Transcript Integumentary System Notes

Body Bugs
NOVA | Bugs That Live on You
Follicular Mites –
found in all hair
follicles
Dust Mites –
found on your
body, your
bed, any
fluffy surface
that you
spend time
with
Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 4
Skin and Body Membranes
Slides 4.1 – 4.32
Lecture Slides in PowerPoint by Jerry L. Cook
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Skin and Body Membranes
 Function of body membranes:
 1. Line or cover body surfaces
 2. Protect body surfaces
 3. Lubricate body surfaces
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Slide 4.1
2 TYPES OF MAIN MEMBRANES
• 1. EPITHELIAL MEMBRANES:
• Cutaneous, mucous, & serous membranes included
• All of these do contain an epithelial sheet  However,
it is always combined with an underlying layer of
connective tissue.
• 2. CONNECTIVE TISSUE MEMBRANES:
• Represented by Synovial Membranes = Areolar
Tissue: NO Epithelial Cells
1. Cutaneous Membrane
 Cutaneous Membrane = skin
 A dry membrane & exposed to air
 Outermost protective boundary
 Composed of: Superficial Epidermis
 Keratinized stratified
squamous epithelium
 Underlying Dermis
 Mostly dense
fibrous connective tissue
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Figure 4.1a
Slide 4.3
2. Mucous Membranes (Mucosa)
 Surface is Composed of Epithelium resting
on loose connective tissue called Lamina
Propria. **Type of Epithelial tissue depends on
site:
 Lines all body cavities
that open to the
exterior body surface: including repiratory,
digestive, urinary, & reproductive tracts.
 In all cases, these membranes are “wet” or
moist
 Often adapted for absorption or secretion: it is
NOT a requirement that they secrete mucus
Figure 4.1b
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Slide 4.4
3. Serous Membranes (Serosa)
 Surface = simple
squamous epithelium
 Underlying epithelial
tissue = areolar
connective tissue
 Lines open body cavities
that are closed to the
exterior of the body
(opposite of Mucous
Membranes)
 Serous layers separated
by serous fluid
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Figure 4.1c
Slide 4.5
Serous Membrane
 **Serous Membranes occur in Pairs**
 Perietal Layer  Lines a specific portion of the
wall of the ventral body cavity
 Visceral Layer  covers the outside of organs in
the cavity (this layer is made from the perietal
layer folding in on itself)
Serous Membranes
 Specific serous membranes:
 Peritoneum
 Abdominal
cavity
 Pleura
 Around the
lungs
** Good Picture to look at
is on Page 97  Figure
4.1 C
 Pericardium
 Around the
heart
Slide 4.6
Connective Tissue Membrane
 1. Synovial
membrane
 Connective tissue
only (areolar): NO
EPITHELIAL CELLS
 Lines fibrous
capsules
surrounding joints,
small sacs of
connectiev tissue
called Bursae, &
Tendon Sheaths
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Figure 4.2
Slide 4.7
Integumentary System
 Skin (cutaneous membrane)
 Skin derivatives:
 Sweat glands
 Oil glands
 Hairs
 Nails
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Slide 4.8
Integumentary Functions
Protection - biological
• Biological – cells – macrophages & Langerhan’s
cells engulf invaders.
Protection - mechanical
• Mechanical – physical
• Continuity – skin is made impermeable through the
tight junctions & desmosomes
• Keratin – physically blocks the passage of water and
water soluble substances
• FYI: Molecules that can pass through your skin:
• Lipid soluble – O2, CO2, ADEK, steroids,
nicotine, & other transdermal medications
• Oleoresins – poison ivy & poison oak, etc – you
have less than 10 min to wash it off!
Protection - Chemical
• Chemical
• Skin secretions: tears, sweat, oil lower pH and contain
lysozyme (chemical that lyses cells)
• Melanin – pigment shield against UV radiation
Excretion
• Limited amounts of nitrogen containing wastes
(most is excreted in urine unless you have a
kidney disorder in which case urea will be
excreted in small amounts through skin)
• Sodium chloride through sweat
• Water through sweat
• Heat through sweat
Homeostasis of Body Temperature
• Heat production – chief determinant is muscle
activity
• Heat loss/gain
• 80% of heat transfer is through the skin – the rest is
through the mucosa (dogs are opposite!)
• Regulated by vasoconstriction & vasodilation since
heat is carried primarily in the water content of the
blood (reminder: on page 1 of notes)
Understand what
is happening in
these diagrams!!
Vitamin D Production
• Vitamin D is important in
the uptake of Calcium
from the food you eat.
