Integument Flashcards Preview

Semester 2 > Integument > Flashcards

Flashcards in Integument Deck (46)
Loading flashcards...
0
Q

What is the main cell type in the epidermal layers?

A

Keratinocytes

1
Q

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

A

Melanocytes

St Basale

2
Q

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

A

Erector pili

3
Q

What are the two types of sweat glands?

A

Apocrine and eccrine

4
Q

Which type of sweat gland is found in the footpad?

A

Eccrine

5
Q

What epithelium does the epidermis consist of?

A

Keratinised stratified squamous

6
Q

What do sudoriferous glands secrete?

A

Sweat

7
Q

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

A

Flat keratinised cells

8
Q

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

A

Dead cell layer

9
Q

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

A

Cuboidal or flat cells

10
Q

What do sebaceous (oil) glands secrete?

A

Sebum

11
Q

What are the functions of sebum?

A
Retards water loss
Lubricates skin
Inhibits growth of certain bacteria
Helps spread sweat
Territorial marker
12
Q

How do androgens affect sebum secretion?

A

Increase it

13
Q

How does oestrogen affect sebum secretion?

A

Decrease it

14
Q

What are the names of the two melanin pigments?

A

Eumelanins (black and brown colouration)

Pheomelanins (red and yellow colouration)

15
Q

Give an example of soft keratin

A

Skin

16
Q

Give an example of hard keratin

A

Nails, horn, hoof

17
Q

What are the three receptor types in skin?

A

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

18
Q

Which nervous system controls blood flow to the skin?

A

Sympathetic

19
Q

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

A

Sweating - loss of water and NaCl

Panting - loss of water

20
Q

What does the epidermis originate from?

A

Ectoderm

21
Q

What does the dermis originate from?

A

Mesoderm

22
Q

Thickness of skin refers to relative thickness of which layer?

A

Epidermis

23
Q

What are the 5 layers of the epidermis?

A
St Corneum
St Lucidum
St Granulosum
St Spinosum
St Basale
24
Q

What processes occur in the epidermis?

A

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

25
Q

How does the epidermis receive blood supply?

A

Nourished by diffusion from blood vessels in dermis

26
Q

How does the dermis receive blood supply?

A

Contains blood vessels, lymphatic vessels, nerves, arteriovenous anastomoses

27
Q

What is contained in the hypodermis?

A

Loose and irregular connective tissue

Large deposits of fat

28
Q

What are the functions of hairs?

A

Mechanical protection
Thermoregulation
Sensory perception

29
Q

What epithelium covers the hair bulb?

A

Stratified squamous

30
Q

Describe the cyclic activity of a hair

A

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

31
Q

Which specialised glands are present in pigs?

A

Preputial-opening of foreskin

Sexual attraction, initiates mating behaviour in sows

32
Q

Which specialised glands are present in sheep?

A

Infraorbital pouch-territorial marking

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

33
Q

Which specialised glands are present in dogs?

A

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

34
Q

How does melanin protect against sun damage?

A

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

35
Q

Where is MSH secreted?

A

Pituitary gland

36
Q

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

A

Red/yellow pheomelanins

37
Q

Melanin pigments are a derivative of which amino acid?

A

Tyrosine

38
Q

What causes the epidermis to be impermeable to water?

A

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

39
Q

What makes hard keratin harder than soft keratin?

A

Contains more sulfar, less elastic, resistant to degradation

40
Q

What is photosensitivity?

A

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

41
Q

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

A

Merkel cell and Ruffini corpuscle

Both located near skin’s surface, sensitive to touch, pressure and duration

42
Q

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

A

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

43
Q

How do tonic receptors differ from phasic receptors?

A

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.

44
Q

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

A

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

45
Q

Which nervous system contracts the erector pili muscle?

A

Sympathetic