DCCC Ventral Body Cavity Organs #8 - Ventral Body Cavity...

Bio 151 – Laboratory Manual Human Anatomy & Physiology II DCCC Ventral Body Cavity Organs

Last updated 08/2019

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#8 - Ventral Body Cavity Organs

Objectives:

Use a cat dissection to study the organs of the ventral body cavity;

Use virtual human dissection software and a human model to observe the organs of the

Respiratory, Digestive, Urinary, and Reproductive systems.

Equipment: Remember to bring gloves, goggles, dissecting kit, appropriate shoes, and

photographic atlas.

I. Virtual Human Dissection and Human Model Observation

A. Preparation

1. Start the Anatomy & Physiology

Revealed® software by double clicking its icon.

2. Select the appropriate System (as indicated in the

tables below) from the Module (top center) drop

down menu.

3. On the home screen, click the dissection icon

(top center, leftmost icon).

4. Using the directions on the following pages, find

all of the structures on your lists. Use the human

models to locate the structures you are viewing with

the human dissection software. Within each system, there will be instructions that guide you in

the removal of the organs from the human model. Remove organs only when instructed. Your

instructor will sign off on the model before you leave the lab. After you have completed the lab,

answer the questions in the laboratory report pages.



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Respiratory System – Virtual Dissection

1. lungs

2. trachea

3. diaphragm

4. larynx

4a. epiglottis

1. From the Module dropdown menu, chose the 11.Respiratory system.

3. Click the dissection icon (top center, leftmost icon).

2. Choose Lower respiratory from the Topic menu.

3. Using the sliders (bottom left), move to Layer 4 (slide Layers 1, 2, and 3

down).

4. From the Select structures type dropdown menu (below View, top left),

choose Respiratory tract.

5. From the Select structures group dropdown menu, click on lung, to view

the structures. Remember that the pleural membranes cover the lung and line

the thoracic cavity.

6. Change the Select structures group to Trachea and bronchi to highlight the trachea (2)

(APR Fig.1).

7. Observe the diaphgram (3) (APR Fig.1), a muscle used for breathing.

8. In the Topic menu, choose larynx, View, anterior. Identify the trachea (2), larynx (4) and

epiglottis (4a) (RA Fig.2).

9. View the epiglottis (part of the larynx) in posterior, by using the sliders (bottom left), to move

to Layer 4 (slide Layers 1, 2, and 3 down) and choose the posterior View (APR Fig.3).

APR Fig.1 APR Fig. 2 APR Fig. 3



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Respiratory System – Human Model

Organ Instructions

☐ Larynx ☐ Left lung ☐ Right lung ☐

Diaphragm

Can be viewed without removing

organs

☐ Trachea Remove the lungs first.

Then, remove the thymus and heart.

Note: Epiglottis is not visible on the human model.

Digestive System – Virtual Dissection

5. greater

omentum

(part of the

peritoneum)

6. liver

7. gallbladder

1. From the Module dropdown menu, chose

the 12. Digestive system.

2. Click the dissection icon .

3. Choose Abdominal cavity from the

Topic menu. Using the sliders (bottom

left), move to Layer 2 (slide Layer 1

down).

4. From the Select structures type

dropdown menu (below View, top left),

choose Peritoneum.

5. Observe the greater omentum (5), liver

(6), and gallbladder (7) (APR Fig.4).

APR Fig.4 (Layer 2)



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Digestive System – Virtual Dissection (cont.)

8. stomach

9. small intestine

duodenum

jejunum

ileum

Large intestine:

10. ascending colon

11. transverse colon

12. descending colon

13. sigmoid colon

14. spleen

15. mesentery (part of

the peritoneum)

16. pancreas

17. appendix

(vermiform)

18. caecum

19.esophagus

6. Click the button under each

Layer label to see labeled pins

on the dissection. You can also

highlight structures by clicking

their name in the list.

7. Go through each Layer and

identify the visible structures.

