Advertisement Upgrade to remove ads

What features of rats make them a good experimental model to learn about factors that affect humans?

small, familiar, and easily bred for experiments


toward the upper surface (back)


toward the lower surface (belly)


toward the head


toward the tail


toward the midline of the body


toward the end of the appendage nearest the body


toward the midline of the body; toward the side


toward the end of the appendage farthest from the body

Frontal plane

divides body into dorsal & ventral halves; 2 dimensional plane parallel to the anterior-posterior axis & perpendicular to the dorsal-ventral axis

Transverse plane

a cross section; 2 dimensional plane perpendicular to the anterior-posterior axis of the body

Sagittal plane

divides body into left & right halves; 2 dimensional plane parallel to the anterior-posterior axis & parallel to the dorsal-ventral axis

cranial region


cervical region


pectoral region

area where forelegs attach


chest region



pelvic region

area where hind legs attach


hairy coat that covers most of the rat's body


tactilely (related to touch) sensitive "whiskers" on the face


nostrils; located at anterior end of head


subterminal mouth has a cleft that exposes large front teeth

large pupils

adaptation to nocturnal life; eyes bulge from head and enable the rat to see in almost all directions

nictitating membrane

located at inside corner of the eye; this translucent membrane may be drawn across the eyeball for protection


similar to those found in humans


external ear

auditory meatus

ear canal


6 pairs of these located on ventral surface


located posteriorly (caudally) and is covered w/ hair & scales


ventral to the base of the tail


a small protuberance from which the urinary aperture opens lies just caudal to the last pair of teats in a female

vaginal orifice

just caudal to the clitoris; located in a small depression called the vulva

scrotal sacs

in males; lie on each side of the anus & contain testes, which produce sperm cells


a bulge of skin surrounding the penis

preputial orifice

where penis can be extended from the prepuce

urogenital orifice

located at the end of the penis; where both urine & sperm cells exit the body


rat has 4 legs w/ 4 digits and a vestigial thumb on each foot


a stance in which both the sole & heel of a rat's foot contact the ground as indicated by the lack of hair from the toes to the heel


animals that walk on their toes

mandible (part of skull)

lower jaw; contains a broad, flat surface for muscle attachment

maxilla (part of skull)

upper jaw

zygomatic arch (part of skull)

place where some jaw muscles pass under and attach to the lateral surface of the cranium

cranium (part of skull)


axial skeleton

formed by the skull & vertebral column

5 groups of vertebral column

cervical, thoracic, lumbar, sacral, caudal vertebrae

atlas & axis

2 cervical vertebrae; form a versatile joint and allow for a variety of head movements


extend from thoracic vertebrae; form an enclosure (rib cage)

caudal vertebrae

form a long tail

pectoral girdle

where bones of anterior appendages (forelegs) attach

pelvic girdle

where bones of the posterior appendages (hind legs) attach

appendicular skeleton

bones of forelegs & hind legs




external sex organs


connective tissue that is tough yet flexible

cutaneous trunci

thin sheets of muscle that attach to the skin

brown fat

a deposit of fat between the shoulder blades that is specialized for heat production if the animal is stressed by low temperatures

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording