structure and function of skin

Question 1

what is the largest organ in body?

Answer 1

skin

Question 2

what is the skin’s outer layer?

Answer 2

epidermis

Question 3

what layer is beneath the epidermis?

Answer 3

dermis

Question 4

what type of epithelium is the epidermis made from?

Answer 4

stratified squamous epithelium

Question 5

which germ layer forms epidermis?

Answer 5

ectoderm

Question 6

what germ layer forms the dermis?

Answer 6

mesoderm

Question 7

what are melanocytes?

Answer 7

pigment producing cells

Question 8

what cell makes up most of epidermis?

Answer 8

keratinocytes

Question 9

name cells that you might find in epidermis?

Answer 9

keratinocytes
melanocytes
langerhans cells
merkel cells

Question 10

what are the 4 layers of the epidermis?

Answer 10

keratin layer
granular layer
prickle cell layer
basal layer

Question 11

name a place where keratin layer would be thicker?

Answer 11

sole of foot

Question 12

what layer does this describe?

2-3 layers
large keratohyalin granules
odland bodies
high lipid content
origin of cornified envelope
cell nuclei lost

Answer 12

granular layer

Question 13

what layer is water proof?

Answer 13

keratin layer

Question 14

what do desmosomes do?

Answer 14

anchor cells to each other

Question 15

what are blaschko’s lines?

Answer 15

developmental growth pattern of skin

Question 16

what does loss of appendages cause?

Answer 16

scar tissue

Question 17

name some appendages?

Answer 17

hair
nail
glands
mucosae

Question 18

where to melanocytes migrate to and from during first 3 months of foetal development

Answer 18

from epidermis to neural crest

Question 19

what are the organelles in melanocytes?

Answer 19

melanosomes

Question 20

what does melanin absorb?

Answer 20

light

Question 21

what is vitilgo?

Answer 21

autoimmune disease with loss of melanocytes

Question 22

what is albinsim?

Answer 22

genetic partial loss of pigment production

Question 23

what is nelson’s syndrome?

Answer 23

melanin stimulating hormone is produced in excess by pituitary

Question 24

what is the function of the langerhans cell?

Answer 24

antigen presenting

picks up antigen in skin and circulates it to lymph nodes

Question 25

what causes merkel cell cancer?

Answer 25

viral infection

Question 26

what are merkel cells?

Answer 26

mechanoreceptors

Question 27

what does anagen mean?

Answer 27

growing

Question 28

what does catagen mean?

Answer 28

involuting (going down)

Question 29

what does telogen mean?

Answer 29

resting

Question 30

what is alopecia?

Answer 30

autoimmune hairloss

Question 31

what makes nails/

Answer 31

specialised keratins

Question 32

what is the dermo-epidermal junction?

Answer 32

interface between epidermis and dermis

Question 33

what gives the epidermis its blood supply?

Answer 33

the dermis

Question 34

what are the main cells in the dermis?

Answer 34

fibroblasts

Question 35

what other cells do you get in the dermis?

Answer 35

``` fibroblasts macrophages mast cells lymphocytes langerhans cells ```

Question 36

localised overgrowth of blood vessels

Answer 36

angioma

Question 37

what do pacinian receptors detect?

Answer 37

pressure

Question 38

what do meissners receptors detect?

Answer 38

vibration

Question 39

what do free nerve endings detect?

Answer 39

touch and temp

Question 40

what is neurofibromatosis?

Answer 40

overgrowth of nerve endings (thickened)

Question 41

what do the apocrine glands secrete?

Answer 41

odour when you start puberty (in armpit and groin)

Question 42

what to eccrine glands secrete?

Answer 42

sweat

Question 43

what do sebaceous glands secrete?

Answer 43

sebum

Question 44

what is sebum?

Answer 44

body's natural moisturiser

Question 45

what can sebum cause?

Answer 45

acne

Question 46

what is toxic epidermal necrolysis?

Answer 46

acute skin failure

Question 47

name some functions of the skin?

Answer 47

``` barrier function metabolsim and detox thermoregulation immune defence communication skills sensory skills ```

Question 48

what happens if skin barrier fails?

Answer 48

fluid loss leading to dehydration protein loss leading to hypoalbuminaemia infection

Question 49

what happens if skin thermoregulation fails?

Answer 49

heat loss leading to hypothermia

Question 50

what happens if the skin immune defence fails?

Answer 50

infection

Question 51

is skin metabolically active?

Answer 51

yes Vitamin D and thyroid hormone metabolism occurs