Integumentary Integumentary System & Body System & Body Membranes Membranes EQ: How does the structure EQ: How does the structure of the integumentary system of the integumentary system relate to its functional role relate to its functional role in protecting the body & in protecting the body & maintaining homeostasis? maintaining homeostasis?
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Integumentary System & Body Membranes EQ: How does the structure of the integumentary system relate to its functional role in protecting the body & maintaining.
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Integumentary Integumentary System & Body System & Body
MembranesMembranesEQ: How does the structure of EQ: How does the structure of
the integumentary system relate the integumentary system relate to its functional role in protecting to its functional role in protecting
the body & maintaining the body & maintaining homeostasis?homeostasis?
GPSGPS
• SAP2. Students will analyze the SAP2. Students will analyze the interdependence of the interdependence of the integumentary, skeletal, and integumentary, skeletal, and muscular systems as these relate to muscular systems as these relate to the protection, support and the protection, support and movement of the human body.movement of the human body.
• a. Relate the structure of the a. Relate the structure of the integumentary system to its functional integumentary system to its functional role in protecting the body and role in protecting the body and maintaining homeostasis.maintaining homeostasis.
Body MembranesBody Membranes• Function of body membranesFunction of body membranes
– Cover body surfaces: epithelial tissueCover body surfaces: epithelial tissue– Line body cavities: epithelial tissueLine body cavities: epithelial tissue– Form protective sheets around organs: Form protective sheets around organs:
connective tissueconnective tissue
Classification of Body Classification of Body MembranesMembranes
• Superficial epidermis Superficial epidermis is composed of is composed of keratinized stratified keratinized stratified squamous epitheliumsquamous epithelium
• Underlying dermis is Underlying dermis is mostly mostly dense dense connective tissueconnective tissue
Mucous MembranesMucous Membranes• Surface epithelium type Surface epithelium type
depends on sitedepends on site– Stratified squamous Stratified squamous
layer) covers the outside layer) covers the outside of the organ.of the organ.
– 2. 2. Parietal layerParietal layer (outer (outer layer) lines a portion of layer) lines a portion of the wall of ventral body the wall of ventral body cavity.cavity.
Serous MembranesSerous Membranes• Specific serous Specific serous
– Secretes a Secretes a lubricating fluid lubricating fluid called called synovial fluidsynovial fluid (which may become (which may become inflamed/ infected)inflamed/ infected)
• 4. Metabolic 4. Metabolic functions- Aids in functions- Aids in excretion of waste- excretion of waste- urea/ uric acidurea/ uric acid
• 5. Make vitamin D5. Make vitamin D
2 main Skin Layers2 main Skin Layers
1.1. Epidermis- top Epidermis- top layerlayer
2.2. Dermis- middleDermis- middle
3.3. Hypodermis Hypodermis (Subcutaneous (Subcutaneous Layer Layer (SubQ/SQ))- not a (SubQ/SQ))- not a real part of skin; real part of skin; layer of fat.layer of fat.
epitheliumepithelium– keratinized (hardened by keratinized (hardened by
keratinkeratin protein) protein)– .07-.12 mm thick/ 4-5 cell .07-.12 mm thick/ 4-5 cell
layerslayers– avascularavascular
• 4 main cell types4 main cell types::– KeratinocytesKeratinocytes-make -make
keratinkeratin, a protein , a protein which replaces cell which replaces cell contents and protects contents and protects skin skin (Structure)(Structure)
– MelanocytesMelanocytes—produce —produce melaninmelanin, a black brown , a black brown pigment which protects pigment which protects us against UV light us against UV light (pigment)(pigment)
– Langerhans cellsLangerhans cells — —respond to microbes respond to microbes (immunity)(immunity)
is deep to dermis (Not real part of is deep to dermis (Not real part of the skin)the skin)
– Made up of lipids/ fats- “fatty layer”Made up of lipids/ fats- “fatty layer”– Anchors skin to underlying organsAnchors skin to underlying organs– What type of connective tissue is this?What type of connective tissue is this?– What role/ function do you think this What role/ function do you think this
layer serve?layer serve?
Layers of the EpidermisLayers of the Epidermis1.1. Stratum basale Stratum basale
(stratum (stratum germinativum)germinativum)
– Deepest layer Deepest layer – Attached to dermis via Attached to dermis via
regeneration rateregeneration rate– Daughter cells are Daughter cells are
pushed upward to pushed upward to become the next layer become the next layer above it (more above it (more superficial layers)superficial layers)
Layers of the EpidermisLayers of the Epidermis2. Stratum spinosum2. Stratum spinosum• 22ndnd deepest layer deepest layer• 8-10 cell layers thick8-10 cell layers thick• Lower mitotic rateLower mitotic rate• Make keratin as cessl get Make keratin as cessl get
b/c when they beign to b/c when they beign to shrink, the desmosomes shrink, the desmosomes connecting adjacent cells connecting adjacent cells look like spikes.look like spikes.
