Download Integumentary Unit PPT 2014

Chapter 6
(Integument)
5/24/2017
1
Introduction to the Integumentary System
• Integument = skin
• Integumentary system
= skin and its
appendages
– Appendages
• Hair
• Nails
• skin glands
– (sweat and sebaceous)
• PRIMARY FUNCTION:
Protection
5/24/2017
2
Cutaneous Membrane Structure
• The skin is called
the cutaneous
membrane
• Two primary layers
– Epidermis
– Dermis
5/24/2017
3
EPIDERMIS
• FEATURES
– Outer, Thinner Layer of Skin
– Tissue Type
• Membranous Epithelium
– (Stratified Squamous Epithelium-Keratinized)
5/24/2017
4
3 CELL TYPES: KERATINOCYTES
• Most Numerous and Important
Cells in the Epidermis
• Filled with (or in the Process of
Becoming Filled with) Keratin
(Keratinization)
– Keratin
• Strong Protein
• Protects and Waterproofs
the Skin
– Keratinization
• Process by Which Cells in
the Epidermis Become Filled
with Keratin and Moved to
the Skin's Surface (Cells Die
in the Process)
5/24/2017
5
3 CELL TYPES: MELANOCYTES
• MELANOCYTES Produce Melanin
•Functions of
Melanin
–Responsible for
Color of Skin,
Hair, and Eyes
–Filters UV Light
5/24/2017
6
5/24/2017
7
3 CELL TYPES: LANGERHANS
• LANGERHAN'S CELLS
– Provide Defense against Foreign Invaders (Work with the
Immune System)
5/24/2017
8
EPIDERMAL CELL LAYERS
• 5 Layers
5/24/2017
9
CELL LAYERS - STRATUM CORNEUM
• 1st layer
• STRATUM CORNEUM
– "Hardened Layer":
• Cells in this Layer are
Totally Filled with Keratin
• (Replaces the Cytoplasm)
– Known as the Barrier
Area
– Cells at the Surface of
this Layer are Dead
5/24/2017
10
CELL LAYERS - STRATUM LUCIDUM
• STRATUM LUCIDUM
– "Clear Layer": Cells in
this Layer have a Clear
Appearance (Keratin
Precursor)
– Only Present in Thick
Skin (palms of hands
and soles of feet)
5/24/2017
11
CELL LAYERS - STRATUM GRANULOSUM
• STRATUM
GRANULOSUM
– "Granular Layer": Cells
in this Layer are Filled
with Granules (Keratin
Precursor)
– Keratinization Begins in
this Layer
5/24/2017
12
CELL LAYERS - STRATUM SPINOSUM
•
STRATUM SPINOSUM
– "Spiny Layer":
• Cells in this Layer Have an
Irregular Shape (Plasma
Membranes Modified To Hold
Tightly Together)
– Rich in RNA (Preparation for
Keratinization)
5/24/2017
13
CELL LAYERS - STRATUM BASALE
• STRATUM BASALE
– "Base Layer": The
Innermost Layer of
Epidermis
– Mitosis Occurs in this
Layer
5/24/2017
14
CELL LAYERS - 2 LAYERS MAKE THE GROWTH LAYER
• STRATUM
GERMINATIVUM
– NOT ANOTHER LAYER,
ACTUALLY COMPOSED OF
2 EXISTING LAYERS
– The growth layer
– Composed of s. spinosum
and s. basale
5/24/2017
15
EPIDERMAL GROWTH AND REPAIR
• TURNOVER (REGENERATION) TIME
– Time Required for Epithelial Cells to Form in the
Stratum Basale and Migrate to the Skin's Surface
– Average Turnover Time = 35 Days (Maintains a
Constant Skin Thickness
– Application: Shortened Turnover Time Results in
Formation of Callus
5/24/2017
16
EPIDERMAL GROWTH AND REPAIR
• EPIDERMAL PROLIFERATING UNIT (EPU)
– Each Group of 8-10 Basal Cells Along with the
Vertical Columns of Cells Above (Up to the Skin's
Surface)
– Epidermis Grows in Units - Not as a Whole
5/24/2017
17
DERMAL - EPIDERMAL JUNCTION
• The Union Between the
Epidermis and the Dermis
• A Basement Membrane
• Functions:
– Tightly "Glues" the Epidermis
