GROSS AND ORGAN ANATOMY - LECTURE
Prelims | Week 1 | | Notes from higher year
INTEGUMENTARY SYSTEM
TOPIC OUTLINE
1
Skin
2
Hair
3
Glands
4
Nail
5
Aging and The Integumentary System
6
Skin Disorders and Conditions
➔ Relates to the external layer of our body
which compose of:
◆ Skin
◆ Hair
◆ Nails
◆ Oil and sweat glands
◆ Sensory receptors
SKIN
➔ Border of structure that separates from one
layer to the other
➔ As one protective mechanism, the skin,
together with the other structures, nails,
and lands, have several functions, normal
aging process, and certain diseases that will
arise
➔ The largest organ of the organ system
➔ Structurally, the skin consist of 2 main parts:
◆ Epidermis - superficial, thinner
portion that contains the epithelial
tissue
◆ Dermis - deeper, thicker portion that
is made of dense irregular
connective tissue
● Deep to the dermis, but not
part of the skin, is the
subcutaneous layer
(hypodermis)
EPIDERMIS
➔ Composed of keratinized stratified
squamous epithelium (no blood vessels –
obtains from the capillaries)
a. Keratinocytes - 90& of the epidermal cells
arraigned in four or five layers and
produce the protein keratin (and
keratohyalin which hardens the skin for
protection and prevention of water loss)
● Keratin - the most abundant
protein in the skin that serves to
protect the skin from trauma such
as scratches, abrasions, heart, and
others.
○ It also controls the head
and entry and exit of water
and foreign materials
b. Melanocytes - 8% of the cells and produce
the pigment melanin
● Melanin - provides the skin color
○ A yellow, red or
brown-black pigment
○ Melanocyte simplify the
melanin from the amino
acid tyrosine with the aid of
enzyme tyrosinase
c. Intraepidermal macrophages
(Langerhans cells) - participate in
immune responses
● Determine, locate, and destroy
invaders that eats out normal cells
● Produced in red bone marrow
d. Tactile epithelial cells (Merkel cells) detect touch
● Responsible for sensation
STRATA
➔ 4 strata: thin skin
◆ Stratum basale
◆ Stratum granulosum
◆ Stratum spinosum
◆ Stratum corneum
➔ 5 strata: thick skin
◆ Stratum basale
◆ Stratum granulosum
◆ Stratum lucidum (only in thick
skin)
◆ Stratum spinosum
◆ Stratum corneum
STRATUM
CORNEUM
➔ Consists of 25-30 layers
of flattened, dead
keratinocytes (thin)
DEIPARINE, CN. | 1
GROSS AND ORGAN ANATOMY - LECTURE
Prelims | Week 1 | | Notes from higher year
(have the capability to stretch and return
to its original state without being
damaged)
PAPILLARY
REGION
RETICULAR
REGION
SUBCUTANEOUS
TISSUE
➔ Part of the dermis makes
up about ⅕ of the
thickness of the total
layer and consists of
areolar connective tissue
containing fine elastic
fibers
◆ Its surface area is
greatly increased
by small,
fingerlike
projections called
dermal papillae
➔ Deeper
➔ Part of the dermis that is
attached to the
subcutaneous layer,
consists of dense
irregular connective
tissue that contains
bundles of collagen and
some coarse elastic
fibers
➔ Adipose cells, hair
follicles, nerves, oil
glands, and sweat
glands are found
between the fibers
➔ Melanin, hemoglobin,
and carotene are three
pigments that impart a
wide variety of colors to
skin
◆ The amount of
melanin causes
the skin’s color to
vary from pale
yellow to
reddish-brown to
black
➔ Attaches the skin to
underlying bone and
muscle
◆ Supplies it with
blood vessels and
nerve
➔ Not part of the
integumentary
➔ Half the body’s stored fat
is in the subcutaneous
tissue (functions as
source of energy,
insulation, and padding)
ACCESSORY STRUCTURES OF THE SKIN
➔ Develop from the epidermis of an embryo
– hair, glands, and nails
HAIR AND
NAILS
➔ Protect the body
SWEAT
GLANDS
➔ Help regulate body
temperature
FUNCTIONS OF THE SKIN
BODY TEMP
REGULATION
➔ The skin
contributes to
the
homeostatic
regulation of
body
temperature by
liberating sweat
at its surface
and by
adjusting the
flow of blood in
the dermis
PROTECTION
