Integument Flashcards
What are skin associated glands?
- Sebaceous glands
2. Sweat glands: encrine and apocrins
What are sebaceous glands?
- oil glands
- nothing to do with thermoregulation
- Alwasy empty itnto hair follicle
- secrete sebum: lipds
What is the function of sebum
- escapes when pilorector muscles alongside hairs contract
- oils hair
- forms oily film on the skin: lubricates skin, stops water loss, inhibits growth of certain bacteria, spread sweat, territorial marker
How are sebaceous glands regulated?
- regulated by sex steroid hormones
- more active after puberty
- larger adn more productive in the breeding season
- androgens (male) increases activity
What are sebaceous glands?
- oil glands
- nothing to do with thermoregulation
- Alwasy empty into hair follicle
- secrete sebum: lipds
Few facts about sebaceous glands comparing with species
- no sebaceous glands with feathers
What are important about sweat glands?
- involved in thermoregulation
Apocrine sweat glands
- common in domestic species, sparce in primates
- important in evaporative heat loss in some animals (horses and cattle)
- autonomically regulated by sympathetic nervous system: noradrenaline
- oily, opaque secretion, initially odourless but becomes smelly with bacterial breakdown
Ecrine sweatglands
- Common in primates, sparce in domestic animals
- important evaoprative heat loss
- Ach releases, sympathetic
- watery NaCl solution that can be modified by aldosterone
What do both apocrine and ecrine sweat glands need and what for?
- Myoepithelial cells
2. single cells needed to get secretion out
Name some glands in our domestic species
- anal glands in dogs and cats (territorial marking)
- Interdigital pouch at front of claw in sheep
- infraorbital pouch in sheep (eye) = territorial marking
- tail glands in dog adn cat (territorial marking)
- preputial gland at opening of foreskin in boars - sexual attraction, scent
What produced melanin?
Where are they locates and structure
- Melanocytes
- These cell bodies interspersed with other cells in basal layer epidermis
- Cell extensions are squeezed between cells
- Melanin is shed when keratinocytes reach the surface of the skin
What is melanin and what are the types?
- melanin is a broad term for a group of natural pigments
- there are 2 pigments
a) Eumelanins (black and brown colouration)
b) Pheomelanins (yellow and red colouration)
How is melanin synthesised?
- Controlled by MSH binding to its specific MSH receptor
2. more MSH = more pigment produced
What regulated how much of the MSH hormone is produced
- UV light
2. Disease states e.g. crushings