to the Dermis
– Provides Support for the
Epidermis
– Serves as a Partial Barrier
Between the Epidermis and
the Dermis
5/24/2017
18
• FEATURES
DERMIS
– Inner, Thicker Layer of Skin
– Tissue Type: Connective Tissue
– Called "True Skin" (Thicker and Gives
Strength to Skin)
5/24/2017
19
STRUCTURES PRESENT IN THE DERMIS
• SENSORY
RECEPTORS
(Skin Functions as a
Sense Organ)
– Specialized Nerve
Endings for
•
•
•
•
•
5/24/2017
Hot
Cold
Pressure
Pain
Touch
20
5/24/2017
21
STRUCTURES PRESENT IN THE DERMIS
• MUSCLE FIBERS - 2
Types
– SKELETAL
• Located Only in the Dermis
of the Face and Scalp
• Function: Voluntary
Movement of the Face and
Scalp
– SMOOTH - ARRECTOR
PILI MUSCLES
• Involuntary
• The Most Abundant of the
2 Types of Muscle Fibers
• Form Arrector Pili Muscles
• Produces "Goose Bumps"
5/24/2017
22
STRUCTURES PRESENT IN THE DERMIS
• HAIR FOLLICLES
– Tubes That Hold Hairs
(More Detail with Hair)
• SWEAT, SEBACEOUS
GLANDS
– Skin Glands (More
Detail with Skin Glands)
5/24/2017
23
STRUCTURES PRESENT IN THE DERMIS
• BLOOD VESSELS
– The Dermis
Contains an
Extensive Network
of Blood Vessels
That Play an
Important Role in
Regulation of Body
Temperature
5/24/2017
24
Dermis is composed of 2 layers
• Papillary layers
– dermal papillae
show through
making fingerprints
5/24/2017
25
Dermis is composed of 2 layers
• Reticular layer
– Inner, thicker layer
– dense network of
collagenous and
elastic fibers
– Contains
• muscle fibers
• hair follicles
• sweat and
sebaceous glands
• blood vessels
• sense receptors
5/24/2017
26
Dermal Growth and Repair: Scars
• Dermis does not continually shed and regenerate
itself.
– In the healing of a wound, fibroblasts reproduce and
begin forming a dense mass of connective tissue fibers.
– If this fiber is not replaced by normal tissue, it remains a
scar.
5/24/2017
27
Dermal Growth and Repair-Reticular Layer
• Collagenous fibers form Langer’s Lines
– the collagenous fibers that characterize the
dermal layer line themselves up in lines
(sometime called cleavage lines).
– If surgical incisions are made along these
cleavage lines, there will be a less
noticeable scar and healing will be much
quicker.
5/24/2017
28
Dermal Growth and Repair-Reticular Layer
• Elastic Fibers:
– If overstretched
and torn, forms
stretch marks.
5/24/2017
29
Tattoo Pigment
Epidermis
Dermis
Tattoo pigment is usually black and is inert and nonpolarizable; however, red tattoo pigment often contains
cinnabar (which has mercury in it).
5/24/2017
30
Subcutaneous Layer
• Subcutaneous Layer
– Hypodermis
– superficial fascia)
– Tissue type: connective
• loose areolar
• adipose
5/24/2017
31
SKIN LAYERS-Review
Primary Layers
•
Epidermis
• Stratum corneum
• Stratum lucidum
• Stratum granulosum
• Stratum spinosum
• Stratum basale
•
Dermal-Epidermal Junction (not a primary layer)
•
Dermis
• Papillary
• Reticular
Subcutaneous Layer (hypodermis; superficial fascia)
• Tissue type: connective (loose areolar and adipose)
5/24/2017
32
Skin Color
• Skin color is essentially determined by the quantity of melanin produced
by melanocytes in the stratum basale.
• Determining Factors
– Number of melanocytes – all races have approximately the same
number of melanocytes.
