+
The Skin 5.1 & 5.2
+
What Does Your Skin Look Like?
Stratum
corneum
Epidermal
ridge
Epidermis
Papillary
layer
Arrector pili
muscle
Dermis
Sebaceous
gland
Subcutaneous
Layer
Hair follicle
Reticular layer
Sweat Gland
Adipose
Pressure receptor (nerves)
+
The Integumentary System
I.
The Integumentary System
A.
Has two major components
a)
The cutaneous membrane (epidermis and
dermis)
b)
The underlying connective tissues of the dermis
(accessory structures)
B.
Has five major functions
a)
Protection
b)
Temperature control
c)
Synthesis and storage of nutrients (Vitamin D3)
d)
Sensory reception
e)
Excretion and secretion
+
EPIDERMIS
II.
The epidermis – consists of stratified (layered)
squamous (flat) epithelium (tissue).
A.
Keratin – water resistant protein that is found
in the upper layers of the epidermis (stratum
granulosum, stratum lucidum, stratum
corneum)
A.
Melanin-Pigment that gives skin, hair its color.
Produced by melanocytes found in the basal
layer of the skin (Fact: UV light stimulates
melanin production to protect the growing
layers of the skin)
+
Dermis
Reticular Layer
Papillary Layer
■
Underneath papillary layer
■
Directly underneath the dermis
■
Irregular dense connective
tissue
■
Loose connective tissue
■
Loosely arranged collagen
fibers
■
Supports and nourishes the
dermis
■
Densely packed collagen
■
Primary location for elastic
fibers are found here.
+
Fun Fact
■
Dermal Papillae - small, nipple-like extensions of the
dermis into the epidermis. At the surface of he skin
in hands and feet they appear as epidermal ridges
also know as Fingerprints.
+
Accessory Structures
+
Sebaceous Glands and Follicles
■
Sebaceous Glands (oil glands) – secrete sebum into hair follicles and
onto the surface of the skin
■
Sebaceous Follicle – large sebaceous glands that discharge sebum
directly onto the skin.
+
Sweat Glands
■
The skin contains two types of sweat glands
■ Apocrine – secrete products into hair follicles in the
armpit, around the nipples and in the groin. At puberty
these glands discharge a sticky, cloudy and potentially
odorous secretion.
■
Merocrine – Secrete sweat directly to the surface.
They are far more numerous and widely distributed.
Sweat secreted from these glands is 99% water.
+
■
Nails
Nails – form the dorsal surface of
the fingers and toes. Consists of a
dense mass of dead, keratinized
cells.
■
Nails protect the exposed tips and
limit their distortion when they are
subject to mechanical stress.
Example: grasping an object
+
Classification of Burns
+
First Degree Burn
■
Killed: superficial cells of epidermis
■
Injured: deeper layers of epidermis.
■
Examples: mild sunburn
+
Second Degree Burn
■
Killed: superficial and deeper cells of
epidermis.
■
Injured: Dermis. Damage may extend
into reticular layer of the dermis, but
many accessory structures are
unaffected. (Blisters are indicators of
a second degree burn)
■
Example: Hot iron burn, boiling water
etc, fire etc.
+
Third Degree Burn
■
Killed: all epidermal and dermal cells
■
Injured: Hypodermis and deeper tissues and organs.
■
Example: chemical burns, fires.
Question to discuss: Does a person with 3rd degree burns feel pain?
+
Your To Do List
■
Complete the remainder of the lesson with your
partner.
■
Answer conclusion questions.
■
What you do not finish in class will be homework.