The Tree Man: Is he for real?
http://www.youtube.com/watch?v=eJLG85gn
0bc
The Tree Man…
• What is the tree man suffering from?
• Is there a cure?
• What system is being affected in this
story?
The Integumentary System
Your job…
• Draw a diagram of skin on the whiteboard
and label the parts
• In a few minutes we will go over the
diagram.
What is Skin?
Skin Cells
• mesodermal cells
– Middle layer of epidermal development in
fetus and some of it eventually becomes skin
• Melanocytes
– Pigment cells
– Contain melanin
Epidermis Layer
Dermis Layer
• What can you see
from this tissue
sample?
Dermis Layer
• second of the three major layers of skin.
• The dermis varies in thickness depending
on the location of the skin. It is .3 mm on
the eyelid and 3.0 mm on the back
• composed of three types of tissue that are
present throughout - not in layers
– collagen, elastic tissue, and reticular fibers
Two layers primarily…
• upper, papillary layer, contains a thin
arrangement of collagen fibers
• lower, reticular layer, is thicker and made
of thick collagen fibers that are arranged
parallel to the surface of the skin.
contains many specialized cells
and structures
• hair follicles
• Arrector pili muscles
• Sebaceous (oil) glands and apocrine
(scent) glands associated w. hair folicle
• eccrine (sweat) glands
• Blood vessels and nerves
• specialized nerve cells called Meissner's
and Vater-Pacini corpuscles that transmit
the sensations of touch and pressure
Skin Glands
• Eccrine glands secrete sweat, a mixture of
99 percent water and 1 percent salts and
fats.
– In warm conditions with low humidity,
perspiration (secretion of sweat) and
evaporation cool the body.
Skin Glands
• The apocrine glands secretions contain
pheromones, substances that enable olfactory
(sense of smell) communication with other
members of the species.
– armpits, areolae of nipples, and the genital region
• Sebaceous glands (oil glands) are all over the
body except on the palms of hands and soles of
feet.
– Sebum keeps hair moist and prevents skin from
drying.
Hair
• cornified threads of cells that
develop from the epidermis
• has a medulla, cortex, and
cuticle
• hair root in a hair follicle is
embedded beneath the skin
• hair shaft protrudes from the
skin
• sheds and is replaced constantly
during growth and rest phases
• eyebrows keep sweat from
running into the eyes, nose and
ear hairs filter dust from the air,
and scalp hairs protect against
abrasion and overexposure to
sun rays.
Nails
• hard plates of keratinized
cells are at the ends of
fingers and toes
• appear pink because their
translucency reveals the
vascular tissue beneath
• aid in grasping objects,
scratching, and protecting
fingers and toes
Nails Continued…
• components of the nail are
the lunula, body, root, and
free edge
• lunula is the white halfmoon shaped part at the
nail base
• body and free edge region
that overhangs the end of
the finger or toe are visible
• thick layer of epithelial skin
called the nail bed
• root is hidden under skin
folds
Skin color
• results from the presence of melanin, carotene (yellow
to orange pigment), and underlying blood reflected
through skin.
• Melanin keeps excessive ultraviolet rays from burning
the skin
• Variety of skin color is caused mainly by the number
and distribution of melanocytes
• different skin colors among individuals and races show
different kinds and amounts of melanin production by
melanocytes
• Asian peoples produce a greater amount of carotene
in the stratum corneum, producing a yellowish tinge
• Albinism is a condition where skin does not produce
melanin.
Hypodermis, aka…
The hypodermis
(subcutaneous layer) lies
beneath the dermis.
Loose connective tissue
such as adipose tissue
(fat) insulates the body,
conserving heat. It also
contains blood vessels,
lymph vessels, and the
bases of hair follicles and
sweat glands.
Tissue Repair and wound
healing
Tissue Repair
Wound Healing
• 2 ways:
– Regeneration: replacement of destroyed
tissue by cells
– Fibrous: “scar tissue”
• Depends on type of tissue damaged &
severity
• wound healing
animation
• Granulation tissue
• Good regeneration:
– Skin, bone
• Poor regeneration:
– Cardiac & nervous
tissue
NEOPLASMS- Cancerous or
Benign
• Cell divides rapidly
(cancerous or benign)
Hyperplasia
• Tissues enlarge because of a stimulus that
irritates the cells
Atrophy