Ciliated

Ciliated Cells

Ciliated cells are specialized epithelial cells that possess hair-like structures called cilia on their surface. These cells play a crucial role in various physiological processes, particularly in the respiratory and reproductive systems.

Structure

Ciliated cells are characterized by the presence of numerous cilia on their apical surface. Each cilium is a slender, microscopic, hair-like structure that extends from the cell body. The core of a cilium is composed of a microtubule-based structure known as the axoneme, which typically follows a "9+2" arrangement: nine pairs of microtubules form a ring around two central microtubules.

Function

Ciliated cells are primarily involved in the movement of fluids and particles across epithelial surfaces. In the respiratory system, ciliated cells line the trachea and bronchi, where they help to trap and expel inhaled particles and pathogens through the coordinated beating of cilia, a process known as mucociliary clearance. This is essential for maintaining respiratory health and preventing infections.

In the reproductive system, ciliated cells are found in the fallopian tubes (also known as oviducts), where they facilitate the movement of the ovum from the ovary towards the uterus. This movement is crucial for successful fertilization and subsequent implantation of the embryo.

Types of Cilia

Cilia can be classified into two main types:

• Motile cilia: These cilia are capable of movement and are involved in the active transport of materials across cell surfaces. They are found in large numbers on ciliated epithelial cells in the respiratory tract and reproductive system.

• Non-motile cilia: Also known as primary cilia, these are typically solitary and do not beat. They serve as sensory organelles and are involved in signal transduction pathways. Primary cilia are found on many cell types throughout the body.

Clinical Significance

Defects in cilia structure or function can lead to a group of disorders known as ciliopathies. These include conditions such as primary ciliary dyskinesia, which is characterized by chronic respiratory tract infections, and polycystic kidney disease, where ciliary dysfunction affects kidney function.

Research and Advances

Recent advances in microscopy and molecular biology have enhanced our understanding of cilia and their roles in health and disease. Studies on cilia have implications for developing treatments for ciliopathies and other related conditions.

See Also

• Epithelial tissue
• Microtubule
• Respiratory system
• Reproductive system

External Links

• Article on Cilia Function
• Ciliopathy Alliance