DMF- Integumentary System Part 1 (until glands)

Largest system of the body

integumentary system

largest organ in the body

skin

2 parts of integumentary system

1. epidermis

2. Dermis

Lining of the epidermis

Keratinized Stratified Squamous Epithelium

4 cell types of epidermis

1. keratinocytes

2. melanocytes

3. langerhans cells

4. merkel cells

Most numerous cells in epidermis

Keratinocytes

Keratinocytes produce what?

keratin

Most numerous protein in the epidermis?

Keratin

Cell of the epidermis that produces the pigment melanin?

Melanocytes

Melanin serves as what?

Protective coating/covering

2 types of melanin pigment

1. Pheomelanin

2. Eumelanin

Yellow-red pigment of melanin

Pheomelanin

Brown-black pigment of melanin

Eumelanin

The nucleus of melanocytes are faced toward where for protection?

Away from UV rays

What is the embryonic origin of melanocytes and neuroglia of PNS?

Neural crest cells

What do you call the supporting sells of neurons?

Neuroglia

Are melanocytes resistant or suscpetible to UV rays?

Susceptible

(Melanocytes are very suscpetible to uv rays of the sun that is why melanin is produced to serve as a protective coating)

True or false: We get dark because of the heat from the sun

False, We do not get dark because of the heat from the sun BUT because if the UV rays present which stimulates melanocytes to produce melanin)

Macrophages of epidermis

Langerhan cells

Langerhans cells are specifically located where in the epidermis?

Stratum spinosum

Least numerous cells in epidermis

Merkel cells

Merkel cells are located in what layer of the epidermis?

Stratum basale

Merkel cells contact what sensory neuron that allows “touch” sensations

Merkel (tactile) discs

Cell of the epidermis for sense of touch

Merkel cells

In the stratum basale and stratum spinosum there are no keratin present but instead there are Building Blocks of Keratin called?

Tonofilaments

What are the 5 layers of the epidermis?

Mnemonic: Come Lets Get SunBurn

1. stratum corneum (most superficial)

2. Stratum lucidum

3. Stratum granulosum

4. Stratum spinosum

5. Stratum basale (deepest)

deepest layer of epidermis

stratum basale

Layer of epidermis with highest mitotic activity of keratinocytes

Stratum basale

2 cells present in stratum basale

1. Melanocytes

2. Merkel cells

Immature keratin, structures that will later convert to keratin?

(2 answers: Give both names)

Tonofilaments or Keratin Intermediate Filaments

What are the two main touch receptors?

1. Rapid Adapting (Meissner’s Corpuscle & Pacinian Corpuscle)

2. Slow Adapting (Merkel’s Disks & Ruffini Endings)

Among the two touch receptors mentioned, which of the 2 is more sensitive?

Meissner’s Corpuscle

During a light touch which touch receptor is easier to be stimulated?

Meissner corpuscle

Two other terms for stratum spinosum

Spiny layer

Prickle cell layer

Layer of epidermis that has decrease in mitotic activity of keratinocytes

Stratum spinosum

Langerhan cells are present in what epidermal layer

Stratum spinosum

True or false: the epidermis has no direct nerve and bloody supply

True

Two layers of the epidermis where there is tonofilament production

Stratum basale and stratum spinosum

Combination of stratum basale and stratum spinosum

Stratum Germinativum

Other term for stratum germinativum

Malphigian layer / Stratum Malpighii

Disease associated with ABSENCE of melanin

Albinism

Disease associated with DEFICIENCY in melanin?

Vitiligo

Amino acid needed to produce melanin, dopamine, epinephrine, norepinephrine and tyroxine?

Tyrosine

How many amino acids are there?

20 amino acids

Amino acids can be classified into 2:

Essential amino acids and non essential amino acids

Amino acids that we/our bodies cannot produce, thats why it must be a part of our body

Essential amino acids

Amino acids that we/our body can produce

Non essential amino acids

True or false: non essential amino acids can be converted to essential amino acids

False, essential amino acids can be converted to non essential amino acids but not the other way around

Food rich in amino acid

Eggs

Keratin is formed in what layer of the epidermis

Stratum granulosum

Layer of the epidermis that has many granules present

Stratum granulosum

2 granules present in stratum granulosum

1. Keratohyalin granules

2. Lamellar granules

Type of granule that converts tonofilaments to keratin

Keratohyalin granules

Why do cells undergo apoptosis at the stratum granulosum?

