A&P for mice and rats Flashcards
rats and mice have tails that are longer than their body length
true
rats have a gallbladder
false
the inguinal canal in males remains open throughout life
true
mice and rats typically breed during daylight hours
false
secretions from the harderian gland in rats is commonly called
red tears
what is brown fat commonly called and where is it located?
hibernation tissue and it is located diffusely around the neck and between the scapulae
how much does the hibernation tissue provides energy storage than other types of fat?
10 times
Gestation for mice/rats
mice: 19-21 days
rats: 21-23 days
when do mice reach puberty? when do rats reach puberty
mice: 35 to 50-60 days
rats: females- 37 to 67 days
males- 40-75 days
what is the average lifespan of mice and rats?
mice: 1-3 years
rats: 2-4 years
normal TPR for mice?
98.6F, HR: 427-697bpm, RR: 91-216bpm
normal TPR for rats?
98.6F, HR: 313-493bpm, RR: 71-146bpm
how many digits do rats and mice have on the forelimbs and hind limbs?
4 digits in the forelimbs and 5 digits in the hindlimbs
how many pairs of mammary glands do female rats have and where are they found?
4-6 pairs and found in the thoracic and inguinal areas
how many pairs of mammary glands do female mice have and where are they found?
5 pairs and extend to the sides and back
do male mice have mammary glands?
yes
the uterus of mice and rats is considered
bicornuate
what do each uterine horn have seperately
cervical canal
what type of ovulators are mice and rats? what type of estrus cycle do they have? How long does their estrous period last?
spontaneous ovulators. they are continously polyestrus and it lasts 4-5 days
in mice and rats the postpartum estrus occurs when?
20-24 hours after parturition
the presence of a copulatory plug can be used to confirm
mating
what type of teeth do mice and rats have?
hysodontic
the direct result of mating between two different inbred strains
hybrid
develop as a result of genetic mutation in existing strains. The mutation is then carried on in future generations
coisogenic
strains are those in which a mutation that arises in one strain is transferred to another strain through a series of backcross mating. this is how nude animals were developed.
congenic
a mouse whos DNA has been modified so that is does not express particular proteins
stock
why do rats have the inability to vomit
the gastroesophageal barrier
describe the unique structures of the rats lungs
left side is small and singular while the right side is larger and divided into 4 sections
what is chromodacryorrhea? When does it commonly occur?
It is red tears which are known as bloody tears. It occurs when the animal is stressed
what is the purpose of tails in mice and rats?
it functions as balance and a mechanism for heat loss
describe the pancreas in rats
diffuse, has a lot of ducts that empty into the intestines
what is a copulatory plug, and how long does it remain in place?
it is a plug that is dried semen mixed with secretions from the vagina and confirms mating It remains in place for 12-24 hours after mating
what is an intestive breeding program for mice and rats?
continuous housing of the male and females
what is a non-intensive breeding program for mice and rats
seperate housing the male and female while the female is pregnant
what is the bruce effect?
a pregnant mouse who is exposed to a new male within 4 days of breeding, the pregnancy will be aborted
what is the whitten effect?
when females are exposed to a male or the odor of a male. they will begin estrus within 3 days
what is a stock breed animal?
type of mouse/rat that has been randomly bred. Not imbred
when is an inbred animal considered a strain?
at least 20 generations of brother-sister or parent have mated
what are 5 ways to ensure genetic purity in inbred mice?
protein electrophoresis, serologic testing, mandible measurements, backcross mating, and tissue transplants
what is a transgenic animal?
when a animal carries a foreign gene that has been deliberately inserted into ints genome
why do we use so many mice and rats in animal research?
they have a well characterized genetic make-up