• Ca has to be absorbed from
your stomach into the
blood to go anywhere
• Cholesterol molecules
when exposed to UV light
become a Vitamin D
precurser
• Precurser becomes active
in the liver & kidneys
Sensation – skin receptors
Don’t need to memorize
• Free nerve ending = pain
• Meissner’s corpuscles = discriminating touch,
light pressure (think fly on your arm)
• Krause’s – cold
• Ruffini’s – heat
• Merkel Disc – Medium pressure
• Pacinian corpuscle – Deep pressure
See diagram in notes
Skin Structure
 Epidermis – outer layer:
 Stratified Squamous epithelium
 Often keratinized (tough & hardened by
keratin)
 Dermis:
 Dense connective tissue
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Slide 4.10a
Skin Structure
 Deep to dermis is the hypodermis
(Subcutaneous Tissue)
 Not part of the skin
 Anchors skin to underlying organs
 Composed mostly of adipose tissue
 Responsible for “curves” on your figure
 *Serve as a shock absorber and insulates
deeper tissues
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Slide 4.10b
Skin Structure page 101 (This is on
pg 4 of notes – You need know all
of your diagrams!
Figure 4.4
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Slide
Epidermis – FIGURE 2 - fill in text
box on left side of diagram
 Epidermis – outer layer – color code
brackets
 Keratinized stratified squamous
epithelium
 Avascular (hardened by keratin)
 Renews itself ~ every 35 - 45 days
 Need to know this slide!
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Slide
Dust Mites – eat your dead keratinocytes
Epidermis – cell types – Go to FIGURE
1 of notes & fill in cell info (upper right)
 Keratinocytes
 produce keratin – waterproofing protein
Why important? To keep you from
gaining/losing water
 Originate in deeper layers & get pushed
to surface – becomes keratin filled & dies
 Reminder: Connected to each other by
desmosomes & tight junctions
 Cell production & keratinization are
accelerated in areas of friction
Callus – thickened skin for
protection
Slide
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Keratinocyte Growth
Epidermis – cell types – FIG. 1
• Melanocytes
• Produce melanin which
accumulates on superficial
(between nucleus & sun) side of
nucleus
• Why that location? to prevent DNA
mutation from the UV radiation
Mutation can
change growth
instructions &
cause cancer
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Slide
Side Note:
• Freckles and moles = areas where melanin is
concentrated in one spot.
• Despite protection of melanin, over time the
exposure eventually damages the skin
permanently:
• Elastic fibers begin to clump = leathery skin
• Depresses the Immune System
• Skin Cancer
Melanocytes
Label the 5 strata on FIGURE 1 left side
Reflection
• Through research it has been found that darker
skinned individuals seldom have skin cancer.
• Why do you think that is?
5 epidermal strata– place info on page 5 right
side
 From deep to superficial
 Stratum basale
 highly mitotic
Approx. 25% melanocytes
 Stratum spinosum
Slightly mitotic
Contains Langerhan’s
macrophages
Slide
5 strata of the Epidermis
 Stratum granulosum
Also contains Langerhans cell
contains keratin granules
 Stratum lucidum
 found in thicker epidermis – palms,
soles, callus
 Completely keratinized (and dead!)
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Slide
5 strata of the Epidermis
 Stratum corneum
 Also completely keratinized (& dead)
 Tough, waterproofing protection
AGAIN: Why is waterproofing
important?
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Slide
How it all fits together
Dermis – back to FIGURE 2
 Left side: Strong, flexible CT - 2
layers
Right side - Papillary dermis
 Contains areolar CT
 Dermal papillae – indent into the
epidermis – form fingerprints
What else is important about
these? Give us grip !
 Also contain
nerve receptors,
capillary loops, glands, etc.
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Slide
Blister: add in margin NEXT TO FIGURE
2
• Dermal – epidermal junction
• Held together by desmosomes
• Blister - separation due to mechanical stress
• What 2 sublayers actually separate? Think about
this!!
Dermis
 FIGURE 2
 right side
 Reticular Dermis
 Reticular CT & Dense irregular CT –
also contains Blood vessels, Nerve
receptors, Glands
 cleavage lines – direction of fibers
in collagen bundles – used in plastic
surgery to reduce scarring
 flexure lines – dermis secured to
hypodermis
Slide
 stretch marks – dermal tears
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Cleavage lines
Decubitus Ulcers
• Any restrictions of normal blood supply to skin,
causes cell death, and if sever and long enough
causes ulcers.
• Common in Bedridden Patients.
DERMIS
• Both Collagen & Elastic Fibers are found
throughout the dermis.
• *Collagen helps with toughness & hydration.