– Amount of melanin produced by melanocytes is determined by:
• Heredity – the primary factor
• Sunlight – sunlight increase melanin production
• Hormones – Adrenocorticotropic hormones (ACTH) and MSH
(Melanocyte stimulating hormone)
• Age – Increase in age may also influence melanocyte activity
(age spots, graying hair)
– Temporary Changes
• Amount of blood flow to skin, more = pinker
• Amount of oxygen in blood, less oxygen = blue (cyanosis)
5/24/2017
33
THE SKIN’S FUNCTIONS: Protection
• Protection From:
– Microbe infection (by layers of nonvascular
keratinocytes)
– Harmful chemicals (by layers of nonvascular
keratinocytes)
– Dehydration (by keratin)
– UV light (by melanin)
– Mechanical injury (by thick, strong dermis)
5/24/2017
34
THE SKIN’S FUNCTIONS: Protection
• SURFACE FILM
– A Thin Film of Materials That Covers the Skin’s Surface
• Consists of Secretions From Sweat and Sebaceous
Glands As Well As Dead Epithelial Cells
– FUNCTIONS
• Barrier
• Antibacterial/Antifungal (D/T Chemical Components)
• Lubricates (D/T Oil)
• Hydrates (D/T Sweat)
• Buffers (D/T Chemical Components)
5/24/2017
35
THE SKIN’S FUNCTIONS: Sensations
• SENSATION
– Skin Functions as a
Sense Organ for the
Sensations of Hot, Cold,
Pressure, Pain, and
Touch - D/T Sensory
Receptors in the Dermis
5/24/2017
36
THE SKIN’S FUNCTIONS: Movement
MOVEMENT WITHOUT INJURY
Ehler’s Danlos syndrome
– Skin Allows
Body Growth
and Movement
of the Body
Without Injury
to Underlying
Tissues and
Organs D/T
Elasticity of
the Dermis
and SQ Layer
Characterized by stretchy skin and loose joints
5/24/2017
Watch:
37
Collagen
Mutations in amino acid sequence causes defects in
collagen
that can
cause
problems
in these
areas:
5/24/2017
38
Collagen & Aging
Collagen Theory of Aging
•with age, collagen gets older
•old collagen gets stiff and not as
flexible causing problems such as:
•Hypertension(vessels cant expand
enough)
•organs malfunction (stiffness)
•hinders metabolic functions
5/24/2017
Wrinkles
Due to changes in
•reduced collagen
•decreased protein synthesis
•affect collagen type 1 & 3 in dermis
•reduced elastin
•general atrophy in extracellular matrix
•due to reduced fibroblasts
39
THE SKIN’S FUNCTIONS: Excretion
• EXCRETION
– Skin Functions as an
Excretory Organ D/T
Sweat Glands Located
in the Dermis
5/24/2017
40
THE SKIN’S FUNCTIONS: Vitamin D
• VITAMIN D PRODUCTION (ENDOCRINE FUNCTION)
– Mechanism: Precursor Compound in Skin Cells Activated By UV
Light  Transported By Blood to Liver, Kidney  Converted to
Vitamin D (Needed for Calcium Absorption)
– Vitamin D Classifies Loosely as a Hormone)
5/24/2017
41
THE SKIN’S FUNCTIONS: Immunity
• IMMUNITY
– Skin Works With the
Immune System to
Defend Against
Microorganisms D/T
Langerhans Cells in the
Epidermis and
Phagocytes
5/24/2017
42
THE SKIN’S FUNCTIONS: Homeostasis
• HOMEOSTASIS OF BODY TEMPERATURE
– Skin Helps to Maintain Constant Body Temperature
(Sweat Glands and Blood Vessels)
– BASIC PRINCIPLE
• To Maintain a Constant Body Temperature: Heat Production
Must Equal Heat Loss
• HEAT PRODUCTION: FROM FOOD CATABOLISM
– Nutrient Catabolism  Energy
» 1) Chemical (ATP)
» 2) Heat (Released)
• RELATES TO ACTIVITY
– Increased Activity  Increased Catabolism  Increased Heat
Production
– Cells That Are the Most Active and Produce the Most Heat: Liver,
Skeletal Muscle
5/24/2017
43
THE SKIN’S FUNCTIONS: Temperature Control-Heat Loss
– HEAT LOSS – 80%
Occurs Through the
Skin FROM
EVAPORATION AND
RADIATION
• Evaporation
– Vaporization of Liquid
(Requires Heat Energy)
– Example: Evaporation
of Sweat
– Most Impt. Way Heat
Loss Occurs in Hot
Temps.
5/24/2017
44
THE SKIN’S FUNCTIONS: Temperature Control-Heat Loss
– HEAT LOSS – 80%
Occurs Through the
Skin FROM
EVAPORATION AND
RADIATION
• Radiation
– Heat Transfer (Warmer
 Cooler) Without
Direct Contact Between
2 Objects
– Example: Dilation of
Blood Vessels in the
Dermis (Text)
– Most Impt. Way Heat
Loss Occurs in Cool
Temps.
