The Integumentary System. Integument means covering. Skin and its appendages make up the...

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The Integumentary System

Transcript of The Integumentary System. Integument means covering. Skin and its appendages make up the...

Page 1: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

The Integumentary System

Page 2: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

The Integumentary System

Integument means covering.

Skin and its appendages make up the integument system

It covers about 3,000 square inches of the surface.

It is made up of hair, nails , sebaceous (oil) glands, and Sudoferious (sweat) glands.

Page 3: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

Functions of skinSkin is covering for the underlying, deeper,

tissue , protecting them from dehydrations, injury, and germ invasions.

Skin helps regulate body temperature by controlling the amount of heat loss .Evaporation of the water from the skin , in the form of perspiration, rids the body of excess heat.

Skin helps manufacture vitamin D. The ultra violet light on the skin is necessary for the first stages of vitamin D formation.

Page 4: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

Functions of The Skin Continuation….

Skin is the sight of many nerve endings. A square inch of skin contains about 72 feet of nerves and hundreds of receptors.

Skin has tissues for the temporary storage of fat, glucose, water, and salts such as sodium chloride. Most of the substances are later contained observed and transferred to other parts of the body.

Skin is designed to screen out harmful ultraviolet contained by sunlight.

Skin has special properties to absorb drugs and bad toxins.

Page 5: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

Structure of the Skin

The skin consists of two basic layers:

o The epidermis or outermost or outermost covering made of epithelial cells with no blood vessels present

o The dermis or true skin is made of connective tissue and is vascular

o ***The hypodermis isn’t really considered but since its in the diagram I’ll go over it.

Page 6: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

EpidermisKeratinized stratified squamous epithelium

Four types of cells Keratinocytes – deepest, produces keratin (tough fibrous

protein) Melanocytes - make dark skin pigment melanin Merkel cells – sensory receptors for touch Langerhans cells – macrophage which are effective in the

defense

Layers (from deep to superficial) Stratum basale or germinativum – single row of cells

attached to dermis; youngest cells Stratum spinosum – spinyness is artifactual; tonofilaments

(bundles of protein) resist tension Stratum granulosum – layers of flattened keratinocytes

producing keratin (hair and nails made of it also) Stratum lucidum (only on palms and soles) Stratum corneum – horny layer (cells dead, many layers

thick)

Page 7: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

Epithelium: layers (on left) and cell types (on right)

Page 8: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

Dermis Corium, is the thicker, inner layer if the skin.

It contains masses of connective tissues, collagen tissue bands, elastic fibers, nerve endings, muscles, hair follicles, oil and sweat glands, and fat cells.

The thickness of the dermis varies over different parts of the body for instance, the dermis is thicker over the soles of the feet and the palms of the hands.

There are many nerve receptor of different types of the dermal layer.

Blood vessels in the dermis aid in the regulation of body temperature to maintain homeostasis.

Page 9: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

*Dermis layers

*

*

*Dermal papillae

Page 10: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

Hypodermis

Not considered apart of the Integumentary system.

It lies under the dermis and called superficial fascia.

It consists of loose connective tissues and contains about ½ of the bodies stored half.

Page 11: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.
Page 12: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

Hair and hair follicles: complexDerived from epidermis and dermisEverywhere but palms, soles, nipples, parts of genitalia

*“arrector pili” is smooth muscle

*

Hair papilla is connective tissue________________

Hair bulb: epithelial cells surrounding papilla

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Skin appendages

Derived from epidermis but extend into dermis.

Include:Hair and hair folliclesSebaceous (oil) glandsSweat (sudoiferous) glandsNails

Page 14: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

Functions of hairWarmth – less in man than other

mammalsSense light touch of the skinProtection - scalp

PartsRoot imbedded in skinShaft projecting above skin surface

Make up of hair – hard keratin

Three concentric layersMedulla (core)Cortex (surrounds medulla)Cuticle (single layers, overlapping)

Page 15: The Integumentary System.  Integument means covering.  Skin and its appendages make up the integument system  It covers about 3,000 square inches of.

Types of hairVellus: fine, short hairs Intermediate hairs Terminal: longer, courser hair

Hair growth: averages 2 mm/weekActive: growingResting phase then shed

Hair lossThinning – age relatedMale pattern baldness

Hair colorAmount of melanin for black or brown; distinct

form of melanin for redWhite: decreased melanin and air bubbles in the

medullaGenetically determined though influenced by

hormones and environment

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Sebaceous (oil) glandsEntire body except palms and soles

Produce sebum by holocrine secretion

Oils and lubricates

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Sweat glandsEntire skin surface

except nipples and part of external genitalia

Prevent overheating

500 cc to 12 l/day! (is mostly water)

Humans most efficient (only mammals have)

Produced in response to stress as well as heat

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Types of sweat glands

Eccrine or merocrineMost numerousTrue sweat: 99% water, some salts, traces of wasteOpen through pores

ApocrineAxillary, anal and genital areas onlyDucts open into hair follicesThe organic molecules in it decompose with time -

odor

Modified apocrine glandsCeruminous – secrete earwaxMammary – secrete milk

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Nails Of hard keratin

Corresponds to hooves and claws

Grows from nail matrix

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Careers Associated with Integumentary System

Dermatologist- Annual salary of 279,000, Dermatologists are medical doctors who deal with skin and skin aliments, the conduct skin evaluations in order to determine how to best treat and prevent conditions and diseases. Education: Undergraduate, 4 years of medical school, residency programs (3-4 years)

Plastic surgeon- Doctors who deal with replacing, repairing or reconstructing various parts of the body, mostly facial features. Annual salary of 300,000 to 791,510, Education: Complete up to medical school requirements and then must complete residencies which takes longer than other normal residencies.

Allergist- Annual salary: 332,450, Specialist in diagnosis and treatment of allergic diseases. Education: The first step towards becoming an allergist is earning a medical degree, then two more years for specialization; the final step is to earn certification from the board of allergy and immunology.

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Disorders of the Integumentary system Burns Threat to life Catastrophic loss of body fluids Dehydration and fatal circulatory shock Infection

Types First degree – epidermis: redness (e.g. sunburn) Second degree – epidermis and upper dermis: blister Third degree - full thickness

Infections

Skin cancer

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BurnsFirst-degree(epidermis only; redness)

Second-degree(epidermis and dermis,with blistering)

Third-degree(full thickness, destroying epidermis, dermis, often part of hypodermis)

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Critical burns

Over 10% of the body has third-degree burns

25 % of the body has second-degree burns

Third-degree burns on face, hands, or feet

Estimate by “rule of 9’s”

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Tumors of the skin Benign, e.g. warts

Cancer – associated with UV exposure (also skin aging) Aktinic keratosis - premalignant Basal cell - cells of stratum basale Squamous cell - keratinocytes Melanoma – melanocytes: most dangerous; recognition:

A - Asymmetry B - Border irregularity C - Colors D - Diameter larger than 6 mm

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Basal cell carcinoma

Sqaumous cell carcinoma

Melanoma

Skin Cancer