Learning Objectives Other Epidermal Cells
1. Describe the general functions of the Melanocytes (mel′ă-nō-sītz), produce the
integumentary system. pigment melanin, which contributes to skin
2. Describe the structure and function of the color.
epidermis.
3. Discuss the epidermal strata and relate them Langerhans cells are part of the immune
to the process of keratinization. system.
4. Describe the structure and functions of the
subcutaneous tissue underlying the skin. Merkel cells are specialized epidermal cells
5. Name the glands of the skin and describe associated with the nerve endings responsible
the secretions they produce. for detecting light touch and superficial
Your text here 1
pressure
Chapter 5-Integumentary System
What does integument mean? Regions (Strata) of Epidermis
-covering (1) stratum basale,
(2) stratum spinosum,
Components: (3) stratum granulosum,
-skin (4) stratum lucidum, and
-hair (5) stratum corneum.
-nails
-glands 1. Stratum basale or stratum germinativum
Functions - deepest layer of epidermis
1. Protection: - single layer of cells of cuboidal or
water loss, microbes, UV light columnar cells.
- firmly attached to dermis
2. Sensation: -The epidermis is anchored to the basement
hot, cold, pain, pressure membrane by hemidesmosomes.
3. Temperature regulation: -The connections formed by the
helps maintain homeostasis hemidesmosomes and desmosomes provide
structural strength to the epidermis.
4. Excretion:
removes waste 2. Stratum Spinosum
5. Vitamin D production: -Superficial to the stratum basale is the
UV light stimulates production stratum spinosum, consisting of 8–10 layers
of many-sided cells.
Skin Facts
-Weighs 9 lbs. -As the cells in this stratum are pushed to the
-Used to determine body fat surface, they flatten; desmosomes break apart,
-2 main regions: epidermis and dermis and new desmosomes form.
Epidermis 3. Stratum Granulosum
-1st major skin region (outside)
-Composed of stratified squamous epithelium -The stratum granulosum consists of two to
-Contains no blood vessels. five layers of somewhat flattened, diamond-
-The living cells of the epidermis receive shaped cells.
nutrients and excrete waste products by the
diffusion of substances between the epidermis -The long axes of these cells are oriented
and the capillaries of the dermis. parallel to the surface of the skin.
-Most cells of the epidermis are called
keratinocytes because they produce a protein -This stratum derives its name from the
mixture called keratin, which makes the cells presence of protein granules of keratohyalin,
more durable. which accumulate in the cytoplasm of the
-It is the durability of the keratinocytes that keratinocytes.
gives the epidermis its ability to resist abrasion
and reduce water loss. 4. Stratum Lucidum
,the stratum granulosum, has dispersed around d. For normal bone growth
the keratin fibers. e. To prevent rickets
5. Stratum Corneum Regions (Strata) of Epidermis
(1) stratum basale,
-The last, and most superficial, stratum of the (2) stratum spinosum,
epidermis. (3) stratum granulosum,
(4) stratum lucidum, and
-This stratum is composed of 25 or more (5) stratum corneum.
layers of dead, overlapping squamous cells
joined by desmosomes. Skin is classified as thick or thin based on
the structure of the epidermis.
-Excessive shedding of the stratum corneum of
the scalp results in dandruff. Thick skin has all five epithelial strata, and the
stratum corneum has many layers of cells.
-Less noticeably, skin cells are continually
shed from other areas as clothes rub against It is found in areas subject to pressure or
the body or as the skin is washed. friction, such as the palms of the hands, the
soles of the feet, and the fingertips.
-The stratum corneum consists of
cornified cells, which are dead keratinocytes, Thin skin covers the rest of the body and is
with a hard protein envelope, filled with the more flexible than thick skin.
protein keratin.
Skin Color
-Keratin is a mixture of keratin fibers and The factors that determine skin color include:
keratohyalin. (1) pigments in the skin,
(2) blood circulating through the skin, and
Callus: (3) the thickness of the stratum corneum.
forms when stratum corneum has
frequent friction Melanin
-the group of pigments primarily responsible for
Let’s Review! skin, hair, and eye color.
