Unit 1 lab rat dissection

Question 1

Do not cut through abdominal wall muscles until

Answer 1

until you have retracted the skin

Question 2

how do you pull the skin free of the underlying muscle ?

Answer 2

by breaking the subcutaneous connective tissue or superficial fascia

Question 3

transverse cut into 4 limbs would help with what?

Answer 3

retraction efforts

Question 4

pink muscles of the abdominal wall are what kind of muscles?

Answer 4

skeletal muscles

Question 5

skeletal muscles are covered by what layer?

Answer 5

-a shiny layer of deep fascia composed of dense fibrous connective tissue

Question 6

central white line of abdomen is the

Answer 6

linea alba

Question 7

linea alba extends from

Answer 7

pubic sumphysis to the xiphoid process of the sternum

Question 8

muscles of the abdominal wall is anterior to what?

Answer 8

the phallus

Question 9

why do the lateral abdominal wall muscles sink in or become concave?

Answer 9

a vacuum was created

Question 10

What does the vacuuming of abdominal wall muscles cause?

Answer 10

caused the lateral abdominal muscles to closely adhere to the underlying intestine

Question 11

what happens after lifting abdominal muscles?

Answer 11

a small incision is made through the abdominal wall

Question 12

heart: Dark colored part of the heart that may be beating are the:

Answer 12

two atria; which contain the pacemaker

Question 13

larger, lighter colored and thicker-walled ventricles are the:

Answer 13

pumping chambers

Question 14

pericardium is the;

Answer 14

MEMBRANOUS SAC WHICH SURROUNDS THE HEART

Question 15

WHERE IS THE PERICARDIUM ATTACHED?

Answer 15

DORSAL SIDE OF THE STERNUM

Question 16

The heart is covered by the:

Answer 16

shiny, glistening visceral pericardium

Question 17

lungs

Answer 17

light pink structures that are shriveled up

Question 18

while the thoracic cavity was intact, the lungs were

Answer 18

inflated

Question 19

as soon as you entered the thoracic cage,

Answer 19

air entered and the lungs deflated

Question 20

the inner deeper surface of the ribs are covered by

Answer 20

parietal pleura

Question 21

lungs is for gas exchange which is

Answer 21

for carbon dioxide to leave and for oxygen to enter

Question 22

artificial respiration=

Answer 22

make transverse slit through trachea
leave dorsal half intact and
insert pipette or straw into lumen

Question 23

thymus

Answer 23

if present will appear as pale mass anterior and ventral to heart, between lungs.

Question 24

function of thymus

Answer 24

create t cells

Question 25

anterior vena cava

Answer 25

drains blood from head and superior extremities back to heart into right atrium

Question 26

aorta

Answer 26

thick walled, whitish, or blue white tube arising form top of heart, arches over to the left side and descends behind or dorsal to the heart and alongside vetebral bodies in thorax MAJOR VESSEL

Question 27

esophagus:

Answer 27

dorsal to trachea and parallel to it | food to stomach

Question 28

peritoneum

Answer 28

shiny, moist serous membrane lining abdominal cavity and covering all organs

Question 29

diaphragm

Answer 29

separates abdominal and thoracic cavities

Question 30

small intestine

Answer 30

major structure in the abdomen

Question 31

The delicate, transparent membrane joining the intestine to the dorsal body wall is the

Answer 31

mesentery | mesentery proper or the mesenteron

Question 32

mesentery is composed of

Answer 32

two layers of peritoneum; between it has blood, vessels, and nerves

Question 33

the mesentery lifts off the dorsal wall at the area called

Answer 33

root of the mesentery; continuous with the parietal peritoneum. at the intestinal end, it splits and surrounds the intestine as the visceral peritoneum

Question 34

surfaces of liver, spleen, stomach, colon, cecum are composed of

Answer 34

visceral peritoneum

Question 35

liver

Answer 35

largest visceral organ in body. posterior to diaphragm and occupies most of the anterior end of the abdominal cavity. performs metabolic functions

Question 36

stomach:

Answer 36

at anterior end of the small intestine is the muscular curved, sac-like stomach. in life it lies on the left side of teh abdominal cavity and somewhat covered by liver. temporary storage organ for ingested food

Question 37

gall bladder

Answer 37

not found in rat, in humans its in dorsal surface of the right lobe of liver. stores bile, which emulsifies fat you have eaten. in the rat the bile is sent directly from liver without storage

Question 38

spleen

Answer 38

in rat, spleen closely resembles liver in color and texture. located on far left side, it resembles thick bay leaf in humans. The spleen is on left side but looks like eggplant. it filters blood and breaks down old RBC

Question 39

pancreas:

Answer 39

in humans, it is a discrete organ with sharp well defined borders which lies behind perotineum between duodenum and stomach. in rat, the pancreas is diffuse and difficult to identify.

