Module 2

Question 1

Name 4 main functions of skin

Answer 1

protection
body temp
reception
absorption

Question 2

What are the two layers of skin?

Answer 2

dermis and epidermis

Question 3

4 layers of the epidermis + which ones are “alive”?

Answer 3

stratum corneum, lucium, granulosum, spinosum, basale (last 3)

Question 4

Stratum corneum - what does it contain?

Answer 4

dead keratinocytes containing keratin

Question 5

Stratum lucidum

Answer 5

squamous cells with no nucleus or organelles which help resist shear forces

Question 6

Stratum granulosum

Answer 6

active keratinocytes with no nucleus, but contain keratohyalin and glycolipids (act as a water barrier. Application: a good lotion should be based on fat; if it’s water-based, it cannot work on the active living cells and cannot penetrate this granulosum level

Question 7

Stratum spinosum

Answer 7

production of keratinization, many desmosomes connecting the cells (create a spinous appearance in histological cross-section)

Question 8

Stratum basale

Answer 8

germ layer or “stem cells” for keratinocytes - constantly dividing

Question 9

4 types of cells - arrange them to lowest to greatest abundance

Answer 9

melanocytes
langerhans
merkel
keratinocytes

Question 10

T or F: you can only find kertainocytes at the s. spinosum layer

Answer 10

F

Question 11

Every 20-30 days, cells near the surface of the epidermis get sloughed off. During the time they are moving from deep to superficial, they are differentiating and accumulating keratin filaments.

Which cell type?

Answer 11

keratinocytes

Question 12

Found in the stratum spinosum. Key role = immune system (allergic reactions)

Answer 12

Langerhans cells

Question 13

Found in the stratum basale. Produce melanin in melanosomes

Answer 13

melanocytes

Question 14

Explain what happens under your skin when you come back from a sunny vacation

Answer 14

Melanocytes
Where? Stratum basale
Production of melanin in melanosomes- pigmentation in skin/hair. What determines colour is not the number but ACTIVITY of the melanocytes (ie. on vacation your melanocytes are very active producing a lot of melanin, after you trip, tans eventually fade)
Melanosomes which contain more melanin results in darker skin/hair

Question 15

2 layers of the dermis

Answer 15

Papillary

Reticular

Question 16

Dense irregular collagenous CT, mostly Type I and elastic fiber (support and binds the dermis to hypodermis)
Resting place of sweat glands, sebaceous glands, and hair follicles

Answer 16

reticular

Question 17

Dermal ridges/papillae - digits projecting into the epidermis (consequently epidermal ridges are projections of the epidermis into the dermis). These two types of ridges form the rete apparatus.

Answer 17

papillary

Question 18

2 smooth muscles in skin. Which one does botox act on?

Answer 18

Arrector pili muscles - erect hair and goosebumps

Striated muscles (face, neck, scalp) - facial expression 
Application: botulinum toxin type A (BOTOX)
Blocks ACh release; therefore no signal for muscle contraction

Question 19

Finer tactile - two point discrimination, texture, shape of objects

Which type of subcutaneous receptor? SA or RA?

Answer 19

Merkel

SA

Question 20

Pain, temperature (unmyelinated)

Which type of subcutaneous receptor?

Answer 20

free nerve endings

Question 21

Pressure, vibration

Which type of subcutaneous receptor?

Answer 21

Pacinian corpuscles

Question 22

Light tactile (sensitive to small movements across skin)

Which type of subcutaneous receptor? SA or RA?

Answer 22

Meissner corpuscle

RA

Question 23

Sole of feet, palms, dermis, joint capsules (onion-like)

Answer 23

Pacinian

Question 24

Fingers, hand, sole of foot, forearm, eyelids, nipples, lips, tongue (among dermal papillae)

Answer 24

Meissner

Question 25

Fingers, lips, external genitalia (among keratinocyte - in the stratum basale)

Answer 25

Merkel

Question 26

Epidermis and corneal epithelium

Answer 26

Free nerve endings

Question 27

3 types of glands of the integument

Answer 27

eccrine apocrine sebaceous glands

Question 28

State their secretion + locations eccrine apocrine sebaceous glands

Answer 28

sweat - sweat pores odour - in dermis (hair follicles in axilla, areola, anus) waxy sebum - hair shaft

Question 29

Wound healing Inflammatory (2) Proliferative (3) Remodelling (2)

Answer 29

5 days - hemostasis, inflammation 3 weeks - granulation, contraction, epithelialization collagen formation scar tissue

Question 30

There are two portions of the respiratory system. Conduction & Respiratory - what's the "boundaries" of each?

Answer 30

Conduction - nasal cavity --> terminal bronchioles Respiratory - respiratory bronchioles --> alveolar

Question 31

What 4 layers of tissue would you find in the respiratory tract?

Answer 31

mucosa muscularis submucosa adventitia

Question 32

4 cells of the olfactory epithelium

Answer 32

BOBS ``` brush cells (microvilli - sensory?) olfactory cells (bipolar) basal cells (stem cells) sustentacular/supporting (metabolic/physical) ```

Question 33

Larynx 3 types of cartilage in this region? - which one is the Adam's Apple True vs. False vocal cords?

Answer 33

False vocal cords (CT, glands, fats) True vocal cords (skeletal muscle) 3 cartilages: thyroid cartilage (hyalin, Adam’s apple), cricoid (ring-shaped), epiglottis

Question 34

Trachea's 4 layers: Mucosa - epithelium type? - 30%, 30%, 30% - these are the proportions of what? - which cells secrete hormones and catecholamines? Submucosa - what time of glands can we find here? what types of CT is present? Muscular Adventitia - usually filled with ____

Answer 34

Mucosa layer – respiratory epithelium: Ciliated pseudostratified epithelium with goblet cells (~30%). Basal cells (30%) - stem cells Lamina propria consists of collagen and elastic fibers (30%) Brush cells with microvilli (sensory?) Endocrine cells - which secretes hormones and catecholamines Submucosa layer – seromucous glands surrounds by collagen and elastic fibers Muscular layer – consists of smooth muscle bridges the gap between free ends of C-shaped cartilage Adventitia layer - usually filled with fat

Question 35

Bronchi Divisions: primary → __?__ → terminal bronchioles → __?__ → alveolar ducts → alveolar sacs and alveoli → pores of ____

Answer 35

primary → secondary bronchi → terminal bronchioles → 1st/2nd/3rd order respiratory bronchioles → alveolar ducts → alveolar sacs and alveoli → pores of Kohn

Question 36

**FEATURES OF THE TERMINAL BRONCHIOLE - What would you not find here? (3) - What would you find here? (1)

Answer 36

NO CARTILAGE & MUCOUS GLANDS OR GOBLET CELLS clara cells!

Question 37

Clara cells Shape? Secrete what? (2) Other functions (2)

Answer 37

Dome-like between ciliated cells Secrete GAG in chemical irritation, inflammation Detoxes substances Secretes surfactant Involved with transporting water and electrolytes (Cl)

Question 38

4 main cells within the alveoli

Answer 38

Endothelial cells of blood capillaries (continuous, non-fenestrated) Squamous epithelial cells (Type I) - connected to endothelial cells via common basal lamina - very thin Secretory cells (Type II, great alveolar cells) - large rounded cells, secrete surfactant (a phospholipid that reduce surface tension, or else alveoli would collapse) Alveolar macrophages