1.Which of the following is NOT a function
of the integumentary system? -Melanin also provides protection against
ultraviolet light from the sun.
a. Production of a protein
b. Synthesis of a hormone -Large amounts of melanin are found in certain
c. Creation of new cells regions of the skin, such as freckles, moles,
d. Excretion of urine the nipples, the areolae of the breasts, the
e. Regulation of body temperature axillae, and the genitalia.
2. Which group most accurately represents -Other areas of the body, such as the lips,
the order of strata in the epidermis? palms of the hands, and soles of the feet,
contain less melanin.
a. basale, granulosum, lucidum, corneum
b. epidermis, dermis, hypodermis -Melanin is produced by melanocytes
c. dermis, epidermis, hypodermis irregularly shaped cells with many long
d. corneum, granulosum, lucidum, spinosum, processes that extend between the
basale keratinocytes of the stratum basale and the
e. corneum, lucidum, granulosum, spinosum, stratum spinosum. (Figure 5.4)
basale
-Melanocytes produce and package melanin
3. At which layer do cells stop dividing and into vesicles called melanosomes, which
start producing keratin? move into cell processes of the melanocytes.
a. stratum basale -Melanin production is determined by
b. stratum corneum genetic factors, exposure to light, and
c. Stratum spinosum hormones.
, Racial variations in skin color are Skin Color and Disease
determined by several major factors: Redness:
fever, hypertension, inflammation,
-types of melanin produced allergies
-amount of melanin produced Pallor:
-size of melanosomes (melanin-filled vesicles anemia or low blood pressure
in cells) Jaundice:
-number of melanosomes liver disorder (yellow)
-distribution of melanosomes Bronzing:
Addison’s disease (kidney disease)
Carotene: Bruising:
- yellow-orange pigment found in plants broken blood vessels
- accumulates in stratum corneum
Hair Components
Hemoglobin: Hair/shaft:
- gives pinkish-red color flexible strands of keratinized cells
- found in red blood cells Root:
below skin (scalp)
Dermis
-2nd major skin region Hair Components
-Dense connective tissue Hair Bulb:
-Contains collagen and elastic fibers - base of root
-Contains fibroblasts, nerve endings, smooth - where hair is produced
muscle, glands, blood vessels, and hair
follicles Hair Follicle:
- group of cells that surround root and bulb
Cleavage lines: - gives hair different shapes
- area where skin is most resistant to
stretching How is Hair Produced?
- due to orientation of collagen fibers -Hair is produced in hair bulb
- important in scarring
-Hair bulb rests on blood vessels to supply it
Layers of Dermis with nutrients
Papillary layer:
- thin connective tissue layer that contains -Hair grows longer as cells are added to base
blood vessels of hair bulb
Dermal papillae: Hair Facts
-projections that extend up into epidermis -Testosterone and good nutrition promote hair
-remove waste and help regulate body temp. growth
-ridged on hands and feet (fingerprints) -Growth occurs in cycles: active and resting
-pattern is genetically determined -Scalp hair grows for 3 years and rests for 1
year
Reticular layer: -Eyelashes grow for 30 days and rest for 105
- deepest layer of dermis days
- accounts for 80% of dermis -We lose about 90 scalp hairs/day
-Grey hair is the loss or fading of melanin
Hypodermis -Male pattern baldness is from the loss of the
-Below dermis hair follicle
-Foundation of skin
-Attaches skin to underlying muscle and bone Hair Muscles
-Contains loose and adipose tissue Arrector Pili:
-Contains ½ of body’s fat -smooth muscle that surrounds each hair
-Body fat for females 20-23%, males 13-25% follicle
Tanning and Sunburns -contracts and hair stands on end (goose
-Exposure to UV light stimulates melanocytes bumps)
to increase production of melanin
1. Describe the general functions of the Melanocytes (mel′ă-nō-sītz), produce the
integumentary system. pigment melanin, which contributes to skin
2. Describe the structure and function of the color.
epidermis.
