The Integumentary The Integumentary SystemSystem

I. The Integumentary System - Epidermis, Dermis, I. The Integumentary System - Epidermis, Dermis, HypodermisHypodermis

Major functions of the skinMajor functions of the skin

1. 1. ProtectionProtection – –

2. 2. Regulation of body temperatureRegulation of body temperature – –

3. 3. Sensation –Sensation –

4. 4. Excretion of waste –Excretion of waste –

5. 5. Vitamin D Production - Vitamin D Production - when exposed to , when exposed to , helps with the absorption of calcium (bone growth)helps with the absorption of calcium (bone growth)..

II. Hypodermis

A. Lies to the skin, but is not apart of the layers of skin.

B. Attached to underlying bone & muscle.

C. Supplied with blood & nerve.

D. Composed of1. 2.

E. Stores half of your body fat.1. 2.

The SkinThe SkinMade up of two parts.Made up of two parts.

1. – structure & strength1. – structure & strength

2. – prevent water loss & 2. – prevent water loss & abrasionabrasion

II. DermisA. Composed of that contain a large supply

1. Dense collagenous connective tissue.

2.

B. – fibers are arranged in a parallel direction for greater resistance to stretching.

1. – cut across the tensions lines, more scare tissue.

2. (striae) – overstretching of the dermis.

C. Holds the accessory organs of the integumentary system.

D. Divided into areas

1. Papillary region a. upper part of dermis, contains .b. the lower part of the , removal of wastes, and temperature regulation.c. – projections upward

1 the connection between the 2 areas.

d. – extended papillae into the epidermis & effects the contour to form friction ridges, help the hand & foot grasp by increasing friction.

2. - Deeper thicker

area.

a. Composed of dense irregular tissue.

b. Strengthens, extensibility, &

elasticity by using protein fibers, elastic, collagenous fibers.

c. Wrinkles that accompany &

are a result of a change in the production or quality of these protein.

III. Epidermis – 40-56 days for cells to be replacedIII. Epidermis – 40-56 days for cells to be replaced

••Region of stratified squamous epithelium that is continuously Region of stratified squamous epithelium that is continuously replaced.replaced.••Water Proof.Water Proof.••Protective wrap around the body.Protective wrap around the body.

A. Layers(strata) of the Epidermis.A. Layers(strata) of the Epidermis.1. 1. deepestdeepest

1 layer of columnar cells1 layer of columnar cellslots of nourishmentlots of nourishment

2. 2. multiple layer of cuboidal cellsmultiple layer of cuboidal cellsNuclei are Nuclei are pyknosispyknosis state of death state of death

3. 3. 3-5 layers of partially flatten cells 3-5 layers of partially flatten cells that that contain granule, granules contain contain granule, granules contain protein protein (keratin)(keratin)

4. 4. - - present only in the thick skin of present only in the thick skin of the palms the palms and soles. and soles.

3-4 rows of flatten dead 3-4 rows of flatten dead transparent transparent “ghost” “ghost” cellscells

5. 5. - - Most superficial layer 25-50 rows Most superficial layer 25-50 rows of of flatten, flatten, dead cells - Wear & Teardead cells - Wear & Tear

Joined by desmosomes, that Joined by desmosomes, that eventually eventually breaks off and the skin breaks off and the skin falls off.falls off.

The EpidermisThe Epidermis

B. ProblemsB. Problems

1. 1.

2. 2.

3. 3.

C. Skin color of the epidermisC. Skin color of the epidermis

1. Determined by melanocytes 1. Determined by melanocytes

a. Cells that lie between cells on the stratum a. Cells that lie between cells on the stratum basale and produce melanin basale and produce melanin

(pigment).(pigment).

b. The golgi apparatus packages the melanin in b. The golgi apparatus packages the melanin in vesicles called melanosomes.vesicles called melanosomes.

c. The packages move out of the cells to c. The packages move out of the cells to neighboring neighboring cells and between them.cells and between them.

d. All humans have the about the same d. All humans have the about the same amount of amount of melanocyte, what causes differences melanocyte, what causes differences in skin color?in skin color?

e. Amount of melanin produced, causes of e. Amount of melanin produced, causes of skin skin color UV light triggers melanocyte to color UV light triggers melanocyte to produce produce melanin - tanmelanin - tan

f. What benefit is provided by the f. What benefit is provided by the production of production of melanin?melanin?

g. Protects the body from harmful UV light.g. Protects the body from harmful UV light.

d. Disorders of skin pigmentsd. Disorders of skin pigments

1.1. – – lack lack of pigmentof pigment

2.2. – – bluish skin bluish skin pigmentpigment

3.3. – – disorders of disorders of blood vessels at blood vessels at birth.birth.

IV. Accessory OrgansOrgans located within the dermis. Provide a role in protection, communication, & excretion

A. Hair

1. Parts of haira. – extends

through the epidermis.

b. – below the epidermis

c. – base of root

d. – hard outer part

e. – soft inner part

f. – outermost covering

2. Cycles of hair2. Cycles of hair

a. a.

b. b.

exex

eyelashes - eyelashes - grows grows for for days, rests for days, rests for days.days.

scalp – grows for scalp – grows for years & rest for years & rest for . .

