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5.1
Skin
The Body’s Largest Organ
Fingerprints
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Functions of the Skin
 Physical barrier -1st line of defense. Protects against injury,
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infection by microorganisms, and damage by harmful rays of
the sun.
protects the internal tissues and organs, helps regulate
internal conditions
protects the body from dehydration
protect the body against changes in temperature
chemicals on the skin kill certain surface bacteria
acidic pH of sweat slows the growth of some microbes
helps dispose of wastes and helps stores water and fat
receptor for touch, pressure, pain and temperature
Skin Tissues
 2 main layers
 Epidermis- the
outermost layer of skin,
waterproof barrier and
creates our skin tone
 Dermis- beneath the
epidermis, contains tough
connective tissue, and
accessory organs.
 accessory organs
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sweat glands
hair follicles.
Epidermis
 made up of epithelial tissue
 makes up the “coverings and linings” in the
human body.
 cells are packed closely together
 avascular, (lacking a blood supply)
 the reasons we shed dry skin cells.
Dermis
 composed of connective tissue
 blood supply located in the lower levels of
connective tissue
 consists of cells embedded in a matrix, or
framework.
 contain elastin or collagen fibers
provide flexibility,
 durability
 stretch to the tissue as in skin.
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Keratin
 a very strong protein
that can be found in
outer layers of the
skin, hair, nails,
hooves, feathers.
 Fingernails and Horse
hoof is an example of
keratin.
Collagen
 gives the skin its
strength and durability
and is responsible for
the smooth, plump
appearance
 providing the structural
scaffolding for shape of
cells, tissues, and
organs.
 if it weren't for collagen
the body would fall
apart
Elastin
 In connective tissue
that is elastic and
allows tissues in the
body to resume their
shape after stretching
or contracting.
 Elastin helps skin to
return to its original
position when it is
poked or pinched.
sweat glands and sebaceous glands
 sweat glands
situated in almost
all of the human
skin
 sebaceous glands
are tiny glands in
the skin which
secrete a
lubricating oily
matter (sebum)
into the hair
follicles to lubricate
the skin and hair
Essential Questions
 Essential Questions
 1. What are the functions of skin?
 2. What types of tissue make up the layers of the skin?
 3. What role do accessory organs such as sweat glands
and sebaceous glands play in the skin?
Activity 5.1.1 Under Your Skin
 add a piece of skin to their maniken.
 Roll out a thin sheet of yellow or orange clay. This layer will
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represent the dermis.
Roll out an even thinner sheet of white clay and place this
sheet over the dermis. This will serve as the epidermis.
Carefully drape the newly formed “skin” over the chest or
upper arm, Place the skin over existing blood vessels and
muscles
This strong tissue will cover and protect structures found
beneath.
Note how these structures that lie beneath contribute to
physical appearance and identity.
Leave an open edge to appreciate layering of skin tissue.
(NOTE) blood vessels do traverse the dermis.
Protection
In what ways can we protect our
skin from stress and injury?
 even with protection our skin, is
going to have natural wear and
tear.
since the skin is the body’s first
line of defense, it is subject to
major damage.
Activity 5.1.2 Burn Unit
st
1
nd
2
rd
3
and
th
4
degree burns
Essential Questions
 4. What happens to skin as it is exposed to
sunlight and as a person ages?
 5. Which layers of the skin are damaged in
different types of burns?
 6. How does burn damage in the skin affect other
functions in the body?
 7. How do medical professionals in different
fields assist with burn care and rehabilitation?
Activity 5.1.3 Hurts so Good
 Raise their hands if they would be happy never to feel
pain again.
 watch a video clip presented in the Discovery Channel
special, Human Body: Pushing the Limits.
 Video 3
 Examine the role pain plays in protection,
Essential Questions
 8. What role does pain play in the human
body?
 9. How does the body interpret and process
pain?
 10. Why would the inability to feel pain
actually put the human body in danger
5.1 Key Terms
 Collagen- An insoluble fibrous protein of vertebrates that is the chief
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constituent of the fibrils of connective tissue (as in skin and tendons) and of the
organic substance of bones.
Connective Tissue- Animal tissue that functions mainly to bind and support
other tissues, having a sparse population of cells scattered through an
extracellular matrix.
Dermis- The sensitive vascular inner mesodermic layer of the skin.
Elastin- A protein that is similar to collagen and is the chief constituent of
elastic fibers.
Endorphin- A hormone produced in the brain and anterior pituitary that
inhibits pain perception .
Epidermis- The outer nonsensitive and nonvascular layer of the skin of a
vertebrate that overlies the dermis.
