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Ch. 5 The Integumentary System
Amerman - Human Anatomy & Physiology 2nd Edition
Amerman2nd EditionHuman Anatomy & PhysiologyISBN: 9780136873822Not the one you use?Change textbook
Chapter 5, Problem 10

Epidermal ridges are created by:
a. The epidermal papillae
b. Mounds of papillary dermis arranged into dermal ridges
c. Gaps between collagen bundles in the reticular layer
d. Tight binding of the reticular layer to deeper structures

Verified step by step guidance
1
Understand the structure of the skin: The skin consists of two main layers, the epidermis (outer layer) and the dermis (inner layer). The dermis is further divided into the papillary layer (upper portion) and the reticular layer (lower portion).
Learn about dermal ridges: Dermal ridges are formed by the arrangement of the papillary layer of the dermis. These ridges push up into the epidermis, creating the patterns known as epidermal ridges (e.g., fingerprints).
Focus on the papillary dermis: The papillary dermis contains mounds of connective tissue that form dermal ridges. These ridges are responsible for the patterns seen on the surface of the skin.
Eliminate incorrect options: a) Epidermal papillae is not a term used to describe the structures forming epidermal ridges. c) Gaps between collagen bundles in the reticular layer do not contribute to epidermal ridges. d) Tight binding of the reticular layer to deeper structures is unrelated to ridge formation.
Select the correct answer: The correct explanation is that epidermal ridges are created by mounds of papillary dermis arranged into dermal ridges, which push up into the epidermis.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Epidermal Ridges

Epidermal ridges are the raised patterns on the surface of the skin, commonly known as fingerprints. They are formed by the interaction between the epidermis and the underlying dermis, specifically through the arrangement of dermal papillae, which project into the epidermis, creating these unique patterns.
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Dermal Papillae

Dermal papillae are small, nipple-like projections of the dermis that extend into the epidermis. They play a crucial role in enhancing the surface area for exchange of nutrients and waste, and they also contribute to the formation of epidermal ridges, influencing the unique patterns found on fingertips.
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1st Dermal Layer

Reticular Layer of the Dermis

The reticular layer is the deeper layer of the dermis, composed of dense irregular connective tissue that provides strength and elasticity to the skin. It contains collagen and elastin fibers, which help anchor the dermis to underlying structures, but it is primarily the papillary layer that interacts with the epidermis to form ridges.
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Introduction to the Dermis