Rats

Question 1

What is a rats lifespan?

Answer 1

2.5-3.5 years
Females live longer on average

Question 2

What is an adult rats bodyweight?

Answer 2

400-800g

Question 3

What is a rats body temp?

Answer 3

38*C

Question 4

What is a rats respiratory rate?

Answer 4

70-150 b/min

Question 5

What is a rats pulse rate?

Answer 5

260-450 b/min

Question 6

What age is a rat sexually mature?

Answer 6

8-10 weeks

Question 7

What is a rats Gestation period?

Answer 7

20-22 days

Question 8

What type of young do rats produce?

Answer 8

Altricial young

Question 9

Do rats perform coprophagia?

Answer 9

Yes but less active as they are omnivores

Question 10

How do rats thermoregulate?

Answer 10

Increased salivation and find shade to cool down.
Tails and ears are important for heat dispersion as the blood vessels vasoconstrict and dilate according to temperatures.
They have a poor heat tolerance as they have few sweat glands and are unable to pant.

Question 11

What are a rats incisors used for?

Answer 11

Fighting, Holding food, Excavating burrows, Gnawing

Question 12

What colour are rats teeth and what gives them this colour?

Answer 12

Yellow/orange due to iron pigments

Question 13

How do rats eyes appear?

Answer 13

Black, spherical, bulging appearance due to poorly formed 3rd eyelid.
Frequently blink.

Question 14

How does a rats tail appear and what are its attributes?

Answer 14

Long tail, sensitive to pain.
Important for thermoregulation and balance.
Has 210 overlapping scales which are heavily keratinised on upper dermis.
Covered in yellow/orange sebum.

Question 15

Explain the male rats external genitalia

Answer 15

Has testicles from 3-4 weeks of age.
Large oblong scrotum.
Anogenital distance twice as long in males than females.
No nipples.

Question 16

Explain the female rats external genitalia

Answer 16

Anogenital distance shorter than in males.
Urethra opens at the base of the clitoris which is enclosed in a little prepuce.
6 mammary glands.

Question 17

Vertebral column of the rat?

Answer 17

7 Cervical
13 Thoracic
6 Lumbar
4 Sacral
27-31 Coccygeal

Question 18

Explain some skeletal attributes of the rat

Answer 18

The 6th cervical vertebrae has a modified rib fused to its transverse processes.
Ribs 1-7 articulate with the sternum and the last 3 are floating ribs.
Fore feet are well developed to allow grasping of food.
Tibia and Fibula are fused distally.

Question 19

What are a rats venipuncture sites?

Answer 19

Lateral tail vein.
Lateral Saphenous Vein.
Ventral Tail Artery - warm tail to cause vasodilation before blood sample.

Question 20

Rat Respiratory System
What is the nasal cavity involved with?

Answer 20

Respiration.
Humidifying and filtering incoming air.
Olfaction (smell) - 50% of the nasal cavity is lined with olfactory epithelium which gives acute sense of smell.

Question 21

Rat Respiratory System
Explain the attributes of the lungs.

Answer 21

The right lung is divided into 4 lobes: cranial, middle, caudal, accessory lobe.
The left lung is smaller and not divided into lobes.

Question 22

Rats Cardiac
Where is the heart positioned?

Answer 22

On the left side of the body.
Can be palpated between ribs 3 and 5.

Question 23

Rats Digestive System
What diet do rats have?

Answer 23

Omnivores - feed frequently.

Question 24

Rats Digestive System
What is the GI transit time?

Answer 24

12-24 hours

Question 25

Rats Digestive System
What is the Dental Formula?

Answer 25

I1/1, C0/0, PM0/0, M3/3 x2 = 16 teeth

Question 26

Rats Digestive System
What does the Diastema do?

Answer 26

Helps close off the back of the mouth to allow gnawing hard substances.

Question 27

Rats Digestive System
What type of stomach and digestion does the rat have?

Answer 27

Simple stomach.
Monogastric digestion.

Question 28

Rats Digestive System
What does the large intestine do?

Answer 28

Allows digestion of plant material

Question 29

Rats Digestive System
Do rats have a gall bladder and why?

Answer 29

No gall bladder because the intestine are efficient at absorbing nutrients and rats have a high level of lipase in their blood which aids the breakdown of fats.

Question 30

Rats Digestive System
How does dentition aid in digestion of food?

Answer 30

Food is grasped with fore paws.
Food is chipped by incisors and ground by molars.

Question 31

Rats Dentition
At what age do molars stop growing?

Answer 31

4 months

Question 32

Dentition
What happens in the diastema when gnawing?

Answer 32

Cheek folds form in the diastema when gnawing enabling the animal to gnaw at hard objects without swallowing sharp materials.