Epithelium- A membranous cellular tissue that covers a free surface or lines a
tube or cavity of an animal body and serves especially to enclose and protect the
other parts of the body, to produce secretions and excretions, and to function in
assimilation.
Exocrine gland- A gland (as a sweat gland, a salivary gland, or a kidney) that
releases a secretion external to or at the surface of an organ by means of a canal
or duct.
5.1 Key Terms
 First-degree burn- A mild burn characterized by heat, pain, and reddening of
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the burned surface but not exhibiting blistering or charring of tissues.
Keratin- Any of various sulfur-containing fibrous proteins that form the
chemical basis of epidermal tissues (as hair and nails) and are typically not
digested by enzymes of the gastrointestinal tract.
Melanin- Any of various black, dark brown, reddish brown, or yellow pigments
of animal or plant structures (as in skin and hair).
Pain- Basic bodily sensation that is induced by a noxious stimulus, is received
by naked nerve endings, is characterized by physical discomfort (as pricking,
throbbing, or aching), and typically leads to evasive action.
Sebaceous gland- Any of the small sacculated glands lodged in the substance
of the derma, usually opening into the hair follicles, and secreting an oily or
greasy material composed in great part of fat which softens and lubricates the
hair and skin.
Second-degree burn- A burn marked by pain, blistering, and superficial
destruction of dermis with edema and hyperemia of the tissues beneath the
burn.
Third-degree burn- Severe burn characterized by destruction of the skin
through the depth of the dermis and possibly into underlying tissues, loss of
fluid, and sometimes shock.
Activity 5.2.1
 Bones -
Remarkable example of engineering combining light
weight, flexibility and incredible strength.
 lb per lb stronger then concrete
 Every 7 years a healthy body completely replaces every bone cell
in the entire body keeping them strong.
 Constantly remodeling
 osteoblast
 osteoclast
 Who in the class has ever broken a bone.
 How does human skeletal system protect us
 Human Body: Pushing the Limits video on strength available at
http://dsc.discovery.com/tv/human-body/explorer/explorer.html.
 Alternatively, view the clip on DVD. The clip is located on the
Strength DVD – Chapter 2 – 1.15.
Bone make up
 Matrix of hollow cells
 Walls thin as paper
 Get flexibility
 elastin
 collagen
 Gets it rigidity
 calcium
 Phosphorus
 Almost ½ of bone mass
is soft and alive allowing
them to bend
Bones
 206 Tough but Flexible
Bones in the human
body.
 Protein fibers wrapped in
hard mineral salts
 4 types
 Long bone
 Short bone
 flat bone
 Irregular bone
 Spongy Bone
 Irregular latticework of thin
plates of bone
 Found inside short, flat and
irregular bones
 In the epiphysis of long bone
 Red bone marrow
 Compact Bone External portion of all bone
 Contains few spaces between
osteons
 Bulk of the shaft of long
bone
 Yellow bone marrow
5.2.2 X-Ray Vision
 Bones are strong
but sometimes
extreme stress will
fracture of break a
bone
Essential Questions
 1. How does the skeletal system assist with protection in
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the body?
2. How does the structure of compact bone differ from the
structure of spongy bone?
3. How does the overall structure of bone provide great
strength and flexibility, but keep bone from being too
bulky and heavy?
4. What is an X-ray?
5. What are the different types of bone fractures and how
are they identified on X-rays?
6. How can damage to a bone affect other human body
systems?
7. What is bone remodeling?
Essential Questions
 8. How do osteoblasts and osteoclasts assist with bone
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remodeling and overall bone homeostasis?
9. What is the relationship between bone remodeling
and blood calcium levels?
10. How do hormones assist in the maintenance of
healthy bone and the release of calcium to be used in
other body processes?
11. What are the four main stages of healing that occur
after a bone fracture?
12. What lifestyle choices relate to the overall strength
and protective properties of bone?
Key terms
 Bone marrow -A soft highly vascular modified connective tissue
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that occupies the cavities and cancellous part of most bones and
occurs in two forms – yellow and red.
Bone remodeling-The continuous turnover of bone matrix and
mineral that involves first, an increase in resorption and
osteoclast activity, and later, reactive bone formation by
osteoblast activity.
Calcitonin -A polypeptide hormone especially from the thyroid
gland that tends to lower the level of calcium in the blood
plasma.
Callus -A growth of new bone tissue in and around a fractured
area, ultimately replaced by mature bone.
Cartilage -A usually translucent somewhat elastic tissue that
composes most of the skeleton of vertebrate embryos and except
for a small number of structures (as some joints, respiratory
passages, and the external ear) is replaced by bone during
ossification in the higher vertebrates.