3. Discuss the epidermal strata and relate them Langerhans cells are part of the immune
to the process of keratinization. system.
4. Describe the structure and functions of the
subcutaneous tissue underlying the skin. Merkel cells are specialized epidermal cells
5. Name the glands of the skin and describe associated with the nerve endings responsible
the secretions they produce. for detecting light touch and superficial
Your text here 1
pressure
Chapter 5-Integumentary System
What does integument mean? Regions (Strata) of Epidermis
-covering (1) stratum basale,
(2) stratum spinosum,
Components: (3) stratum granulosum,
-skin (4) stratum lucidum, and
-hair (5) stratum corneum.
-nails
-glands 1. Stratum basale or stratum germinativum
Functions - deepest layer of epidermis
1. Protection: - single layer of cells of cuboidal or
water loss, microbes, UV light columnar cells.
- firmly attached to dermis
2. Sensation: -The epidermis is anchored to the basement
hot, cold, pain, pressure membrane by hemidesmosomes.
3. Temperature regulation: -The connections formed by the
helps maintain homeostasis hemidesmosomes and desmosomes provide
structural strength to the epidermis.
4. Excretion:
removes waste 2. Stratum Spinosum
5. Vitamin D production: -Superficial to the stratum basale is the
UV light stimulates production stratum spinosum, consisting of 8–10 layers
of many-sided cells.
Skin Facts
-Weighs 9 lbs. -As the cells in this stratum are pushed to the
-Used to determine body fat surface, they flatten; desmosomes break apart,
-2 main regions: epidermis and dermis and new desmosomes form.
Epidermis 3. Stratum Granulosum
-1st major skin region (outside)
-Composed of stratified squamous epithelium -The stratum granulosum consists of two to
-Contains no blood vessels. five layers of somewhat flattened, diamond-
-The living cells of the epidermis receive shaped cells.
nutrients and excrete waste products by the
diffusion of substances between the epidermis -The long axes of these cells are oriented
and the capillaries of the dermis. parallel to the surface of the skin.
-Most cells of the epidermis are called
keratinocytes because they produce a protein -This stratum derives its name from the
mixture called keratin, which makes the cells presence of protein granules of keratohyalin,
more durable. which accumulate in the cytoplasm of the
-It is the durability of the keratinocytes that keratinocytes.
gives the epidermis its ability to resist abrasion
and reduce water loss. 4. Stratum Lucidum
,the stratum granulosum, has dispersed around d. For normal bone growth
the keratin fibers. e. To prevent rickets
5. Stratum Corneum Regions (Strata) of Epidermis
(1) stratum basale,
-The last, and most superficial, stratum of the (2) stratum spinosum,
epidermis. (3) stratum granulosum,
(4) stratum lucidum, and
-This stratum is composed of 25 or more (5) stratum corneum.
layers of dead, overlapping squamous cells
joined by desmosomes. Skin is classified as thick or thin based on
the structure of the epidermis.
-Excessive shedding of the stratum corneum of
the scalp results in dandruff. Thick skin has all five epithelial strata, and the
stratum corneum has many layers of cells.
-Less noticeably, skin cells are continually
shed from other areas as clothes rub against It is found in areas subject to pressure or
the body or as the skin is washed. friction, such as the palms of the hands, the
soles of the feet, and the fingertips.
-The stratum corneum consists of
cornified cells, which are dead keratinocytes, Thin skin covers the rest of the body and is
with a hard protein envelope, filled with the more flexible than thick skin.
protein keratin.
Skin Color
-Keratin is a mixture of keratin fibers and The factors that determine skin color include:
keratohyalin. (1) pigments in the skin,
(2) blood circulating through the skin, and
Callus: (3) the thickness of the stratum corneum.
forms when stratum corneum has
frequent friction Melanin
-the group of pigments primarily responsible for
Let’s Review! skin, hair, and eye color.
