QUADRUPED LAB:  BODY CAVITIES, REGIONS, PLANES, DIRECTIONS

 

Name: ______________________________________                                                    E. N. _____

 

OBJECTIVES:

1.      Apply the anatomical planes and directional terms to a quadruped.  Note those which are used in a different manner from the human.

2.      Recognize each of the 2 major body cavities and each of their subdivisions.

3.      Identify the organs located within each body cavity ( major and subdivisions).

4.      Use the cat dissection manual pages.

 

Procedure:

1.      Place the cat ventral side up on the dissection tray.

2.      Locate the diaphragm muscle.

Question:  Why is it important to locate this structure?

 

3.      Run your thumbs or fingers along the inferior surface of the diaphragm muscle from the ventral to the dorsal side, and then from the median plane to the lateral borders.

Q:  Which body cavity lies anterior/cranial of the diaphragm muscle?

 

4.      Examine this body cavity.  Locate the lungs, heart, larynx, trachea (has cartilaginous rings), the esophagus (lies deep to the trachea), the large blue veins, and large red arteries.  The thyroid gland, and the thymus gland have been removed in a previous dissection. 

5.      Look at the lungs.  Notice there is a very thin shiny membrane around the lobes.  This is a membrane called the pleura.  It separates the lungs from the heart and other structures, so it creates a SUBDIVISION within this large cavity.

Q:  What is the name of this cavity?

 

Q:  How many lobes (parts) are there to the lung on the right side of the cat versus the left side of the cat?   How does this compare to the humans lung orientation?

 

6.      Examine the other structures which lie more within the midline of the body.  These are considered within a separate subdivision.

Q:  What is the name of this particular subdivision?

 

7.      Gently probe around the heart.  Originally, the heart and the nearest portions of the blood vessels entering and leaving it, were encased in a membrane.  The membrane was slit and pushed to the dorsal part of the heart so the parts of the heart could be made more visible.  Locate this membrane and pull it around the heart.  This now creates another sub-subdivision of this larger cavity.  The membrane is known as the parietal pericardium and therefore the cavity is the PERICARDIAL CAVITY.

8.      Move to the large cavity posterior/caudal to the diaphragm muscle.

Q:  What is the name of this cavity?

 

9.      Locate the  stomach, small intestines, large intestines, Caecum/ appendix, rectum, liver, spleen, kidneys, ureters, urinary bladder.  If the cat is female, you can find the uterus, ovaries, and fallopian tubes.  Other structures which lie in this cavity, but are not as easy to locate or have been removed are the pancreas, gall bladder, intestinal mesentery,  greater omentum, lesser omentum, numerous blood vessels, lymph nodes, and ducts.

Q:  Which appears to be longer, the small or large intestine?

 

Q:  Which appears to be wider, the small or large intestine?

 

Q:  Which of the organs listed are considered to be in the pelvic region of this cavity?

 

Q:  What separates the abdominal, from the pelvic cavity?

 

10.   Examine the vertebra (it is human and is very valuable and irreplaceable). Notice the hole through the center. 

Q:  What subdivision of which cavity is this?

 

Q:  What organ lies within this cavity?

 

11.   Turn the cat over onto its vental side, so that the dorsal side is up.  Use the bone clippers to cut between three vertebrae  in the lumbar region.  Carefully separate the muscle tissue from the bone, and remove this section.  You should be able to see the cavity and  a section of the organ it contains.  Attempt removal of the spinal cord.  Place the cord section in the specimen jar indicated.

12.   We will not get into the cranial cavity at this time. 

Q:  What organ is housed in the cranial cavity?

 

Q:  If you are at the lumbar region of the cat, and are moving in the direction of the cephalic , in what direction are you moving?

 

Q:  If you section the cat between the eyes and ears from the head to the tail, it will create what two sections?

 

Q:  If you section the cat along the transverse plane it will create what two sections?

 

Q:  If you are on the plantar region  of the cat, and move toward the coxal region, in what direction did you move?

 

Q:  The cat has an extended beak like) face, so do cows, horses, dogs.  What is this part called?

 

13.   Use the string to identify the planes on the cat.  Ask yourself, and partners, “What is this plane called, and what areas does it create?  Point with the mall probe in the direction of the tail, head, belly, back and ask what direction is this, and is it referred to differently in the human?

14.   Locate the following regions of the body:

Carpal, brachial, antebrachial, olecranal, sacral, gluteal, femoral, calcaneal,  frontal, buccal, mental, cervical.