Integument

Question 0

What is the main cell type in the epidermal layers?

Answer 0

Keratinocytes

Question 1

What cells of the epidermis are responsible for producing pigment and colouration?
Which layer of the epidermis are they found?

Answer 1

Melanocytes

St Basale

Question 2

What is the name of the muscle which causes hair to become erect?

Answer 2

Erector pili

Question 3

What are the two types of sweat glands?

Answer 3

Apocrine and eccrine

Question 4

Which type of sweat gland is found in the footpad?

Answer 4

Eccrine

Question 5

What epithelium does the epidermis consist of?

Answer 5

Keratinised stratified squamous

Question 6

What do sudoriferous glands secrete?

Answer 6

Sweat

Question 7

Which cells are present in the outer cuticle of the hair shaft?

Answer 7

Flat keratinised cells

Question 8

Which cells are present in the cortex of the hair shaft?

Answer 8

Dead cell layer

Question 9

What cells are present in the medulla of a hair shaft?

Answer 9

Cuboidal or flat cells

Question 10

What do sebaceous (oil) glands secrete?

Answer 10

Sebum

Question 11

What are the functions of sebum?

Answer 11

Retards water loss
Lubricates skin
Inhibits growth of certain bacteria
Helps spread sweat
Territorial marker

Question 12

How do androgens affect sebum secretion?

Answer 12

Increase it

Question 13

How does oestrogen affect sebum secretion?

Answer 13

Decrease it

Question 14

What are the names of the two melanin pigments?

Answer 14

Eumelanins (black and brown colouration)

Pheomelanins (red and yellow colouration)

Question 15

Give an example of soft keratin

Answer 15

Skin

Question 16

Give an example of hard keratin

Answer 16

Nails, horn, hoof

Question 17

What are the three receptor types in skin?

Answer 17

Mechanoreceptors (touch and pressure)
Thermoreceptors (temperature)
Nociceptors (intense stimuli-pain_

Question 18

Which nervous system controls blood flow to the skin?

Answer 18

Sympathetic

Question 19

What is the difference between panting and sweating, in terms of what is lost from the body?

Answer 19

Sweating - loss of water and NaCl

Panting - loss of water

Question 20

What does the epidermis originate from?

Answer 20

Ectoderm

Question 21

What does the dermis originate from?

Answer 21

Mesoderm

Question 22

Thickness of skin refers to relative thickness of which layer?

Answer 22

Epidermis

Question 23

What are the 5 layers of the epidermis?

Answer 23

St Corneum
St Lucidum
St Granulosum
St Spinosum
St Basale

Question 24

What processes occur in the epidermis?

Answer 24

Continuous proliferation of keratinocytes in basal layer Migration, differentiation and keratinisation of keratinocytes Squamous cells sloughed off at surface

Question 25

How does the epidermis receive blood supply?

Answer 25

Nourished by diffusion from blood vessels in dermis

Question 26

How does the dermis receive blood supply?

Answer 26

Contains blood vessels, lymphatic vessels, nerves, arteriovenous anastomoses

Question 27

What is contained in the hypodermis?

Answer 27

Loose and irregular connective tissue | Large deposits of fat

Question 28

What are the functions of hairs?

Answer 28

Mechanical protection Thermoregulation Sensory perception

Question 29

What epithelium covers the hair bulb?

Answer 29

Stratified squamous

Question 30

Describe the cyclic activity of a hair

Answer 30

Anagen phase-growth Catagen-hair atrophies Telogen-hair is displaced distally and new hair matrix begins to form Anagen-new hair matrix is established, renewed growth

Question 31

Which specialised glands are present in pigs?

Answer 31

Preputial-opening of foreskin | Sexual attraction, initiates mating behaviour in sows

Question 32

Which specialised glands are present in sheep?

Answer 32

Infraorbital pouch-territorial marking | Interdigital glands-produces a fatty secretion, marking of footprints to signal to others in flock

Question 33

Which specialised glands are present in dogs?

Answer 33

Anal glands-release a fatty secretion during defaection, territorial marking Tail gland-oval patch on dorsal tail, territorial marking, skin has sparser hair

Question 34

How does melanin protect against sun damage?

Answer 34

Melanin is able to absorb UV radiation, protecting cells from UVB radiation damage

Question 35

Where is MSH secreted?

Answer 35

Pituitary gland

Question 36

If MSH receptors are not stimulated, what colour pigments are produced?

Answer 36

Red/yellow pheomelanins

Question 37

Melanin pigments are a derivative of which amino acid?

Answer 37

Tyrosine

Question 38

What causes the epidermis to be impermeable to water?

Answer 38

Stratum corneum and granular cell layer Sebaceous gland secretion contributes to water resistance Keratinocytes contain insoluble keratin and synthesise lipids

Question 39

What makes hard keratin harder than soft keratin?

Answer 39

Contains more sulfar, less elastic, resistant to degradation

Question 40

What is photosensitivity?

Answer 40

Abnormal reaction to sunlight due to accumulation of photosensitive compounds below the skin

Question 41

Which are the two types of tonic, slow-adapting sensory cells?

Answer 41

Merkel cell and Ruffini corpuscle | Both located near skin's surface, sensitive to touch, pressure and duration

Question 42

Which are the two types of phasic, fast-adapting sensory cells?

Answer 42

Meissner corpuscle-phasic receptor sensitive to fine touch, concentrated in hairless skin Pacinian corpuscle-pressure-sensitive phasic receptor deep below skin in subcutaneous tissue

Question 43

How do tonic receptors differ from phasic receptors?

Answer 43

Tonic receptors are slowly adapting, but respond for the duration of a stimulus. Fire rapidly when first activated then become slower. eg baroreceptors. Phasic receptors are fast adapting. They rapidly adapt to a constant stimulus then turn off.

Question 44

How does the brain locate and detect intensity of a stimulus?

Answer 44

Frequency of action potentials Number of receptors stimulated Different receptors have different thresholds

Question 45

Which nervous system contracts the erector pili muscle?

Answer 45

Sympathetic