➔ Keratin in the
skin protects
underlying
tissues from
microbes,
abrasion, heat,
and chemicals
➔ Lipids released
by the lamellar
granules inhibit
evaporation of
water from the
skin surface
CUTANEOUS
SENSATIONS
➔ These include
tactile
sensations,
touch, pressure,
DEIPARINE, CN. | 3
GROSS AND ORGAN ANATOMY - LECTURE
Prelims | Week 1 | | Notes from higher year
vibration, and
tickling),
thermal
sensations
(warm and
coolness), and
pain (warns the
body to avoid
those irritants)
EXCRETION AND
ABSORPTION
➔ Excretion of
sweat, salts,
water and heat
➔ Absorption of
fats, soluble
vitamins (A, D,
E, K) certain
drugs, oxygen
and CO2
SYNTHESIS OF
VITAMIN D
➔ Fight infections
and enhances
phagocytic
activities of cells
to regulate and
help immunity,
and reduce
inflammation
HAIR
➔ Hair or pili, are present on most skin
surfaces except the palms, palmar surfaces
of the fingered, soles, and plantar surfaces
➔ It is a thread of fuse, dead, keratinized
epidermal cells that consists of a shaft (most
superficial), a root (into the dermis), and
follicle
3 LAYERS
INNER MEDULLA
➔ Responsible for hair
color
MIDDLE CORTEX
➔ Forms the hair
structure
OUTER CUTICLE
HAIR HUB
➔ Covers the shaft
➔ forms the base of the hair
➔ Receives nutrients from
the dermal layers
HAIR MATRIX
➔ where the hair growth
starts
➔ Associated with hairs are bundles of smooth
muscles called arrector pili and sebaceous
glands (oil glands)
SEBACEOUS GLANDS
➔ Usually connected to the hair follicles
◆ They are absent in the palms and
soles
➔ Produce sebum, which moistens hair and
waterproofs the skin
ARRECTOR PILI
➔ Extends from the superficial dermis of
the skin to the dermal root sheath around
the side of the hair follicle
➔ Under physiological or emotional stress,
such as cold or fright, autonomic nerve
endings stimulate the muscles to
contract, which pulls the hair shafts
perpendicular to the skin
◆ This is called goosebumps or
goose flesh because the skin
around the shaft forms slight
elevations)
➔ Color of hair is due to melanin
◆ Gray hair - occurs with a decline in
melanin
◆ White hair - results from
accumulation of air bubbles in the
hair shaft
TYPES OF HAIR
LANUGO
➔ Babies
TERMINAL
HAIR
➔ Long, course, heavily
pigmented (normal hair in
the body)
◆ Ex. head, brows,
lashes
VELLUS
➔ Hair short, fine, pale, barely
visible
DEIPARINE, CN. | 4
GROSS AND ORGAN ANATOMY - LECTURE
Prelims | Week 1 | | Notes from higher year
◆
Ex. baby hair, body
hair
FUNCTION
during childhood
➔ Activated during
puberty
GLANDS
SUDORIFEROUS GLANDS (SWEAT)
➔ They are single or groups of epithelial cells
that secrete a substance
SEBACEOUS GLANDS
Secretes an oily substance called sebum
Keep hair from drying out
Prevents excessive evaporation of water
Keeps the skin soft
Inhibit certain bacteria
Connected and released from the neck of
the hair follicle in the dermal layer and is
secreted in lips, genitals
➔ Absent in palms and soles
➔
➔
➔
➔
➔
➔
FEATURES
DISTRIBUTION
➔ Largely in lips, glans
penis, labia minora,
and tarsal glands
➔ Small in trunk and
limbs
➔ Absent in palms and
soles
LOCATION OF
SECRETORY
PORTION
➔ dermis
TERMINATION OF
EXCRETORY DUCT
➔ Mostly connected to
hair follicle
SECRETION
➔ Sebum - mixture of
triglycerides,
cholesterol, proteins
and inorganic salts
FUNCTIONS
➔ Prevents hairs from
drying out
➔ Prevent water loss
from skin
➔ Keep skin soft
➔ Inhibit growth of
some bacteria
ONSET OF
➔ Relatively inactive
APOCRINE
SWEAT
GLANDS
➔ Found mainly in the:
◆ Skin of the axilla
(armpit)
◆ Groin
◆ Areolae
(pigmented areas
around the
nipples) of the
breasts
◆ Bearded regions
of the face in
adult males
(simple, coiled
tubular glands
but have larger
ducts and
lumens)
➔ Odorless in nature
(milky/yellowfish)
➔ If exposed to bacteria,
body odor occurs
◆ Starts to function
at puberty
● Distribution - skin of
axillae, groin, areolar,
bearded regions of face,
clitoris, and labia minora