8. In Layer 3, the stomach (8),

small intestine (9), most of the

parts of the large intestine (10,

11, 13), and the mesentery (15)

are visible (APR Fig.5). The

mesentery is also part of the

peritoneum.

9. Dissect further to Level 5 to

view the spleen (14), pancreas

(16), appendix (17), and the

caecum (18) which is attached to

the ascending colon (10). Also

view the descending (12) and

sigmoid colon (13) (APR Fig. 6).

10. Type esophagus (19) into the

search box. Choose

“Esophagus: Digestive:

Dissection: Esophagus:

Anterior”. It is underneath the

trachea and most easily viewed

with the lungs removed. It leads

to the stomach (8) (APR Fig.

7).

APR Fig.5 (Layer 3)

APR Fig.6 (Layer 5)

APR Fig. 7



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Digestive System – Human Model

Organ Instructions

☐ Liver ☐ Esophagus ☐ Stomach Can be viewed without removing organs

☐ Gallbladder ☐ Spleen ☐ Pancreas Remove the diaphragm, liver and stomach

☐ Duodenum ☐ Jejunum ☐ Ileum

☐ Ascending colon ☐ Transverse colon

☐ Descending colon ☐ Caecum

Can be viewed without removing organs

☐ Sigmoid Colon ☐ Appendix (vermiform) Remove the small and large intestines

Notes: The mesentery cannot be seen on the human model.

Urinary System – Virtual Dissection

20. kidney

21. ureter

22. urinary

bladder

23. urethra

1. From the Module dropdown menu,

chose the 13. Urinary system.


3. Chose Upper urinary from the

Topic menu.

4. Using the sliders (bottom left), move

to Layer 4 (slide Layers 1-3 down).

5. View the kidneys (20). The ureters

(21) and urinary bladder (22) (APR

Fig. 8).

6. The urethra (23) is visible in the

reproductive system (see below). APR Fig.8 (Layer 4)

Urinary System – Human Model

Organ Instructions

☐ Kidney (Left and Right)

☐ Ureter (Left and Right)

Remove pancreas and duodenum



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Reproductive System (Male) – Virtual Dissection

23. urethra

24. scrotal sac

(scrotum)

25. testis

26. vas

(ductus)

deferens

27. penis

28. epididymis

29. spermatic

cord

1. From the Module dropdown menu,

choose the 14. Reproductive

system.


3. From the Topic menu chose Pelvis -

male.

4. Click on the radio button under

Layer 1 to see the labeling pins.

5. View the male structures shown in

APR Fig. 9. Note that the testis (25)

and epididymis (28) are enclosed

within the scrotum (24).

6. From the Topic menu, choose Testis

and spermatic cord (isolated).

Dissect down each Layer to view the

vas deferens (26) and the spermatic

cord (29) (APR Fig 10). A closer

view of the testis (25) and

epididymis (28) is also visible. Note

that the spermatic cord contains the

vas deferens and the testicular

arteries and veins.

APR Fig.9

APR Fig.10

Male Reproductive and Urinary Systems – Human Model

Organ Instructions

☐ Scrotum ☐ Penis ☐ Testis ☐ Epididymis

☐ Spermatic Cord

Can be seen without removing organs

☐ Vas (ductus) Deferens ☐ Urinary Bladder

☐ Urethra

Remove male reproductive organs

NOTE: Before you proceed, insert the female reproductive organs

into the human model.



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Reproductive System (Female) – Virtual Dissection

30. vagina

31. uterus

32. ovary

1. From the Topic menu chose Pelvis -

female.

2. Choose Sagittal, from the View

menu.



4. View the vagina (30), uterus (31),

and ovary (32) (APR Fig. 11).

5. Choose Superior, from the View

menu.



7. View the uterus (31) and both

ovaries (32) Note the position of the

uterus superior to the urinary bladder

(22) (APR Fig. 12).

