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/o Gland Adip/o Fat Albin/o White Aut/o Self Bi/o Life Blephar/o Eyelid Carcin/o Carcinoma Cutane/o Skin

Root Words Contd:

Cry/o Cold Cyan/o Blue Derm/o, Dermat/o Skin Diaphor/o Profuse sweating Erythem/o Red Hidr/o sweat Histi/o Tissue Kerat/o Hard, horny like

Root Words contd:

Leuk/o White Lip/o Fat Melan/o Black Myc/o Fungus Necr/o Deat (cell or body) Onych/o Nail Pil/o Hair Py/o Pus

Root words Contd:

Sclera/o Hardening Seb/o Sebum Squam/o scale Steat/o Fat Xanth/o Yellow

Prefix:

Epi- On, over, upon Para- Beside, beyond,

around Per- through Sub- Under, below

Suffix:

-itis inflammation -malacia softening -opsy view of -orrhea excessive

flow/discharge

-phagia eating or swallowing

-plasty surgical 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 analysisPerformed 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

Sun Block Reduce your Exposure of the Sun Protective Clothing Self Exam Dermatology visits 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.