• Recall: What are Recall: What are desmosomes & what do desmosomes & what do they do?they do?
Do you see the spines?Do you see the spines?
Layers of the EpidermisLayers of the Epidermis
3. Stratum granulosum3. Stratum granulosum• 3-5 cell layers thick3-5 cell layers thick• Cells begin to flatten Cells begin to flatten
& die out.& die out.• Contains keratin & a Contains keratin & a
waterproofing proteinwaterproofing protein• ( if water can’t diffuse ( if water can’t diffuse
upward, how would upward, how would the cells above this the cells above this layer receive layer receive nutrients? What would nutrients? What would happen to them?)happen to them?)
Layers of the EpidermisLayers of the Epidermis4. Stratum lucidum4. Stratum lucidum
– 3-5 cell layers of 3-5 cell layers of flat, dead flat, dead keratinocyteskeratinocytes
– Formed from dead Formed from dead cells of the deeper cells of the deeper strata (layer)strata (layer)
– Occurs only in thick, Occurs only in thick, hairless skin of the hairless skin of the palmspalms of hands and of hands and solessoles of feet of feet
– Gives palms/ soles it Gives palms/ soles it light color.light color.
Layers of the EpidermisLayers of the Epidermis5. Stratum corneum5. Stratum corneum
– 20-30 layers of flat, 20-30 layers of flat, keratinized, dead cells.keratinized, dead cells.
– toplayer of epidermis toplayer of epidermis (most superficial)(most superficial)
– Shingle-like dead cells Shingle-like dead cells are filled with keratin are filled with keratin (tough, protective (tough, protective protein prevents water protein prevents water loss from skin)loss from skin)
– AKA: cornified layerAKA: cornified layer• (What type of tissue (What type of tissue
make up this layer?)make up this layer?)• (Why do you think the (Why do you think the
cells died out the cells died out the farther they move up? farther they move up? How do cells in the How do cells in the epidermis get their epidermis get their nutrients?)nutrients?)
Skin Color
Due to 3 pigments:1. Melanin2. Carotene3. Hemoglobin
Melanin• Pigment (melanin) produced by melanocytes• Melanocytes are mostly in the stratum
basale• Color is yellow to reddish-brown to black• All people have the same # of melanocytes,
individual variation in skin color due to how much & what types of melanin is made.
• Amount of melanin produced depends upon genetics and exposure to sunlight
• Protects DNA from UV damage from sun
CaroteneCarotene
CaroteneCarotene::• yellow- to orange yellow- to orange
pigment in plants; not pigment in plants; not made by humans/ made by humans/ animals.animals.
• (how do you think it (how do you think it gets in our skin & gets in our skin & contribute to color?)contribute to color?)
• When large amts are When large amts are eaten, it can deposit in eaten, it can deposit in the stratum corneum the stratum corneum of thick thin. of thick thin. (Which (Which layer is that)?layer is that)?
• Temporary.Temporary.
Hemoglobin:Hemoglobin:• Pigment produced in Pigment produced in
blood cells that blood cells that transport oxygen.transport oxygen.
• Visible in fair-skinned Visible in fair-skinned individuals when individuals when blood rushes to blood rushes to surface of skin.surface of skin.
– Collagen & elastic fibers located Collagen & elastic fibers located throughout the dermisthroughout the dermis• Collagen fibers give skin its toughnessCollagen fibers give skin its toughness• Elastic fibers give skin elasticityElastic fibers give skin elasticity
– Blood vessels play a role in body Blood vessels play a role in body temperature regulation temperature regulation (HOW?)(HOW?)
Dermis- 2 layersDermis- 2 layers
1.1. Papillary layer (upper Papillary layer (upper 1/5 of dermal region)1/5 of dermal region)
• Projections called Projections called dermal papillae dermal papillae – Some contain capillary Some contain capillary
to waterto water• Kills bacteria (bactericidal)Kills bacteria (bactericidal)
– Most have ducts that empty into hair follicles; Most have ducts that empty into hair follicles; others open directly onto skin surfaceothers open directly onto skin surface
– Glands are activated at puberty Glands are activated at puberty (How is this (How is this related to acne in teens? Why don’t kids get related to acne in teens? Why don’t kids get acne?)acne?)
