The Integumentary System

Stephanie ChildsJean-Philippe DionValancy Miranda

Genevieve Perreault-Murphy

Anatomy and Physiology of the Skin

Epidermis

Dermis

Hypodermis/Subcutaneous Layer

The Skin

EpidermisProtects, senses, insulates, and regulates temperature

• Stratum Granulosum

• Stratum Corneum

• Stratum Spinosum

• Stratum Basale

Consists of dead cells

Stratified squamous

Langerhans’ cells function in defense

Columnar cellsMerkel’s cells function in sensation Melanocytes produce melanin (skin shade)

Epidermis

DermisProvides nutrients, removes wastes, protects,

senses• Collagen

• Sweat Glands

• Hair Follicles

• Blood Vessels

• Nerves

Retain waterConnected by elastin fibres

Insulate, protect and regulate temperatureHeld by erector pili musclesOil and scent glands are located near the follicle

Produce sweat

Bring nutrients and O2 to skin, and remove waste Transmit sensory messages to brain

Dermis

Hypodermis/Subcutaneous Layer

• Made mostly of fat and connective tissue

• Insulates

• Cushions

• Connects skin tissue to surrounding tissues

The Human Fingernail

Cross-section of Human Hair

How the System Contributes to the Overall Well-Being of the

Organism

Protection

Homeostasis

Sensory Functions

Secretion

Protection:Provides a barrier against

potentially harmful agents • Nails protect the tips of fingers and

toes

• The skin serves as a barrier

• Melanocytes protect the skin by providing its colour

Nail Bed

Homeostasis:Preserving the Internal &

External Environments• The skin and hair provide insulation

• The skin cells synthesize melanin and carotenes, which give the skin its colour• The skin assists in the synthesis of vitamins• The skin serves as a selectively permeable membrane, allowing the passage of certain substances to the bloodstream

Sensory Functions:Provides information and

responds to various stimuli • The skin houses many types of sensory

receptors called cutaneous receptors

• Include phasic receptors (hair follicle receptors and Meissner’s corpuscles) and tonic receptors (Ruffini endings and touch dome endings)

• Pacinian corpuscles are sensitive to pressure

Sensory Receptors in the Skin

Secretion:Secretes Chemicals and

Sweat• The skin protects the body by

secreting chemicals on its surface

• The skin’s pH is acidic (3 to 5), which inhibits the growth of many microorganisms, due to oil and sweat glands• Sweat secretions also include the enzyme lysozyme, which digests bacterial cell walls

Sweat Gland (Secretory Portion)

Diseases Affecting the Integumentary

System

Skin Cancer

Acne

Rosacea

Psoriasis

Alopecia Areata

Eczema

Skin Cancer• Melanoma

• Basal Cell Carcinoma

• Squamous Cell Carcinoma

It affects the melanocytes (cells that give skin its colour)

Signs can be moles that appear and grow in size

Affects the basal cells located in the epidermis

A type of skin cancer arising in squamous cells (flat cells on surface of skin)

Melanoma

Basal Cell Carcinoma

Squamous Cell Carcinoma

Acne• Acne refers to plugged pores, pimples

and even deeper lumps that can occur on the face, neck, chest, back and shoulders

• Types of acne include Comedo, Papule, Macule and Cyst

• Acne can be treated by:

Reducing sebum production in the skin

Reducing P. acnes (acne bacteria)

Normalizing the shedding of skin cells

Acne

Psoriasis• A chronic, genetic, non-contagious disorder

that can affect the skin, nails or scalp

Plaque Psoriasis 

     Pustular Psoriasis

Erythrodermic Psoriasis

Gutate Psoriasis

• Types of Psoriasis include:

Psoriasis

Alopecia Areata Inflammatory, hair loss disease that

can affect men, women and children

Possibly an autoimmune disease where an individual’s own immune system prevents hair follicles from producing hair fibres

There are several other factors that may affect the onset of alopecia

Alopecia Areata

Eczema It seems to be linked to an abnormal response of the

body’s immune system. The inflammatory skin response to irritating substances is overactive.

Usually characterized by dry, red and itchy patches on the skin

New drugs known as Topical immunomodulators can be used to modulate the responses of the immune system to different irritating substances

Eczema

Rosacea A chronic disease that causes redness and

swelling, primarily of the face

Some scientists believe that heredity is what causes the blood vessels in the face to dilate

Another theory is that a mite known as Demodex folliculorum lives in the hair follicles and could be the cause of rosacea

Rosacea

Comparative Anatomy of the Integumentary System

All Vertebrates

Mammals

Other Vertebrates

Arthropods

All Vertebrates Share…

• Two basic layers, the dermis and epidermis

• Structures such as hair and feather follicles

found in the dermis

Mammals

• Some kind of hair covering their bodies

• Some non-human structures present

in other mammals

Horns Antlers

Comparison of Horn and Antler

Claws

Nails

Hoofs

Comparison of Claws, Hoofs and Nails

Amphibian

Bony Fish

Birds

Comparison of Other Vertebrates

• Amphibians

• Birds (Class Aves)

• Bony Fish

Skin is smooth, moist, loosely attached to underlying muscles

No scales, hair or sweat glands – instead mucous glands in the upper dermis

Recovered by a coat of mucous to prevent infections Layers which compose scales

Feather types: flight, down, contour, filoplumes Scales similar to reptiles on legs and feet

Arthropods• Exoskeleton made primarily of chitin

• Most important layer of the exoskeleton is the cuticle

• Crustacean organisms tend to have large deposits of calcium carbonate, whereas many terrestrial organisms lack a waterproof lipid layer

The Arthropod Integument

Works Cited“Comparative Anatomy - Topic 6: The Integument” from the Auburn University

website. http://www.auburn.edu/academic/classes/zy/0301/Topic6/Topic6.html Last updated Feb. 12 2002, Accessed April 14 2004.

 Johnson, Laubengayer Cole and DeLanney. Biology, Third edition. Holt Rinehart and

Winston. New York: 1966. p. 359  Winchester, A.M. Biology and its Relation to Mankind, Fourth Edition. Van Nostrand

Reinhold company. New York: 1969. p. 449-452.  Farb, Peter. “The Insects” from the Life Nature Library. Time inc. New York: 1962.p.34-35. Hutchison, Rob. “How the Arthropod Skeleton has been exploited in the

Colonization of the Land” from Veterinary Entomology. http://www.roberth.u-net.com/ectoskel.htm. Last Update: July 11 1998. Accessed April 18, 2004.

Raven, Peter H. & Johnson, George B. Biology, Sixth Edition. McGraw Hill Publishing Company. New York: 2002.

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