APR Fig.11

APR Fig.12

Female Reproductive and Urinary Systems – Human Model

Organ Instructions

☐ Uterus ☐ Ovary Can be seen without removing organs

☐ Vagina ☐ Urinary Bladder ☐ Urethra Remove female reproductive organs

Before you proceed, replace the organs in the following sequence. When all of the organs

have been replaced, have your instructor check the model and initial your lab report.

☐ Male Reproductive Organs

☐ Pancreas and Duodenum

☐ Small and Large Intestines

☐ Stomach

☐ Liver and Diaphragm

☐ Heart and Thymus

☐ Right and Left Lungs

22



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II. Cat Dissection

A. Preparation

1. Wear goggles, gloves, and an apron for the entire time that you are working with

preserved specimens.

2. Use scissors to cut open the bag and remove the cat, but do not let the preservative

spill out of the bag.

3. Carefully dump the preservative into a special bin provided at certain lab sinks.

DO NOT DUMP THE PRESERVATIVE DOWN THE SINK.

4. The plastic bag should then be thrown away in the regular trash containers.

5. Do not use a scalpel for dissecting.

6. For most of your work, use only your scissors and blunt probe. It is the safest and most

efficient dissecting tool for muscles.

7. Use scissors only when specifically directed to do so in the dissection directions.

B. The Respiratory System - CAT

1. Lungs

2. Trachea

3. Diaphragm

4. Larynx

4a. Epiglottis

Lungs - Observe the lungs on either side of the heart. Note that like in humans, the left lung is

smaller and has fewer lobes than the right lung.

Trachea – The trachea can be seen as a white tube at the midline of the neck leading to the

lungs. Feel the hard cartilage rings in the trachea with your finger. Note that the trachea is still

wide open because of the support provided by the cartilage rings.

Diaphragm – Observe the diaphragm at the base of the lungs. This large dome shaped muscle

flattens to expand the thoracic cavity during inhalation. Note that it is skeletal muscle.

Larynx – Follow the trachea towards the head. The larynx can be observed as a widening of the

cartilage in the neck and will appear shiny white. The largest cartilage visible is the thyroid

cartilage. The larynx contains the vocal folds and epiglottis.

Epiglottis – Very carefully use your scissors to cut open the connective tissue at the very

superior end of the larynx above the cartilage in an upside-down “V” shape. Use your

finger or your blunt probe to lift up the flap-like epiglottis. This structure closes off the

larynx during swallowing to prevent food from entering the airways.



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C. Digestive System – CAT

5. Greater omentum

6. Liver

7. Gall bladder

8. Stomach

9. Small intestine (duodenum, jejunum, ileum)

Large intestine:

10. Ascending colon

11. Transverse colon

12. Descending colon

13. Rectum

14. Spleen

15. Mesentery

16. Pancreas

17. Caecum (no appendix in the cat)

19. Esophagus

Greater omentum – The fatty lace-like structure covering the abdominal organs is the greater

omentum. It is part of the peritoneum – the serous membrane of the abdominopelvic cavity. Lift

the greater omentum up and place it to the side to view the other organs. Do not detach it.

Liver – Observe the large red/brown liver in the right upper quadrant. Note that there are several

lobes similar to humans.

Gallbladder – Between the lobes of the liver find the gallbladder. Sometimes a dark greenish

stain is visible on the surface of the liver. The gallbladder itself is a sac-like structure with a

green tint. In some animals you will have to spread the lobes of the liver apart to find the

gallbladder.

Stomach – In the left upper quadrant, locate the stomach. You may need to move the greater

omentum. It is a pinkish sac that varies in size. Find where the esophagus attaches to it close to

the diaphragm. Use your scissors to cut open the stomach and observe the interior folds called

rugae.

Small Intestine –The small intestine leads from the stomach. It coils around and is connected

together by the mesentery. The first part of the small intestine is short called the duodenum. In

the cat it continues to the first bend (flexure) and then it becomes the jejunum. This portion is

the longest and leads to the ileum which empties into the caecum of the large intestine.



