Objectives  To explain the function of the integumentary system.  To identify the components of the epidermis.  To list the strata of the epidermis.

Definitions  Epi – ___________________, on top of  Hypo – _______________  Derm – ______________  Serous membrane – membranes that line the body cavities  Mucous membrane – membranes that open to the outside of the body  Synovial membrane – Membranes in our joints

The Integumentary System: An Overview

Introduction  Organs are body structures composed of two or more different __________________________.  The skin and its accessory organs make up the ________________________ system

Parts of the integumentary system  ________________ – largest organ in our body  Body membranes  _________________  Nails

Functions:  Protective ______________________  Helps regulate body ________________________________ (homeostasis)  Prevents ___________________ loss from deeper tissues  Houses sensory receptors  Synthesizes biochemicals  Excretes small quantities of waste

Consists of…  ____________________ membrane _______________________ – Outermost layer ____________________ – Middle layer  Accessory structures- hair, ___________________________, sebaceous glands etc.  Subcutaneous layer (hypodermis) – innermost layer

Components Figure 5.1

Cutaneous Membrane  Cutaneous membrane is another word for skin. _____________ membrane  Act as protective covering from…. __________________________ damage (bumps) ___________________ damage (acids and bases) Bacterial damage ___________ radiation Thermal damage Desiccation (drying out)

Cutaneous Membrane  Regulate body _____________________________  Prevent water loss  House _________________________ _______________________________ Send signals to your brain about what you can __________________  Synthesize various biochemicals Like Vitamin D

3 Layers of Cutaneous Membrane  _____________________: Structure: Top layer; stratified squamous tissue Function: protection  ______________________: Structure: middle layer, largest layer. Hair, sweat glands, nails, oil glands  _______________________________: Structure: Bottom layer. Loose connective tissue and adipose tissue. Function: Insulation, houses major blood vessels.

The Epidermis

Thin Skin and Thick Skin  The epidermis is composed of layers of ____________________________- cells that produce keratin Thin skin = ______________ layers (strata) Thick skin = ________________ layers Figure 5.2

The Epidermis  Composed of _____________________________ epithelium  Lacks ________________________________  Older cells are pushed to the top and harden in a process called ________________________.

Layers of the epidermis:  Stratum _________________/ germinativum (cells undergoing mitosis)  Stratum ____________________  Stratum _____________________  Stratum _____________________ (only occurs in thick, hairlss skin of palms and hands and soles of feet)  Stratum _________________ (cells filled with keratin to protect and prevent water loss from skin) From deep to superficial….

The Structure of the Epidermis Figure 5.4

Epidermis Cell Layers  ___________________________ Basal cells (stem) are reproducing  __________________________- spiny layer  _________________________- grainy layer Stops dividing, start producing keratin  ____________________ The clear layer found only in thick skin  ____________________ Exposed to surface and shed every 2 wks.

Skin color depends on…  Genetics Differing amounts of _________________ and size of melanin ______________________  Blood supply Interrupted blood supply leads to _______________- blue!  ________________________ Orange-yellow pigment found in orange vegetables  Melanin Yellow-brown ______________________ Protects deeper cells from UV radiation Produced by ___________________________

Melanocytes Figure 5.5a, b

Epidermal cells  Synthesize ____________________ (cholecalciferol) when exposed to UV  Aids in absorption of ____________________ and phosphorus- needed for bone strength  Respond to epidermal growth factor _________________ Division _________________ Secretion

Objectives  The explain the components of the dermis.  To understand why tattoos are permanent.  To identify accessory organs of the integument and explain their function.

