Skin

Question 1

Why is skin an organ

Answer 1

combination of 4 primary tissues- epithelium, connective, muscle, nerve. has its own pathological conditions eg sunburn, acne, melanoma. Reflects underlying systemic conditions eg liver disease

Question 2

functions of skin

Answer 2

barrier between internal and external environment. needs to be sensitive and protect. thermoregulation

Question 3

3 layers of skin

Answer 3

epidermis (outer layer) , dermis, hypodermis

Question 4

4 cell types in epidermis

Answer 4

keratinocytes (waterproofing, self generating), melanocytes (pigment formation), langerhans (immune surveillance), Merkel cells (touch receptors)

Question 5

layers of the epidermis

Answer 5

stratum basale (where melanocytes are found), stratum spinosum, stratum granulosum, stratum cornium (thickness)

Question 6

Dermis layers

Answer 6

papillary layer (loose connective tissue), reticular layer (dense irregular tissue)

Question 7

what muscle is associated with hair follicles

Answer 7

arrector pili muscles. at an angle, attached to follicle root, hair straightens when muscle contacts. next to sebaceous gland

Question 8

2 types of sweat glands

Answer 8

eccrine, apocrine

Question 9

sensory nerves in skin

Answer 9

meissner’s corpuscles (light touch fingertips), paccinian corspuscles (vibration and pressure), pain receptors, thermoreceptors

Question 10

keratinisation

Answer 10

keratin is deposited in cells and these become horny as in dead skin, nails, hair

Question 11

what is the main type of connective tissue found in hypodermis

Answer 11

adipose

Question 12

sweat glands in the axilla have which type of secretion

Answer 12

apocrine

Question 13

which specific stratum of the epidermis does squamous refer

Answer 13

stratum spinosum

Question 14

which layer of dermis gives most elasticity to skin

Answer 14

reticular layer

Question 15

which epidermal layer determines thickness

Answer 15

stratum corneum

Question 16

what connects the epidermis to the dermis

Answer 16

hemidesmosomes by connecting cells of the stratum basale to the dermis via basal lamina

Question 17

What is the function of the numerous myoepithelial cells (in sweat glands)?

Answer 17

Myoepithelial cells are what propel the secretory contents of the glands to the surface of the body.

Question 18

What is the function of the epidermal ridges and dermal papillae?

Answer 18

Epidermal ridges and dermal papillae provide increased surface area for the epidermis and dermis to connect.

Question 19

Where do the ducts empty?

Answer 19

Ducts of eccrine sweat glands empty onto the surface of the skin. Apocrine glands, however, empty into hair follicles in the axillary, areolar and perianal regions.

Question 20

How does sweat get to the surface?

Answer 20

Eccrine sweat glands have ducts that lead to the surface of the skin. Eccrine sweat glands are a type of merocrine gland (a gland that releases its product by exocytosis). The secretory cells of the eccrine gland are surrounded by myoepithelial cells which can contract to propel its secretions to the surface. Apocrine sweat glands (apocrine being a misnomer, they are truly a merocrine gland, not an apocrine gland) function in the same way, however, their ducts lead to hair follicles, not directly to the skin surface.

Question 21

tonofibrils

Answer 21

keratin filaments that help provide the cell with strength and support and insert into the desmosomes