Dermis Layers: Papillary and Reticular

Questions and Answers

What kind of tissue/fibers make up the papillary layer?

Loose connective tissue (areolar) made of collagen and elastic fibers.

Why is loose connective tissue of the papillary layer a good immune defense?

More space in between fibers for white blood cells to move through the area and patrol for pathogens.

What are dermal papillae?

Papillary layer projects upward into the epidermis with capillaries and nervous tissue.

How are fingerprints produced?

Dermal papillae + epidermal ridges = friction ridges. Signup and view all the answers

What are epidermal ridges?

Downward extensions of the epidermis. Signup and view all the answers

What kind of tissue/fibers is the reticular layer?

Dense irregular connective tissue (adipose) with collagen and elastic fibers. Signup and view all the answers

What is the deeper layer in the dermis?

Reticular layer. Signup and view all the answers

Where do collagen fibers from the reticular layer extend?

They extend into the papillary (up) and into the hypodermis (down). Signup and view all the answers

What are cleavage lines?

Spaces in between the collagen fibers that run parallel to the skin surface. Signup and view all the answers

What is the function of the reticular layer?

Allows skin the ability to resist forces applied from all different directions. Signup and view all the answers

What is Ehlers-Danlos syndrome?

Connective tissue disorder. Collagen fiber is not as strong so skin is more fragile and bruises easily and is stretchy. Signup and view all the answers

Collagen fibers and elastic fibers are arranged in parallel bundles along __________.

cleavage lines. Signup and view all the answers

How do cleavage lines provide a guide for incisions during surgery?

Cuts along parallel lines heal more quickly and most of the fibers stay intact so they can repair easily. Signup and view all the answers

What happens if you cut against the parallel lines of the cleavage furrow?

They will be continually pulled open by elastic fibers. Longer healing time with scarring. Signup and view all the answers

Study Notes

Papillary Layer

Comprised of loose connective tissue (areolar), containing collagen and elastic fibers.
Supports immune defense by allowing more movement for white blood cells due to space between fibers.
Dermal papillae project upward, containing capillaries and nerve tissue that enhance nutrient delivery and sensation.
Fingerprints are formed by the combination of dermal papillae and epidermal ridges, known as friction ridges.
Epidermal ridges are the downward extensions of the epidermis into the papillary layer.

Reticular Layer

Made of dense irregular connective tissue, primarily adipose, with high collagen and elastic fiber content.
Serves as the deeper layer of the dermis, supporting skin strength and resilience.
Collagen fibers extend into the papillary layer above and into the hypodermis below, anchoring the skin structure.
Contains cleavage lines, created by spaces between collagen fibers running parallel to the skin's surface.

Functions and Clinical Relevance

The reticular layer enables the skin to resist forces from various directions, contributing to its overall integrity.
Cleavage lines act as a guide for surgical incisions, as cuts along these lines promote quicker healing and minimize scarring by maintaining fiber integrity.
Cutting against the cleavage lines can lead to prolonged healing and increased risk of scarring due to the elastic fibers pulling the edges apart.
Ehlers-Danlos syndrome is a connective tissue disorder characterized by weak collagen fibers, leading to fragile skin that bruises easily and has increased stretchiness.