Week 3 (skin)

Question 1

What are the 3 basic layers of the skin

Answer 1

Epidermis , dermis, hypodermis

Question 2

Answer 2

Question 3

What are the three main cell types of the epidermis

Answer 3

Keratinocytes, Melanocytes, and Langerhans

Question 4

What are the 5 layers of the epidermis

Answer 4

(Stratum = Layer)
- Stratum Corneum (“horny” outermost layer)
- Stratum Lucidum (clear layer) (lucid = clear)
- Stratum Granulosum (granular layer)
- Stratum spinosum (“spiny” layer)
- Stratum Basale (germinativum) (innermost – base)
Downloaded by

Question 5

Answer 5

Question 6

where is the Stratum lucidum Found

Answer 6

hands and feet

Question 7

Answer 7

Question 8

Melanocytes do what?

Answer 8

Secrete melamin which accumalates in membrane-bound granules called melanosomes that are trafficked to kertinocytes via actin filaments

Question 9

What are the two types of Melanin

Answer 9

Eulamelanin (dark) and Phaeomelanin (red/yellow)

Question 10

Is the dermis vascularised

Answer 10

yes

Question 11

The Dermis consists of _____
layers (elaborate)

Answer 11

Papillary 20%
- Areolar
connective
tissue – loose
- Dermal
papillae

Reticular 80%
- Dense
irregular
connective
tissue

Question 12

Two types of sweat glands

Answer 12

o Eccrine
o Apocrine

Question 13

Where are Eccrine Sweat Glands found

Answer 13

Everywhere but especially the Palms of hands, soles of feet and forehead

Question 14

What type of glands are sweat

Answer 14

Exocrine

Question 15

Where are Apocrine Sweat Glands

Answer 15

armpits and genitals

Question 16

What differentiates Apocrine Sweat Gland from Eccrine sweat glands

Answer 16

Larger than eccrine glands and deeper in the dermis

Secrete into ducts that empty into hair follicles

Similar components as true sweat but also the addition of fatty substances and proteins

Role in pheromone secretion and sexual arousal

Question 17

What differentiates Eccrine Sweat Gland from Apocrine sweat glands

Answer 17

Major role is to regulate body temperature

Similar components as true sweat but also the addition of fatty substances and proteins

Secrete “true” sweat
o 99% water, slats vitamin C, antibodies

Question 18

Answer 18

Question 19

Answer 19

Question 20

Modified Apocirne sweat glands

Answer 20

Ceruminous glands
o Secrete cerumen – bitter, waxy secretion (ear-wax)
o Found in the outer one third of the external ear canal

Mammary glands
o Secrete milk (in human female)
 A specialized “sweat” secretion

Question 21

What do Sebaceous (oil) glands secrete, what type of galnd is it, and its purpose and controlled by what

Answer 21

Secrete sebum (oily substance), Holocrine gland, Functions to lubricates hair and slow water loss from the skin, and Secretion is controlled mainly by sex hormones
o E.g. testosterone

Question 22

how does a sebaceous cyst form

Answer 22

Sebaceous glands fills with sebum

Question 23

how do blisters form

Answer 23

extracellular fluid seberates the epimeris and the sermis

Question 24

What are the coats of hair and where are they located

Answer 24

During our lifetime, humans have 3 different types of hair
o Lanugo (down – lose it 1 to 2 months before birth)
o Vellus (fleece – fine, pale, body hair)
o Terminal hair (scalp, eyebrow, lashes, axilla, pubis)

Question 25

what is hair made up of

Answer 25

keratinised cells

Question 26

outline the diagram

Answer 26

Question 27

Characteristics of the hypodermis

Answer 27

Anchors the skin to the underlining structures (mostly muscle)

Consists of
adipose tissue
(adipo = fat)

Question 28

Hair colour is determined by pigments produced (which melanin and colour associated 3)

Question 29

Hair-raising experiences

Around hair follicles and associated oil glands are:

Answer 29

o Nervous (sensory) tissues
o Microscopic muscle tissue

 Arrector pili muscle -controls each hair
o Causes “goose-bumps” – hair stands on end
o Contraction forces sebum out of hair follicles lubricating the skin