Myomorphs

What is the largest and most diversified mammalian group?

Rodentia

What is the normal heart rate range for rats?

330-480 bpm

What is the normal respiratory rate range for rats?

85-130 breaths/min

What is the average lifespan of a rat?

2-3.5 years

What is the diet of rats and mice?

Omnivorous

What is the normal heart rate range for mice?

420-700 bpm

What is the normal respiratory rate range for mice?

100-250 breaths/min

What is the average adult body weight range for Mongolian gerbils?

Males 80-110g, females 60-100g

What is a unique adaptation of hamsters?

Large cheek pouches for storing food and transporting materials.

What glands do Syrian hamsters have on their flanks?

Scent glands

What is a unique adaptation of gerbils?

Long colon and large renal medulla to conserve water effectively.

What should be avoided when handling gerbils?

Lifting by the tail (risk of degloving)

What gland do gerbils have near the umbilicus?

Large sebaceous gland

What causes dark, red ocular-nasal discharge (chromodacryorrhea) in rats?

Stress or illness induced porphyrin secretion from Harderian glands

How many pairs of incisors do rodents have in the upper and lower jaws?

One pair each

What type of roots do rodent incisors have?

Open roots (elodont)

What type of roots do rodent cheek teeth have?

Closed roots

What colour is the enamel on the outer surface of rodent incisors often and why do they have it?

Orange - it contains iron, which strengthens the teeth.

How does the dentary move in rodents?

Forwards and backwards

When are rodent incisors not in occlusion?

During chewing

Do rodents have separate urinary and genital orifices?

Yes

When is the genital opening sealed in rodents?

Except during oestrus and parturition

What type of mammary tissue do mice and rats have?

Very extensive

What are mice and rats prone to due to their extensive mammary tissue?

Mammary tumors

What are some venipuncture sites for larger blood volumes in rodents?

Jugular vein, cranial vena cava (not recommended)

What are some venipuncture sites for smaller blood volumes in rodents?

Lateral saphenous vein, cephalic vein, tail vein (rat), gingival vein

What type of placenta do rodents have?

Discoid, haemochorial

How many pairs of mammary glands do female hamsters have?

6-7 pairs

How many pairs of mammary glands do female gerbils have?

4 pairs

Do male gerbils or hamsters have observable nipples?

No

What is the gestation period for hamsters?

15-18 days

What is the gestation period for gerbils?

23-26 days

What is unique about gerbil mating behaviour?

They form monogamous pairs and are known to display strong bonds with their partners, often grooming each other and maintaining close physical contact.

What is the normal discharge produced by female Syrian hamsters after ovulation?

Off-white, stringy discharge on day 2 of oestrus cycle

What is unique about rodent testicles?

They have open inguinal canals and can retract testicles into the abdomen

Do rodents have an os penis?

Yes

What are some prominent accessory glands in male rodents?

Vesicular glands, coagulating glands, bulbourethral glands, preputial glands, prostate gland

What is the function of vesicular glands in rodents?

Produce fluid with fructose for sperm energy and mobility

What is the function of vesicular and coagulating glands together in rodents?

Secrete fluids that form a copulatory plug

What is a copulatory plug?

A gelatinous plug formed during mating that blocks the female's reproductive tract, preventing sperm from leaving and increasing the chance of fertilization.

What is the function of bulbourethral glands in rodents?

Secrete pre-ejaculatory fluid to clear and lubricate the urethra

What is the function of preputial glands in rodents?

Secrete smegma to moisturize the glans and provide antibacterial properties

What is the function of the prostate gland in rodents?

Produces most of the fluids in semen and transports sperm to the urethra