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Mesentery – This thin membrane connects the small intestine coils. Note the many blood vessels

running through it. It is part of the peritoneum.

Large intestine (colon) – The large intestine has a diameter of about twice the small intestine.

Find where the ileum of the small intestine meets the caecum, a pouch at the beginning of the

colon. Unlike the human, the cat has no appendix attaching to the caecum. Follow the colon up

(the ascending colon) to the very short transverse colon (basically a turn) and down the

descending colon to the rectum. Most of the cat’s rectum is not visible without further

dissection. The anal opening is visible from the exterior.

Spleen – The spleen is a reddish-brown structure visible behind the left side of the stomach.

Pancreas – The pancreas is best visible under the stomach by lifting the greater omentum and

placing it up over the stomach. At the juncture where the omentum attaches to the stomach you

can see a very delicate lobular material sometimes pinkish-white embedded in the connective

tissue. The pancreas runs horizontally across the abdomen and may continue down the

duodenum of the small intestine.

Esophagus – In the thoracic cavity, find the esophagus by gently moving the trachea aside to the

cat’s right. It is a soft brown/pink flattened tube directly underneath the trachea. Follow it down

to the stomach.

D. Urinary System – CAT

20. kidney

21. ureter

22. urinary bladder

23. urethra

Kidney – The kidneys are located on either side of the abdomen behind the other organs.

They are behind the peritoneum and so are called, retroperitoneal. You will need to remove this

layer to see the kidneys. Be careful not to damage the ureters as you do so. Remove one of the

kidneys and use your scalpel to slice it open using a frontal section. Observe the outer cortex and

inner medulla – note differences in color and texture.

Ureter – From the medial surface of each kidney a ureter attaches. These delicate flattened tubes

carry urine produced in the kidneys down to the urinary bladder for storage.

Urinary bladder – The urinary bladder is found in the pelvic cavity as a rounded sac. The

ureters attach to the posterior wall of the bladder and the urethra lies inferior to it.



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Urethra – The urethra is visible by lifting the bladder slightly and cleaning away the connective

tissue at the base of the bladder. Observe the beginning of the tubular urethra coming out of the

bladder which carries urine from the bladder to the outside of the body. The rest of the urethra

goes through the pelvis and its opening can be observed near the anal opening (see description of

the vagina below).

E. Male Reproductive System - CAT

24. scrotal sac (scrotum)

25. testis (testes pl.)

26. vas (ductus) deferens

27. penis

28. epididymis

29. spermatic cord

Scrotal sac (scrotum) – The scrotum is the skin covering the testicles (testes). The skin with fur

will need to be removed with scissors and forceps to view the testes. If your male cat has been

castrated, it will have no scrotum or testes.

Testis (testes pl.) – Two testes can be seen once the fur is removed. To view the testis better, as

well as the epididymis, remove the capsule around one testis using scissors and forceps.

Epididymis – The epididymis is a coiled tube located along the posterior surface of each testis

more easily visible when the testis capsule has been removed. It collects and helps to mature

sperm produced in the testes and passes them to the vas deferens.

Vas (ductus) deferens – The vas deferens is a tube leading from the epididymis through the

spermatic cord and loops behind the urinary bladder to fuse with the urethra at the prostate. In

the cat with the pelvis intact, it is most easily viewed within the spermatic cord near the testes.

Spermatic cord – This structure encompasses the vas deferens, testicular arteries, veins and

nerves from each testis. It passes through the inguinal canal to the abdominal cavity.

Penis – The penis of the cat is visible externally, located between and slightly above the testes.

To view the structures more closely you can remove the fur covered skin using scissors.

F. Female Reproductive System -CAT

30. Vagina (viewed as the urogenital sinus)

31. Uterus

32. Ovary



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Vagina – In the cat the urethra and the vagina open into a common orifice called the urogenital

sinus. It is located ventral to the anal opening.

