physiology

Question 1

epidermis is derived from?

Answer 1

ectoderm

Question 2

dermis is derived from?

Answer 2

mesoderm

Question 3

melanocytes derived from?

Answer 3

neural crest

Question 4

what is the epidermis structure?

Answer 4

stratified squamous epithelium

Question 5

layers of the epidermis

Answer 5

keratin, granular, prickle cell, basal

Question 6

what is characteristic of the prickle cell layer

Answer 6

lots of desmosomes

Question 7

what is present in palms/soles

Answer 7

a fifth layer called stratum lucidium

Question 8

where is the stratum lucindium

Answer 8

between corner-granulosum

Question 9

what are basal cells

Answer 9

cuboidal shaped stem cells that are precursors of the keratinocytes

Question 10

what are most epidermal cells

Answer 10

keratinocytes

Question 11

where are keratinocytes dead

Answer 11

in the corneum

Question 12

what are keratinocytes

Answer 12

cells that excrete and store keratin

Question 13

how long for keratinocytes to migrate from the basement membrane

Answer 13

28days

Question 14

what are melanocytes

Answer 14

pigment producing dendritic cells

Question 15

what do melanocytes to

Answer 15

convert tyrosine to melanin

Question 16

what do melanocytes contain

Answer 16

melanosomes

Question 17

what does melanin do

Answer 17

absorb light

Question 18

what happens with meloanosomes are full

Answer 18

they are transferred to adjacent keratinocytes by dendrites

Question 19

what do full melanosomes do

Answer 19

form a protective cap over the nucleus protecting nuclear DNA in basal cells

Question 20

where are langerhans cells found

Answer 20

in spinous level

Question 21

what are langerhans cells

Answer 21

antigen presenting dendritic cells

Question 22

where are Merkel cells found

Answer 22

basal level between keratinocytes and nerve fibres

Question 23

what are Merkel cells

Answer 23

mechano- receptors

Question 24

what causes pigmentation in hair

Answer 24

melanocytes above dermal papilla

Question 25

what causes hair growth

Answer 25

hormones - thyroxine androgens

Question 26

stages of hair

Answer 26

anagen, catagen, telogen

Question 27

what happens in anagen

Answer 27

growth

Question 28

what happens in catagen

Answer 28

involuting

Question 29

what happens in telogen

Answer 29

resting (balding)

Question 30

what can cause hair growth in cancer

Answer 30

cancers that release excess androgen

Question 31

what is a nail body made of

Answer 31

densely packed dead keratinocytes

Question 32

where is the derma-epidermal junction

Answer 32

between dermis and epidermis

Question 33

what bonds layers together at the derma-epidermal junction

Answer 33

collagen fibres

Question 34

what increases the strength of the layers at the dermal epidermal junction

Answer 34

dermal papilla

Question 35

what is the dermis made of

Answer 35

two layers of connective tissue (collagen and elastin)

Question 36

what does the dermis contain

Answer 36

blood and lymphatic vessels and nerves

Question 37

somatic sensory nerves

Answer 37

dermatomes

Question 38

pressure

Answer 38

pacinian

Question 39

vibration

Answer 39

meissners

Question 40

sabecous glands produce

Answer 40

sebum

Question 41

apocrine glands produce

Answer 41

oily fluid - cause sweat smell

Question 42

eccrine

Answer 42

true sweat gland

Question 43

nerve supply of eccrine

Answer 43

sympathetic cholinergic nerve supply

Question 44

functions of skin

Answer 44

barrier, metabolism and detoxification, thermoregulation, immune defence, communication, sensor function s

Question 45

what does skin metabolise

Answer 45

vit D and Thyroid hormone

Question 46

Thyroid hormone changed

Answer 46

T4- T3