1.Which of the following is NOT a function
of the integumentary system? -Melanin also provides protection against
ultraviolet light from the sun.
a. Production of a protein
b. Synthesis of a hormone -Large amounts of melanin are found in certain
c. Creation of new cells regions of the skin, such as freckles, moles,
d. Excretion of urine the nipples, the areolae of the breasts, the
e. Regulation of body temperature axillae, and the genitalia.
2. Which group most accurately represents -Other areas of the body, such as the lips,
the order of strata in the epidermis? palms of the hands, and soles of the feet,
contain less melanin.
a. basale, granulosum, lucidum, corneum
b. epidermis, dermis, hypodermis -Melanin is produced by melanocytes
c. dermis, epidermis, hypodermis irregularly shaped cells with many long
d. corneum, granulosum, lucidum, spinosum, processes that extend between the
basale keratinocytes of the stratum basale and the
e. corneum, lucidum, granulosum, spinosum, stratum spinosum. (Figure 5.4)
basale
-Melanocytes produce and package melanin
3. At which layer do cells stop dividing and into vesicles called melanosomes, which
start producing keratin? move into cell processes of the melanocytes.
a. stratum basale -Melanin production is determined by
b. stratum corneum genetic factors, exposure to light, and
c. Stratum spinosum hormones.
, Racial variations in skin color are Skin Color and Disease
determined by several major factors: Redness:
fever, hypertension, inflammation,
-types of melanin produced allergies
-amount of melanin produced Pallor:
-size of melanosomes (melanin-filled vesicles anemia or low blood pressure
in cells) Jaundice:
-number of melanosomes liver disorder (yellow)
-distribution of melanosomes Bronzing:
Addison’s disease (kidney disease)
Carotene: Bruising:
- yellow-orange pigment found in plants broken blood vessels
- accumulates in stratum corneum
Hair Components
Hemoglobin: Hair/shaft:
- gives pinkish-red color flexible strands of keratinized cells
- found in red blood cells Root:
below skin (scalp)
Dermis
-2nd major skin region Hair Components
-Dense connective tissue Hair Bulb:
-Contains collagen and elastic fibers - base of root
-Contains fibroblasts, nerve endings, smooth - where hair is produced
muscle, glands, blood vessels, and hair
follicles Hair Follicle:
- group of cells that surround root and bulb
Cleavage lines: - gives hair different shapes
- area where skin is most resistant to
stretching How is Hair Produced?
- due to orientation of collagen fibers -Hair is produced in hair bulb
- important in scarring
-Hair bulb rests on blood vessels to supply it
Layers of Dermis with nutrients
Papillary layer:
- thin connective tissue layer that contains -Hair grows longer as cells are added to base
blood vessels of hair bulb
Dermal papillae: Hair Facts
-projections that extend up into epidermis -Testosterone and good nutrition promote hair
-remove waste and help regulate body temp. growth
-ridged on hands and feet (fingerprints) -Growth occurs in cycles: active and resting
-pattern is genetically determined -Scalp hair grows for 3 years and rests for 1
year
Reticular layer: -Eyelashes grow for 30 days and rest for 105
- deepest layer of dermis days
- accounts for 80% of dermis -We lose about 90 scalp hairs/day
-Grey hair is the loss or fading of melanin
Hypodermis -Male pattern baldness is from the loss of the
-Below dermis hair follicle
-Foundation of skin
-Attaches skin to underlying muscle and bone Hair Muscles
-Contains loose and adipose tissue Arrector Pili:
-Contains ½ of body’s fat -smooth muscle that surrounds each hair
-Body fat for females 20-23%, males 13-25% follicle
Tanning and Sunburns -contracts and hair stands on end (goose
-Exposure to UV light stimulates melanocytes bumps)
to increase production of melanin