B. - Oil glands (sebum)

-Occasionally they can be blocked by dirt or dead cells. - Become plugged or swollen – blackhead

C. Sweat Glands - Function

through out life, watery substance - Sudoriferous -

- During puberty in response to sex hormones

Proteins, which promote the growth of bacteria, which produce odoriferous materials (armpits, & groin)

D. Receptors -

Accessory Organs

NailsE. Nails -

flap of stratum corneum that overlies the

proximal edge of the nail

active stratum basale - nail matrix

light color crescent - sign of calcium

deficiency

V. Homeostasis - Temperature Regulation

Good health - 37C +/- 1CProper function of enzymesMovement of moleculesChemical reactions

A. Integumentary System helps to Maintain Body TemperatureHot

Receptors in the skin external temperature which relay’s information

to the brain.

Brain

Sweat glands to secretion

Blood vessels dilate or relax which blood flow to the skin

Carries heat to the skin which is removed from the body by evaporation.

Breathe to exhale heat

Heart beats to move more blood to the skin to remove heat faster.

Cold

Goose bumps, arrector muscles contract

Skeletal muscle slightly

Blood vessels slightly

volume of warm blood to the skin, therefore reducing heat lose by the skin

Temperature Regulation

B. Skin Repair

Skin damage

Bleeding

- increase blood flow to damage area.1. Remove

2. Promote - clotting, scabs, temporary barrier.

a. minor cut - are produced and migrate there.

b. Major - large number of are present - scar ( )

Skin Repair – –new cells are new cells are

the same as the ones lost.the same as the ones lost.

– – new tissue new tissue develops leaving a scar and develops leaving a scar and has los some function.has los some function.

– – do not divide do not divide after growth stops, but can after growth stops, but can grow if there is an injury.grow if there is an injury.

– – little or no little or no dividing ability.dividing ability.

- fibers to stop the - fibers to stop the bleedingbleeding

– – a dried clota dried clot

– – revascularize area revascularize area under the scab (small under the scab (small wounds).wounds).

– – (large wounds)(large wounds)

Skin RepairSkin Repair

VI. Skin Disease

A. - Pimples

B. - Bacteria infection of a hair follicle - abscess

Can spread to other tissue if not treated with antibiotics.

C. - Metabolic disease because it effects a metabolic balance that the cells must maintain.

Fatal - 50% or more is burned3 types

– epidermis ( week to heal)

- epidermis & dermis ( weeks to heal)

- completely damage in the epidermis, dermis, & hypodermis,

including all accessory organs.

Cannot regenerate itself - grafting.

Burns, Partial & full –Burns, Partial & full –thickness burnsthickness burns

D. - Fungus - athletes foot, jock itch.

E. - Virus

F. - Disease from the formation of a groups of cells with NO function.

- (non invasive) freckles, moles

- - cancer

G. - Virus- Contagious-Reoccurring outbreaks

H. - Shingles-Similar to herpes-forms from chicken pox-common in people over 50- along a nerve usually in trunk region

I. -Congenital disease - 3% - 4%

-Small round skin elevation that are covered with flaky

skin- Flare Ups

J. - Infestation of parasites

- lice, tick, crabs, spiders, insects

K. - Inflammation of the dermis

- redness, swelling, vesicles- secondary infections - bacteria

L. Skin CancerL. Skin CancerToo may Too may overwhelm the function of overwhelm the function of melanin resulting in melanin resulting in sunburn or mutation in sunburn or mutation in which may lead to which may lead to skin cancer.skin cancer.

a.a. carcinoma–carcinoma– invasive invasive cancer.cancer. Common in fair skin Common in fair skin

individuals.individuals. Lesions that grow Lesions that grow

rapidly ½ cm per rapidly ½ cm per week.week.

Red hard nodules Red hard nodules break opening after break opening after forming.forming.

Treated by surgical Treated by surgical removal or X-ray removal or X-ray radiation.radiation.

b. carcinomab. carcinoma

Tumors arise from Tumors arise from the cells from the the cells from the layer.layer.

Grows slowly 1 -2 Grows slowly 1 -2 cm/yr.cm/yr.

Red waxy nodules in Red waxy nodules in the skin.the skin.

May cause lesion in May cause lesion in organs under the organs under the skin if left skin if left untreated.untreated.

Excision is the Excision is the treatment.treatment.

c. - c. - Most life threatening.Most life threatening.

Tumor arises from Tumor arises from melanocyte in the melanocyte in the

basal basal layer.layer.

May appear to be May appear to be discolored, tender, discolored, tender,

or a or a small nodule.small nodule.

Starts as a small Starts as a small mole mole that bleeds easily that bleeds easily to to injury.injury.

Spreads quickly to Spreads quickly to nearby lymphs nearby lymphs

nodes nodes then vital organsthen vital organs

4,000 die each year4,000 die each year Since 1973 there Since 1973 there

has been an average has been an average of a - 4% increase in of a - 4% increase in cases per yearcases per year

30,000 new cases a 30,000 new cases a yearyear

Treatment is only effective Treatment is only effective if the cancer is detected if the cancer is detected early - widespread X-ray early - widespread X-ray radiationradiation

Malignant MelanomaMalignant Melanoma

IX. Determining Your Skin IX. Determining Your Skin Surface AreaSurface Area

[(height in inches x weight in lbs)/3131][(height in inches x weight in lbs)/3131].5.5

Average is 2mAverage is 2m22

Your answer X 10.7639104 ft2Your answer X 10.7639104 ft2

Source: Mosteller 1987Source: Mosteller 1987