Very few nutrients present

2 other terms for stratum lucidum

Translucent layer

Clear cell layer

Layer of epidermis found in thick skin

stratum lucidum

Horny layer

stratum corneum

The most numerous layer of the epidermis

stratum corneum

Abnormal thickening of the stratum corneum due to constant friction

Callus

Excess keratinocytes shedding from the scalp?

Dandruff

Excess skin that sheds from different parts of the body

Danders

5 layers of the scalp

SCALP

1. skin

2. Connective tissue

3. Aponeuroses

4. Loose connective tissue

5. Periosteum

Cardinal histopathological sign of psoriasis

Munro's Microabscess

Condition where keratinocytes divide and move more quickly than normal

Psoriasis

3 signs and symptoms of psoriasis mentioned

SMA

1. Silvery scales

2. Monroe's abscess

3. Auspitz sign

Sign/symptom of psoriasis where there is abnormal kerarin production

Silvery scales

Bleeding spots in psoriasis

Auspitz sign

Abscess seen in osteomyelitis

Brodies abscess

Inflammation or infection of bone marrow

Osteomyelitis

Osteomyelitis is commonly due to what bacteria

Staphylococcus aureus

Bacteria known for being pus producing

Staphylococcus aureus

One of the organisms that are known for having antibiotic resistance

Staphylococcus aureus

True or false: staphylococcus aureus is foreign bacteria to the skin

False, staphylococcus aureus is normal bacteria of the skin

Radiographic appearance of osteomyelitis

Moth-eaten appearance

3 conditions mentioned that have a mOth EatEn radiographic appearance

OEE

1. Osteomyelitis

2. Ewing’s sarcoma

3. External root resorption

Radiographically ewings sarcoma can have a moth eaten appearance, but aside from that what else can its appearance

Onion skin

Sunburst

Board Question: Radiographic interpretation of ewings sarcoma?

Moth eaten appearance

Where is dermal papillae found? Dermis or epidermis

Dermis

Where are rete pegs found? Dermis or epidermis

Epidermis

Dermis is made up of: (2)

1. Collagen

2. Elastic fibers

What is thicker, dermis or epidermis?

Dermis

What provides blood supply for/to the epidermis?

Dermis

BECAUSE THE EPIDERMIS HAS NO DIRECT NERVE OR BLOOD SUPPLY

2 layers of dermis

PR

1. papillary layer

2. reticular layer

Among the 2 layers of the dermis, which one is thinner?

Papillary layer

Nipple like projections towards epidermis

Dermal papillae

In what layer of the dermis can dermal papillae be found?

Papillary layer

What are the epidermal extensions toward dermis?

Rete pegs

Other term for rete pegs

Epidermal ridges

Disease associated with saw tooth like rete pegs

Lichen planus

White lesions on the buccal mucosa

Lichen planus

What do you call the lines that can be seen in lichen planus?

Wickham’s striae

The reticular layer of the dermis is attached to?

Subcutaneous layer or hypodermis

Layer of the dermis that is a major nutient supplier for the skin

Reticular layer

8 Mechanoreceptors mentioned

1. Merkel disc/Tactile disc

2. Meissner corpuscle / Corpuscle of touch

3. Ruffini corpuscle / Bulbous corpuscle

4. End-bulb of Krause

5. Pacinian corpuscle

6. Proprioceptors

7. Nociceptors

8. Free nerve endings or Naked Nerve

Other term for ruffini corpuscles

Bulbous corpuscle

Mechanorecptor for pain (2)

Nociceptor

Free nerve ending/Naked Nerve

Main receptor for proprioception found in joints

Proprioceptors

Mechanoreceptor with an Onion ring shape

Pacinian corpuscle

Mechanoreceptor for Pressure and proprioception

Pacinian corpuscle

Ability to percieve position of the body

Proprioception