimal canaliculi, lacrimal sacs, nasolacrimal ducts; lb. acrimal ducts, lacrimal canaliculi, nasolacrimal ducts; c. nasolacrimal ducts, lacrimal canaliculi, lacrimal sacs.

Verified step by step guidance

1. Identify the structures involved in the flow of tears: lacrimal canaliculi, lacrimal sacs, and nasolacrimal ducts.
2. Understand the function of each structure: lacrimal canaliculi collect tears from the eye surface, lacrimal sacs store the tears temporarily, and nasolacrimal ducts drain the tears into the nasal cavity.
3. Determine the correct order of tear flow based on their functions: tears first enter the lacrimal canaliculi, then move to the lacrimal sacs, and finally drain through the nasolacrimal ducts into the nasal cavity.
4. Compare the options provided with the correct sequence: lacrimal canaliculi, lacrimal sacs, nasolacrimal ducts.
5. Select the option that matches the correct sequence of tear flow.

Key Concepts

Tear Production

Tears are produced by the lacrimal glands located above the outer corner of each eye. They serve to lubricate the eye, provide nutrients, and protect against infection. Understanding the origin of tears is essential for tracing their pathway through the eye's drainage system.

Lacrimal System

The lacrimal system consists of several structures that facilitate the drainage of tears. This includes the lacrimal canaliculi, which collect tears from the eye, the lacrimal sacs that store them, and the nasolacrimal ducts that transport tears into the nasal cavity. Familiarity with this system is crucial for understanding the flow of tears.

Anatomy of the Nasal Cavity

The nasal cavity is a hollow space behind the nose that plays a role in the respiratory system and is connected to the lacrimal system via the nasolacrimal ducts. When tears drain into the nasal cavity, they can cause a runny nose, illustrating the connection between these two systems. Recognizing this anatomy helps clarify the pathway of tear flow.