Integumentary 1

Question 1

What structures does the integumentary system contain?

Answer 1

Skin, hair, nails, glands, adipose tissue, muscles and nerves

Question 2

What structures of the integumentary system contain epithelium tissue

Answer 2

epidermis, blood vessels, sweat glands, sebaceous glands, hair

Question 3

What structures of the integumentary system contain connective tissue

Answer 3

dermis, hypodermis, blood vessels

Question 4

What structures of the integumentary system contain muscle tissue

Answer 4

blood vessels, arrector pili muscles

Question 5

What structures of the integumentary system contain nervous tissue

Answer 5

sensory receptors, blood vessels

Question 6

What the the three layers of skin and what are they made of?

Answer 6

Epidermis (stratified cuboidal keratinised epithelium)
Dermis (loose connective tissue -papillary layer and dense irregular connective tissue - reticular layer
Hypodermis (adipose and dense irregular connective tissue)

Question 7

What is the purpose of keratinisation?

Answer 7

To produce lamellar bodies as tonofilamenta and keratohylaine granules combine.

Question 8

What are the 5 layers of epidermis?

Answer 8

Stratum basale 
Stratum spinosum 
Stratum granulosum 
Stratum lucidum (only in thick skin)
Stratum corneum

Question 9

What are the layers of dermis?

Answer 9

Papillary layer (loose CT) 
Reticular layer (dense irregular CT, the reticular layer is the largest layer in the dermis).

Question 10

What non-keratinocytes are in epidermis and in which layers?

Answer 10

Merkel cells found in stratum basale.
Melanocytes found in stratum basale
Langerhans cells found everywhere but mostly in stratum spinosum.

Question 11

Why are stratum lucidum and corneum acidophilic

Answer 11

They are filled with protein and are dead so have no nuclei

Question 12

What are keratinocytes?

Answer 12

Keratinocytes are responsible for the visible layers of the skin. They contain tonofilaments and keratohyaline granules (when they combine keratin is formed). Keratinocytes also secrete glycolipids (lamller bodies) Keratinocytes produce in the basale layer from mitosis. As they progress through the layers, keratinocytes are removed by abrasion

Question 13

What is keratinisation?

Answer 13

It is the process as keratinocytes progress through the epidermis. It goes from cuboidal, irregular spiny, flattened with granules and then squamous. Lamellar bodies are also produced. It is done by cell divison.

Question 14

Describe the stratum basale

Answer 14

Contain merkel cells and melanocytes. Contains many cell junctions (hemidesomones and desmosomes). Production of keratinocytes also occurs here. Melanin granules are also found here

Question 15

Describe the stratum spinosum

Answer 15

The largest layer of the epidermis. Langerhans cells are identified here. The intercellular bridges are held by demosomes. Tonofilaments (found in keratinocytes) are found here

Question 16

Describe the stratum granulosum

Answer 16

As the tonofilments and keratohyaline granules combine, glycolipids (lamellar bodies) are produced.

Question 17

Describe the stratum lucidum and corenum

Answer 17

Found only in thick skin (lucidum). dead skin filled w/ keratin. Surface keratin is lost through abrasion

Question 18

Describe the lifespan of keratinocytes

Answer 18

The lifespan is shorter the high friction areas (25-30 days) and is longer in ares w/ low friction (40-50 days). Diseases (ie psorasis) can influence this.

Question 19

Describe merkle cells

Answer 19

Merkle cells are found in the basale layer. They are associated with light touch

Question 20

Describe melanocytes

Answer 20

Produce melanin. located in the stratum basale.

Question 21

What are the three types of melanin?

Answer 21

Eumelanin (black/brown)
pheomelanin (pink/skin)
Neuromelanin (in neurons)

Question 22

Describe langerhans cells

Answer 22

Langerhans cells are dendritic cells and are associated w/ the innate immune system.

Question 23

Describe the difference between thick and thin skin

Answer 23

Thick skin is hairless whilst thin skin contains hair however some thin skin such as the border of the lips nipples penis and clitoris do not contain hair.
Both skins have sweat glands (apocrine sweat glands = thin).
Thick skin has thicker dead cell layers (lucidum +corneum) and folds to better attach the epidermis to dermis. This is done by dermal pipillae.