Integument Flashcards
1
Q
Integument Composed of…
A
- Epidermis
- Dermis
- Skin Appendages: Hair (nails)
- Glands
2
Q
Hypodermis
A
NOT part of integument
-Fatty cell layer with adipose tissue
3
Q
Dermis ->
A
Dermal Scales (denticles)- fish and amphibians
4
Q
Epidermis->
A
Terrestrial Vertebrates Epidermal Scales (stratum Corneum)-reptiles, feathers- dinosaurs and birds
5
Q
Epidermis->
A
Hair, Nails (mammals)
6
Q
Sweat Glands
A
Apocrine
-Mammary Glands (mammals)
7
Q
Zoological definition of a mammal
A
Presence of mammary gland in an animal
8
Q
Epidermis Classification of skin
A
- Thick Skin
- Thin skin
9
Q
Thin Skin Characteristics
A
Covers most of the body
10
Q
Thick Skin Characteristics
A
thicker St. Corneum
- Presence of St. Lucidum
- On palms of hands and souls of feet
11
Q
Cells of the Epidermis
A
- Keratinocytes
- Langerhan’s Cells
- Merkel’s Cells
- Melanocyte
12
Q
Keratinocyte
A
- Filled with Keratin (intermediate) Filaments
- Attached to each other by Desmosomes
13
Q
5 Layers of Thick Skin
A
From Top to bottom:
- Stratum Corneum
- Stratum Lucidum
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basale
14
Q
Stratum Basale (Germinativum)
A
- living cell layer
- Layer restsing on basement membrane and under the dermis
- most mitotic! Rise up
- Connected by desmosomes
- Hemidesmosomes use integrins
- Desmosomes use Cadherins
15
Q
Stratum Spinosum
A
- Tonofibrils Cytokeratin Filaments
- Desmosomes
- Artifact of tissue shrinkage
- Spiny Cell layer
- Spiney occurs from tissue shrinkage
- During preparation of tissue, the cell shrink but held by desmosomes so as cells shrink, the desmosomes rise to spiny apearances because theyre holding on 2 cells together
16
Q
Stratum Granulosum
A
- Keratohyalin Granules (no membrane) (flaggrin binds keratin)
- Lamellar Granules (membrane coated)
-Lipid sheets secreted into intercellular space to form intercellular cement and barrier
17
Q
Stratum Lucidum and Corneum (non-living layers)
A
- Squames
- St. Granulosum
18
Q
Layers of Thin Skin
A
- St. Corneum
- St. granulosum
- St. Spinosum
- St. Basale
19
Q
Layers of Thick Skin
A
- St. Corneum
- St. Lucidum
- St. granulosum
- St. Spinosum
- St. Basale
20
Q
Dermatoglyphics
A
(finger prints)
-unique to everyone except if you are an identical twin (still some changes from nature and nurture)
21
Q
Functions of Epidermis
A
- Abrasion Resistance (loose cells of the stratum corneum)
- Physical- Chemical Barrier- skin is physical barrier to bacteria
- Water Proofing (adaptation to terrestrial environemtn against desiccation)-inhibits evaporative loss
22
Q
Cells of Epidermis
A
- Keratinocytes
- Langerhan’s Cells
- Merkel’s Cell
- Melanocyte (originate from neural crest)
23
Q
Melanocyte
A
Eumelanin (black)
Pheomelanin (red)
-Tyrosinase converts DOPA into dopaquinone into melanin
PIC
24
Q
Melanocyte Function
A
Give rise to melanin and pigmentation
- secreted into cytoplasm of adjacent keratinocytes
- migrate to lcoation above nucleus above of that keratinocyte bc they act as a barrier to sunlight
- Purpose is to protct DNA material from UV light/damage
25
Skin color is dependent on amount of...
