Biology

Question 1

How do mice respond to cold exposure? Can they tolerate nocturnal cooling?

Answer 1

Nonshivering thermogenesis. Cannot tolerate nocturnal cooling.

Question 2

What heat adaptions do mice lack?

Answer 2

Cannot sweat, pant, and have limited ability to salivate.

Question 3

What is the thermoneutral zone of mice? At what temperature do they begin to die?

Answer 3

29.6 - 30.5 C (85-87 F) thermoneutral zone. Die at temperatures greater than 37 C (98.6 F)

Question 4

Describe mouse lung anatomy.

Answer 4

Single left lung, four lobes of right lung consisting of superior, middle, inferior, and post caval.

Question 5

Which sex of inbred mice has heavier kidneys?

Answer 5

Male

Question 6

Describe the filtering capacity of mice compared to rats.

Answer 6

Mice have small glomeruli, but 4.8x that present in rats, with twice the filtering surface/gram of kidney tissue.

Question 7

Why, functionally, is mouse urine so concentrated?

Answer 7

Long loops of Henle and giant vascular bundles (vasa recta) associated with loops in the medulla.

Question 8

What compound is present in large amount in mouse urine? Which products are present (2), absent (1), and what is the ratio of uric acid to allantoin?

Answer 8

Protein. Taurine and creatinine are present, tryptophan is absent, and more allantoin is present than uric acid.

Question 9

Describe the submandibular gland in the mouse.

Answer 9

Seromucuscular gland, not mixed as in other species.

Question 10

What tissue lines the esophagus?

Answer 10

Thick, cornified squamous epithelium

Question 11

Characterize the cranial portion of the stomach.

Answer 11

Keratinized

Question 12

What is Schaedler’s flora? What agents are not included? Why is this problematic?

Answer 12

Mixture of aerobic and less oxygen-sensitive anaerobes used to colonize mouse G.I. Does not include extremely oxygen-sensitive fusiform bacteria, which make up the majority of normal rodent microflora.

Question 13

What is the composition of altered Schaedler flora? Which group created it?

Answer 13

8 bacteria = 4 original, 1 spiral, 3 fusiform extremely oxygen sensitive fusiform bacteria.
Created by NIH

Question 14

What components make up the lymphatic system? (6)

Answer 14

1. Lymph vessels
2. Lymph nodes
3. Thymus
4. Spleen
5. Solitary peripheral nodes
6. Intestinal Peyer’s patches

Question 15

What structures make up a lymph node? What is contained in each section?

Answer 15

Cortex and medulla. Cortex contains primary follicles which contain B lymphocytes and diffuse cortex which contains T lymphocytes.

Question 16

Which tonsils do mice lack?

Answer 16

Palatine and pharyngeal

Question 17

Where is the white pulp of the spleen found? What cell types does it contain?

Answer 17

White pulp along central arteriole and contains T- and B-cell zones. Periarteriolar sheath contains CD4 and CD8 T cells. Periphery has lymph follicles with germinal centers.

Question 18

What does the red pulp of the spleen contain?

Answer 18

Sinusoids and hemoreticular tissue.

Question 19

When is the thymus at maximum size? When does it regress?

Answer 19

Maximum size at sexual maturity (4-7 weeks). Involutes between 35 and 80 days.

Question 20

Is the function of the thymus complete at birth? What occurs following thymectomy in newborn mice? Adult mice?

Answer 20

Function of thymus not complete at birth. Thymectomy in newborn mice leads to decrease in circulating lymphocytes and impairment of cellular immune responses. Thymectomy in adults leads to no immediate effect, but progressive effects as seen in neonates.

Question 21

What does MALT stand for? What tissues does it comprise? How does it’s productive capacity compare to the spleen and lymph nodes?

Answer 21

Mucosal associated lymphoid tissue. All peripheral lymphoid tissue connected to external cavities. MALT contains more lymphoid cells and produces more immunoglobulin that spleen and lymph nodes.

Question 22

Are body temperature and blood pressure linked in the mouse?

Answer 22

No.

Question 23

What is the vertebrae formulae for mice? In which sections are variation most likely to exist?

Answer 23

C7 T13 L6 S4 C28
Thoracic and lumbar

Question 24

What is the dental formula of mice? In which direction do teeth erupt? Which tooth is smallest and most likely to be missing?

Answer 24

I1 M3
Erupt front to back. 3rd molar the smallest tooth and most likely to be missing.

Question 25

What is the function of the clitoral glands?

Answer 25

Secrete sebaceous substance through the ducts entering the lateral walls of the clitoral fossa

Question 26

How many mammary glands do mice have? Where are they located?

Answer 26

5, 3 cervicothoracic, 2 inguinoabdominal

Question 27

List the accessory sex glands of male mice (5)

Answer 27

Ampulla, seminal vesicles, prostate (anterior, ventral, and dorsal), bulbourethral, and preputial gland