Unit 4 The Integumentary System - Badger Anatomy &...
Transcript of Unit 4 The Integumentary System - Badger Anatomy &...
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Unit 4The Integumentary
System
I. Classification of Body MembranesA. Epithelial Membranes ﴾3﴿
1. Cutaneous membrane> Stratified Squamous> Sits on Dense Connective Tissue> Skin: Dermis & Epidermis> Dry Membrane
2. Mucus Membrane > Epithelial Cell type varies> Sits on Loose Connective Tissue> Lines all body cavities that open to exterior> Wet & Moist Membrane
3. Serous Membrane > Simple Squamous> Sits on Areolar Connective Tissue> Lines body cavities closed to exterior> Found in pairs– parietal layer: lines body cavity– visceral layer: covers outside of organ
*Layers are separated by Serous Fluid
PeritoneumAbdominalPericardiumHeartPleuraLungs Visceral PleuraParietal Pleura
Serosae
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1. Synovial membrane> Surrounds joints> Provides smooth surface> Secretes lubricating fluid
– reduces friction
B. Connective Tissue Membranes ﴾1﴿
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A. Structure of the Skin1. Epidermis
• New every 3545 days• Avascular• Cell Types:
> Keratinocytes> Melanocytes> Dendritic> Tactile
• Stratified Squamous epithelium with ability to Keratinize & "Waterproof"> hardening & drying out of cells through production of Keratin> "Waterproof" from glycolipid produced that coats cells
> Stratum Corneum: outermost layer– 2030 layers of Keratinized dead cells
> Stratum Lucidum> Stratum Granulosum> Stratum Spinosum
> Stratum Germinativum: Deepest layer of epidermis– area of cell division– also known as stratum basale
nourishment via diffusion from dermis
- produce Keratin- produce Melanin
- defense- sensory reception
II. Cutaneous Membrane ﴾skin﴿
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1. Epidermis cont'd
• Production of Melanin> by Melanocytes found in S. Germinativum
> What happens when skin is exposed to sunlight?– Melanocytes are stimulated to make more melanin
– Melanin phagocytized by Kertinocytes
– Natural "Sunscreen"« Melanin creates shield/umbrella over underlying
nucleus« prevents DNA mutations from UV rays
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2. Dermis "hide"
• Composed of mostly Dense Connective Tissue• Split into two regions:
> Papillary: upper dermal region ﴾dermal papillae﴿– Aerolar Connective Tissue– Provide nutrients to epidermis ﴾blood vessels﴿– House pain receptors– Phagocytes– Creates patterns: "finger prints"
> Reticular: deepest dermal layer– Composed of collagen & elastic fibers ﴾Dense Irregular﴿– Houses blood vessels ﴾vascularized﴿– Houses sweat & oil glands– Phagocytes
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• Protection From:> Mechanical, Chemical, Thermal Damage
– S. corneum ﴾like "bricks & mortar"﴿« multiple layers of dead keratinized cells = bricks« glycolipids = mortar
> Bacterial Damage– low pH– chemicals in sweat & oil– dendritic cells ﴾epidermis﴿ & macrophages ﴾dermis﴿
> Ultraviolet Radiation– melanin = natural sunscreen
> Dessication ﴾drying out﴿– glycolipids = waterproof barrier
• Aids in temperature regulation
• Excretion
• Vitamin D synthesis
B. General Functions
C. Skin Color• Determined by...
> Amount & Type of Melanin
> Amount of Carotene deposited in the S. Corneum
> Amount of O2 bound to Hemoglobin in dermal blood vessels
• Homeostatic Imbalances:> Cyanosis
> Jaundice
> Anemia
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III. Accessory StructuresA. Glands
1. Sebaceous Glands ﴾oil﴿• Found all over body except palms & soles• Most are open to hair follicle• Secretes sebum (grease)
> Prevents hair from becoming brittle> Chemicals that kill bacteria
• If gland is blocked, sebum backs up => Whitehead
2. Sweat Glands• Eccrine Gland
> found all over body> secretes H2O, salts, & little urea> functions: helps regulate body temperature &
excretion
• Apocrine Gland> found in axillary ( ) & pubic ( ) regions> secretes everything eccrine does + f.a. & proteins> unknown function> odorless
– Bacteria who utilize fatty acids & proteins are not!!
B. Hair
C. Nails
• Made of protein (hard Keratin)• Protects eyes & respiratory tract• Produced by hair follicle
> Root is in follicle> Shaft (dead tissue) is above skin
• Arrector Pili Muscle> Connects hair follicle to dermis> When cold, this contracts and stands hair upright...
• Scalelike modifications of the skin
• Colorless• Appears pink because dermis (rich in blood vessels) lies just below
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