GLANDS Flashcards
What glands have a raspberry like texture?
sebaceous glands
circumoral meaning?
around the mouth
what hairs do carpal glands have?
tactile hairs
what glands are very important for communication between dogs?
circumanal glands
possible bald patch on older dogs on their tail, due to?
tail gland
infraorbital pouch
skin pouch inner medium of eyes
two types of sweat glands?
apocrine and eccrine
what are mammary glands unique to?
mammals
colostrum?
the first milk from mammary gland, rich in antibodies
what are udders?
collections of mammary glands in ruminants and horses
what is milk produced by?
mammary cuboidal epithelial cells
dry period?
keratin plug forms during non-lactating period
what species don’t have sweat glands?
birds
how do birds lose heat?
skin (blood flow to lightly feathered areas)
Respiratory evaporation (panting)
how does panting help cool birds?
gets rid of water vapour
What is the name of the secretion made from sebaceous glands in sheep?
lanolin –> this can be an allergen for humans
What are the functions of the named sebaceous glands?
Trail marking
Dominance
Helping young animal find udder
Sexual status
What glands help the lamb find the udder?
Inguinal
What glands help with trailmarking?
Interdigital pouch glands
What glands help communicate an animal’s sexual status?
Pheromones in sebaceous secretions can help communicate an animal’s sexual status to help them find a mate
Why do some animals need their anal glands to be expressed?
obesity, low fibre diet, narrow ducts/anal glands opening, pre-existing damage
Explain why obese animals need help expressing their anal glands?
might find it hard to exert enough pressure on the glands to empty them
Explain why animals with a low fibre diet need help expressing their anal glands?
not enough fibre or very soft stools can inhibit the proper/normal emptying of the anal glands
What are some of the sings that an animal may have impacted anal glands?
Scooting can be a sign
Bad breath
Licking the anus
Biting their back or tail
Turning suddenly
Describe the signs of an animal with possible affected anal glands?
Scooting can be a sign. It is thought the animal may be trying to express the glands and relieve their irritation.
Bad breath can be a sign, if the animal has been licking the area to try and express the anal glands
The animal may lick the area to relieve irritation and try to express the glands
The animal may bite their back or tail due to pain and irritation from their back end
The animal may turn suddenly due to pain or irritation from the back end
What is the preen gland’s anatomical name?
uropygial gland
What are the four main functions of the uropygial gland?
waterproofing, feather care, antimicrobial and antiparasite function, conversion of vitamin D precursor to vitamin D
Name the components of the mammary gland of a sheep:
Teat sinus/cistern
Teat orifice and sphincter
Gland cistern
Annular ring
Body wall
Parenchyma
What is the annular ring also known as?
the vascular ring, mucosal fold
What is the udder parenchymal tissue mainly composed of?
of alveoli and ducts
What is the udder parenchymal tissue?
the functional tissue involved in milk production
What is the udder suspended from the body wall from?
suspensory apparatus
Where is the annular ring found?
at the boundary between the gland and teat sinus, it can be seen as a fold in the mucosa
What happens at the annular ring?
Blood vessels that supply the teat originate in this area and course distally through the wall of the teat
What do the teat and gland cistern make up together?
lactiferous sinus
Describe the distal portion of the teat of a sheep:
The channel through the distal portion of the teat from the teat cistern is termed the streak canal. The teat orifice is the hole on the bottom of the teat and represents the opening of the distal end of the streak canal
What is the streak canal lined with?
with stratified squamous epithelium and is covered by keratin
What is the teat sphincter?
a muscular ring surrounding the streak canal
what is the streak canal?
the channel through the distal portion of the teat from the teat cistern
Mastitis - what reduces the risk of infection crossing across cow mammary gland quarters?
each quarter has independent secretory units, ductal systems and sinuses
Mastitis - infection from the right fore-quarter is most likely to spread to which other quarter?
right hind-quarter
The ductal systems of the fore and hind systems are distinct but there is still some potential for infection to cross
The left and right side of the cow mammary gland quarters are completely separated - by what?
the median suspensory ligament, making cross infection less likely
What sinus is found above the teat sinus?
the gland sinus
What are the three identifiable components of a histological section of a cow’s mammary gland during lactation?
Alveolar spaces (filled w/ milk)
Lobules
Ducts (filled w/ milk)
Why is it important to keep a cow standing for some time after milking?
The teat sphincter is smooth (involuntary) muscle so can take time to fully close - it takes one hour to close fully so infection risk if cow lies in dirty environment
Dogs - where is the main blood supply to the mammary glands?
Via the epigastric arteries.
Describe the epigastric arteries?
there are two arteries (cranial and caudal) that anastomose in the umbilical area, with some branches crossing the midline. The venous drainage mirrors the arterial pattern
What does anastomose mean?
join
What are the three main lymph nodes involved in mammary gland drainage?
the axillary, accessory axillary and the superficial inguinal
There are 5 mammary glands on a dog, label them in order going from cranial –> caudal
Cranial thoracic mammary gland (MG)
Caudal thoracic MG
Cranial abdominal MG
Caudal abdominal MG
Inguinal MG
Inguinal mammary gland?
supplied by the caudal superficial epigastric artery and vein
the drainage of lymph is to the superificial inguinal lymph nodes
Cranial abdominal gland?
Are supplied by the cranial superficial epigastric artery and vein
Drainage of lymph mainly to the axillary lymph node, although other nodes may also drain this gland e.g. accessory axillary, sternal and inguinal lymph nodes
Caudal abdominal mammary glands?
supplied by the caudal superficial epigastric artery vein
drainage of lymph is to the inguinal lymph nodes
Cranial thoracic mammary gland?
supplied by the internal thoracic artery and its branches ( cranial superficial epigastric) AND the lateral thoracic + intercostal arteries
Drainage of lymph is mainly the axillary lymph node
caudal thoracic mammary gland?
supplied by the internal thoracic artery and its branches (cranial superficial epigastric) + lateral thoracic + intercostal arteries
Drainage of lymph is mainly to the axillary lymph node
Describe the difference between cats mammary glands and dogs mammary glands?
cats typically have four pairs of glands not 5 like dogs. Cats typically have the cranial and caudal thoracic, abdominal and inguinal.
(ONLY ONE PAIR OF ABDOMINAL)
Why is the lymphatic drainage of mammary glands important to know in cases of mammary tumours?
Malignant tumours can spread to other parts of the body (in contrast, benign tumours don’t tend to spread or invade). Malignant tumours can have small pieces or cells that break away and metastasise (spread) via the lymphatics. In a bitch, the vet may test whether a tumour is maligant and decide how much tissue needs to be removed based on the results. In cats, because most tumours are malignant, the vet may not wait for test results and may just remove the whole mammary strip as well as the draining lymph nodes as a precaution.