• *Elastic Fibers help with elasticity when we are
young
• As we age the amount of these fibers decrease
skin begins to sag and wrinkle
Dermis
Hypodermis – FIGURE 2 left side
 Deep to dermis is the hypodermis superficial fascia
 Anchors skin to underlying organs,
shock absorption, insulation
 Composed mostly of adipose tissue
 Very vascular
 Site of subcutaneous injections
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Slide
5 Tissues
• There have been 5 types of tissues during the
previous slides
• You will need to MEMORIZE the
location/function/slide of these 5 for this unit test
Skin Structure
Figure 4.4
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Slide 4.13b
Skin color
Normal Skin Color Determinants
 Determined by a combo of:
Types of pigments present
Blood circulation
Stratum corneum thickness
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Slide 4.14
Normal Skin Color Determinants
 Melanin
 Yellow, brown or black pigments
produced in melanocytes found in
stratum basale – transferred to
keratinocytes
 Local accumulations form freckles &
pigmented moles
 Amount of melanin produced
depends upon genetic and exposure
to sunlight
 Solar elastosis – clumping of elastin
fibers = leathery looking skin
Slide 4.14
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Slide 4.14
Normal Skin Color Determinants
 Carotene
 Orange-yellow
pigment from some
vegetables
 Vitamin A precurser
– vitamin A forms
retinal which is
needed for sight
 Accumulates in
adipose and
stratum corneum
cells
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Normal Skin Color Determinants
 Hemoglobin & blood
circulation
Red coloring from
oxygenated blood cells in
dermis capillaries
Oxygen content
determines the extent of
red coloring
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Slide 4.14
Blood flow
 Vasodilation causes increase in
flow
 Vasoconstriction causes
decrease in flow
Skin as a Diagnostic
 Skin color is influenced by emotional
& disease states: You should know
the states that cause these.
 Cyanosis – bluish color - lack of oxygen
 Erythema – redness – heat, inflammation,
fever
 Add this -Pallor – paleness – lack of
blood flow
 Jaundice – yellowish color – liver damage
 Bronzing – bronze (tan) – Addison’s
disease
 Hematomas – black & blue – blood under
skin
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Slide 4.14
Skin Derivatives
Hair Anatomy
 Central medulla
 Cortex surrounds
medulla
 Cuticle on outside of
cortex
 Single layer of
overlapping cells
 Split ends –
cuticle flakes off –
fibers in cortex
fray out
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Figure 4.7b
Slide 4.19
Hair anatomy
• Hair shaft –
above skin
• Hair root –
below skin
Appendages of the Skin
 Hair
 Shaft – projects from
skin
 Add in margins:
Shape determines
hair curliness
 Flat = curly
 Oval = wavy
 Round = straight
Figure 4.7c
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Slide 4.18
Hair Follicle
 Hair - Extends into
dermis &
hypodermis
 Produced by hair
bulb- expanded
end
 Papilla contains
capillaries in bulb
for hair
nourishment (fix
in notes!)
 Matrix = growth
zone – directly
Figure 4.7c
Slide 4.18
Associated Hair Structures
 Arrector pilli
 Smooth muscle
regulated by emotions
 Contraction pulls hair
upright - Normally at
angle
Figure 4.7a
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Slide 4.20
Arrector Pili Muscle
Hair Color
 Caused by
proportions of 3
types of melanin
 Determined by
genetics
 Melanin is replaced
by air bubbles in
gray/white hair –
causes different
texture
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Figure 4.7b
Slide 4.19
Hair Types
 Vellus hair – softer
body hair
 Terminal hair – coarser
hair found in axillary &
anogenital regions &
other body regions
 Lanugo – newborn
baby fuzz
Figure 4.7a
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Slide 4.20
Hair Growth
 Influenced by (in
order):
Nutrition: main
influence
hormones
Blood flow
Figure 4.7a
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Slide 4.20
Cycles
Thought Question: know the answers to
these questions!!
• Why is the hair on your head longer than the hair
in your eyebrows?
• Why does some hair fall out every day?
• Approx 100 hairs per day are lost from your head!
That is why your sink is stopped up!
Androgenetic Alopecia
 Male pattern
baldness
 Sex linked,
recessive trait
 Punnett Square!
Causes thinning
hair in women
Figure 4.7a
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Slide 4.20
Androgenetic Alopecia
 Increased activity in androgen receptors
causes hair loss & increases other health risks
such as coronary heart disease and prostate
cancer in men and polycystic ovary syndrome in
women
Terminal hair replaced by vellus hair -progresses
posteriorly
Treatment: drugs that inhibit testosterone
production (Rogaine, Propecia)
FYI: Polycystic Ovarian Syndrome
More on these
topics when we
study the
Endocrine System
Imbalance: FYI
• Thinning hair can be caused by an abundance of
factors.
• Heterozygous traits
• Nutrition
• Medications
• Stress (affects nutrition & hormones)
• Hormones
• Physical factors
Appendages of the Skin
 Nails: Just know diagram & these
imp. facts – add to diagram:
 Scale-like modifications of the
epidermis
 Heavily keratinized
 Stratum basale extends beneath the nail
bed to form nail matrix
 Which is responsible for growth
 Lack of pigment makes them colorless
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Slide 4.21
Nail Structure
Nail Structure
 Know all parts labeled on diagram
 Why is lunula white?
