Difference Between Papillary and Reticular Layer

The key difference between papillary and reticular layer is that papillary layer is the thin superficial layer of the dermis composed of loose connective tissue while the reticular layer is the deeper thick layer of the dermis composed of dense connective tissue.

The dermis is the thickest layer of skin, and a fibrous structure composed of collagen, elastic tissue, and other extracellular components including vasculature, nerve endings, hair follicles, and glands. It is located beneath the epidermis and above the subcutaneous layer. The dermis provides strength and flexibility to our skin. Apart from supporting and protecting the skin, it also assists in thermoregulation, and aids in sensation. Besides, the dermis has two layers as the papillary layer and the reticular layer. Of these two layers, the papillary layer is the upper layer or superficial layer while the reticular layer is the lower or deep layer of the dermis.

CONTENTS

1. Overview and Key Difference
2. What is Papillary Layer
3. What is Reticular Layer
4. Similarities Between Papillary and Reticular Layer
5. Side by Side Comparison – Papillary vs Reticular Layer in Tabular Form
6. Summary

What is Papillary Layer?

The papillary layer is the superficial layer of the dermis. It is relatively thin and composed of loose connective tissue. It lies beneath the epidermis, attached to it. It has loosely arranged elastic fibres and thin collagen fibres. However, the papillary layer of the dermis is rich in blood vessels; hence it is highly vascularized compared to the deeper layer.

Moreover, the papillary layer contains a lot of cells, including many macrophages, mast cells and other inflammatory cells. Papillary layer increases mechanical adhesion and facilitates the diffusion of nutrients from the dermis to epidermis.

What is Reticular Layer?

The reticular layer is the deeper layer of the dermis. It is a thick layer which constitutes the bulk of the dermis. It is composed of dense connective tissue. There are coarse collagen fibres arranged irregularly and a small number of elastic fibres. Compared to the superficial layer, the reticular layer has fewer cells, including adipocytes, melanocytes and mast cells. It is also less vascularized, having fewer and small blood vessels.

Furthermore, the reticular layer also contains hair follicles, sweat glands, and sebaceous glands. The main functions of the reticular layer are strengthening the skin and providing elasticity to our skin.

What are the Similarities Between Papillary and Reticular Layer?

• Papillary and reticular layers are the two layers of the dermis.
• They are connective tissues.
• They have collagen and elastic fibres.
• Moreover, they consist of blood vessels.

What is the Difference Between Papillary and Reticular Layer?

The papillary layer is the most superficial layer of the dermis while the reticular layer is the deepest layer of the dermis. So, this is the key difference between papillary and reticular layer. The papillary layer is composed of the loose connective layer while the reticular layer is composed of dense connective tissue. Also, there are lots of cells in the papillary layer compared to the reticular layer. Besides, the papillary layer is thin compared to the reticular layer.

Moreover, the papillary layer functions include nutrient supply and temperature regulation of our skin. Meanwhile, the reticular layer strengthens the skin and provides our skin with elasticity. Thus, this is the functional difference between papillary and reticular layer.

Summary – Papillary vs Reticular Layer

The dermis is the fibrous layer of our skin located between the epidermis and subcutaneous layer. It consists of two layers: papillary layer (superficial layer) and reticular layer (deeper layer). The papillary layer is thin compared to the reticular layer, which is thick and constitutes the bulk of the dermis. Moreover, the papillary layer lies attached to the epidermis. It is composed of loose connective tissue of elastic fibres and fine collagen fibres. Meanwhile, the reticular layer lies beneath the papillary layer. It is composed of dense connective tissue of coarse collagen fibres arranged irregularly and a small number of elastic fibres. Also, the papillary layer is rich in blood vessels, unlike the reticular layer. This is the summary of the difference between papillary and reticular layer.

Reference:

1. Brown, Thomas, and Karthik Krishnamurthy. “Histology, Dermis”. Ncbi.Nlm.Nih.Gov, 2020, Available here.
2. Yolanda Smith, B.Pharm. “What Is The Dermis?”. News-Medical.Net, 2020, Available here.

Image Courtesy:

1. “Blausen 0802 Skin DermalCirculation” By Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia
2. “506 Layers of the Dermis” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013 (CC BY 3.0) via Commons Wikimedia