Download Integumentary system – part 2

Integumentary system – part 2
Key terms
Dermis:
• Also called “corium”
• Directly below the epidermis
• Contains blood and lymph vessels
• Contains accessory organs – hair, sweat glands,
sebaceous glands
• Contains connective tissue cells and fibers
Dermis:
• Fibers present are collagen and elastic
• Collagen – tough, resistant, also flexible
– Found in bones, ligaments, cartilage, tendon
– Loose in infants, harder as age increases
– Support and protect the blood and nerve networks
– Connective tissue diseases: Scleroderma, Lupus
Dermis
• Dermis (corium) –can be divided into 2 sublayers:
• papillary sublayer and reticular sublayer
Papillary sublayer
- highly vascular structures that provide oxygen and
nutrients to the epidermis that surrounds them.
- Contain pain receptors and tactile sensory receptors.
Reticular layer
• Reticular Sublayer –
• dense form of connective tissue
• contains blood vessels, sweat glands, sebaceous
glands, and the sensory receptors for cold, heat,
and pressure.
• Unlike the epidermis, the dermis contains blood
vessels and nerves
• Contains both sebaceous (oil-producing) glands
and sudoriferous (sweat-producing) glands
Dermis layer
Interesting fact
• Did you know that skin is water proof, it
does not allow water to go in and more
importantly it does not allow water to go
out!
Subcutaneous layer:
• Another connective tissue layer
• Mainly the formation and storage of fat
• Lipocytes – fat cells – numerous in this layer
• Areas in the body where fat is stored, varies from person
to person
• Important for protection of deeper tissues, heat insulator,
energy storage
Hair:
• Single hair fiber: tightly fused meshwork of keratin-filled
cells
• Growth of hair cells similar to skin cells
• Hair follicle: shaft that holds the hair fibers
• Meaning of follicle – “small sac”
• Melanocytes are present in the root of hair follicle – give
color to the hair
• 5 million hair on the body, 100,000 on the head
• Grow half an inch per month
Nail:
• Hard keratin plates, composed of hardened cells of
the stratum corneum.
• Cover the back of the last bone (phalanx) of each
toe and finger.
• Cells are cemented together.
• Can grow indefinitely if not cut.
• 1 mm per week, toenails are slower.
Nail:
• Lunula: semilunar white region at the base of the
nail, air mixed with the keratin and cells rich in
nuclei give the lunula its whitish color.
• Cuticle: narrow band of epidermis at the base and
sides of the nail
• Paronychia: infection in the soft tissue surrounding
the nail border
Nail:
• Grooves in nails occur in high fever and serious
illness
• Flattening of nails – called spoon nail – happens in
iron deficiency anemia
• Loosening of the nail and separation from the nail
bed – Onycholysis – happens with infection of nail.
Sebaceous gland:
• Found all over the body, in the dermis, except on the
palm and sole
• Secrete sebum, an oily substance – lubricates the skin
and minimizes water loss
• Closely associated with hair follicles
• Influenced by sex hormones – can cause hypertrophy at
puberty and atrophy in old age
• Blackheads and acne: due to overproduction of sebum
Sebaceous gland
Sweat gland:
• Tiny, coiled glands
• Found almost everywhere on the body
• About 2 million
• Most numerous in the hand
• Coiled in the dermis, straightens out as it reaches the surface
• Opens into the “pore” of the skin
• Also known as sudoriferous (latin - sudor – sweat + ferre –
bear) glands
Sweat gland:
• Sweat – almost pure water, other material like salt is
only 1%
• Colorless, odorless
• Odor – from action of bacteria on accumulated
sweat
• Sweat cools the body
Sweat gland:
• Secretion is controlled by sympathetic nervous system
• Signal comes from hypothalamus (part of the brain)
• Specialized sweat glands – “apocrine glands”
• Concentrated around the reproductive organs and armpits,
grow especially after puberty
• Mammary gland is a modified sweat gland
Interesting fact:
• If you laid out all your skin on a flat
surface, it would have an area of about 2
square meters.