Key terms
 Compact bone -Bone tissue that contains few spaces between osteons;
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forms the external portion of all bones and the bulk of the diaphysis
(shaft) of long bones.
Diaphysis-The shaft of a long bone.
Epiphysis-The end of a long bone, usually larger in diameter than the
shaft.
Fracture -The breaking of hard tissue (as bone).
Osteoblast-A bone-forming cell.
Osteoclast -Any of the large multinucleate cells closely associated with
areas of bone resorption (as in a fracture that is healing).
Osteocyte -Cell that is characteristic of adult bone and is isolated in a
lacuna of the bone substance.
Parathyroid hormone -A hormone of the parathyroid gland that
regulates the metabolism of calcium and phosphorus in the body.
Spongy (cancellous) bone-Bone tissue that consists of an irregular
latticework of thin plates of bone called trabeculae; found inside short,
flat, and irregular bones and in the epiphyses of long bone.
5.3 Lymph and Blood Cells
Essential Question
 1. What body systems function to protect the human
body?
 The immune system is the primary system that
helps protect the body. The skeletal system
supports the immune system by making immune
cells within the bone marrow. The cardiovascular
system supports the immune system by moving
immune components through the body.
Blood Cells
 How do specific components of the blood protect the
body?
 White blood cells fight disease and platelets
prevent blood loss by facilitating clotting
White Blood Cells
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Largest of the blood cells
Normally 5000 to 10,000 WBC per mL blood
Variable life span – from a few days to years
Produced in bone marrow
Part of the immune system
Increase in number when infection or inflammation is
present
White Blood Cells ~ Leukocytes
 5 Types
 Monocyte
 Neutrophil
 Lymphocyte
 Basophil
 Eosinophil
Monocytes
 Monocytes share the
"vacuum cleaner"
(phagocytosis)
 They present pieces of
pathogens to T cells so that
the pathogens may be
recognized again and killed.
 Signal other immune cells
that foreign material is
inside body
Neutrophils
 Neutrophils defend against
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bacterial or fungal infection.
They are usually first
responders to microbial
infection; their activity and
death in large numbers forms
pus.
Neutrophils are the most
common cell type seen in the
early stages of acute
inflammation.
They make up 60-70% of
total leukocyte count in
human blood.
The life span of a circulating
human neutrophil is about 5.4
days.[
Lymphocytes
 Destroy abnormal cells
 Produce antibodies
 Moderate immune
response
Basophils
 Can destroy foreign material
 Involved in inflammation
response
 Involved in development of
allergies
Eosinophils
 Kill multicellular
parasites (e.g.
blood fluke)
Lymph and Lymphatic System
 Activity 5.3.1 To Drain and Protect
 Equipment Needed
 Computer with Internet access
 Anatomy in Clay® Maniken®
 Green clay
 Spaghetti gun and extruder
 Body system graphic organizer handout
 Colored pencils or markers
 Laboratory journal
Essential Question
 2. How does the structure of the lymphatic
system relate to its function?
 The lymphatic (“water”) system is part of the
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cardiovascular system.
It’s made up lymphatic vessels that carry lymph
fluid (recycled blood plasma with WBCs) toward
the heart.
It overlaps with the immune system & contains
organs like the lymph nodes & tonsils.
It makes and circulates lymphocytes (WBCs that
are the main cells of the system).
The spleen, thymus and bone marrow are
considered parts of the system.
There are rounded masses of lymph tissue called
lymph nodes (“water knots”) that contain lots of
lymphocytes and filter the lymph fluid.
The lymph vessels empty into ducts that drain into
veins.
Blood Typing
Red Blood
Cell Surface
Antigen(s)
Plasma
Antibodies
Can Receive
Blood from…
TYPE A
TYPE B
TYPE AB
TYPE O
A antigens
B antigens
A and B
antigens
No antigens
Anti-B
antibodies
Anti-A
antibodies
No antibodies
Anti-A and
Anti-B
antibodies
Type A or
Type O
Type B or
Type O
All types
Type O only
Blood Typing Game
 Type in
 http://www.nobelprize.org/educational/medicine/blo
odtypinggame/ or type in Nobelprize Blood Typing
Game
 Watch the 3min tutorial first- before you begin the
game
Essential Question
 3. What is an antigen?
Antigen (“against formation”)
 Proteins found on the outside of pathogens (“disease starters”—
viruses and disease-causing bacteria), unique to each pathogen.