● Location of secretory
portion - mostly in deep
dermis and upper
subcutaneous layer
● Termination of
excretory duct - hair
follicles
● Secretion - perspiration,
which consists of same
components as eccrine
sweat glands plus lipids
and proteins
● Functions - stimulated
during emotional stress
and sexual excitement
● Onset of function puberty
DEIPARINE, CN. | 5
GROSS AND ORGAN ANATOMY - LECTURE
Prelims | Week 1 | | Notes from higher year
ECCRINE
SWEAT
GLANDS
➔ Most prevalent sweat
glands distributed
throughout most of the
body especially in the:
◆ Skin of the
forehead
◆ Palms
◆ Soles (simple,
coiled tubular
gland)
➔ help regulate body
temperature through
secretion of sweat (starts
to function after birth)
● Distribution throughout skin of most
regions of the body,
especially skin of
forehead, palms and
soles
● Location of secretory
portion - mostly in deep
dermis (sometimes in
upper subcutaneous
layer)
● Termination of
excretory duct - surface
of epidermis
● Secretion - perspiration,
which consists of water,
ions (Na, Cl), urea, uric
acid, ammonia, amino
acids, glucose, and lactic
acid
● Functions - regulation of
body temperature, waste
removal, stimulated
during emotional stress
● Onset of function - soon
after birth
CERUMINOUS
➔ It is present in the outer ear canal, a
yellowish secretion
➔ Also known as earwax or cerumae
FEATURES
DISTRIBUTION
➔ External auditory canal
LOCATION OF
SECRETORY
PORTION
➔ Subcutaneous layer
TERMINATION
OF
EXCRETORY
DUCT
➔ Surface of external
auditory canal or into
ducts of sebaceous
glands
SECRETION
➔ Cerumen, a waxy
material
FUNCTIONS
➔ Impede entrance of
foregin bodies and
insects into external ear
canal, waterproof canal,
prevent microbes, from
entering cells
ONSET OF
FUNCTION
➔ Soon after birth
NAILS
➔ Nails are hard, dead, keratinized epidermal
cells covering the terminal portions of the
fingers and toes
PRINCIPAL PARTS OF A NAIL
NAIL BODY
➔ Extension of stratum
corneum
➔ Pink in color because
of the blood
underneath
FREE EDGE
➔ Distal part of the nail
NAIL ROOT
➔ Buried in skin fold
LUNULA
➔ White-ish crescent
shape
HYPONYCHIUM
➔ Secures the nail to the
finer tip
NAIL BED
➔ Starts from the lunula
to hypochium
CUTICLE
(EPONYCHIUM)
➔ Found laterally to the
nail
DEIPARINE, CN. | 6
GROSS AND ORGAN ANATOMY - LECTURE
Prelims | Week 1 | | Notes from higher year
NAIL MATRIX
➔ Proximal portion of the
epithelium deep to the
nail root
➔ Cell division of the
matrix cell produces
new nails
○
○
Proliferative - extensive epithelial
tissue formation
Maturation - return to normal
state
■ Removal of scalp formation
SKIN DISORDERS AND CONDITIONS
AGING AND THE INTEGUMENTARY SYSTEM
➔ Most of the age-related changes begin at
about age 40 and occur in the proteins in
the dermis
➔ Collagen fibers in the dermis begin to
decrease in number, stiffen, break apart,
and disorganized into a shapeless, matted
tangle
➔ Elastic fibers lose some of their elasticity,
thicken into clumpy, and fray, and effect
that is greatly accelerated in the skin of
smokers
➔ Fibroblasts - which produce both collagen
and elastic fibers, decrease in number, the
results the skin forms crevices known as
wrinkles
GENERAL OVERVIEW OF WOUND HEALING
EPIDERMAL
WOUND
HEALING
➔ Appears to limit until
epidermis, but varies to
the depth of injury
(scratch, abrasion,
superficial burns)
DEEP
WOUND
HEALING
➔ Extends beyond dermal to
subdermal layer
●
Stages or phases of wound healing:
○ Inflammatory - blood clot
formation
■ inflammatory response to
eliminate micro_materials;
vasodilation of blood
vessels to aid for healing)
○ Migratory - scab formation to
bridge the broken skin
■ regrowth for the damaged
skin and blood vessels, and
formation of new collagen
fibers
NORMAL MOLE
MALIGNANT
MELANOMA
BURNS
FIRST DEGREE
BURN
Mild pain
Redness (no blisters)
Skin functions normally
Treatment - flush with
cold water to relieve
pain
➔ Heals within 3-6 days
Example - sunburn
