13 - Integument Flashcards
1
Q
What are the 3 major regions of the Integument?
A
- epidermis - outermost
- dermis - middle region (areolar & reticular CT)
- hypodermis - deepest region (adipose & areolar CT)
2
Q
What are the functions of the integumentary system?
A
- Protection - chemical (low pH, glycolipid waterproofing), physical and mechanical barrier
- Cutaneous sensation - called exoreceptors b/c they sense external touch & pain
- Body temperature - blood vessel contstriction & sweat gland secretions
- Metabolic functions - synthesizes vitamin D in dermal blood vessels
- Blood reservoir - skin blood vessels store up to 5% of the body’s blood volume
- Excretion - limited amounts of nitrogenous wastes are eliminated from the body in sweat
3
Q
What are the 4 cell types in the epidermis?
A
- keratinocytes - produce keratin
- melanocytes - produce melanin
- Langerhans’ cells - macrophages
- merkel cells - touch receptors
4
Q
What are the layers of the Epidermis? from superficial to deep
A
- stratum corneum
- stratum lucidum (thick skin ONLY)
- stratum granulsoum
- stratum spinosum
- stratum basale
5
Q
What are the 2 types of granules in stratum spinosum? what do they do?
A
- Keratohyaline granule - involved in cross-linking keratin & cellular dehydration
- meshwork of keratin
- Lamellar granules - waterproofing glycolipid granules that is spewed into the extracellular space
- Water proofing agents
6
Q
What cells are in the Dermis?
A
- fibroblasts
- macrophages
- mast cells
- WBC
7
Q
What are the layers of the Dermis?
A
- papillary layer - loose areolar CT
- reticular layer - dense irregular CT
8
Q
What is present in the Papillary layer of the Dermis?
A
- areolar CT - collagen & elastic fibers
- dermal papillae
9
Q
What are Dermal Papillae?
A
- superior surface peg-like projections
- dermis -> epidermis
- contain: capillary loops, meissner’s corpuscles, free nerve endings
10
Q
What is in the Hypodermis layer?
A
- composed of adipose & areolar CT
- blood vessel layers - involved in thermoregulation
10
Q
What is in the Reticular layer of the Dermis?
A
- collagen fibers
- elastin fibers
11
Q
What are the 3 pigments that contribute to skin colour?
A
- melanin - yellow to black colour
- carotene - yellow to orange colour
- hemoglobin - reddish pigment
12
Q
What are the 4 gland types?
A
- Sudoriferous sweat glands
- Ceruminous glands
- Mammary glands
- Sebaceous (oil) glands
13
Q
Apocrine vs. Eccrine
A
- Apocrine - larger, highly vascularized, secrete along hair shaft, viscous secretion
- Eccrine (merocrine) - over most of body, open directly onto skin surface, hypotonic filtrate of the blood
14
Q
What are Ceruminous Glands?
A
- Secrete cerumen or earwax - thought toe deter insects & block entry of foreign material
- Combo of apocrine & eccrine
15
Q
What are Mammary Glands?
A
- Specialized sweat glands that secrete milk
- Modification of apocrine
- Stimulated by prolactin to produce milk
16
Q
What are Sebaceous glands?
A
- Holocrine type oil secretion called sebum (made of cholesterol, proteins, fats & salts)
○ Lose cell as mode of secretion - Keeps hair & skin soft & pliable & inhibits growth of bacteria & fungi (ringworm)
- Activated during puberty when androgens begin to rise
○ Sensitive to DHT, Testosterone - Acne caused by a clogged sebaceous gland pore
17
Q
What are the layers in the hair follicle? (starting at medulla)
A
- Medulla > Cortex > Cuticle > Internal epithelial root sheath > external epithelial root sheath
18
Q
How does the hair alert the body to insects on the skin?
A
- sensory nerve endings called hair follicle receptor or root hair plexus wrap around each bulb
- if the hair is bent, stimulates endings -> suggests something is on skin
19
Q
What are Hair papilla?
A
- dermal tissue that protrudes into the hair bulb & has capillaries
- type of CT
20
Q
What is the Hair Matrix?
A
- actively dividing area that produces hair, as cells are pushed upwards they become increasing keratinized & die
- similar to basale layer
21
Q
What causes hair colour?
A
- pigment made by melanocytes at base of hair follicle
- blond & red have little eumelanin
- black hair has lots of eumelanin
- red hair also has pheomelanin
22
Q
What are the 3 steps in the Hair Growth Cycle?
A
- Growth Stage - cells of matrix differentiate, keratinize & die, 2-6 years
- Resting stage - hair growth stops, lasts for 3 months on scalp
- After resting stage - hair falls out, replaced & new growth stage
23
Q
What is the structure of the nail?
A
- modification of the epidermis made of hard keratin
- nail cells are produced by matrix
- nail cells become heavily keratinized & nail body slides over nail bed
24
What are the types of Cancer & what cells are they derived from?
* carcinoma - epithelial cells
* sarcoma - connective tissue or mesenchymal cells
* lymphoma & leukemia - hematopoietic cells
* germ cell tumor - pluripotent cells
* blastoma - embryonic tissue
25
What are the 3 major types of skin cancers?
* basal cell carcinoma - most common, stratum basale, slow growing & often does NOT metastasize
* squamous cell carcinoma - stratum spinosum, grows rapidyly & metastisizes if not removed
* melanoma - melanocytes, highly metastatic & resistant to chemotherapy
26
What is a crucial risk factor for nonmelanoma skin cancer?
* disability of the p53 gene (tumor suppressor gene)
27
What is the ABCD rule for melanoma?
* A - asymmetry
* B - border (irregular & indentations)
* C - colour (black, brown, tan)
* D - diameter (larger than 6mm)
28
What is the rule of 9 for burns?
* anterior/posterior head & neck = 9%
* anterior/posterior upper limbs = 18%
* anterior/posterior trunk = 36%
* anterior/posterior legs = 36%
29
Burns are considered critical when...
* Over 25% of body has 2nd degree burns
* Over 10% of body has 3rd degree burns
* 3rd degree burns on face, hands or feet
30
What are potential fatal complications from burns?
* shock
* infection
* electrolyte imabalance
* respiratory distress
