The document discusses the structure and functions of the skin and its appendages. It describes the layers of the skin - epidermis, dermis and hypodermis - and explains their composition and roles in protection, insulation, and other physiological functions. It also discusses various skin conditions like rashes, blisters, athlete's foot, sunburn, albinism and skin neoplasms, and provides prevention tips for some of these conditions.

1. GROUP 8
II-DARWIN

4. INTRODUCTION
The skin and its derivatives ( sweat and
oil glands, hairs, nails) serve a number of
functions, mostly protective. Together,
these organs are called the integumentary
system.

6. FUNCTIONS OF THE SKIN
• It insulates and cushions the deeper body
organs and protects the entire body from
mechanical damage ( bumps and cuts),
chemical damage ( such as from acids and
bases), thermal damage ( heat and cold),
ultraviolet rays ( in sunlight), and bacteria.

7. FUNCTIONS OF THE SKIN
• Protect the body’s internal living
tissues and organs
• Protect the body from dehydration.

8. FUNCTIONS OF THE SKIN
• Protect the body against abrupt
changes in temperature, maintain homeostasis.
• Protect the body against sunburns by secreting
melanin.

9. FUNCTIONS OF THE SKIN
• Store water, fat, glucose, and vitamin D
• Help excrete waste materials
through perspiration

10. FUNCTIONS HOW ACCOMPLISHED
Physical barrier contains keratin, which
MECHANICAL DAMAGE toughen cells, and pressure receptors,
which alert the nervous system to possible
damage
Has relatively impermeable keratinized;
CHEMICAL DAMAGE contains pain receptors , which alert the
nervous system to possible damage
Has an unbroken surface and “acid mantle”
( skin secretions are acidic, and thus
BACTERIAL DAMAGE inhibit bacteria). Phagocytes ingest foreign
substances and phatogens, preventing
them from penetrating into deeper body
tissues.

13. EPIDERMIS
• made up of stratified squamous epithelium
that is capable of keratinizing or becoming
hard and tough.
• Its main function is protection, absorption of
nutrients, and homeostasis.

14. EPIDERMIS
• Composed of five zones or layers called
strata. From the inside of these called
stratum basale, spinosum, granulosm,
lucidum, and corneum.
• It does not contain blood vessels.

15. EPIDERMIS
• Most cells of the epidermis are
keratinocytes (keratin cells), which
produces keratin, the fibrous protein that
makes the epidermis a tough protective
layer.

19. DERMIS
• It is a strong, stretchy envelope that helps to
hold the body together.
• The dermis is the middle layer of skin,
composed of dense irregular connective
tissue such as collagen with elastin arranged in
a diffusely bundled and woven pattern.

20. DERMIS
• The dense ( fibrous) connective tissue
making up the dermis consists of two major
regions- the papillary and the reticular area.

21. PAPILLARY LAYER
• The papillary layer is the upper dermal layer
region. It is uneven and has fingerlike
projections from it’s superior surface, called
dermal papillae, which indent the
epidermis above.

22. RETICULAR LAYER
• It is the deepest skin layer. It contains
blood vessels, sweat and oil glands, and
deep pressure receptors called Pacinian.

26. HYPODERMIS
• The hypodermis, or subcutaneous tissue, is the
layer of tissue directly underneath the dermis. It
is composed mainly of connective and adipose
tissue. Its physiological functions include
insulation, the storage of energy, and aiding in
the anchoring of the skin. This is the thickest
layer of the integumentary system.

29. APPENDAGES OF THE SKIN
• The skin appendages include
cutaneous glands, hairs and
hair follicles, and nails.

30. CUTENEOUS GLANDS
• are all exocrine glands release their
secretions to the skin via ducts.
• They fall into two groups; sebaceous glands
and sweat glands.

31. Sebaceous (Oil) Glands
• These are found all over the skin, except on
the palms of the hand and the soles of the
feet.

32. Hair Follicles
• is a skin organ that produces hair.
• Attached to the follicle is a sebaceous gland.

34. Nails
• is a horn-like envelope covering
the dorsal aspect of the
terminal phalanges of fingers and toes in
humans, most non-human primates, and a
few other mammals

37. RASH
• is a change of the skin which affects its
color, appearance or texture
• may be localized in one part of the body, or
affect all the skin.

39. BLISTERS
• is a small pocket of fluid within the upper
layers of the skin, typically caused by
forceful rubbing (friction), burning,
freezing, chemical exposure or infection

41. ATHLETE’S FOOT
• is a fungal infection of the skin that causes
scaling, flaking, and itch of affected areas.
• It is caused by fungi in the
genus Trichophyton and is typically
transmitted in moist areas where people
walk barefoot, such as showers or
bathhouses.

43. SUNBURN
• is a burn to living tissue, such as skin, which
is produced by overexposure to
ultraviolet(UV) radiation, commonly from
the sun's rays
• Usual mild symptoms in humans and other
animals include red or reddish skin that is
hot to the touch, general fatigue, and mild
dizziness.

45. ALBINISM
• is a congenital disorder characterized by
the complete or partial absence
of pigment in the skin, hair and eyes due to
absence or defect of an enzyme involved in
the production of melanin.

47. SKIN NEOPLASM
• are skin growths with differing causes and
varying degrees of malignancy.
• Skin cancer generally develops in
the epidermis (the outermost layer of skin),
so a tumor can usually be seen

50. RASH
• make use of aloevera gel or olive oil on
rashes and this can cure it fast.

51. BLISTERS
• Avoid wearing shoes that are too tight or
that rub your feet.
• Wear gloves to protect your hands when you
are doing heavy chores or yard work.

52. SUNBURN
• The best way to prevent a sunburn is to
avoid sun exposure.
• Stay out of the midday sun (from 10 in the
morning to 4 in the afternoon)

53. ATHLETE’S FOOT
• Keeping your feet clean and dry.
• Wear leather shoes or sandals that allow
your feet to breathe.
• When indoors, wear socks without shoes.

54. ALBINISM
• There is no known way to prevent albinism.
• Genetic counseling should be considered for
individuals with a family history of albinism or
hypopigmentation.

55. SKIN NEOPLASM
• Studies have suggested that avoiding
sunburns, especially in childhood and
adolescence, may reduce the incidence of
melanoma skin cancer.