Integumentary system

Question 1

What is the integumentary system?

Answer 1

The skin and its accessory organs

Question 2

What is the structure of the skin?

Answer 2

Epidermis
Dermis
Hypodermis

Question 3

What is the function of the hypodermis?

Answer 3

Anchors the dermis to the epidermis

Question 4

What are the 2 zones of the dermis?

Answer 4

Papillary layer
Reticular layer

Question 5

Structure and function of papillary layer?

Answer 5

Thin region of loose connective tissue (areolar)
Allows mobility of leukocytes, mast and macrophage cells

Question 6

Structure and function of the reticular layer

Answer 6

Thick layer of dense irregular connective tissue
Adipocyte clusters
Stretches skin in weight gain

Question 7

Function of a fibroblast

Answer 7

Produces laminin and fibronectin

Question 8

What are the accessory organs of the dermis

Answer 8

Hair
Nails
Oil
Sweat glands

Question 9

What are some specialisations of the dermis?

Answer 9

Rich layer of blood and lymphatic vessels
Nerve endings
Arteriovenous anastomoses

Question 10

What is an arteriovenous anastomoses?

Answer 10

Direct connections between small arteries and small veins
Aids in thermoregulation

Question 11

Structure of the dermal-epidermal boundary?

Answer 11

Wavy boundary of finger like projections
Dermal papillae and epidermal ridges

Question 12

What do tall dermal papillae facilitate?

Answer 12

Nerve fibres reaching close to the dermal epidermal boundary in highly sensitive areas

Question 13

What type of epithelium is the epidermis?

Answer 13

A keratinised stratified squamous

Question 14

Name the 4 layers of thin skin

Answer 14

Stratum Basale
Stratum spinosum
Stratum granulosum
Stratum corneum

Question 15

Where is ‘thick’ skin found?

Answer 15

Palms and feet

Question 16

Name the 5 layers of thick skin

Answer 16

Stratum corneum
Stratum lucidium
Stratum granulosum
Stratum spinosum
Stratum Basale

Question 17

What is the self-regeneration time for the epidermis?

Answer 17

2-4 weeks

Question 18

What cells does the stratum basale contain?

Answer 18

Keratinocytes
Melanocytes
Tactile/Merkel cells

Question 19

Where are keratinocytes mitotically active?

Answer 19

Basement membrane

Question 20

What pigment does pheomelanin give off?

Answer 20

Red soluble pigment

Question 21

What pigment does eumelanin give off?

Answer 21

Brown insoluble pigment

Question 22

Function of tactile/Merkel cells

Answer 22

Connect to sensory nerves to give sense of touch

Question 23

What are dermal papillae interdigitated with?

Answer 23

Epidermal rete ridges
At the junction of tissues

Question 24

What is melanin?

Answer 24

UV absorbent antioxidant
Radical scavenge

Question 25

What does melanin pigmentation depend on?

Answer 25

Carotene pigments Amount of blood and haemoglobin

Question 26

Where are carotene pigments found?

Answer 26

In subcutaneous fat Stratum corneum

Question 27

What are melanosomes phagocytosed by?

Answer 27

Keratinocytes to surround the nucleus

Question 28

What is the thickest 'thin' skin layer?

Answer 28

Stratum spinosum

Question 29

What is the thickest 'thick' skin layer?

Answer 29

Stratum corneum

Question 30

What are 3 specialisations of the stratum spinosum?

Answer 30

Produce keratin filaments causing cells to flatten The deepest cells are mitotic, pushed upwards and cease to divide Tight junctions ensure water retention

Question 31

What are keratinocytes linked to in stratum spinosum?

Answer 31

Desmosomes

Question 32

What are keratohyalin granules?

Answer 32

Dark staining Bind to cytoskeleton and are converted keratin

Question 33

How many layers is the stratum granulosum?

Answer 33

3-5 layers of flat keratinocytes

Question 34

What stage of the cell cycle is stratum granulosum in?

Answer 34

Post mitotic

Question 35

Specialisation of stratum granulosum

Answer 35

Produce glycolipid filled vesicles which sit between the stratum spinosum for waterproofing

Question 36

What is the name for conversion of keratohyalin to keratin ?

Answer 36

Transglutaminases

Question 37

What is the structure of the stratum lucidium?

Answer 37

2-3 cell layers

Question 38

What cells are found in stratum lucidium?

Answer 38

Dead keratinocytes Cytoplasmic granules of eleidin

Question 39

What are cytoplasmic granules of eleidin?

Answer 39

A product of keratohylain

Question 40

Structure of stratum corneum

Answer 40

15-30 layers Upper layer is terminally differentiated with dead keratinocytes

Question 41

Specialisation of the stratum corneum

Answer 41

Has a cornified envelope Resistant to abrasion, penetration and water loss

Question 42

How is an iron deficiency displayed in nails?

Answer 42

Flat or concaved

Question 43

How is long term hypoxemia displayed in nails?

Answer 43

Clubbed

Question 44

Structure of nails

Answer 44

Dead scaly cells densely packed with hard keratin fibres Derived from stratum corneum

Question 45

Structure of hair

Answer 45

Slender filament of keratinised cells from follicle

Question 46

What are the 3 stages of hair?

Answer 46

Lanugo Vellus Terminal

Question 47

What are the 3 layers of the hair follicle?

Answer 47

Medulla Cortex Cuticle

Question 48

Name the 5 types of skin glands

Answer 48

Merocrine Apocrine Sebaceous Ceruminous Mammary (female only)

Question 49

Function of merocrine gland

Answer 49

Sweat gland Secretes watery perspiration to skin Associated with myoepithelial cells

Question 50

Function of Apocrine cells

Answer 50

Sweat glands Scent glands responding to stress and sexual stimulation

Question 51

Structure of physical barrier

Answer 51

Cross linked keratin layer on a scaffold of keratinocytes

Question 52

Describe the biochemical barrier

Answer 52

Slightly acidic Contains bacteriocidal agents

Question 53

What bactericidal agents are in the biochemical barrier?

Answer 53

Saturated and unsaturated fatty acids (inhibit growth) Lysozyme (cleaves cross links in bacterial cell wall)

Question 54

Describe the immunological layer

Answer 54

Langerhans cells (in stratum spinosum) take up and process antigens. They migrate to lymph nodes and present antigens to the skin lymphocytes which circulate to secondary lymphoid organs.

Question 55

Where are the warm and cold receptors found?

Answer 55

The preoptic anterior hypothalamus

Question 56

Where does counter current heat exchange occur?

Answer 56

Between arterial and venous blood in the dermis

Question 57

Blood flow at 250ml/min dissipates heat at ...

Answer 57

80kcal/hr