Melanin in Carotene NOT Melanocytes
26
Albinism
-Albinos lack the enzyme Tyroisnase and they cant make melanin- pinkness is reflection of blood
27
Langerhan's Cells
- Dendritic Cells
| - APC (from monocytes)
28
Merkel's Cell
(sensory)
- Rare type of tumor
- Lean on nerve fiber
29
3 main types of skin cancer
- Basal Cell Carcinoma
- Squamoud Cell Carcinoma
- Melanoma
30
Melanocytes
Cells that produce skin coloring or pigment known as melanin (where Melanoma Starts)
31
Dermal- Epidermal Junction
PIC
32
Dermis
- Papillary Layer
| - Reticular Lyaer
33
Dermis, Papillary Layer
(Peg and socket) locks epidermis to dermis to lock them together
- Capillaries
- Meissner Corpuscles (light touch)
34
Dermis, Reticular Layer (arteriovenous shunts)
(leather from animals)
| -Animals use leather in reticular layer to keep warm
35
Dermis (dense irregular connective tissue)
Irregular desposition responsible for wrinkles
- fibroblasts
- bundle of Type I collagen
- Elastic fibers
36
Arteriovenous (AV) shunts
(thermoregulation)
- Control flow of blood up to papillary layer
- When youre cold , blood vessels clamp and reduces flow of blood into papillary laye-- reduces evaporative cooling
When youre hot- start getting pink/ red- blood vessels open up and increase blood flow into
campilalries of papillary layer right underneath the epidermis for more cooling (releasing more water to cool)
37
Afferent Nerve Fibers and Sensory Structures of Skin
- Free Nerve ending
- Merkel's Cell
- Meissner's Corpuscle
- Pacinian Corpuscle
38
Dermis, Pacinian Corpuscle
Deep Touch/pressure, reticular layer
39
Nails (epidermal)
Derived from epidermis
| -Nail Matrix gives rise to nail plate (part that if hanging above skin)
40
Hair Follice and bulb (epidermal)
Consists of shaft
Beneath skin is called root
-epidermal in origin
41
Hair Bulb
- Germinal Matrix (Chemotherapy destroys fast growing cells causing hair loss)
- Melanocytes
- Hair Papila (dermal)
- Blood Vessel
42
Scalp cooling device
- Reduces hair loss caused by chemo
- Cooling reduces blood flow through the hair papilla by redirecting blood
- Less chemo reaches papila and haird dont fall out
43
Internal Root Sheath
Epidermal, At level of sebatious gland
44
External Root Sheath
Epidermal, Continuous beyond the sebatious gland onto the surface of body as epidermis
45
Hair Shaft
- Medulla
- Cortex
- Cuticle (small barbs)
46
Structure of Hair follicle
- Hair Shaft Cubicle (small Barbs)
- Internal Root Sheath
- External Root Sheath
- Glassy Membrane
47
Arrector Pili Muscle
Functions in cold- contracts and pulls to straighten hair shaft, increasing boundary effect to incease boundary layer on surface of skin- contract on fear and fligt reactions
48
Cause of Graying of hair
Loss of melanin with age
49
Glands of the Skin
- Sebaceous Gland (secretes onto hair shaft NOT epidermis)
- Eccrine (merocrine) Sweat gland
- Apocrine Sweat Gland
50
Sebaceous Gland consist of
Simple branched acinar gland
- Holocrine mode of secretion (whole cell reptures and expells)
- Sebum maintains stratum corneum weak antibacterial/fungal activity
51
Eccrine (merocrine) Sweat gland consist of
- Myopethelial Cells
- Secretory Portion
- Dark Cells: Nucleoid, Antibacterial, Secretory Granules
- Clear Cells: Produce sweat
- Duct is lined by stratified cuboidal epithelium
52
Eccrine (merocrine) Sweat gland- Excretory Duct
Absorption mainly Na+ and Cl- Ions
53
Eccrine (merocrine) Sweat gland- Secretory Duct
Secretion mainly protein free filtrate
54
Apocrine Sweat Gland structure
- Secretes onto hair shaft, larger diamete than eccrine glands
- Only Dark Cells (antibacterial, Pheronomes)
55
Apocrine Sweat Gland Function
(Name is misnomer, secretes via merocrine mode)
- Restricted to axillary parts of body (armpit and groins)
- -larger luminal diameter
- Secretes via merocrine mode of secretion as well