Question 40

omentum:

Answer 40

mesentery like sheet extending from stomach -pink scrambled eggs is pancreas. Fat is white in color. Pancreas produces enzymes for digestion of food and two hormones that regulate blood sugar level. INsulin and glucose.

Question 41

cecum

Answer 41

traced to smaller end of small intestine by following posterior end. at junction of small and large intestine, there is a large, thin-walled pouch called cecum. In herbivores it is quite large and harbors vast numbers of bacteria that assist in breakdown of ingested cellulose. Fairly large in rat and much smaller in humans. IT IS BLIND ENDED

Question 42

large intestine

Answer 42

it emerges from cecum near where small intestine enters. can be identified by presence of oblong fecal pellets present in lumen. In humans the large intestine can be divided into an ascending and transverse, descending and sigmoid colon and the rectum. Function of colon is to absorb water, vitamins, and store feces until expelled

Question 43

kidneys

Answer 43

dark red and bean shaped. lies against dorsal body wall and are covered by parietal peritoneum. Regulates fluid and electrolyte balance of body

Question 44

ureters

Answer 44

tubes that drain urine from kidneys to urinary bladder. like fine white threads just barely visible through transparent parietal peritoneum. can see where they enter bladder by pulling it posteriorly and noting two delicate white thread like structures entering from antero lateral borders

Question 45

urinary bladder

Answer 45

small sac like structure located in pubic region. can be mistaken for a penis. in female rats, it is a white mushroom like object sticking up just anterior to the pubic bones

Question 46

urethra

Answer 46

passage from urinary bladder to outside. probably wont see this

Question 47

aorta:

Answer 47

whitish vessel known as inferior vena cava. Drains blood from most organs in posterior part of the body. runs ventral to the aorta and will be dark in color

Question 48

female uterus

Answer 48

looks like letter Y. Stem of Y is body characterized by thickened ring of cervix. arms of Y are the uterine horns. Horns are where rat embryos develop. rat maybe pregnant and uterine horns with be HEAVILY VASCULARIZED and have swelling depending on age of embryos. when non pregnant, it is small. in humans it is a singular midline muscular organ the size and shape of pears.

Question 49

vagina:

Answer 49

passage connects with uterus and can be identified by inserting probe into it from outside. Terminates below muscular uterine cervix. it is the copulatory organ of the female and birth canal

Question 50

oviducts

Answer 50

in rat, an oviduct at the anterior end of each uterine horn. it is a fine white thread twisted like coil. in human females, each oviduct=fallopian tube=uterine tube connects with single midline uterus. convey egg from ovary to uterus and are site for fertilization as sperm swims up toward ovaries adn descending egg

Question 51

scrotum

Answer 51

sac lies at base of tain and contains testes. in rat, testes can be retracted back into abdominal cavity through inguinal canal. push on external surface of scrotom and observe the large white structures in comparison to tiny ovaries. have prominent sinusoidal or wave like vessels across surface involved in temperature regulation

Question 52

epidydymus

Answer 52

alongside testis is large dumbell shaped feature. see a mass of tubules through thin outer covering, actually a long very twisted tubule which serves to store sperm and eject them during copulation. epidydymis starts with swelling at anterior pole of testis, narrows down near center of testis and swells again near posterior pole. The ductus deferens arises form posterior pole

Question 53

vas deferens

Answer 53

tube conveys sperm during ejaculation from epidydymis to urethra for delivery to female reproductive tract, follow passage of ductus to its attachment to urethra

Question 54

seminal vesicle

Answer 54

large, paired pale-colored paisley patterned shaped structure lies attached at place where the ductus deferens joins urethra. produces substantial portion of seminal ejaculate

Question 55

prostate

Answer 55

round, somewhat translucent organ lies at base of urinary bladder making the bladder resemble small penis, and prostate like a miniature scrotum. like in seminal vesicle, it provides some of seminal ejaculate