– Found everywhere except palms & solesFound everywhere except palms & soles
Appendages of the SkinAppendages of the Skin
Figure 4.6a
The sebaceous gland is indicated by the The sebaceous gland is indicated by the arrow. Note how its duct is unbranched and arrow. Note how its duct is unbranched and how it empties into a hair follicle.how it empties into a hair follicle.
2.2. ApocrineApocrine sweat sweat glandsglands– Ducts empty into hair Ducts empty into hair
folliclesfollicles
Sweat and Its FunctionSweat and Its Function• Composition:Composition:
– Mostly waterMostly water– Salts (mostly NaCl) and vitamin C, Salts (mostly NaCl) and vitamin C,
lactic acidlactic acid– Some metabolic waste: urea, uric acid, Some metabolic waste: urea, uric acid,
ammoniaammonia– Fatty acids and proteins (more in Fatty acids and proteins (more in
apocrine)apocrine)• Function:Function:
– Helps dissipate excess heat Helps dissipate excess heat (how does (how does this help maintains homeostasis?)this help maintains homeostasis?)
– Excretes waste productsExcretes waste products
Eccrine sweat glandsEccrine sweat glands• More numerous than More numerous than
apocrine glandsapocrine glands• Prominent on the Prominent on the
palms, soles & foreheadpalms, soles & forehead• Ducts empty in pores Ducts empty in pores
on skin surfaceon skin surface• Major function is to Major function is to
cool the body- cool the body- thermoregulation.thermoregulation.
• Mostly water & salts Mostly water & salts (mainly NaCl)(mainly NaCl)
• Acid pH of 4-6; acid Acid pH of 4-6; acid environment kills environment kills bacteria (i.e. chemical bacteria (i.e. chemical protection)protection)
Apocrine sweat glandsApocrine sweat glands• Located in axillary, pubic, anal Located in axillary, pubic, anal
regions.regions.• Larger & thicker than eccrine Larger & thicker than eccrine
glands.glands.• Ducts empty into hair follicle, not Ducts empty into hair follicle, not
directly through pore.directly through pore.• Contain more Contain more lipids & proteins- lipids & proteins-
when degraded by bacteria a foul, when degraded by bacteria a foul, sometimes musty odor is formed.sometimes musty odor is formed.
• Milky or yellow in color.Milky or yellow in color.• Active during pubertyActive during puberty• Secretes during times of pain, Secretes during times of pain,
stress & sexual activity.stress & sexual activity.• No role in thermoregulation.No role in thermoregulation.• (What causes the yellow stains you (What causes the yellow stains you
sometimes see on t-shirt in the sometimes see on t-shirt in the underarm area?)underarm area?)
• (What causes the musty odor?)(What causes the musty odor?)
Ceruminous glandsCeruminous glands
• Modified apocrine glands in the inner Modified apocrine glands in the inner lining of the external ear canal.lining of the external ear canal.
• Secretes a sticky waxy substance called Secretes a sticky waxy substance called cerumen (earwax)cerumen (earwax). It combines w/ . It combines w/ sebum & dead epidermal cells to form sebum & dead epidermal cells to form a bitter compound that offers a barrier a bitter compound that offers a barrier to entry of the ear.to entry of the ear.
• How does this keeps your How does this keeps your
ear germ-free?ear germ-free?
Appendages of the Appendages of the Skin- HAIRSkin- HAIR
• Hair is a flexible strand made of highly keratinized dead cells.
• The keratin in both hair & nails is hard keratin, a stiffer, more compact version of the soft keratin that dominates the epidermis. It is tougher & its cells do not individually flake off.
• The hair is made by the living hair follicle.• MelanocytesMelanocytes provide pigment for hair provide pigment for hair
color.color.• Found all over except- palms, soles, Found all over except- palms, soles,
nipples, lips.nipples, lips.
HAIRHAIR• The hair consists of 3
concentric regions:1. Medulla the
innermost region consisting of large cells and air spaces.
2. Cortex surrounds the medulla and consists of flattened keratinized cells
3. Cuticle outer layer of flat keratinized cells that overlap like shingles with their free edges pointing upward.
Figure 4.7b
HAIRHAIR
Figure 4.7c
Hair and Hair Follicles
• Hair Follicle: Dermal and Hair Follicle: Dermal and epidermal sheath surround hair epidermal sheath surround hair root.root.
• Wrapped around the bulb of the follicle is a network of sensory nerve endings known as the hair root plexus. Allow the hairs to serve a sensory function.
• Attached to each hair is a bundle of smooth muscle known as an arrector pili muscle. In times of fright or cold, these muscles contract and cause the hair to stand on end – and produces goose bumps.– (Increases airflow in mammals with
significant hair (i.e., not humans) and increases the apparent size of an animal with significant hair. Vestigial function in humans).
