Unit 2 Chapter 5 in Textbook · 2018. 8. 15. · Dermis 2 Layers: 2. Reticular layer- connects to hypodermis a.Sudoriferous & sebaceous glands, arrector pili muscle, nerves, blood

Integumentary System

Unit 2Chapter 5 in Textbook

https://www.youtube.com/watch?v=fXIcwm1oqQw

Integumentary- made up of

• Skin (epidermis, dermis, hypodermis)

• Hair• Nails• Glands(sudoriferous

, sebaceous, ceruminous

https://www.youtube.com/watch?v=AhbPPd-YeiU

8 Main Functions

1. Protection2. Sensation3. Excretion of wastes4. Synthesis of Vitamin D in sunlight5. Temperature regulation6. Coloration7. Waterproof8. Growth and repair

Skin Structure

3 MAIN Layers:1.Epidermis

a.Outer layerb.Stratified squamous tissue

2.Dermisa.Middle layerb.Thickest

3.Hypodermis (subcutaneous)a.Bottom layerb.Adipose tissue

http://science.nationalgeographic.com/science/health-and-human-body/human-body/skin-article/

Epidermis

➢Outermost layer

➢Made of keratinized

stratified squamous

tissue, so it:

● Many flattened

layers (mostly

dead)

● Lacks blood

vessels

Epidermis

➢There are 5 distinct

layers (deepest to

superficial)

● Stratum basale

● Stratum spinosum

● Stratum

granulosum

● Stratum lucidum*

● Stratum corneum

Epidermis

Stratum basaleDeepest layer- directly above the basement

membrane

Cells Types

Merkel Cells- function as touch

receptors in association with

sensory nerve endings

Epidermis

Stratum basaleMelanocytes-

produce the

brown pigment

melanin

Keratinocytes-

produce the

strong protein

keratin.

Simple cuboidal

Cells undergo mitosis here

Epidermis

Stratum spinosumLayers of rounded cells

with large nuclei

Cell types:

Langerhans’ cells-

macrophages that

help activate the

immune system

response

Epidermis

Stratum granulosum3-5 layers of flattened

granular cells

Keratinization process

here→ the process of

cells formed in the

stratum basale moving

up, flattening, dying,

and becoming hard

and waterproof

Epidermis

Stratum lucidum**Translucent layer**Only found in:

palms of hands & soles of feet

Not shown in textbook

Stratum corneumSuperficial layerDead, keratinized cells

Epidermis

Dermis

Dermis

2 Layers:1.Papillary layer-

connects to stratum basale

a.Dermal ridges-

allow us to grip

things

b.Creates

fingerprints & toe

prints

c.Loose areolar

connective tissue

Dermis

2 Layers:2. Reticular layer- connects to hypodermis

a.Sudoriferous & sebaceous glands, arrector pili muscle, nerves, blood vessels, & sensory receptors

b.Contains:i. Collagenous fibers: provide strength

ii.Elastic fibers: provide elasticity

iii.Reticular fibers: provide resilience

Hypodermis

AKA. Subcutaneous (Sub-Q)

Beneath the dermis

Made of adipose tissue

Insulation, protection, cushion

Accessory Organs

Accessory Organs

Hair

● Shaft: visible part of the

hair

○ Medulla: inner core of

the hair

○ Cortex: layer covering

medulla

○ Cuticle: Superficial

portion of hair

● Root: in dermis

Accessory Organs

NailsTightly packed, hardened, keratinized cells

Functions = manipulation and protectionMain parts:

nail plate cuticlelunulanail bed

Accessory Organs

Sudoriferous (sweat) Glands- 2 types

1.Eccrine-

a.most common

b.mainly in forehead, palms, & soles.

c.These function right at birth. -no odor in secretion (water plus salts)

2.Apocrine-

a.Mainly in armpits, groin, ear canals & breasts.

b.Begin to function at puberty.

Cermunious- secrete cerumen (ear wax)

Mammary- secretes milk in lactating females

Accessory Organs

Sudoriferous (sweat) Glands- 2 types

1.Eccrine-

a.most common

b.mainly in forehead, palms, & soles.

c.These function right at birth. -no odor in secretion (water plus salts)

2.Apocrine-

a.Mainly in armpits, groin, ear canals & breasts.

b.Begin to function at puberty.

Cermunious- secrete cerumen (ear wax)

Mammary- secretes milk in lactating females

Accessory Organs

Sebaceous (oil) GlandsConnected to every hair follicleSecrete sebum (oil) (keeps skin and hair

soft)Contains lysozyme-kills bacteria

Accessory Organs

Cutaneous Sensation1. Light touch detection:

a.Meissner’s

Corpuscles-located in

dermal papillae of

dermis

2. Pressure detection:a.Pacinian Corpuscles-

located deep in dermis

and subcutaneous

regions

Skin Color

1.Melanin- brown shadesa.Produced by melanocytesb.Same # in all races- just

darker skin have more active melanocytes

c.Determined by genetics (sun can play a small factor)

d.Albinism- lack enzyme tyrosinase which prevents melanocytes from being active

Freckles & moles – result from local

accumulations of melanin

https://www.youtube.com/watch?v=WwcVvrmALsI

Skin Color

2. Hemoglobin-reddish pigment responsible for the pinkish hue of the skin (protein found on red blood cells)

https://www.youtube.com/watch?v=WwcVvrmALsI

Body Temperature Regulation

Skin regulates temperature through blood vessels & sweating

Cold-muscles shiver and blood vessels constrict to increase body heat

Warm-vessels dilate increasing blood flow to skin which turns into sweating to release heat through evaporation

Wound Healing

1.Hemostasis- stop bleeding with clot

a.clot forms by constricting blood vessels

b.platelets come in to form “white clot”

c.fibrin threads make a spider-web like network to reinforce the area wounded

2.Inflammation-white blood cells remove bacteria and cellular debris

Wound Healing

3. Proliferation-new cells and fibers are deposited, new blood vessels form4. Remodeling-collagen and elastin fibers, cells no longer needed undergo apoptosis

Let’s Review!

What are the layers of the Epidermis from deep to superficial?

What is a burn?

A burn is a damage caused by the

intense heat

Chemical burns

Electricity

Radiation

Severe Burns Cause Immediate threat to life due to:

Dehydration and Electrolyte imbalance.

Can lead to renal shutdown and circulatory shock.

Burns

Concerns with burns:1.Heat loss- no barrier2.Fluid loss- no barrier3.Infection- open wounds

Burns

Evaluated by:1.% of body surface area burned2.Depth of burn

Burns

Estimating % of body surface area burned:

RULE OF 9’s (pg 167)11 areas of 9%=99%Genital is 1%Total area burned is

compared to the diagram to calculate a %

Must memorize

What type of Burns

1st Degree Burns

(typical sunburn)a.reddening of

skinb.may peelc.no blisteringd.“partial-

thickness

2nd Degree Burns

deep epidermis & upper dermis

- damage to sudoriferous & sebaceous glands, and hair follicles

2nd Degree Burns

- blisters, severe pain, & edema

scarring is common“partial-thickness

Third degree burn

Destruction of epidermis & entire dermistissue dies.May involve muscle or boneno pain due to nerves being burned off“full-thickness” burn

3rd degree Burns

Healing process

Skin Grafting Procedure

Life-span changes of integumentary system

http://www.youbeauty.com/skin/aging-skinFibers lose elasticity-causing wrinklesSome melanocytes stop functioning-causes

gray hairSome melanocytes become more active-

causing liver spotsMitosis of skin cells slows down-healing takes

longerHair & nails take longer to grow due to dehydration