Uterus – The cat uterus has two “horns” which are extensions going up the lateral abdominal

wall each attaching to an ovary. Each long uterine horn allows space for many offspring to grow.

The cat uterus lacks the long uterine (Fallopian) tubes seen in the human. The thickness and

color of the uterine horns varies according to whether the cat has had / does have a pregnancy.

The uterine horns can vary from very thin and pinkish, similar in appearance to the ureters, or

very thick. A pregnant cat will have an enlarged uterus with large blood vessels.

Ovary – At the end of each uterine horn, a small flattened lobular ovary is attached. It may

appear whitish, yellowish, or pinkish in color and often resembles a very small bean.

G. Directions for Putting Your Cat Away and Cleaning Up

1. All loose cat parts should be thrown away in the appropriate container as indicated by

your instructor. Please do NOT allow cat parts to end up in the sink. They will clog the

drain and cause extra work for lab assistants.

2. Place the cat into the container provided for disposal as directed by your instructor.

3. Thoroughly wash your dissecting tray with soap and water, dry, and return it to the lab

bench where you found it.

4. Use the spray disinfectant cleaner provided to thoroughly wipe down your lab bench

area so that it will be ready for the next group of students.

5. Dispose of your gloves, paper towels and old plastic bags in the regular trash

containers as directed by your instructor.

6. Make sure that you take your dissecting kit and goggles with you when you leave the lab.

Bio 151 – Laboratory Manual Human Anatomy & Physiology II

DCCC Ventral Body Cavity Organs Name:__________________________


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Laboratory # 8 Report

I. Cat and Human Dissection

1. Label the human and cat organs indicated on the next page. Note that some organs are visible

on only one or both of the specimens.




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1. Diagram labels: A. ______________________________________

B.______________________________________

C. ______________________________________

D. ______________________________________

E. ______________________________________

F. ______________________________________

G. ______________________________________

H. ______________________________________

2. Name the two parts of the peritoneum that a.) __________________________

we observed in the human and cat: b.) _________________________

3. What part of the respiratory system contains the vocal folds? _______________________

4. Name the three parts of the small intestine: a)__________________________

b)__________________________

c)__________________________

5. Name the tubes which take urine from the kidneys to the urinary bladder. ________________

6. What tube eliminates urine from the body? _____________________

7. What four structures are in the spermatic cord? a)_________________________

b)_________________________

c)_________________________

d)_________________________

II. Human Model

8. Examine the kidneys on both sides. Which kidney is lower? _______________________

Suggest a possible reason for this difference in kidney location.

________________________________________________________________




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9. Place the following in order from superior to inferior: transverse colon, liver, diaphragm.

A. ______________________________________

B._______________________________________

C. ______________________________________

10. Since most of this organ lies behind the stomach, the ____________________ can only be

observed clearly after the stomach is removed from the human model.

11. Identify the digestive structures indicated on the diagram below. Then draw in and label:

spleen, liver, gall bladder

A. _______________________

B. _______________________

C. _______________________

D. _______________________

E. _______________________

F. _______________________

G. _______________________

H. _______________________

I. _______________________

J. _______________________

K. _______________________

L. _______________________

12. Identify the urinary system structures.

1. _____________________________

2. _____________________________

3. _____________________________

4. _____________________________

A

D

E

L

B

C

F

G

H

I

J

K




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Identify structures indicated for the respiratory, male, and

female reproductive systems.

Respiratory System

1. ________________________

2. ________________________

3. ________________________

4. ________________________

5. ________________________

6. ________________________

7. ________________________

8. ________________________

Male Reproductive System

9. _______________________

10. _______________________

11. ________________________

12. ________________________

13. ________________________

Female Reproductive System

14. ___________________________

15. ___________________________

16. ___________________________

17. ___________________________

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3

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DCCC Ventral Body Cavity Organs #8 - Ventral Body Cavity...

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