The Skin

Question 1

Cutaneous membrane

Answer 1

Another word for skin

Question 2

Epidermis

Answer 2

topmost layer

Question 3

2 dermal layers

Answer 3

papillary and reticular

Question 4

Integument

Answer 4

tough outer protective layer (skin) that covers an organism

Question 5

Papillary layer

Answer 5

superficial of two dermis layers. deep to epidermis. composed of highly vascular loose tissue

Question 6

reticular layer

Answer 6

deep dermal layer, forming a thick layer of dense connective tissue forming the bulk of the dermis

Question 7

subcutaneous layer/hypodermis

Answer 7

Deepest layer of skin. Composed mostly of adipose and connective tissue. Acts as a layer of insulation to protect your internal organs and muscles from shock and changes in temperature.

Question 8

muscle attached to hair follicle

Answer 8

arrector pili muscle

Question 9

lamellated corpuscle (Pacinian corpuscle)

Answer 9

• primary function is sensing of deep touch/pressure or vibration
• located in dermis and hypodermis

Question 10

tactile corpuscle (Meissner corpuscle)

Answer 10

• concentrated in fingertips
• located at papillary dermis
• detect light touch

Question 11

cutaneous plexus

Answer 11

network of arteries present along the boarder of the hypodermis

Question 12

capillary of subpapillary plexus

Answer 12

subpapillary plexus supplies blood to epidermis via capillary in dermal papillae

Question 13

Thick vs thin skin (dermis size)

Answer 13

• Thick skin has thinner dermis
• Thin skin has thicker dermis

Question 14

Thick vs thin skin (location)

Answer 14

• Thick skin is only located in high areas of abrasion, fingertips, palms and foot sole
• Thin skin is located everywhere except fingertips, palms and foot sole

Question 15

Thick vs thin skin (general contents)

Answer 15

• Thick skin doesn’t contain hairs, sebaceous glands or apocrine sweat glands
• Thin skin does

Question 16

Thick vs thin skin (histologically)

Answer 16

• Thick skin contains stratum lucidum
• Thin skin doesn’t contain stratum lucidum

Question 17

insensible perspiration

Answer 17

water loss not via perceivable sweat. no solutes are lost

Question 18

desquamation

Answer 18

loss of outer skin via peeling/shedding in scales

Question 19

epidermal layers

Answer 19

• stratum corneum
• stratum lucidum
• stratum granulosum
• stratum spinosum
• stratum basale

Question 20

stratum corneum

Answer 20

• Multiple layers of flattened dead, interlocked keratinocytes
• resistant to water
• but allow slow water loss by ‘insensible perspiration’.
• Dead cells are shed by desquamation.

Question 21

stratum lucidum

Answer 21

• only present in thick skin.
• densely packed cells without nuclei or organelles
• appears glassy

Question 22

stratum granulosum

Answer 22

• cells undergo keratinisation.
• characterised by granules with keratohyalin

Question 23

stratum spinosum

Answer 23

• synthesises keratin, Langerhans and melanocytes

Question 24

stratum basale

Answer 24

• connected to basal membrane
• cells divide/regenerate
• contains stem cells, melanocytes and Merkel cells

Question 25

Epidermal cell types

Answer 25

- keratinocytes - melanocytes - Langerhans cells - Merkel cells

Question 26

Keratinocytes

Answer 26

- Highly specialised epithelial cells which act to separate an organism from its external environment - 85% of epidermal cells

Question 27

Melanocytes

Answer 27

- pigment producing cells - 5% of cells in epidermis

Question 28

Langerhans cells

Answer 28

- Antigen presenting cells - Involved in signalling in the immune system - 2-8% of cells in epidermis