Cutis
• Cutis - skin (latin)
- cutis is also the origin of the
adjective cutaneous, which refers to the skin
• Ex. Cutis Ansernia, also known as goose
bumps, a temporary local change in the skin
when it becomes rougher due to erection of
little muscles, as from cold, fear, or
excitement.
Cyan/o
• Cyan/o – blue
• Ex. Cyanosis is a bluish discolouration of
the skin and mucous membranes due to
excessive concentration of reduced
hemoglobin in the blood.
-Cyte
• -Cyte – cell
• Ex. Melanocyte are special cells in the skin
and the eye that synthesize melanin
pigments.
Derm/o; Dermat/o
• Derm/o; dermat/o – skin
• Ex. Dermatology is the study of the skin
and its diseases.
Dermatologist is a physician who
specializes in dermatology and who
diagnoses and treats skin abnormalities.
Kerat/o
• Kerat/o – horn-like tissue
• Ex. Keratin is a protein that is the primary
constituent of hair, nails, and skin.
Leuk/o
• Leuk/o – white
• Ex. Leukocyte is a
white blood cell.
Leukoderma: is the
absence of pigment,
partial or total, in the
skin.
Partial or total loss of
skin pigmentation,
often occurring in
patches. Also called
vitiligo.
Onych/o
• Onych/o – having to do with the nails;
fingernails, toenails
• Ex. Onychia Lateralis is inflammation
involving the folds of tissue surrounding the
nail.
Pil/o
• Pil/o – hair
• Ex. Pilocystic denotes a dermoid cyst
containing hair.
• Dermoid cyst: A benign tumor
resulting from abnormal embryonic
development, occurring in the skin or
ovary.
Sub• Sub- - below
• Ex. Subcutaneous Layer is under the skin.
Dermatomycosis
• Dermatomycosis – fungal infection of the
skin
• dermat/o – “skin”
• myc/o – “fungus”
• -osis – “abnormal condition”
Dermatopathy
• Dermatopathy – any disease of the skin
• derm/a/t/o – “skin”
• -pathy – “disease”
Dermatoplasty
• Dermatoplasty – plastic surgery performed
on the skin
• derm/a/t/o – “skin”
• -plasty – “surgical repair”
Epidermatitis
• Epidermatitis – inflammation of the
epidermis
• epi – “upon”
• -dermis – “skin”
• -itis – “inflammation”
Melanoma
• Melanoma – tumor of the melanocytes;
black colored skin tumor
• melan/o – “black”
• -oma – “tumor”
Onychectomy
• Onychectomy – surgical removal of a nail
• onych/o – “nail”
• -ectomy – “incision”
Onychomalacia
• Onychomalacia – softening of the nails
• onych/o – “nail”
• malacia – “softening”
Onychomycosis
• Onychomycosis – fungal infection of a nail
• onych/o – “nail”
• mycosis – “fungal infection”
Onychopathy
• Onychopathy – any disease of the nails
• onych/o – “nail”
• -pathy – “disease”
Onychoplasty
• Onychoplasty – surgical repair of a nail
• onych/o – “nail”
• plasty – “repair”
Onychotomy
• Onychotomy – incision into a nail
• onych/o – “nail”
• -tomy – “incision”
Paronychia
•
•
•
•
Paronychia – infection around a nail
para – “adjacent”
onych/o – “nail”
-ia – “condition”
Cuticle
• Cuticle – common word used as a synonym
for the eponychium
• from the latin word cutis meaning “skin”
Eponychium
• Eponychium – thin, transparent layer of
skin located at the nail root
Lunula
• Lunula – white, crescent-shaped area of a
nail
• from the latin word luna meaning “moon”
Vellus
• Vellus – fine hair that covers much of the
body
• from the latin word meaning “fleece”
• The End