HAIRHAIR
Figure 4.7a
Notice the hair shaft, hair follicle, papilla, and the multiple sebaceous glands. Where
is the epidermis?
HAIR HAIR
Figure 4.8
Notice the 3 layers of the hair itself.
NAILSNAILS– Scale-like modifications of the epidermisScale-like modifications of the epidermis
• Heavily keratinized dead (hard keratin) cellsHeavily keratinized dead (hard keratin) cells
– Stratum basale extends beneath the nail bedStratum basale extends beneath the nail bed• Responsible for growthResponsible for growth
– Lack of pigment makes them colorless. Lack of pigment makes them colorless. (What (What protein is lacking)? (Why do nails look pink?)protein is lacking)? (Why do nails look pink?)
– (What structure does the nails correspond to (What structure does the nails correspond to in cow, horses, birds, etc.)?in cow, horses, birds, etc.)?
NAILNAIL• Nail structuresNail structures
1.1. Free edgeFree edge
2.2. Body- is the visible attached portionBody- is the visible attached portion
3.3. Root- embedded in skinRoot- embedded in skin
4.4. Nail folds- skin folds form from Nail folds- skin folds form from overlapping cells.overlapping cells.
5.5. Cuticle- is the proximal nail fold that Cuticle- is the proximal nail fold that projects onto the nail bodyprojects onto the nail body
NAIL
1. Nail bed- extension of the stratum basale beneath the nail.
2. Nail matrix- thicken proximal are of nail bed; causes nail growth.
3. Lunula- “crescent”- thicken, white crescent at base of nail.
• Imbalance in homeostasis is often Imbalance in homeostasis is often revealed in the skin. More than 100 revealed in the skin. More than 100 different skin conditions.different skin conditions.– Allergies, bacterial, viral or fungals infection.Allergies, bacterial, viral or fungals infection.– BurnsBurns– cancercancer
Rule of NinesRule of Nines• Way to determine the extent of Way to determine the extent of
burnsburns• Body is divided into 11 areas for Body is divided into 11 areas for
quick estimationquick estimation• Each area represents about 9% of Each area represents about 9% of
total body surface areatotal body surface area
Rule of NinesRule of Nines
Figure 4.11a
Severity of BurnsSeverity of Burns• First-degree burnsFirst-degree burns
– Only epidermis is damagedOnly epidermis is damaged– Skin is red and swollenSkin is red and swollen
• Second-degree burnsSecond-degree burns– Epidermis and upper dermis are damagedEpidermis and upper dermis are damaged– Skin is red with blistersSkin is red with blisters
• Third-degree burnsThird-degree burns– Destroys entire skin layerDestroys entire skin layer– Burn is gray-white or blackBurn is gray-white or black
Severity of BurnsSeverity of Burns
Figure 4.11b
Critical BurnsCritical Burns• Burns are considered critical ifBurns are considered critical if
– Over 25% of body has second-degree Over 25% of body has second-degree burnsburns
– Over 10% of the body has third-degree Over 10% of the body has third-degree burnsburns
– There are third-degree burns of the There are third-degree burns of the face, hands, or feetface, hands, or feet
Skin CancerSkin Cancer• Cancer—abnormal cell massCancer—abnormal cell mass• Classified two waysClassified two ways
– BenignBenign• Does not spread (encapsulated)Does not spread (encapsulated)
– MalignantMalignant• Metastasized (moves) to other parts of the Metastasized (moves) to other parts of the
bodybody
• Skin cancer is the most common Skin cancer is the most common type of cancertype of cancer
Skin Cancer TypesSkin Cancer Types• Basal cell carcinomaBasal cell carcinoma
– Least malignantLeast malignant– Most common typeMost common type– Arises from stratum basaleArises from stratum basale
Skin Cancer TypesSkin Cancer Types
Figure 4.12a
Skin Cancer TypesSkin Cancer Types• Squamous cell carcinomaSquamous cell carcinoma
– Metastasizes to lymph nodes if not Metastasizes to lymph nodes if not removedremoved
– Early removal allows a good chance of Early removal allows a good chance of curecure
– Believed to be sun-inducedBelieved to be sun-induced– Arises from stratum spinosum Arises from stratum spinosum
Skin Cancer TypesSkin Cancer Types
Figure 4.12b
Skin Cancer TypesSkin Cancer Types• Malignant melanomaMalignant melanoma
– Most deadly of skin cancersMost deadly of skin cancers– Cancer of melanocytesCancer of melanocytes– Metastasizes rapidly to lymph and blood Metastasizes rapidly to lymph and blood