Integumentary System Flashcards
(48 cards)
1
Q
Pilosebaceous apparatus
A
Hair
Sebeceous Glands
Arrector pili muscle
2
Q
Skin
A
Epidermis
Dermis
Hypodermis under skin
3
Q
Functions of skin
A
Protection Permeability barrier Thermoregulation Sensation Metabolic functions Immunologic defense Sexual attractant
4
Q
Developmental Sources of skin
A
- Epidermis from ectoderm
- Demis from Mesoderm
(in back from dermatomes and in Abdomen and limbs from parietal Mesoderm)
5
Q
Epidermis
A
Stratifies squamous keratinized that produces protein keratin
6
Q
Cells of epidermis
A
keratinocytes
Melanocytes
Langerhans cells
Merkel cells
7
Q
Cellular layers of Epidermis in thin skin
A
basal layer
spinous cell layer
Granular layer
Keratin layer
all layers are composed of keratinocytes
8
Q
Basal layer
A
- single layer of cuboidal cells
- divide and are responsible for Regeneration
- each cell is Bound to b.m. by hemidesmosomes
- cells are conencted by desmosomes
- keratinocytes contain tonofilaments
9
Q
Spinous cell layer
A
- polyhedral keratinocytes
- Synthesis of tonfilaments continues
- tonofilaments converge into the desmosomes
10
Q
Granular layer
A
- cells are flatter
- contain keratoyalin adn membrane Coating granules
11
Q
Membrane- Coating granules
A
- in granular layer cells
- contain Lipids
- secreted by exocytosis into intercellular spaces
- responsible for Formation of epidermal water barrier
12
Q
Keratohyalin granules
A
- in granular layer cells
- contain intermediate Filament- associated proteins
- released into keratinocyte cytoplasm
- filaggrin and trichohyalin promote Aggregation of tonofilaments into tonofibrils –> initiaton the production of keratinization
13
Q
Keratin layer
A
- no nuclei
- flakes of keratin
- coated with anti-wetting agents
- breakdown of nucleus and other organelles
- thickening of Plasma membrane
pH decreases
14
Q
Epidermal water barrier
A
two structural Elements:
1. Lipid envelope of anti-wetting agents
2- Cell envelope with insoluble proteins on inner Surface of Plasma membrane
15
Q
Epidermis of thin skin
A
Clear layer between granular layer and keratin layer
Deep epithelial ridges and ling dermal papillae
16
Q
Clear layer
A
in thick Skin
eosinophilic cells full of eleidin
17
Q
Skin Color depends on
A
Melanin
Red blood cells in dermal vascular beds
Carotenes
Bilirubin
18
Q
Melanin
A
Eumelanin (yellowish Brown to black)
Pheomelanin: pink to red blue
19
Q
Melanocytes
A
- in basal layer
- from neural crest
- round with numerous processes
- contain promelanosomes and melanosomes –> Synthesis of Melanin
- Melanin is produced from tyrosine
20
Q
Langerhans cells
A
- in all layers except keratin layer
- lobulated nucleus
- cytoplasmic processes
- present Antigens to T-lymphocytes
- derived from monocytes
21
Q
Merkel cells
A
- in basal layer
- rounded, branchd
- contain vesicles
- make synaptic Connection with sensory nerve
- intra-epidermal touch receptors!!!
22
Q
Epithelial ridges and dermal papillae
A
epithelial downsgrowths
dermal outgrowth
23
Q
Dermis
A
CT blood and lymphatic vessels, nerves hair follicles sebaceous Glands arrector pili muscles Sweat glands
24
Q
Layers of dermis
A
Papillary layer (superficial) Reticular layer (deeper)
25
Papillary layer of dermis
loose CT with type I and III collagen
26
Reticular layer of dermis
dense irregular CT with type I Collagen and elastic fibers
27
Hypodermis
loose CT and adipose tissue
for Energy storage and insulation
28
Nerve supply of skin
free nerve endings
Meissner's coupuscles: in dermal papillae, touch receptors
Pacinian corpuscles: in deeper dermis and hypodermis, detect pressure
Ruffini's corpuscles: Respons to mechanical displacement
29
Hair (parts)
Hair follicle
| hair shaft
30
hair follicle
3 Segments
1- infundibulum (until Opening ob sebaceous Gland)
2- Isthmus: until arrector pili muscle
3- Inferior Segment with hair bulb
5 layers: inner three: shaft, outer two: sheaths
31
External root sheath
basal layer of Epithelium continiuation
| separated by surrounding CT by glassy membrane
32
Internal root sheath
- cells whihc become lighlty keratinized and disintegrate at Level of sebacous gland
33
Hair shaft structure
Medulla (moderate keratinization)
Cortex (highly keratinized, contains Pigment)
Cuticle (contains overlapping keratin plates)
34
Hair color
Melanocytes are in Matrix in Cortex
| Melanin is in cells of cortex
35
Sebaceous glands
- surround hair follicles
- branched acinar
- sebum onto hair shaft
- short duct is called pilosebaceous canal
- sebum is product of holocrine secretion
36
Arrector pili muscle
smooth msucle
one end in follicle and the other into papillary layer of dermis
surrounds sebaceous gland
37
Contraction of arrector pili muscle results in:
hair rises
sebum is discharged
goose skin
38
Types of Sweat glands
eccrine and apocrine
39
Eccrine Sweat glands
- almost everywhere (mostly in Palms and soles)
- Secretory Portion is tubular and coiled in reticular layer
- clear and dark cells
- secretory mode is eccrine
coiled duct has stratified cuboidal epithelium
40
Apocrine Sweat glands
- large Glands in axillae and genital regions
- Deep in hypodermis
- secrete into adjacent hair follicle via duct
- secretory Portion is tubular and coiled and has cuboidal and myoepithelial cells
- secretion is eccrine!!!
41
Fingernail
- nail bed is stratified squamous
- nail root in dermis
- growth: Proliferation, differntiation, keratinizationof Epithelium --> nail Matrix
- lunula at base of nail
- Eponychium: Skin overlying the root
- Hyponyhcium: Skin beneath free end of nail
42
Breast (mammary Gland)
Compund tubular
during lactation (tubule-acinar)
12-25 lobes
43
Development of mammary gland
6th to 7th week: ectodermal thickening --> two mammary lines
small Portion in thoracic Region invaginates into Underlying Mesenchyme --> lactiferous ducts
44
Stroma in mammary gland
Interlobular stroma: dense irregular CT and adipose tissue
Intralobular stroma:loose, more cellular and less fibrous CT
45
Changes in mammary gland
inactive Gland: undifferentiated ducts, no alveoli, simple cuboidal, interlobular dense CT, adipose CT
Active Gland: Differentaition of alveoli
Active lactating Gland: Secretion of milk, simple columanr, thin Septa, adipose CT
46
Secretion of milk
Merocrine for proteins
Apocrine for droplets
in first few days after birth: alveoli begin to secrete a protein-rich fluid called COLOSTRUM
production is controlld by prolactin
47
Lactiferous ducts
15-25 ducts each draining into one of the lobes
within nipple: duct is dilated to form lactiferous Sinus
lined by stratified epithelium
48
myoepithelail cells in mammary gland
surround alveoli and ducts
| contract under Oxytocin and help to discharge the milk