5/24/2017
45
THE SKIN’S FUNCTIONS: Temperature Control
• HOMEOSTATIC
CONTROL OF BODY
TEMPERATURE
– MECHANISM
INVOLVED WHEN
BODY TEMPERATURE
INCREASES
5/24/2017
46
THE SKIN’S FUNCTIONS: Temperature Control
– HOMEOSTATIC
CONTROL OF
BODY
TEMPERATURE
• MECHANISM
INVOLVED
WHEN BODY
TEMPERATUR
E DECREASES
5/24/2017
47
Burns
• Burns are classified
based on depth
– 1st is just epidermal (top
layer)
– 2nd is deeper, involves
both dermal and
epidermal layers.
– 3rd is deepest, involves
epidermis, dermis, and
sometimes deeper
levels.
5/24/2017
48
Burns-1st degree
• 1st degree
–
–
–
–
–
causes minor discomfort
some reddening
typical sunburn
Peeling
no blistering.
5/24/2017
49
Burns-2nd degree
• 2nd degree
– involves the deep
epidermal layers
– and some dermal
layers
– may damage sweat
glands, etc
– blistering
– swelling
– scarring.
5/24/2017
50
Burns-3rd degree
• 3rd degree burns
– full-thickness
burns
– complete
destruction of
dermis and
epidermis
– no pain due to
destruction of
nerve endings
5/24/2017
51
Rule of 9s
• Estimation of body
surface area is
accomplished by
the rule of 9s.
• Victim’s palm size is
roughly 1% Of body
surface.
5/24/2017
52
Rule of Nines
5/24/2017
53
Appendages: Hair-Follicle
•
HAIR FOLLICLE & GERMINAL MATRIX
– Hair Follicle
• Tubelike, Holds Hair Root
• Formation: Cells from the
Epidermis Push Down into the
Dermis
• Follicle Wall: 2 Layers
– 1) Outer: Dermal Root
Sheath
– 2) Inner: Epithelial Root
Sheath
5/24/2017
54
Appendages: Hair-Germinal Matrix
– Germinal Matrix
• Cap-shaped Cluster of
Cell at Bottom of Hair
Follicle
• Formed from stratum
germinativum
• Forms the Hair (Mitosis
and Keratinzation)
• Papilla’s (from dermis)
capillaries nourish g.
matrix-next slide.
5/24/2017
55
Appendages: Hair-Papilla, Root, Shaft
• HAIR PAPILLA
– Dermis that Protrudes
into the Germinal Matrix
– Contains Blood Vessels
• HAIR ROOT
– Hidden Portion of the
Hair (Lies in Hair
Follicle)
• HAIR SHAFT
– Visible Portion of the
Hair
5/24/2017
56
Appendages: Hair-Cortex & Medulla
• CORTEX AND
MEDULLA OF HAIR
– Medulla: Inner Core of
the Hair
– Cortex: Outer Portion of
the Hair (Cells Contain
Melanin and Keratin)
– Cuticle: Covers Cortex
5/24/2017
57
Appendages: Hair-Sebaceous Glands
• SEBACEOUS
GLANDS
– Oil Glands; Part of Hair
Follicle
– Secrete Sebum Directly
into Follicle
– Functions of Sebum:
• 1) Lubricates Skin, Hair
• 2) Antifungal
– Located in Dermis in All
Areas Except Palms and
Soles
5/24/2017
58
Appendages: Nails
• Nail body – visible part of
the nail
– Heavily keratinized cells.
• Root – invisible part found
behind cuticle
• Cuticle – fold of skin
• Lunula – moon shape,
– Cells beneath are stratus
germinativum that produce
nail cells by mitosis.
• Nail bed – cells supporting
the nail
5/24/2017
59
Appendages: Skin Glands
• Sweat Glands
– most numerous skin
glands
– produces watery liquid in
which waste materials
such as ammonia and
urea and salts are
excreted
– bacterial growth causes it
to stink
– Two types:
• Eccrine
– most common type
• Apocrine
– deep in the
subcutaneous layer;
armpit, areola,
around anus
5/24/2017
60
Appendages: Skin Glands
• Sebaceous glands
– Oil glands;
sebum (oil) has
antifungal and
antibacterial
properties
5/24/2017
61
Appendages: Skin Glands
• Ceruminous glands
– specially modified
sweat glands;
found in external
ear canals; produce
cerumen (wax)
5/24/2017
62