The Dermis

Dermal Organization  Located between __________________ and subcutaneous layer  Consists of connective tissue with ___________ and elastic fibers within a gel-like substance  Anchors accessory structures- hair follicles, sweat glands, blood vessels etc.  Carry nutrients to upper layers of skin and help regulate temperature.  Two components: Outer _______________________ layer Deep _______________________ layer

Layers of the Dermis  Papillary layer _____________________ tissue Contains blood vessels, lymphatics, sensory nerves of epidermis  Reticular layer _________________ irregular connective tissue Contains network of collagen and ____________ fibers to resist tension

Stretch Marks  Caused by excessive stretching of the ___________________  Patterns of ___________________ and elastic fibers form lines of cleavage

Lines of Cleavage of the Skin Figure 5.7

Hypodermis (subcutaneous)  Elastic areolar tissue and ___________________ tissue  Stabilizes skins position against underlying organs and tissues  Shock absorber and ___________________  Few capillaries and no vital organs  Subcutaneous injection is useful to administer drugs

Structures  Hair __________________ Connective tissue containing capillaries and _________________  _______________ Anchors hair into skin  Shaft Part we see on the surface Consists of three layers ○ __________________- overlapping shingle layer ○ ____________________- underlying layer- pigments ○ _______________________- core of hair

Structures Contd.  Sebaceous Glands Also called holocrine glands Associated with __________________________ Discharge oily substance into hair follicles (waterproofs and moisturizes the hair shafts) Inhibits growth of _______________________ Activated at puberty  ____________________________ muscle Pulls on follicle, forcing the hair to stand up Cold or emotional states- goosebumps

Anatomy of a Single Hair Figure 5.9

Hair Follicles and Hair

Hair Follicles Figure 5.10a-c

Hair

Hairs  Individual hairs develop from cells at the base of the hair follicle, an invagination of the lower _____________________ that dips down into the ____________________.  As new cells are formed, old cells are pushed outward and become _____________________, forming the hair shaft.  Project deep into the dermis and often into the hypodermis

Hair Color  Melanin produced by ____________________ at the hair papilla  Red hair also contains the pigment trichosiderin  Determined by ___________________

Function of Hair  Head Protection from ______________________ Cushion a light blow to head Insulation  Nostrils, ears, and eyes Prevent entry of _______________________  Sensory Sensory _______________________ at base of every hair

Appendages of the Skin

Exocrine Glands- Reach Outside  Sebaceous glands (Oil glands) Associated with hair Secrete ____________________, which lubricates and inhibits bacteria growth ______________- condition when they are clogged  Sweat glands (Watery Glands) 2 kinds ○ Ecrine: __________________________ ○ Apocrine: _______________________

Sweat Glands  Eccrine – respond to body ______________________; open via duct to pore on skin surface  Apocrine – responds to body temperature, ___________________; ducts empty into hair follicles  Ceruminous glands – modified sweat glands that secrete ___________ in the ear canal  Mammary glands – modified type of sweat glands that secrete ________________

Sebaceous Glands and Hair Figure 5.11

Sweat Glands

Figure 5.12 Sweat Glands Figure 5.12a, b

Sweat and Its Function  Composition: Mostly _________________ ______________________ and vitamin C Some metabolic waste Fatty acids and __________________ (apocrine only)  Function: Helps dissipate excess ____________ Excretes _________________ products Acidic nature inhibits bacteria growth  Odor is from associated bacteria

Regulation of body temperature  Heat may be lost to surroundings from the skin.  Body responds to excessive heat by __________________ of dermal blood vessels and sweating.  Body responds to excessive cooling by ______________________ dermal blood vessels, inactivation sweat glands and shivering.

Nails  ___________________ cells that protects the tips of fingers and toes  ________________________________ overlying the nail bed _________________ is the most actively growing region of the nail root

Structures  Nail Body Covers an area of the epidermis called the ______________________  Nail ____________ Where nail production occurs Not visible on surface  Cuticle Portion of ________________________ ___________________________

Structure Contd.  _________________ Pale crescent area near the root were ___________________________________ are absent

Figure 5.13 The Structure of a Nail Figure 5.13

Loss of Homeostasis in Skin

Skin Homeostatic Imablance  Infections Athlete’s foot (tinea pedis) – _______________ infection Boils and carbuncles – ___________________ infection Cold sores – caused by ________________

Skin Homeostatic Imbalance

Skin Homeostatic Imabalance  _________________ Tissue damage and cell death caused by heat, electricity, _____________________, or chemicals Associated dangers ○ ________________________________ ○ Electrolyte imbalance ○ Circulatory shock

