Chapter 5 Integumentary

Integumentary system consists of: (5)

1. Skin

2. Hair

3. Nails

4. Sweat glands

5. Sebaceous (oil) glands

What is the largest organ in the body.

SKIN (cutaneous Membrane or integument)

The SKIN has 2 major layers what are they?

Dermis and Epidermis

What type of layer skin is this?

superficial region

 Consists of epithelial tissue and is avascular

Epidermis

What type of layer is this?

underlies epidermis

 Mostly fibrous connective tissue and its vascular

Dermis

Name the part?

Subcutaneous layer deep to skin

• Not part of skin but shares some functions

• Mostly adipose tissue that absorbs shock and insulates

• Anchors skin to underlying structures: mostly muscles

Hypodermis (superficial fascia)

Name each Part of the SKIN

Define.

consists mostly of keratinized stratified squamous epithelium. It is the outer, thinner region of the skin.

Epidermis

[4] cell types found in EPIDERMIS

1. Keratinocytes

2. Melanocytes

3.Dendritic (Langerhans) cell

4. Tactile (Merkel) cells

Name the Cell type of Epidermis

 Produce fibrous keratin (protein that gives skin its protective properties)

 Major cells of epidermis

 Tightly connected by desmosomes

 Millions slough off every day

Keratinocytes

Name the Cell type of Epidermis

 Spider-shaped cells located in deepest epidermis

 Produce pigment melanin, which is packaged into melanosomes

– Melanosomes are transferred to keratinocytes, where they protect nucleus from UV damage

Melanocytes

Name the Cell type of Epidermis

Star-shaped macrophages that patrol deep epidermis

Are key activators of immune system

Dendritic (Langerhans) cells

Name the Cell type of Epidermis

sensory receptors that sense touch

Tactile (Merkel) cells

Epidermis is made up of 4 or 5 distinct layers. Name them from DEEPEST to the SUPERIOR

1. Stratum basale

2. Stratum spinosum

3. Stratum granulosum

4. Stratum lucidum (only in thick skin)

5. Stratum corneum

Name the epidermis Layer

– Deepest of all epidermal layers (base layer)

– Layer that is firmly attached to dermis

– Consists of a single row of stem cells that actively divide (mitotic),

producing two daughter cells each time

– Layer also known as stratum germinativum because of active mitosis

– 10–25% of layer also composed of melanocytes

Stratum Basale (basal layer)

Name the epidermis Layer

– Several cell layers thick

– Cells contain weblike system of intermediate prekeratin filaments attached to desmosomes

 Allows them to resist tension and pulling

– Keratinocytes in this layer appear spikey, so they are called prickle cells

– Scattered among keratinocytes are abundant melanosomes and dendritic cells

Stratum spinosum (prickly layer)

Name the epidermis Layer

– Four to six cells thick, but cells are flattened, so layer is thin

– Cell appearance changes

 Cells flatten, nuclei and organelles disintegrate

 Keratinization begins

 Cells also accumulate lamellar granules, a water-resistant glycolipid that slows water loss

– Cells above this layer die

 Too far from dermal capillaries to survive

Stratum granulosum (granular layer)

Name the epidermis Layer

– Found only in thick skin

– Consists of thin, translucent band of two to three rows of clear, flat, dead keratinocytes

– Lies superficial to the stratum granulosum

Stratum lucidum (clear layer)

Name the epidermis Layer

– 20–30 rows of flat, anucleated, keratinized dead cells

– Accounts for three-quarters of epidermal thickness

– Though dead, cells still function to:

 Protect deeper cells from the environment

 Prevent water loss

 Protect from abrasion and penetration

 Act as a barrier against biological, chemical, and physical assaults

Stratum corneum (horny layer)

Cells change by going through ___________ (controlled cell death)

Dead cells slough off as dandruff and dander

Humans can shed ~50,000 cells every minute

APOPTOSIS

Name each one of them

What is the dermis? What does the dermis have?

Strong, flexible connective tissue

• Contains nerves, blood vessels,

and lymphatic vessels

• Contains epidermal hair follicles,

oil glands, and sweat gland

The dermis has only 2 layers. Name them.

• Papillary

• Reticular

Where is the papillary layer?

Superficial layer of areolar connective tissue consisting of loose, interlacing collagen and

elastic fibers and blood vessel

What is Dermal papillae layer function?

superficial region of dermis that sends fingerlike projections up into epidermis. It helps so that the 2 types of tissue (Connective and epithelial) stick together

What does Fingerprints consist of? Whats its main function?

• Friction ridges

• Enhance gripping ability

Dermis Reticular

• How many percent does it make up dermis thickness?

• 80%

Dermis Reticular layer:

What does it consist of?

Dense Fibrous connective tissue

Dermis reticular layer:

Define Cutaneous plexus

network of blood vessels between reticular layer and hypodermis

Define Cleavage Lines

Represent separations between underlying collagen fiber bundles in the reticular dermis.(used for surgical incisions)

Flexure Lines what does it contain? Where is it? Function?

Reticular, Palm of hands, to grip

Name [3] pigments contribute to skin color

• MELANIN

• CAROTENE

• HEMOGLOBIN

Name the pigment of skin

Does not make it in skin

Yellow to orange pigment

 Most obvious in palms and soles

 Accumulates in stratum corneum and hypodermis

 Can be converted to vitamin A for vision and epidermal health

Contributes to what you eat like tomatoes, carrots etc.

