Module on Anatomy and PhysiologyThe Integumentary SystemObjectives:On completion of this module, the learner will be able to:1.Describe the physical characteristics and parts of the skin.2.Describe the functions of the different layers as well as the accessory organelles in theintegumentary system.3.Explain the physiology behind the principal processes of wound healing.Instructional Materials:Handout on Anatomy and Physiology of the Integumentary System.Online video resource materials.Pre-recorded video annotations.Disclaimer:This is a study guide for Anatomy and Physiology of the Integumentary System. As such, it is expected that not all topicsunder this section of anatomy is contained herein. Instead, key areas which the lecturers deemed essential for the students’learnings are presented here. It is expected that the students shall supplement their study by reading the suggested textbookwhich is Principles of Anatomy and Physiology 15thEd. by Tortora and Derrickson. This outline is lifted from an article byMarianne Belleza, RN of nurseslabs.com and all rights and credits are therefore reserved for the author.Teaching-Learning Activity/Lesson Proper:Introduction to Skin Anatomy andPhysiologyIntegumentary SystemThe integumentary system (in- = inward; -tegere = to cover) is composed of the skin,hair, oil and sweat glands, nails, and sensory receptors.Dermatology is the medical specialty that deals with the structure, function, anddisorders of the integumentary system.The skin, also known as the cutaneous membrane covers the external surface of thebody and is the largest organ of the body in weight. In adults, the skin covers an area of about2 square meters (22 square feet) and weighs 4.5–5 kg (10–11 lb), about 7% of total bodyweight. It ranges in thickness from 0.5 mm (0.02 in.) on the eyelids to 4.0 mm (0.16 in.) on theheels. Over most of the body it is 1–2 mm (0.04–0.08 in.) thick.The skin consists of two main parts: The superficial, thinner portion, which iscomposed of epithelial tissue, is the epidermis (epi- = above). The deeper, thicker connectivetissue portion is the dermis. While the epidermis is avascular, the dermis is vascular. For this
reason, if you cut the epidermis there is no bleeding, but if the cut penetrates to the dermisthere is bleeding.Deep to the dermis, but not part of the skin, is the subcutaneous (subQ) layer. Alsocalled the hypodermis (hypo- = below), this layer consists of areolar and adipose tissues.Fibers that extend from the dermis anchor the skin to the subcutaneous layer, which in turnattaches to underlying fascia, the connective tissue around muscles and bones. Thesubcutaneous layer serves as a storage depot for fat and contains large blood vessels thatsupply the skin. This region (and sometimes the dermis) also contains nerve endings calledlamellated corpuscles or pacinian corpuscles that are sensitive to pressure.