 What happens if matrix is damaged?
Cutaneous Glands
• Are ALL Exocrine Glands  they release
secretions to the surface using DUCTS. Reside in
the Dermis. (Made in the Stratum Basale)
• These fall into 2 groups:
• 1. Sebaceous Glands
• 2. Sweat Glands
Appendages of the Skin
 1. Sebaceous glands  found all over skin
except palms and soles of feet.
 Produce oil  called Sebum.
 Lubricant for skin
 This sebum also kills bacteria
 Most with ducts that empty into hair follicles
 Glands are activated at puberty
 If these glands are blocked causes acne  if
material oxidizes and dries, get blackheads.
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Slide 4.15
Sweat Glands
 Sudoriferous (sweat) glands
 Three types
 Eccrine glands
 Widely distributed in skin: abundant
on palms, soles, forehead
 Open via duct to pore on skin
surface
 Sweat composition: mostly water
with a slightly acidic 4-6 pH
 Function: thermoregulation
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Slide 4.16
Sweat Glands
• Apocrine glands (also sudoriferous)
 Ducts empty into hair follicles
 Found mainly in anogenital & axillary
region
 Begin to function at puberty due to
hormones
 Organic contents: Fatty acids and
proteins – can have a yellowish color
that stains clothes
 Odor is from associated bacteria
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Slide 4.17
Sweat Glands
Ceruminous glands
 Modified apocrine gland
 Found in outer 1/3 of ear canal
 Produce ear wax to trap “invaders”
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Slide 4.17
Appendages of the Skin
 Sebaceous glands (all over except
palms and soles of feet)
 Produce oil for waterproofing
 Lubricant for skin & kills bacteria
 Most with ducts that empty into hair
follicles
 Glands are activated at puberty:
stimulated by hormones
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Slide 4.15
Imbalances
• Upper right hand box in notes;
• Acne – active infection of sebaceous glands
• Whitehead - Sebaceous gland duct blocked
by sebum
• Blackhead – sebum oxidizes, dries, and
darkens
• Seborrhea – “cradle cap” – Over activity of
sebaceous glands in infants
Skin Homeostatic Imbalances
 Infections
 Athletes foot
 Caused by fungal infection
 Boils and carbuncles
 Caused by bacterial infection
 Cold sores
 Caused by virus
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Slide 4.23
Skin Homeostatic Imbalances
 Infections and allergies
 Contact dermatitis
 Exposures cause allergic reaction
 Impetigo
 Caused by bacterial infection
 Psoriasis
 Cause is unknown
 Triggered by trauma, infection, stress
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Slide 4.24
Skin Homeostatic Imbalances
 Burns
 Tissue damage and cell death caused by
heat, electricity, UV radiation, or chemicals
 Associated dangers
 Dehydration
 Electrolyte imbalance
 Circulatory shock
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Slide 4.25
Rules of Nines
 Way to determine the extent of burns
 Body is divided into 11 areas for quick
estimation
 Each area represents about 9%
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Slide 4.26
Severity of Burns
 First-degree burns
 Only epidermis is damaged
 Skin is red and swollen
 Second degree burns
 Epidermis and upper dermis are damaged
 Skin is red with blisters
 Third-degree burns
 Destroys entire skin layer
 Burn is gray-white or black
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Slide 4.27
Critical Burns
 Burns are considered critical if:
 Over 25% of body has second degree
burns
 Over 10% of the body has third degree
burns
 There are third degree burns of the face,
hands, or feet
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Slide 4.28
Skin Cancer
 Cancer – abnormal cell mass
 Two types
 1. Benign
 Does not spread (encapsulated)
 2. Malignant
 Metastasized (moves) to other parts of
the body
 Skin cancer is the most common type of
cancer
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Slide 4.29
Skin Cancer Types
 Basal cell carcinoma
 Least malignant
 Most common type
 Arises from statum basale
 Squamous cell carcinoma
 Arises from stratum spinosum
 Metastasizes to lymph nodes
 Early removal allows a good chance of cure
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Slide 4.30
Skin Cancer Types
 Malignant melanoma
 Most deadly of skin cancers
 Cancer of melanocytes
 Metastasizes rapidly to lymph and blood
vessels
 Detection uses ABCD rule
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Slide 4.31
ABCD Rule
 A = Asymmetry
 Two sides of pigmented mole do not match
 B = Border irregularity
 Borders of mole are not smooth
 C = Color
 Different colors in pigmented area
 D = Diameter
 Spot is larger then 6 mm in diameter
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Slide 4.32