2. skin glands Flashcards
what are the 2 basic types + subtypes of skin glands?
- sebaceous
- sweat glands: eccrine + apocrine
what are skin glands modifications of?
Modifications of the epidermis, even though they penetrate into the dermis
what are skin glands modifications of?
Modifications of the epidermis, even though they penetrate into the dermis
what are skin glands modifications of?
modifications of the dermis even though they penetrate into the dermis
what are sebaceous glands and what do they produce?
They are glands associated with hair follicles that have many lobes (acinar structure). They produce sebum which is fatty and oily
What is sebum called in sheep?
lanolin
what are the main 4 functions of sebum?
- waterproof hair and skin
- allows sweat to spread
- antimicrobial function
- pheromones and other scented compounds for communication
Name the 10 sebaceous glands and the main species they are found in
- Circumoral: cats
- Cirucumanal : dogs
- Carpal : cats and pigs
- Tail : cats and dogs
- Anal sac: cats and dogs
- Horn: goats
- Glands of infraorbital pouch: sheep
- Glands of interdigital pouch: sheep
- glands of inguinal pouch: sheep
- Preputial glands : boar
What are the two sweat glands and the differences between them?
- Apocrine discharge albuminous (protein-rich) while eccrine is watery
- Apocrine sweat is released into hair follicles while eccrine is released directly onto the skin
- apocrine glands are found over most of the body (haired skin) in domestic animals while eccrine are generally found only in certain areas (naked skin) e.g footpads
what do apocrine sweat glands secrete and how?
apocrine secretion
vesicles pinch off from cells to secrete packets of cell membrane and cytoplasm
what do eccrine sweat glands produce and how?
merocrine secretion
- exocytosis
- cell vesicles fuses with membrane to discharge its contents
- no part of the cell is lost
what are mammary glands and what are their functions?
they are extremely modified apocrine sweat glands
- the secretion (milk) is rich in protein and fat for nourishing the young
- contains antibodies for immune transfer
- first milk (colostrum) os rich in antibodies especially
what is the structure of a mammary gland?
- mammae body and teat
- collections of mammary glands called udders in ruminants and horses
each gland contains 1+ secretory units
sometimes extra buds develop into supernumerary teats
How many teats do these animals have?
- sow
- dog
- cat
- cow
- sheep
- horses
- sow: 14
- dog: 10
- cat: 8
- cow: 4
- sheep: 2
- horses: 2
how is milk made in the mammary glands?
- milk is produced by mammary cuboidal epithelial cells lining the alveoli
- alveoli are surrounded by muscle cells (myoepithelial cells) that push the milk out of the alveolus
- milk drains through milk ducts (lobular ducts -> lactiferous ducts)
- Milk is stored in the lactiferous sinus
- smooth muscle sphincter at teat or orifice
- milk is let dow under influence of hormones