Lymphocytes recognize antigens as foreign and produce
antibodies specific to each antigen
 4. What is an antibody?
 Y-shaped structures produced by lymphocytes to fight against
pathogens by attaching to their antigens. Antibodies destroy
the antigen (and therefore the pathogen) and it is then
consumed by macrophages (“big eaters”). Memory cells
remember past pathogens and can quickly make the right
antibodies if attacked again, giving immunity in the future.
Essential Question
5. How do circulating antibodies protect a person
from receiving incompatible blood during a
transfusion?
 Antigens are found on the surface of blood cells and
platelets and if the antigens trigger an immune response
(happens if blood types don’t match), the body produces
antibodies to attack the antigens.
 This results in agglutination, which is a clumping of
blood cells caused by the antigen-antibody interaction.
 Agglutination can be deadly, which is why it is critically
important to know a person’s blood type before
performing a transfusion.
 Type O blood does not contain antigens, which is why
people with type O blood are considered “universal
donors”—it won’t trigger agglutination in others.
Immunity
 Has anyone in here had chicken pox?
 If so, could you be able to catch them again?
 Why or Why Not?
 Antigens and Antibodies
 Circulating antibodies can protect the body from
foreign invaders.
Activity 5.3.3 Fighting the Common
Cold
 Equipment Needed
 Computer with Internet access and Inspiration® software
 Red and blue colored pencil or marker
 Graph paper
 Laboratory journal
Essential Question
 6. What is specific immunity?
 Specific immunity is immunity against a
particular antigen (or pathogen).
Essential Question
 7. What role do lymphocytes play in specific immunity?
 T lymphocytes (T cells) and B lymphocytes (B cells)
are the two kinds of lymphocytes. All lymphocytes
begin in the bone marrow and then mature into one
of these types, with T cells maturing in the bone
marrow and B cells maturing in the thymus gland. B
cells are like military intelligence, seeking out
pathogens and sending T cells to attack. B cells make
the antibodies that match to each antigen. T cells are
like solders, binging to antigens and then releasing a
protein that punctures the pathogenic cells,
destroying them.
Essential Question
 8. How does your body react the second time it is
exposed to a particular antigen?
 Once produces, antibodies stay in a person’s body,
so if the same pathogen shows up again, the
antibodies to attack it are already present and the
person doesn’t usually get sick (hence the beauty
of a vaccine!)
Key Terms
Agglutination
Alleles
Antibody
Antigen
B lymphocyte (B cell)
Blood type (group)
Immunity
Lymph
Lymph node
Lymphocyte
Macrophage
Memory cell
Pathogen
Pedigree
T lymphocyte (T cells)
Clumping of microorganisms or blood cells, typically due to an antigen-antibody interaction.
Alternate forms of a single gene that control the same inherited trait (such as type A blood) and are
located at the same position on homologous chromosomes.
An antigen-binding immunoglobulin, produced by B cells, that functions as the effector in an immune
response.
A foreign macromolecule that does not belong to the host organism and elicits and immune response.
A type of lymphocyte that develops in the bone marrow and later produces antibodies, which mediate
humoral immunity.
One of the classes (as A, B, AB, or O) into which individual vertebrates and especially human beings
or their blood can be separated on the basis of the presence or absence of specific antigens in the
blood.
A condition of being able to resist a particular disease especially through preventing development of a
pathogenic microorganism or by counteracting the effects of its products.
A usually clear fluid that passes from intercellular spaces of body tissue into the lymphatic vessels, is
discharged into the blood by way of the thoracic duct and right lymphatic duct, and resembles blood
plasma in containing white blood cells and especially lymphocytes but normally few red blood cells
and no platelets.
Any of the rounded masses of lymphoid tissue that are surrounded by a capsule of connective tissue,
are distributed along the lymphatic vessels, and contain numerous lymphocytes which filter the flow of
lymph passing through the node.
Any of the colorless weakly motile cells that originate from stem cells and differentiate in lymphoid
tissue (as of the thymus or bone marrow), that are the typical cellular elements of lymph, that include
the cellular mediators of immunity, and that constitute 20 to 30 percent of the white blood cells of
normal human blood.
An amoeboid cell that moves through tissue fibers, engulfing bacteria and dead cells by
phagocytosis.
A long-lived lymphocyte that carries the antibody or receptor for a specific antigen after a first
exposure to the antigen and that remains in a less than mature state until stimulated by a second
exposure to the antigen at which time it mounts a more effective immune response than a cell which
has not been exposed previously.
A specific causative agent (as a bacterium or virus) of disease.
A diagram of a family tree showing the heritable characters in parents and offspring over multiple
generations .
A type of lymphocyte responsible for cell-mediated immunity that differentiates under the influence of
the thymus.