Transcript Pain or touch receptor

Integumentary System
Skin & Membranes
Anatomy and Physiology
Integument – Membrane
Parts of the Integumentary System
1.
2.
Skin (cutaneous membrane) – dry,
stratified epithelium over dense fibrous
connective tissue
Mucous membranes – wet, simple or
stratified epithelium over fibrous
connective, line all cavities open to the
outside, protect from infection and
leakage
Parts of the Integumentary System Continued
2.
Serous membranes – wet, simple
epithelium over areolar, coating every
cavity not open to the outside, double
layered membrane with serous fluid in
between the layers
A> peritoneum – abdominal cavity
B> pleura – around lungs
C> pericardium – around heart
D> meniges – around brain and spinal
column
Parts continued
4.
Synovial Membranes – wet, around joint
cavities, only non-epithelial membrane –
fibrous connective tissue that secretes
synovial fluid to lessen impact of friction
in joints.
Functions:
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Waterproofing (keeps water out and in)
Synthesizes Vitamin D (allows Ca++ Absorption)
Protects internal structures from:
 UV rays
 Bacteria
 Heat, cold, chemical damage
Temperature Control
Through sweat glands
 Through blood vessel dilation and constriction
 Through subcutaneous fat layer for insulation

Structure of the Skin
(Superficial to Deep)
I.
Epidermis (epithelium)
A.Stratum Corneum (cornified layer)
dead cells, keratinized, tough and waterproof
B. Stratum Lucidum (clear layer)
flat, full of keratin, dead or dying
C. Stratum Granulosum (granular layer)
some keratin and lipids
D. Stratum Spinosum (Spiny layer)
living with a little keratin
E. Stratum Germinativum (Germinating layer or basal
layer)
living, only mitotic (growing) layer
contain the melanoctyes that make melanin
SC
SGR
SGR
SS
SS
B
←D
E →
C →
↑
↑
A
As you go from deep to
superficial the cells are becoming
flatter, more keratin filled and less
blood supply
Cells start to die as go away from
germinativum – starting to die at
granulosum layer and entire
corneum is dead
Melanocyte
Structure of Skin Continued
II. Dermis
–
Dense fibrous connective tissue (collagen
and elastin)
– Good blood supply
A. Papillary layer
•
projects into the epidermis forming
dermal papillae (forms ridges known as
finger prints used for gripping)
•
Pain and touch receptors
→
Pain or touch receptor
http://www.udel.edu/Biology/Wags/histopage/colorpage/cin/cin.htm
Structure Continued (Dermis)
B. Reticular Layer (most of dermis)
- Still dense fibrous with good blood supply
• Sebaceous glands (oil glands)– make sebum
(oil & dead cells) softens skin and kills
bacteria
• Sudoiferous glands (sweat glands) for
temperature regulation
•
Eccrine – water and salt – all over
•
Appocrine – arm pits and groin – only start
at puberty – secrete proteins, lipids with
water and salt which bacteria feed off of
making b.o.
• Pressure and temperature receptors
C. Subcutaneous Layer (Fat) for insulation
Pacinian Corpusle(Pressure Receptor)
Hair Follicles

Hair grows from epithelium which is an
extension of the stratum germinativum – called
the epidermal sheath (growth occurs from the
hair bulb)

Melanocytes are embedded in the hair bulb
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The hair itself has three parts:
Cuticle – outside coat with overlapping cells
 Cortex – body of the hair
 Medulla – center of hair
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Skin Cancer
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Basal Cell Carcinoma – cancer of the stratum
germinativum or basal layer – usually doesn’t
metastasize
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Squamous Cell Carcinoma – cancer of the
stratum spinosum – metastasizes very slowly
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Melanoma – cancer of the melanocytes – most
dangerous – metastasizes
ABCD – method to recognize suspicious moles that
could be a sign of melanoma
 A = asymmetry
 B = borders irregular
 C = color is different throughout
 D = diameter > 6mm
Burns
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First Degree – only epidermis damaged, appears
red and swollen
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Second Degree – epidermis and upper dermis
damaged, red, painful, blisters
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Third Degree – through entire epidermis and
dermis, white due to no blood or black from
charring, no pain all of nerves destroyed
>25% second degree is critical or
>10 % third degree is critical
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Rule of 9’s