Lecture Note Integumentary System

8/3/2019 Lecture Note Integumentary System

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Integumentary System 2012In

Assalamualaikum

First of all, I would like to apologize because during this class mostly the Dr

talked in Arabic, which I couldn’t understand (very sad )and most of the time

the doctor just repeat what’s in the slide. So you’ll going to find lots of similarity

between this lecture note and the slide -.- ( Which I couldn’t help for. Sorryagain)

Bismillah.

Skin :

- Largest & heaviest organ in the body (16% of body weight)

- Selective Barrier between internal and external

- Site of Vitamin D synthesis (by exposure to sunlight)

- Identification ( fingerprint)

- Secrete natural crane of protection of skin

- Regulator of body temperature ( by secreting sweats- regulate acid base

balance)




- Site where different types of sensory receptor present ( heat,

pain,sensation,pressure, temperature)

- Can be divided by thick and thin skin ( according to thickness of epidermis

without looking at the underneath)

The skin is originated from two parts, one from ectoderm (epidermis) and

another from mesoderm (dermis). *refer to slide three*

[ Sometimes, hypodermis (adipocytes) is consider as part of skin]

Epidermis

- Consist of stratified squamous epithelium ( keratinized/non keratinized)

*doctor asked us to forget the term of stratified squamous epithelium in

skin*

- Have many cell and each one of the cell is called keratinocytes.

Three types of cell which embedded in between is :

Melanocytes = secrete melanin

Langerhans = macrophages of the skin

Merckel = one of the mechanoreceptor (some nerve fibre underneath)

Can be further subdivide by few layers of epidermis :

- Stratum basale = basal layer

- Stratum spinosum = spinous layer

- Stratum granulosum = glandular layer

- Stratum lucidum = lucidal layer

- Stratum corneum = cornial layer

*refer to the slide eight for picture*

*Takenote*

The ONLY example of thick

skin : palms of the hand &

bottom of the feet




Stratum basal

- single & thin layer at the bottom of epidermis

- Characterized by active in mitosis, divide continuously

- Each cell in basal layer attach to each other by desmosomes

- Have low columnar basal ground nucleus ( columnar to cuboidal)

- In the Inside we can see, some keratinized fibre and intermediate filament.

Stratum spinosum

- About nine layers ( thickest epidermal layer)

- At the corner of the picture, there are many keratin of dead squames

(stratum corneum) which will push the cell away from circumference

- Rich occupied by desmosomes (attach between two cell)

- Shape round nucleus in the middle

- Synthesis and secrete keratin ( increase from bottom to top)

Stratum granulosum

- Shape : flat cell (as moving upward) – full with granules

- About three to five layers

- Insulator between in and out of cell

They are two types of granule Keratohyaline (no membrane

outside)

What is malphigian layer?

Term that generally defined as

both stratum basal and stratum

spinosum as a unit.Dark colour-

marked the

presence of

granules




Lamellar ( surrounded by

granules)

Synthesize lipid and secrete

lipid outside the cell

Stratum lucidum

- Only seen in thick skin

- Thin, clean layer of dead skin cell of epidermis

- Transparent appearance

- Apparently no cell in this layer , actually they are cell which is very good

keratinized fiber that covers the other organelles.

- Desmosomes are still evident between adjacent cells.

Stratum corneum

- Dead cell full with keratinized

- Act as a protective layer of skin from infection,dehydration,chemical and

mechanical stress.

- Help the skin hydrated by prevent water evaporation

Melanocytes

- Situated at the bottom of basal layer

- Secrete melanin ( pigment which responsible for colour of the skin)

Did you know?

Sunlight activate

melanocyte to

secrete more

melanin.

White skin people and black skin people have the SAME number of

melanocyte but why their skin colour is different?

Pigment in the melanocyte does not go outside in the white

skin people.

This is also why white skin people can develop skin cancer

more compared to black skin people.




Melanin divided into two types of melanin Eumelanin (normal

melanin)

Pheomelanin

( red melanin)

Dermis

- Surface irregular and many projections (dermal papillae)

- Composed of two layer Papillary layer (outermost)

-constitute major part of

dermal papillae

(loose connective tissue)

-type 7 collagen fiber

Reticular layer (deeper)

-composed of irregular dense connective

tissue

(mainly bundles of type 1 collagen) & has

more fibers & fewer cells

Skin disease Pemphigus

A rare group of blistering autoimmune diseases that

affect the skin

& mucous membrane ( Wikipedia)

Bullous Phemphigoid




A skin disorder characterized by large blisters.

Epidermal derivatives

• Hair follicles

• Sweat glands

• Sebaceous glands

• Nails

------------------------------------------------- ---

FINISH-------------------------------------------------------------

Because of insufficient of time, the doctor just simply explain the slide in

Arabic. Therefore, I couldn’t understand it. So this is the end of this lecture

note.

I wish you good luck for the final exam ( 9th January 2012) , May all of us

manage to score this paper with flying colours . Insya-ALLAH (‘:

I am sorry for any inconvenience and mistakes in this lecture note.

Done by : Amirafathiah.

Lecture Note Integumentary System

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