L18 - the skin

Question 1

functions of the skin

Answer 1

protection
metabolic function
thermoregulation
sensory organ
rapid repair of injuries

Question 2

metabolic function of the skin

Answer 2

vitamin D

Question 3

protection function of the skin

Answer 3

moisture control
barrier to pathogens
barrier to UV

Question 4

3 main layers of the skin

Answer 4

epidermis
dermis
subcutis

Question 5

epidermis cell type

Answer 5

keratinised stratified squamous epithelial

Question 6

epidermis

Answer 6

• produces keratin
• no blood vessels
• constantly being shed
• direct contact with the outside

Question 7

layers of the dermis

Answer 7

papillary dermis

reticular dermis

Question 8

dermis cell type

Answer 8

fibrous and fibroadipose tissue which supports the epidermis physically and metaboilcally

Question 9

dermis

Answer 9

• contains blood vessels
• contains nerves and sensory organs
• contains some muscles

Question 10

subcutis cells

Answer 10

adipose tissue with supporting fibrous bands

Question 11

subcutis

Answer 11

• large blood vessels

Question 12

which layer of the skin has no blood vessels

Answer 12

epidermis

Question 13

what type of epithelium is epidermis

Answer 13

continually proliferating

Question 14

thick skin

Answer 14

• no hair follicles

Question 15

5 layers of the epidermis (in thick skin)

Answer 15

• basal layer (stratum basale)
• prickle cell layer (startup spinosum)
• granular layer (stratum granulosum)
• stratum lucidum (skin of sole)
• keratin layer (stratum corneum)

Question 16

layers of the epidermis in thin skin - only 4

Answer 16

• basal layer (stratum basale)
• prickle cell layer (stratum spinosum)
• granular layer (stratum granulosum)
• keratin layer (stratum corner)

Question 17

stratum lucidum

Answer 17

• Nuclei already begin to degenerate in the outer part of the stratum granulosum
• faint nuclear outlines are visible in only a few of the cells
• ONLY IN THICK SKIN

Question 18

what type of cells are found in the stratum lucidum

Answer 18

Several layers of flattened dead cells

Question 19

cells found in the epidermis

Answer 19

keratinocytes
melanocytes
langerhan cells

Question 20

melanocytes location

Answer 20

stratum basale

Question 21

function of melanocytes

Answer 21

synthesise melanin (pigment in skin) which is transferred to adjacent keratinocytes.

Question 22

melanocytes under microscrope

Answer 22

have a halo surrounding the nucleus (white clearing around the nucleus)

Question 23

what type of cells are langerhan cells

Answer 23

intra-epidermal antigen presenting cells

historically referred to as histiocytes

Question 24

which layer of the epidermis are langerhan cells most easily recognised

Answer 24

prickle cell layer

stratum spinosum

Question 25

sebaceous glands

Answer 25

secrete sebum

Question 26

types of sebaceous gland

Answer 26

- associated with hair follicles and secrete sebum into hair follicle - secrete sebum directly onto the surface of the skin

Question 27

location of hair follicle

Answer 27

- Start quite deep down in sub cut tissue | - Extend through dermis and up though epidermis

Question 28

eccrine glands

Answer 28

produce sweat (thermoregulation function)

Question 29

apocrine glands

Answer 29

produce odour

Question 30

which glands screen sweat

Answer 30

eccrine

Question 31

arrector pili muscle

Answer 31

- smooth muscle fibres | - Make the hair stand on end of lay down flat, depending on how warm somebody is

Question 32

location of arrector pili muscle

Answer 32

Insert at one end into the follicle sheath just below sebaceous glands and the other in the superficial dermis

Question 33

structure of hair follicle

Answer 33

hair bulb hair shaft surrounding it hair follicle surrounding it

Question 34

cytoplasm of sebaceous gland under microscope

Answer 34

bubbly | due to sebum inside of it

Question 35

epidermis in thick skin

Answer 35

thicker

Question 36

skin receptors

Answer 36

- meissner corpuscles - merkel cells - pacinian corpuscles - Ruffini endings

Question 37

Meissner corpuscles

Answer 37

fast adapting | detect touch and vibration

Question 38

location of meissner corpuscles

Answer 38

papillary dermis (in dermis)

Question 39

merkel cells

Answer 39

slow adapting | touch and pressure receptors

Question 40

pacinian corpuscles location

Answer 40

deep in skin

Question 41

pacinian corpuscles

Answer 41

fast adapting | rapid touch, pressure and vibration

Question 42

Ruffini endings

Answer 42

slow adapting | pressure and vibration

Question 43

lamella of pacinian corpuscle

Answer 43

composed of flattened Schwann cells and endometrial fibroblasts

Question 44

what is between the lamella of the pacinian corpuscle

Answer 44

- fluid - collagen fibres - capillaries

Question 45

which stains should and should not be used to see Merkel cells

Answer 45

not H&E stain should use CK20

Question 46

location of Merkel cells

Answer 46

basal layer of epidermis

Question 47

which layers of the skin does first degree burn penetrate?

Answer 47

epidermis

Question 48

which layers of the skin does second degree burn penetrate?

Answer 48

epidermis and dermis

Question 49

which layers of the skin does third degree burn penetrate?

Answer 49

epidermis, dermis and sub-cut

Question 50

why may 3rd degree burn not be as painful

Answer 50

you may damage nerve fibres and pain receptors

Question 51

nociceptors

Answer 51

pain receptors

Question 52

where is thick skin located in humans

Answer 52

- palms of hands | - soles of feet

Question 53

which layer of the skin does basal cell carcinoma originate

Answer 53

stratum basale

Question 54

which layer of the skin does squamous cell carcinoma originate?

Answer 54

epidermis

Question 55

which layer of the skin does malignant melanoma originate?

Answer 55

Deepest layer of the epidermis, located just above the dermis

Question 56

what is a wart?

Answer 56

small lumps on the skin | - extra keratin produces a rough, hard texture of a wart

Question 57

what is the dermis made up of

Answer 57

connective tissue containing irregular bundles of collagen fibres plus networks of elastic fibres

Question 58

papillary dermis

Answer 58

superficial | loosely woven

Question 59

reticular dermis

Answer 59

deeper thicker denser

Question 60

rete ridges

Answer 60

epithelial down growths which result from epidermis and dermis interdigitating with one another

Question 61

dermal papillae

Answer 61

upward projections which result from epidermis and dermis interdigitating with one another

Question 62

what is a blister?

Answer 62

- Fluid collects between dermis and epidermis | - Cushioning the tissue underneath, protecting it from damage

Question 63

dermatome

Answer 63

A specific region of skin of the body innervated by the sensory fibres of a single segmental spinal nerve (spinal cord segment)

Question 64

two groups of cutaneous sensory receptors

Answer 64

- Free nerve endings/unencapsulated nerve endings/simple receptors - Encapsulated nerve endings/compound receptors.

Question 65

free nerve ending receptors

Answer 65

nociceptors | thermoreceptors

Question 66

encapsulated nerve ending receptors

Answer 66

mechanoreceptors

Question 67

fast adapting receptors

Answer 67

pacinian corpuscle | meissner's corpuscle

Question 68

slow adapting receptors

Answer 68

Ruffini endings | merkel cells

Question 69

which receptors are involved in detecting light stroking

Answer 69

Merkel’s disks | - Respond to light touch / discriminative touch

Question 70

which receptors are involved in reading braille

Answer 70

Meissner corpuscles | - Allows for discriminatory touch and grip control