Chapter 5 Integumentary System

Learning Outcomes:  Describe the Integumentary system  List the functions of the skin  Indentify medical words related to the Integumentary system  Describe laboratory tests and procedures related to the Integumentary system  Identify and define some abbreviations

Integumentary System Includes:  Skin (cutaneous membrane)  Subcutaneous tissue below the skin  Accessory Structures Sweat glands Sebaceous or oil glands Hair Nails

Introduction:  The Integumentary system is also known as the skin.  This includes hair, nails and glands. (Known as the Accessory Organs)  Integument means covering  Skin is the outer covering of the body  Weighs about 8 to 10 pounds  Covers 18 to 22 square feet of an adult

Functions:  Protective membrane  Maintains and regulates body temperature (holds moisture in)  Acts as receptors for sensation Such as pain, pressure, pleasure (touch), temperature  Fights off bacterial invasion

Structure:  Varies through out the body  Stretchable and tough with different thickness  Thick on palms of hand, soles of feet  Thin on eyelids  Initially firm and elastic, but with age becomes dry and wrinkled  Three layers

Epidermis:  Outer most totally cellular layer: basal; prickle-cell; granular; clear; and horny.  Composed of epithelium (squamous) which covers the internal and external surfaces of the body  Has no blood vessels, lymphatic vessels, connective tissue, cartilage or fat  Depends on the deeper dermis (corium) for nourishment

Epidermis contd:  Deepest layer in the epidermis is called the basal layer  Cells in the basal layer are always growing and multiplying  As they die they are pushed upwards and away from the blood supply of the dermis layer by younger cells  These cells then shrink, loose their nuclei, die and become filled with a hard protein called keratin which are then called Horney cells.

Epidermis contd:  Cells die at the same rate at which they are born  Basal Layer contain cells called melanocytes.  Melanocytes contain black pigment called Melanin  Amount of active Melanin in our skin dictates the color of our skin

Dermis:  Second layer  Also known as the corium  Living tissue composed of blood, lymph, vessels and nerve fibers as well as the accessory organs of the skin  Contains connective tissue cells and fibers that support this system  Has 3 different types of connective tissue cells

Dermis contd:  Fibroblasts: acts to repair an injury to the skin  Histiocytes: protects the body surface by surrounding foreign materials  Mast Cells: contain histamine, a substance released in allergies that causes itching

Dermis contd:  Fibers in the dermis are composed of collagen  Collagen means ‘glue’  It is a fibrous protein material found in bone, cartilage, tendons, and ligaments as well as the skin  It is tough but also flexible.  Collagen fibers support and protect the blood and nerve networks that pass through the dermis

Subcutaneous:  Beneath the skin containing adipose tissue, connective tissue, vessels and nerves  Protects deeper tissues of the body  Acts as a heat insulator  Connects the Dermis to the muscles and organs below it.

Accessory Organs of the skin: Hair  Composed of a network of horny cells filled with a hard protein called Keratin  Deep –lying cells in the hair roots move forward through the hair follicles, or shafts that hold the hair fibers creating growth  Melanocytes are located at the root of the hair follicles

Nails  Hard Keratin plates that cover the top surface of the last bone of each finger and toe.  Composed of Horney cells that are cemented together and can extend indefinitely until cut or broken  Nail grows in thickness and length as a result of division of cells in the region of the nail root (base)

Glands: Sebaceous  Located in the dermal layer  Located through out body except in the palms and soles of feet.  Secrete an oily substance called Sebum  It lubricates the skin and minimizes water loss  Influenced by sex hormones.

Sebaceous Gland These glands produce a substance called sebum.  This oil spreads out on the skins surface making the skin: more flexible and waterproof.

Sweat:  Tiny coiled glands found on almost all body surfaces (~2 mil)  A large number are found in the palm of your hand and sole of feet  The tiny opening on the surface is called a pore  Sweat cools the body as it evaporates  Perspiration is controlled by the sympathetic nervous system

Root words:  Aden/oGland  Adip/oFat  Albin/oWhite  Aut/oSelf  Bi/oLife  Blephar/oEyelid  Carcin/oCarcinoma  Cutane/oSkin

Root Words Contd:  Cry/oCold  Cyan/oBlue  Derm/o, Dermat/oSkin  Diaphor/oProfuse sweating  Erythem/oRed  Hidr/osweat  Histi/oTissue  Kerat/oHard, horny like

Root Words contd:  Leuk/oWhite  Lip/oFat  Melan/oBlack  Myc/oFungus  Necr/oDeat (cell or body)  Onych/oNail  Pil/oHair  Py/oPus

Root words Contd:  Sclera/oHardening  Seb/oSebum  Squam/oscale  Steat/oFat  Xanth/oYellow

Prefix:  Epi-On, over, upon  Para-Beside, beyond, around  Per-through  Sub-Under, below

Suffix:  -itisinflammation  -malaciasoftening  -opsyview of  -orrheaexcessive flow/discharge  -phagiaeating or swallowing  -plastysurgical repair

Papule  Small solid elevation of the skin  < 1 cm in diameter e.g. pimple Nodule  Solid elevation of the skin  >1cm in diameter e.g. enlarged lymph node  Very large nodule is a Tumor

Testing: Two major ways:  Bacterial analysis Performed by taking a sample of a purulent (pus filled) material or exudates (fluid that accumulates in the space of tissue)  Fungal testing: Occurs when scrapings from the skin lesion are placed on a growth medium for several weeks and then examined for evidence of fungal growth.

Statement of the Problem Even though we have been educated on the dangers of skin cancer and its prevention, Melanoma/skin cancer continues to increase at an alarming rate.

Prevention SSun Block RReduce your Exposure of the Sun PProtective Clothing SSelf Exam DDermatology visits EEducation and Awareness

Need to review:  Diagnostic and Lab test page 114 – 115  Abbreviations page 115

Anatomy of the Skin  Upper layer of skin is called EPIDERMIS EPI- means on top of DERMIS means skin  The lower layer of skin is called the DERMIS.