Carotene

Name the pigment of skin

 Made from amino acid tyrosine by tyrosinase

 Packaged into melanosomes that are sent to shield DNA of keratinocytes from damaging UV sunlight

 The more sun, the more need for protective shield, the more melanin will be produced

 Two forms: reddish yellow to brownish black

 Skin color differences are due to amount it receives

 Freckles and pigmented moles are local accumulations of melanin

Only pigment made in skin; made by melanocytes

Melanin

Name the pigment of skin.

Pinkish hue of fair skin is due to lower levels of melanin

– Skin of Caucasians is more transparent, so color of hemoglobin shows through

Pinkish blush on cheeks

HEMOGLOBIN

What can Sun damage do to skin? (4)

• Elastic fibers clump, causing skin to become leathery

• Can depress immune system and cause alterations in DNA that may lead to skin cancer

• UV light destroys folic acid

• Photosensitivity is increased reaction to sun

Some drugs (e.g., antibiotics, antihistamines) and perfumes

cause photosensitivity, leading to skin rashes

Alterations in Skin Color

Define: Cyanosis

Blue skin color: low oxygenation of hemoglobin

Alterations in Skin Color

Define Pallor:

Anemia, low blood pressure, fear, anger (Pale)

Alterations in Skin Color

Define: Erythema

Fever, hypertension, inflammation, allergy (redness)

Alterations in Skin Color

Define: Jaundice

Liver disorders (yellow)

Alterations in Skin Color

Define Bruises:

• Also referred to as ecchymoses or hematomas, are a result of clotted blood beneath skin

• As clot is broken down, color of bruise change

Alterations in Skin Color

Define Brown or black “necklace” or bruises

Hyperpigmented dark areas in axillae and around neck may be

a sign of insulin resistance and elevated blood glucose levels

What does hair consist of?

Consist of dead keratinized cells

Hair Function?

1. Warn of insects on skin

2. Hair on head guards against physical trauma

3. Protect from heat loss

4. Shield skin from sunlight

Hair structural regions

Shaft:

Root:

explain what they do

1. Shaft: area that extends above scalp, where keratinization is complete

2. Root: area within scalp, where keratinization is still going on

3 parts of hair shaft name them

1. Medulla: central core of large cells and air spaces

2. Cortex: several layers of flattened cells surrounding medulla

3. Cuticle: outer layer consisting of overlapping layers of single cells

What are Vellus hair?

The hairs of a new born body and found on adults

What is Terminal hair?

Coarse, long hair.

• Found on scalp and eyebrows

• At puberty

 Appear in axillary and pubic regions of both sexes

 Also on face and neck of male

Nutrition and hormones affect hair growth

ALOCPECIA meaning

hair thinning in both sexes after age 4

TELOGEN EFFLUVIUM meaning?

abrupt hair thinning caused by an abundance of hair follicles entering resting phase at same time (aggressive thinning)

Nail Function

• Scale-like modifications of epidermis that contain hard keratin

• Act as a protective cover for distal, dorsal surface of fingers and toes

• Consist of free edge, nail plate, and root

Nail bed location

Underneath the nail plate

Nail Matrix function

Responsible for nail growth

Nail folds location

THe part where the nail folds at the border of nail

Eponychium location

Its the cuticle the little light pink area of nail.

Hyponychium Location

The part of the nail that you clean or cut

Sweat Glands 2 main types

1. Eccrine (merocrine) sweat glands

2. Apocrine sweat glands

On sweat glands

what are Myoepithelial cells?

Contract upon nervous system stimulation to force sweat into ducts

What are eccrine sweat glands?

Most numerous type they are in pams, soles, forehead, open to the surface of the skin

Thermoregulation

ECCRINE Sweat Glands Secretion is what?

Sweat

• 99% water, salts, vitamin C, antibodies, dermcidin (microbe-killing

  peptide), metabolic wastes

  
  

What are Apocrine sweat glands?

• Open into hair follicles

• Armpits and its the “bio”

• Secrete viscous milky or yellowish sweat that contains fatty substances and

  protein

MODIFIED APOCRINE GLANDS are? and explain

• Ceruminous glands: secrete cerumen (earwax)

• Mammary glands: secrete milk

  
  

Define Acne

usually an infectious inflammation of the sebaceous glands,

resulting in pimples (pustules or cyst

Define WHITEHEADS

are blocked sebaceous glands

– If secretion is oxidized, whitehead becomes a blackhead (stuff on top of nose)

Name functions of skin (6)

Protection

2. Body temperature regulation

3. Cutaneous sensations

4. Metabolic functions

5. Blood reservoir

6. Excretion of waste

The Skin FUNCTION of PROTECTION

Constitutes 3 barriers

• Chemical barrier

• Physical barrier

• Biological barrier

Name each of their function on what they help specialize the skin

• Chemical barrier -Skin secretes many chemicals like sweat. sebum, defensins (bacteria killer) Melanin provides a chemical barrier against UV radiation damage

• Physical barrier- Flat, dead, keratinized cells of stratum corneum, surrounded by

  glycolipids, block most water and water-soluble substances

• Biological barriers- Epidermis contains phagocytic cells

Dermis contains macrophages cells

Both activate when a invader enters and tells on immune system.

The skin FUNCTION BODY TEMPERATURE REGULATION

What is insensible perspiration?

What is sensible perspiration?

• Under normal, resting body temperature, sweat glands produce about 500 ml/day

of unnoticeable sweat

• If body temperature rises, dilation of dermal vessels can increase sweat gland

  activity to produce 12 L (3 gallons) of noticeable sweat designed to cool body

Skin Function of CUTANEOUS SENSATIONS

What part of the body system is it located?

Nervous system

Skin function of METABOLIC FUNCTION

Skin can synthesize what vitamin?

Keratinocytes can activate all/ some/ no homromones? Which?

• Vitamin D

• Activate some hormones

Skin