Transcript Chapter 6--Integumentary System - USA-AP

CHAPTER 6
AFTER YOU HAVE COMPLETED THIS CHAPTER, YOU SHOULD BE ABLE TO:
1. Classify, compare the structure of, and give
2.
3.
4.
5.
6.
examples of each type of body membrane.
Describe the structure and function of the
epidermis and dermis.
List and briefly describe each accessory organ of
the skin.
List and discuss the three primary functions of
the integumentary system.
List and describe major skin disorders and
infections.
Classify burns and describe how to estimate the
extent of a burn injury.
In this presentation we will discuss the following:
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CLASSIFICATION OF BODY MEMBRANES
 Epithelial Membranes
 Connective Tissue Membranes
THE SKIN
 Structure of the Skin
 Appendages of the Skin
 Functions of the Skin
DISORDERS OF THE SKIN
 Skin Lesions
 Burns
 Skin infections
 Vascular and Inflammatory Skin Disorders
 Skin Cancer
CLASSIFICATION OF
BODY MEMBRANES
A. Classification of body membranes (Figure 6-1)
1. Epithelial
membranes—
composed of
epithelial tissue
and an underlying
layer of
connective tissue
2. Connective tissue
membranes—
composed largely
of various types
of connective
tissue
Page(s) 147-149
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CLASSIFICATION OF
BODY MEMBRANES
B. Epithelial membranes
1. Cutaneous membrane—the skin
2. Serous membranes—simple
squamous epithelium on a
connective tissue basement
membrane
a. Types
(1) Parietal—line walls of body
cavities
(2) Visceral—cover organs found
in body cavities
b. Examples
(1) Pleura—parietal and visceral
layers line walls of thoracic
cavity and cover the lungs
(2) Peritoneum—parietal and
visceral layers line walls of
abdominal cavity and cover
the organs in that cavity
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CLASSIFICATION OF
BODY MEMBRANES
B. Epithelial membranes
2. Serous membranes—simple
squamous epithelium on a
connective tissue basement
membrane
c. Diseases
(1) Pleurisy—inflammation of
the serous membranes
that line the chest cavity
and cover the lungs
(2) Peritonitis—inflammation of
the serous membranes in
the abdominal cavity that
line the walls and cover the
abdominal organs
3. Mucous membranes
a. Line body surfaces that open
directly to the exterior
b. Produce mucus, a thick
secretion that keeps the
membranes soft and moist
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CLASSIFICATION OF
BODY MEMBRANES
C. Connective tissue membranes
1. Do not contain
epithelial
components
2. Produce a lubricant
called synovial fluid
3. Examples are the
synovial
membranes in the
spaces between
joints and in the
lining of the bursal
sacs
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THE SKIN
A. Structure (Figure 6-2)-two primary layers
called epidermis and dermis
1. Epidermis
a. Outermost and thinnest primary
layer of skin
b. Composed of several layers of
stratified squamous epithelium
c. Stratum germinativum—innermost
layer of cells that continually
reproduce; the new cells move
toward the surface
d. As cells approach the surface, they
are filled with a tough,
waterproof protein called keratin
and eventually flake off
Page(s) 150-152
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THE SKIN
A. Structure (Figure 6-2) —two primary
layers called epidermis and dermis
1. Epidermis
e. Stratum corneum—outermost layer of
keratin—filled cells
f. Pigment-containing layer—epidermal
layer that contains pigment cells
called melomocytes, which produce
the brown pigment melanin
(1) Vitiligo—acquired loss of epidermal
melanocytes (Figure 6-4)
g. Blisters—caused by breakdown of
union between cells or primary layers
of skin
h. Dermal-epidermal junction—specialized
area between two primary skin layers
Page(s) 151-158
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THE SKIN