Severity of Burns  First-degree burns Only ___________________________ is damaged Skin is red and swollen  Second-degree burns Epidermis and ________________________ are damaged Skin is red with blisters  Third-degree burns Destroys ______________________________ Burn is gray-white or black

Severity of Burns

Critical Burns  Burns are considered critical if Over ___________ of the body has second-degree burns Over ___________ of the body has third- degree burns There are third-degree burns on the _________________, ________________, or __________________

Healing of Wounds  _______________________________ – blood vessels dilate and become more permeable Causes tissues to become red and _________________ This is the body’s normal response to injury  Superficial cuts are filled in by reproducing ______________________________________  Deeper cuts are closed off by ________________, covered by scabs and eventually filled in by fibroblasts, making connective tissue.  Blood vessels extend into the area, the injured tissues are replaced, and the scab falls off.  Large wounds leave _______________________ and healing may be accompanied by the formation of granulations.

Skin Cancer  _____________________ – unregulated mitotic cell division producing abnormal mass  Classified in two ways _____________________ – does not spread _____________________ – metastasized (moves) to other parts of the body  Skin cancer is the most common type of cancer!!

Basal Cell Carcinoma  Least _______________________  Most _______________________ type  Arises from stratum basale

Squamous Cell Carcinoma  Metastasizes to __________________________ if not removed  Early removal allows a good chance of cure  Believed to be __________________________  Arises from stratum spinosum

Malignant melanoma  Most deadly of skin cancers  Cancer of melanocytes  Metastasizes rapidly to ____________ and blood vessels  Detection uses ABCD rule

ABCD rule  A = ________________________ Two sides of pigmented mole do not match  B = ________________________________ Borders of mole are not smooth  C = _______________ Different colors in pigmented area  D = ________________________ Spot is lager than 6 mm in diameter

The Skeletal System  provides structural support The Integumentary System synthesizes vitamin D 3, essential for calcium and phosphorus absorption (bone maintenance and growth) Copyright © 2010 Pearson Education, Inc.

The Muscular System The Muscular System’s facial muscles pull against skin of face, producing expressions important in communication The Integumentary System synthesizes vitamin D 3, essential for normal calcium absorption (calcium ions play an essential role in muscle contraction) Copyright © 2010 Pearson Education, Inc.

The Nervous System The Nervous System controls blood flow and sweat gland activity for thermoregulation; stimulates contraction of arrector pili muscles to elevate hairs The Intergumentary System’s receptors in dermis and deep epidermis provide sensations of touch, pressure, vibration, temperature, and pain Copyright © 2010 Pearson Education, Inc.

The Endocrine System The Endocrine System includes the sex hormones that stimulate sebaceous and apocrine gland activity, and develop secondary sexual characteristics; suprarenal hormones alter blood flow to skin and mobilize lipids from fat cells The Integumentary System synthesizes vitamin D 3, precursor of calcitriol, a hormone produced by the kidneys Copyright © 2010 Pearson Education, Inc.

The Cardiovascular System The Cardiovascular System provides oxygen and nutrients; delivers hormones and cells of immune system; carries away carbon dioxide, waste products, and toxins; provides heat to maintain normal skin temperature The Integumentary System’s mast cells produce localized changes in blood flow and capillary permeability Copyright © 2010 Pearson Education, Inc.

The Lymphatic System The Lymphoid System assists in defending the integument by providing additional macrophages and mobilizing lymphocytes The Integumentary System provides physical barriers that prevent pathogen entry; macrophages resist infection; mast cells trigger inflammation and initiate the immune reponse Copyright © 2010 Pearson Education, Inc.

The Respiratory System The Respiratory System provides oxygen and eliminates carbon dioxide The Integumentary System’s hairs guard entrance to nasal cavity Copyright © 2010 Pearson Education, Inc.

The Digestive System The Digestive System Provides nutrients for all cells and lipids for storage by adipocytes The Integumentary System synthesizes vitamin D 3, needed for absorption of calcium and phosphorus Copyright © 2010 Pearson Education, Inc.

The Urinary System The Urinary System excretes waste products, maintains normal body fluid pH and ion composition The Integumentary System assists in elimination of water and solutes; keratinized epidermis limits fluid loss through skin Copyright © 2010 Pearson Education, Inc.