The Integumentary System (/Skin)

Question 1

What are the five functions of the integumentary system?

Answer 1

• Protection
• Synthesis and storage or nutrient (Vitamin D3 synthesis)
• Temperature maintenance
• Sensory reception
• Excretion and secretion

Question 2

What does the integumentary system consist of?

Answer 2

Skin and accessory strucutres

Question 3

How many layers does the skin have?

Answer 3

Epidermis, dermis, hypodermis

Question 4

Examples of accessory structures

Answer 4

Glands (2 sweat glands, sebaceous gland), hair, nails

Question 5

What are the two types of skin?

Answer 5

Thick skin and thin skin

Question 6

Where might thick skin be found and give some characteristics?

Answer 6

Palm of hands, sole of feet
No hair 5 layers (stratum)
stratified, squamous, keratinised epithelium

Question 7

Where is thin skin found and how many layers does it have?

Answer 7

Rest of the body

4 layers

Question 8

Which layer of skin regenerates throughout life?

Answer 8

Epidermis

Question 9

Epidermis and keratinocytes

Answer 9

Keratinocytes are born in the lower layer and migrate upwards during their life

Question 10

Where are dead keratinocytes found?

Answer 10

On the very lateral of the epidermis

Question 11

What are the five stratum in the epidermis?

Answer 11

Basal
Spinosum
Granulosum
Lucidum
Corneum

Question 12

What 3 cell types are found in stratum basale?

Answer 12

Keratinocytes - majority, mitotic in this strata
Melanocytes - responsible for skin colour
Tactile (/Merkel) cells - connected to sensory nerves and participate to the sense of touch

Question 13

Give 2 examples of pigments from melanocytes

Answer 13

• Eumelanin: brown insoluble pigment

- Pheomelanin: red soluble pigment

Question 14

What is the thickets layer of the epidermis?

Answer 14

Stratum spinosum

Question 15

Stratum spinosum characteristics

Answer 15

Keratinocytes - still mitotic

• higher content in keratin
• cells detach from the basement membrane and migrate apically

Question 16

What is the last layer of the epidermis to have cells containing nuclei?

Answer 16

Stratum granulosum

Question 17

How many layers of flat keratinocytes does stratum granulosum contain?

Answer 17

3-5

Question 18

Stranum granulosim characteristics

Answer 18

Keratinocytes- post mitotic, make large amount if keratin and a glycolipid

Keratin forms filaments that are durable
Glycolipid spreads over keratinocytes and make the skin water-resistant

Question 19

Which strata only exists in thick skin?

Answer 19

Stratum lucidum

Question 20

What are the keratinocytes like in stratum lucidum?

Answer 20

Densely packet and contain no nuclei or organelles

Question 21

Which strata is the most superficial layer?

Answer 21

Stratum corneum

Question 22

Stratum corneum characteristics

Answer 22

15-30 layers of dead, keratinised cells

- high lipid content –> permeability barrier

Question 23

What happens to cells at the surface of stratum corneum?

Answer 23

Cells at the surface flake off

Question 24

Mnemonic to remember layer (inwards to outwards)

Answer 24

Basic spiny grans look corny

Question 25

Is the dermis or epidermis thicker?

Answer 25

Dermis

Question 26

How many layers does the dermis have and what are they?

Answer 26

- Papillary layer | - Reticular layer

Question 27

In which of the 3 layers are blood vessels present?

Answer 27

Dermis

Question 28

Which layer is also called the subcutaneous layer?

Answer 28

Hypodermis

Question 29

What does the hypodermis consist of?

Answer 29

Connective tissue with adipocytes

Question 30

Examples of cutaneous glands

Answer 30

mammary glands, ceruminous glands, sebaceous glands, sweat glands

Question 31

Two types of sweat glands

Answer 31

Apocrine and merocrine

Question 32

Where do apocrine glands secrete product?

Answer 32

These sweat glands secrete products into hair follicles of armpits

Question 33

Which sweat glands secrete product into hair follicles of armpits?

Answer 33

Apocrine glands

Question 34

Which sweat glands are heavily involved in thermoregulation?

Answer 34

Merocrine glands

Question 35

Three ways in which skin is a barrier

Answer 35

Physical - toughness of keratin Biochemical - Sebum contains bactericidal substances and sweat bring the pH down Immunological - Langerhans cell in epidermis trigger immunological response during infection

Question 36

Which strata are Langerhans cells present in the epidermis?

Answer 36

Stratum spinulosum

Question 37

Which strata is vitamin D3 produced in?

Answer 37

Stratum basale and spinulosum

Question 38

Where is vitamin D3 further processed? What does this produce?

Answer 38

In the liver and kidneys to produce the cofactor of VDR (vitamin D receptor) that acts as a transcription factor