A. Structure (Figure 6-2) —two primary layers
called epidermis and dermis
A. fibers 2. Dermis
a. Deeper and thicker of the two
primary skin layers; composed
largely of connective tissue
b. Upper area of dermis characterized
by parallel rows of peglike dermal
papillae
c. Ridges and grooves in dermis form
pattern unique to each individual
(basis of fingerprinting)
d. Deeper areas of dermis filled with
network of tough collagenous
and stretchable elastic fibers
Page(s) 151, 158-159
THE SKIN
A. Structure (Figure 6-2) —two primary layers
called epidermis and dermis
2. Dermis
e. Number of elastic fibers decreases with
age and contributes to wrinkle
formation
(1) Striae—stretch marks
f. Dermis also contains nerve endings,
muscle fibers, hair follicles, sweat and
sebaceous glands, and many blood
vessels
(1) Birthmarks—malformation of dermal
blood vessels
(a) Strawberry hemangioma
(b) Port-wine stain
(c) Stork bite
Page(s) 151, 158-159
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THE SKIN
B. Appendages of the skin
1. Hair (Figure 6-6)
a. Soft hair of a fetus and newborn called
lanugo
b. Hair growth requires epidermal
tubelike structures called hair follicle
c. Hair growth begins from hari papilla
d. Hair root lies hidden in follicle; visible
part of hair called shaft
e. Alopecia (Figure 6-7) hair loss
f. Arrector pili—specialized smooth
muscle that produces “goose
pimples” and causes hair to stand up
straight
Page(s) 151, 159-160
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THE SKIN
B. Appendages of the skin
2. Receptors (Figure 6-2)
a. Specialized nerve endings—
make it possible for skin to act
as a sense organ
b. Meissner’s corpuscle—capable
of detecting light touch
c. Pacinian corpuscle—capable of
detecting pressure
Page(s) 151, 161
THE SKIN
B. Appendages of the skin
3. Nails (Figure 6-8)
a. Produced by epidermal
cells over terminal ends
of fingers and toes
b. Visible part called nail
body
c. Root lies in a groove and
is hidden by cuticle
d. Crescent-shaped area
nearest root called
lunula
e. Nail bed may change
color with change in
blood flow
Page(s) 161
THE SKIN
B. Appendages of the skin
3. Nails (Figure 6-9)
f. Normal variations in nail
structure
(1) Longitudinal ridges in
light-skinned individuals
(2) Pigmented bands in darkskinned individuals
Page(s) 161-162
THE SKIN
B. Appendages of the skin
3. Nails
g. Abnormal variations in
nail structure (Figure 610)
(1) Onych0lysis—
separation of nail
from nail bed
(2) Pitting—common in
psoriasis
Page(s) 161-162
THE SKIN
B. Appendages of the skin
4. Skin glands
a. Types
(1) Sweat or sudoriferous
(2) Sebaceous
b. Sweat or sudoriferous glands
(1) Types
(a) Eccrine sweat glands
(1) Most numerous, important, and wide-spread of the sweat
glands
(2) Produce perspiration or sweat, which flows out through pores
on skin surface
(3) Function throughout life and assist in body heat regulation
Page(s) 162
THE SKIN
B. Appendages of the skin
4. Skin glands
b. Sweat or sudoriferous glands
(1) Types
(b) Apocrine sweat glands
(1) Found primarily in axilla and around genitalia
(2) Secrete a thicker, milky secretion quite different from eccrine
perspiration
(3) Breakdown of secretion by skin bacteria produces odor
(c) Sebaceous glands
(1) Secrete oil or sebum for hair and skin
(2) Level of secretion increases during adolescence
(3) Amount of secretion regulated by sex hormones
(4) Sebum in sebaceous gland ducts may darken to form a
blackhead
(5) Acne vulgaris (Figure 6-11) inflammation of sebaceous gland
ducts
Page(s) 162-163
Page(s) 162-163
THE SKIN
C. Functions of the skin
1. Protection—first line
of defense
a. Against infection by
microbes A
b. Against ultraviolet
rays from sun
c. Against harmful
chemicals
d. Against cuts and
tears
e. Skin grafts (Figure
6-12)
Page(s) 163-164
