Answered: What are the concentric regions of a…

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

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Related questions

Question

What are the concentric regions of a hair shaft, from the outside in?

Expert Solution

Step 1

The hair shaft is the hair segment that is not connected to the follicle, much of which is found on the skin's surface. The remainder of the scalp attached to the follicle, referred to as the hair root, is beneath the skin's surface.

Step 2

The shaft is the free part of the hair that extends to the free surface and into the upper follicle. Each hair is divided in cross-section into three concentric layers: the cuticle, medulla, and cortex from outside to inside. The cuticle is the outermost layer formed from dead cells, and the cortex is the medial layer containing hair pigment and medulla, which consists of soft and fragile tissues.