SECOND
DEGREE BURN
➔ Pain
➔ Blisters
◆ Epidermis
separates from
underlying
layers and fluid
fills void)
➔ Edema
➔ Hair follicles and glands
are not injured
➔ Some skin function is
lost
➔ If there is no infection
and no grafting is
required, heals within
3-4 weeks
THIRD DEGREE
BURN
➔ Severe pain
◆ Burned region is
dumb due to
nerve damage
➔ Marked edema
➔ Marble-white to black
color
➔ Most skin functions are
➔
➔
➔
●
DEIPARINE, CN. | 7
GROSS AND ORGAN ANATOMY - LECTURE
Prelims | Week 1 | | Notes from higher year
CONTACT
DERMATITIS
● Derma - skin
● Itis - inflammation
➔ Inflammation of the
skin characterized by
redness, itching, and
swelling
➔ Caused by exposure of
the skin to chemicals
that bring about an
allergic reaction, such
as poison ivy toxin
CONTUSION
➔ A collection of serous
fluid within the
epidermis or between
the epidermis and
dermis, due to
short-term but severe
friction
● Bulla - refers to a large
blister
● Contudere - to bruise
➔ Condition in which
tissue deep to the skin
is damaged, but the
epidermis is not broken
CORN
➔ An area of hardened
and thickened skin that
is usually seen in palms
and soles and is due to
persistent pressure and
friction (overproduction
of keratin)
➔ A painful conical
thickening of the
stratum corneum of the
epidermis found
principally over toe
joints and between the
toes, often caused by
friction or pressure
CYST
➔ A sac with a distinct
connective tissue wall,
containing fluid or any
other material
ECZEMA
● Ekzeo - to boil over
➔ An inflammation of the
skin characterized by
patches of red,
blistering, dry,
extremely itchy skin
FROSTBITE
➔ Local destruction of
skin and subcutaneous
tissue on exposed
surfaces as a result of
extreme cold
➔ In mild cases, the skin is
blue and swollen and
there is slight pain
HEMANGIOMA
●
●
●
➔
➔
➔
➔
➔
lost
Tissue damage
Susceptible to infection
Slow healing
May require skin graft
to promote healing and
minimize scarring;
MEDICAL TERMS
ABRASION
BLISTER
CALLUS
➔ An area where skin has
been scraped away
COLD SORE
➔ A lesion, usually in an
oral mucous
membrane, caused by
type 1 herpes simplex
virus (HSV) termitted by
oral or respiratory
routes
COMEDO
➔ A collection of
sebaceous material and
dead cells in the hair
follicle and excretory
duct of sebaceous (oil)
gland
➔ Usually found over the
face, chest, and back,
and more commonly
during adolescence
➔ Blackhead
Hem - blood
-angi - blood vessel
-oma - tumor
Localized benign tumor
DEIPARINE, CN. | 8
GROSS AND ORGAN ANATOMY - LECTURE
Prelims | Week 1 | | Notes from higher year
of the skin and
subcutaneous layer
that results from an
abnormal increase in
the number of blood
vessels
HIVES
KELOID
➔ Reddened elevated
patches of the skin that
are often itchy
➔ Most commonly caused
by infections, physical
trauma, medications,
emotional stress, food
additives and certain
food allergies
➔ Urticaria
●
Kelis - an elevated,
irregular darkened area
of excess scar tissue
caused by collagen
formation during
healing
KERATOSIS
● Kera - horn
➔ Formation of a
hardened growth of
epidermal tissue, such
as solar keratosis, a
premalignant lesion of
the sun-exposed skin of
the face and hands
LACERATION
● Lacer - torn
➔ Irregular tear of the skin
LICE
➔ Contagious arthropods
that include two basic
forms
● Head lice - tiny,
jumping arthropods
that suck blood from
the scalp
○ They lay eggs
called “nits”
○ Their saliva
causes itching
that may lead to
complications
● Pubic lice - tiny
arthropods that do not
jump
○ Miniature crabs
PAPULE
● Papula - pimple
➔ A small, round skin
elevation less than 1 cm
in diameter
PRURITUS
● Pruri - to itch
➔ Itching, one of the most
common
dermatological
disorders
RINGWORM
●
●
●
●
WART
Tinea corporis - body
Tinea cruris - groin
Tinea pedis - feet
(athlete’s feet)
Tinea unguium - fingers
➔ Mass produced by
uncontrollable growth
of epithelial skin cells
➔ Caused by
papillomavirus
DEIPARINE, CN. | 9