FETAL PIG EXTERNAL ANATOMY
NAME____________________
THE PLANE TRUTH
Today you will explore the various structures of the pig’s external anatomy and, if time, you will explore the oral cavity.
Before we get started, let’s review the basic anatomical terms, planes, and positions. Using the diagram below, place the
following terms in their proper location and sketch in the line that shows the proper body plane:
ANATOMICAL POSITIONS
Dorsal surface
Ventral Surface
Anterior
Posterior
Cranial
Caudal
Superior
Inferior
CM
1.1
1.7
2.8
4.0
22.0
30+
APPROXIMATE
AGE (DAYS)
21
35
49
56
100
112-115 full term
BODY PLANES
Transverse
Medial
Frontal
HOW OLD IS MY PIG?
In processing the female pigs for meat, the uterine horns often reveal unborn
litters. These are removed and made available for biological study. There are
usually 7-12 young in a litter. The age of your fetal pig can be determined by its
length. Using a string measure the body length along its dorsal surface following
the natural curvature of the spine from the tip of the snout to the base/start of the
tail. Measure the length of the string in cm and refer to the chart in order to
determine the age of your pig.
HOW OLD IS YOUR PIG?____________________
WHAT A BODY!
The body of the fetal pig is divided into a head (cranial), neck (cervical), trunk (thoracic and abdominal), and tail (caudal).
Using the diagram below, hypothesize where you think the following structures are located and label the diagram on the
left: nose, tongue, outer ear, wrist, shoulder, elbow, knee, ankle, tail, digit, umbilical cord, eye, and nostril/external nares.
IT’S A BOY! NO WAIT, IT’S A GIRL! HOW TO DETERMINE THE SEX OF YOUR PIG
Regardless of whether you have a male or a female, both sexes have other noticeable external feature. Before we attempt
to determine the sex of your pig, please locate and provide the function for the following structure: anus, teats/mammary
papillae
ANUS:
MAMMARY PAPILLAE:
MALES:
If you have a male, you should be able to locate the urogenital opening and scrotal sac. The urogenital in males is located
on the midventral surface, posterior to the umbilical cord. Please locate the opening on your pig and label the opening on
the diagram below. The male testes lie in the scrotum. This double pouch structure is ventral to the tail. In older
specimens this area is enlarged and readily visible. In younger specimens it may be necessary to touch the area to detect
the testes. Please locate and label this structure on the diagram below.
FEMALES:
If you have a female, you will see a cone shaped structure ventral to the anus. This is the urogenital papilla. The female
urogenital opening is located at the base of the urogenital papilla. Please locate and label these structures on the diagram
below.
MALE
FEMALE
MALE
WHAT FUNCTION DOES THE UROGENITAL OPENING SERVE IN THE MALE? IN THE FEMALE?
AN ORAL EXAM:
The first system we will explore is the digestive system and its components. The beginning of the digestive system is the mouth.
In the following activity you will explore the oral cavity of the pig.
Please follow your teacher’s instructions as to how to cut open the oral cavity of the pig.
A
TONGUE (E):
The tongue is an elongated muscular structure containing taste buds or papillae.
 WHERE ON THE TONGUE ARE MOST OF THE PAPILLAE?
B
TEETH (A):
The pig has a full complement of teeth ranging from incisors for cutting, canines for
tearing, and premolars/molars for chewing. Please look for the teeth in your pig.
 WHICH TEETH ARE PRESENT AT THIS EARLY AGE?
HARD PALATE (B):
This hard, bony structure makes up the roof of the mouth. This separates the oral from
the nasal cavity.
 WHAT IS THE TEXTURE OF THIS PALATE?
SOFT PALATE (C):
This is the posterior portion of the hard palate. It too separates the oral from the nasal
cavity.
 HOW DOES THE HARD PALATE COMPARE TO THE SOFT PALATE?
EPIGLOTTIS (D):
This fleshy flap covers the trachea. Find this flap.
 WHAT FUNCTION DOES THIS FLAP SERVE?
TRACHEA: This opening leads to the lungs. Carefully insert the probe into the trachea.
ESOPHAGUS:
This food tube is located dorsal to the trachea. Find this tube.
C
D
E