THE SKIN
C. Functions of the skin
2. Temperature regulation
a. Skin can release almost 3000 calories of
body heat per day
(1) Mechanisms of temperature regulation
(a) Regulation of sweat secretion
(b) Regulation of flow of blood close to the
body surface
3. Sense organ activity
a. Skin functions as an enormous sense organ
b. Receptors serve as receivers for the body
keeping it informed of changes in its
environment
Page(s) 164
DISORDERS OF THE SKIN
(DERMATOSES)
A. Skin lesions (Table 6-1)
1. Elevated lesions—cast a shadow outside their edges
a. Papule—small, firm raised lesion
b. Plaque—large raised lesion
c. Vesicle—blister
d. Pustule—pus-filled lesion
e. Crust—scab
f. Wheal (hive)—raised, firm lesion with a light center
2. Flat lesions—do not cast a shadow
a. Macule—flat, discolored region
3. Depressed lesions cast a shadow within their edges
a. Excoriation—missing epidermis, as in a scratch
wound
b. Ulcer—crater-like lesion
c. Fissure—deep crack or break
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DISORDERS OF THE SKIN
(DERMATOSES)
B. Burns
1. Treatment and recovery or survival depend on total
area involved and severity or depth of the burn
2. Classification of burns (Figure 6-13)
a. First—degree (partial-thickness) burns—only
surface layers of epidermis involved
b. Second-degree (partial-thickness) burns—involve
the deep epidermal layers and always cause injury
to the upper layers of the dermis
c. Third-degree (full-thickness) burns (Figure 6-14)
characterized by complete destruction of the
epidermis and dermis
(1) May involve underlying muscle and bone (fourth
degree)
(2) Lesion is insensitive to pain because of destruction of
nerve endings immediately after injury—intense
pain is soon experienced
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DISORDERS OF THE SKIN
(DERMATOSES)
B. Burns
3. Estimating body
surface area
using the "rule
of nines"
(Figure 6-15) in
adults
a. Body divided
into 11 areas
of 9% each
b. Additional 1%
of body
surface area
around
genitals
Page(s) 165, 167
DISORDERS OF THE SKIN
(DERMATOSES)
C. Skin infections (Figure 6-16)
1. Impetigo—highly contagious staphylococcal
infection
2. Tinea—fungal infection (mycosis) of the skin;
several forms occur
3. Boils—furuncles; staphylococcal infection in
hair follicles
4. Scabies—parasitic infection
Page(s) 167-169
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DISORDERS OF THE SKIN
(DERMATOSES)
D. Vascular and inflammatory skin disorders
1. Decubitus ulcers (bedsores) develop when
pressure slows down blood flow to local areas of
the skin
2. Urticaria or hives—red lesions caused by fluid loss
from blood vessels
3. Scleroderma—disorder of vessels and connective
tissue characterized by hardening of the skin;
two types: localized and systemic
4. Psoriasis—chronic inflammatory condition
accompanied by scaly plaques
5. Eczema—common inflammatory condition
characterized by papules, vesicles, and crusts;
not a disease itself but a symptom of an
underlying condition
Page(s) 169-170
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DISORDERS OF THE SKIN
(DERMATOSES)
E. Skin cancer
1. Three common types
a. Squamous cell carcinoma—the most common
type, characterized by hard, raised tumors
b. Basal cell carcinoma—characterized by papules
with a central crater; rarely spreads
c. Melanoma—malignancy in a nevus (mole); the
most serious type of skin cancer
2. The most important causative factor in common
skin cancers is exposure to sunlight
3. Kaposi sarcoma, characterized by purple lesions, is
associated with AIDS and other immune
deficiencies
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CREDITS

All photos and references are taken from:
Thibodeau, Gary, & Patton, Kevin. (2005).
The Human body in health & disease.
Mosby.
ISBN: 0-323-03161-7