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Outline chapter 5

Test back Corrections tonight after school,

tomorrow at 7:00 am

Outline p. 100-105 due tomorrow

Project: building day on Wednesday

Due on Friday

Tuesday: finish notes

Wednesday: build models

Thursday: Review page, some build time

Friday: notes, microscope if time

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Chapter 5: Integumentary System

Objectives List functions of skin Explain role of skin in temperature regulation

Describe layers of skin and characteristics

Explain factors that affect skin color

Describe accessory organs of skin

Functions

ProtectionTemperature Regulation

Vitamin DSensoryExcretion

Integumentary SystemConsists of skin and accessory organs

Skin is 2 regions: Dermis epidermis

A fatty layer lies deep (hypodermis)

Hair Follicles Skin Glands Nails

Skin is the body’s outer covering and its largest organ.

Epidermis

Dermis

HypodermisOr subcutaneous

Structure of Skin

Epidermis

Stratified Squamous Epithelium (tissue)

Keratinized: keratin is a tough protein

Keratinized: By the time cells reach surface, little more than keratin filled sacsDesquamification: shedding of outermost layer of a tissue

Epidermis

No direct blood supplyNutrients must diffuse into the epidermis

Four types of cellsKeratinocytes – deepest, produce keratin Melanocytes - make dark skin pigment melanin Merkel cells – associated with sensory nerve endings Langerhans cells – macrophage-like dendritic cells

Review

1. The functions of the skin include all of the following except:

a. Taking in nutrientsb. Preventing entry of microorganismsc. Retarding water lossd. Regulating body temperature

Review

1. Which layer of the Integumentary System is the foundation for the skin?

a. Epidermisb. Hypodermisc. Dermisd. Stratum Corneum

Review

1. Which of the following is NOT considered an accessory organ of the Integumentary System?

a. nailsb. hairc. arteriesd. glands

Review

1. Which of the following cell types is responsible for sensory in the epidermis?

a. Langerhansb. Keratinocytesc. Melanocytesd. Merkel

Epidermis: most superficial

Stratum Corneum: Many layers of dead cells keratin, Moisture lock

Stratum Lucidum:Stratum Granulosum:Statum Spinosum:Stratum Basale:

Stratum Corneum: Stratum Lucidum:

Protect from UV Thick layer Only in frequently used areas

Stratum Granulosum:Statum Spinosum:Stratum Basale:

Stratum Corneum: Stratum Lucidum:Stratum Granulosum:

Thin middle layer Layers of keratinocytes Initiate keratinization

Statum Spinosum:Stratum Basale:

Stratum Corneum: Stratum Lucidum:Stratum Granulosum:Statum Spinosum:

Cells interlock to support skin Resist tension Langerhans cells (found more here than other layers)

Stratum Basale:

Stratum Corneum: Stratum Lucidum:Stratum Granulosum:Statum Spinosum:Stratum Basale:

Single layer of cells Rest on basement membrane Cells divide continuously Youngest cells found here Melanocytes & Merkel cells here

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