INTEGUMENTARY SYSTEM
*Skin care is either need or want depending on
the location, the skin type, and the economical
status. It is considered a need if it is for the
survival of a person.
3. Merkel cells - combined with sensory
receptors; nerve endings to create a
sensory receptor for touch.
LAYERS OF SKIN
-
It is the external or outermost part of
the body (skin, nails, hair).
Functions:
1. Protection (abrasions, UV radiation,
microorganisms, water loss)
2. Sensation (heat, cold, pressure, &
pain)
3. Vitamin D production (vitamin D is
inside the body and activated in the
liver; the presence of sunlight sends a
signal towards the liver to activate
vitamin D; important for the skeletal
system)
4. Temperature regulation (blood flow and
sweat glands; vasoconstriction and
vasodilation happen)
5. Excretion (sweat)
*Keratin provides a certain strength for the
skin.
●
SKIN
● The largest organ of the body (inside
the body is the liver)
● The first line of defense
● Two major layers 1) Epidermis 2)
Dermis
●
EPIDERMIS
Divided into 5 strata namely:
- Stratum corneum, stratum lucidum,
stratum granulosum, stratum spinosum,
stratum basale (MNEMONICS: Come,
Let’s Get Sunburn)
- Keratinization
- An epithelial tissue
Special Cells:
1. Melanocyte; coloration of the skin
2. Langerhans cells; ingesting the
unwanted invaders; the first line of
defense
●
●
●
STRATUM BASALE - different color to
spinosum (orange cells); active in
mitosis production; it will push the cells
into the superficial parts.
STRATUM SPINOSUM - keratinocyte
is present; keratin is produced for the
different cells in the spinosum
(makapasok or malagyan) to make the
cells dead and dead skin cells are
important for the protective layer of the
skin.
STRATUM GRANULOSUM - lamellar
granules are present, cells that have
keratins ready for dying.
STRATUM LUCIDUM - thin layer, cells
are now 50/50 (possibly that this is not
present for some specimens).
STRATUM CORNEUM - a collection of
dead cells filled with keratin.
Melanocyte
- It is the one producing melanin, a
pigment for shielding UV rays from the
sun.
- In the Philippines, melanin is needed
because it is a tropical region.
- A specialized cell because it can
extend its cell membrane in the spaces
of the extracellular matrix of the skin.
Cells present in the dermis:
1. Fibroblasts (collagen), adipocytes, and
macrophages (immune cells in the
dermis)
2. Two major layers: Papillary Layer and
Reticular Layer
3. Nerves, Glands, and Capillaries
GOLGI APPARATUS - packaging and
modifying proteins; creates an organelle called
melanosomes, a structure that contains
melanin.
*Melanosomes are present also in the
extension of melanocyte; it is extended to
reach the different cells of the epidermis; the
melanocyte will stream off itself allowing it to
combine with the different cells and will be
engulfed by different cells, causing melanin
inside the cell.
Epidermis Diseases
➢ ALBINISM - a recessive genetic trait
that causes a deficiency or an absence
of melanin.
➢ VITILIGO - a disease in which the
pigment cells of the skin, melanocytes,
are destroyed in certain areas.
➢ DANDRUFF - excessive sloughing of
stratum corneum cells.
➢ CALLUS - a thickened area of the
stratum corneum due to friction.
DERMIS
*Tension lines are important to learn for
incisions; it can lead to the difference of the
healing process of the wound.
Across the cleavage line (perpendicular) = can
gap, slow healing, and will leave a mark or
scar
Parallel to the cleavage line = less gaping,
faster healing, and less scar tissue
-
The deepest layer of cell in the stratum
basale is the basement membrane.
Beneath the basement membrane is
the connective tissue.
PAPILLARY DERMIS - the waves is important
because it is the fingerprints. The line and
ridges along the fingerprints are just followed
by the epidermis. Fingerprints are because of
the orientation of the papillary layer of the
dermis.
RETICULAR DERMIS - deepest layer of the
dermis; the area that is damaged when a
stretch mark is present (collagenous fibers | it
is strong but resists stretching).
HYPODERMIS
● A minor layer of the skin; subcutaneous
tissue
● Attaches the skin to the underlying
muscles and bones
● For insulation and energy storage
SEBACEOUS GLAND - produces sebum
(made up of lipids), on oily, white substance
rich in lipids; too much sebum can cause acne
or pimples
- During puberty, this gland is active and
accumulates too much oil, causing
bacterial accumulation because of
sweat and oil = inflammation = acne or
pimple.
SUDORIFEROUS GLAND - produces sweat.
Either ECCRINE (water secretion; sweats and
salts) or APOCRINE (with part of cells; the
presence of biomolecules)
- Body odor is present in the armpit
because it is APOCRINE; the presence
of
biomolecules
|
bacterial
accumulation is present | there is
moisture
- Ex. wet rice is prone to pagpapanis
because of biomolecules and moisture
ACCESSORY SKIN STRUCTURE
Glands
● Exocrine glands; 1) holocrine - whole
cells are removed from the lining of
gland 2) merocrine - mode of secretion
is very intact and only secretion is
released 3) apocrine - pinched off a
portion of the cell that is joined in the
secretion
● All these are able to discharge their
products via a duct system
● Endocrine glands are direct to the
bloodstream
Hair
1. Hair Shaft - above skin surface; dead
keratinized cells
2. Hair Bulb - the base of hair root;
receives the nutrients
3. Hair Root - a hair inside the skin; still
not protruded
4. Hair follicle - entire thing that covers
the hair bulb; it can be circular (hair is
straight) and flat (hair is curly).
5. Hair papilla - found inside the hair
bulb; creates intertwining of different
arteries and veins (supply of oxygen
and nutrients for it to create new hair
cells). It leads to keratinization later
on.
6. Arrector pili - a smooth muscle
associated per hair strand ( it is the
reason why hair
goosebumps)
is
erecting
=
NAIL MATRIX - mitosis is active; cells are
produced for cells and where keratinization
happens.
NAIL BED - the entire thing where the nail
rest.
LUNULA - a nail root that is supposedly under
the skin but extended outside; can be present
sometimes or not; it is because of deficiency
that there’s no lunula or there is a certain
indication.
*Nails are important and placed in their
position for better grasping and providing
rigidity.
––––––––—–—
*Hair loss is NORMAL.
Nails
➢ A thin plate consisting of dead stratum
corneum cells that contain a very hard
type of keratin.
➢ Cuticle = eponychium
BP CONTINUATION…
Body Parts and Regions
1. Orbital (eye)
2. Nasal (nose)
3. Oral (mouth)
4. Buccal (cheek)
5. Cervical (neck)
6. Axillary (armpit)
7. Cranial (skull)
8. Occipital (base of the skull)
9. Olecranon (point of the elbow)
10. Calcaneal (heal)