Dissection of Sheep Heart, Fetal Pig Cardiovascular System, Respiratory System, Urinary System, and Digestive System

This article discusses the dissection of the sheep heart, fetal pig cardiovascular system, respiratory system, urinary system, and digestive system. It covers the similarities and differences between the organs, their functions, and physical characteristics.

Running head: ANATOMY 1
Anatomy
Student’s Name
Institutional Affiliation

ANATOMY 2
1. Discuss your dissection of the sheep heart and the cardiovascular system of the fetal pig
by doing the following:
a. Describe the similarities and differences between the fetal pig heart and the sheep heart.
I did not notice much differences between the two hearts. However, the difference
between the fetal pig heart along with the sheep heart is that the heart of the fetal pig is smaller
than that of the sheep heart. On the other hand, the similarities are that both the specimens
possesses the same anatomy. Accordingly, both have right and left atriums similar to right and
left ventricles. The third similarity is that both have prominent great vessels just like the
pulmonary artery along with the aorta (Rizzo, 2015).
b. Describe the four valves of the heart, including their name, location, and function.
The 4 valves of the heart in the fetal pig are the tricuspid valve, pulmonic valve, mitral
and aortic valve. The tricuspid valve is located between the right atria and the right ventricle. As
an illustration, the right atrium usually gets deoxygenated blood which returns from circulation
within the body via superior Vena cava which is then pushed via the tricuspid valve into the right
ventricle (Allen & Harper, 2014). The deoxygenated blood is then forced from the right ventricle
through the pulmonic valve to the lungs to get oxygen.
The pulmonic valve is termed as the semilunar cusped valve which is found within the
ostium of the pulmonary artery. Blood usually moves to the heart from the lungs via the
pulmonary vein into the left atrium. From there, blood then moves through the mitral valve into
the left ventricle. The mitral valve is usually a bicuspid or leaflet atrioventricular valve. The left
ventricle usually contracts when it gets full, and hence blood is pushed into the aortic valve via
aorta into the body (Rizzo, 2015). The aortic valve are found along the root of the aorta at its
junction with left ventricle. It is usually a high pressure, cusped semi lunar valve which must

ANATOMY 3
withstand tremendous pressures during the election from left.
c. Discuss the similarities and differences between the left and right sides of the heart.
The heart is usually masculine on the left ventricle together with the left atrium.
Conversely, the difference is their sizes. In this case, the left side of the heart was larger than the
right side. Furthermore, the right and left ventricles had papillary muscles along with chordae
tendinea which attaches the tricuspid and mitral valves to the interventricular wall. Accordingly,
the right side circulates blood without oxygen while the left side circulates oxygenated blood.
Last but not least, the aortic and tricuspid valve was at the left side of the heart while the
tricuspid along with pulmonary valve was on the right side (Reece & Rowe, 2017).
d. Compare the structure of the atrioventricular valves to the structure of the semilunar
valves.
The mitral along with tricuspid valve are both atrioventricular valves. However, the
mitral valve possesses two cusps while the other valves have three (Allen & Harper, 2014). The
valves are anchored to the walls of the ventricle with the chordae tendineae which is absent in
semi-lunar valves. Furthermore, they are responsible for the first sound of the heart called LUB
sound (Denbow, 2015).
The aortic and pulmonary valves termed as the semi-lunar valves. Conversely, they
usually work more like the valves in veins to avoid backflow of blood. Accordingly, the semi-
lunar valves are typically responsible for the second sound of the heartbeat which is called the
DUB sound (Roper & Voss, 2014).
e. Describe the appearance of the papillary muscles.

ANATOMY 4
The Papillary muscles are small muscles within the heart which attaches to the chordae
tendineae. However, this tendinea are usually attached to the mitral valve along with tricuspid
valve thus preventing the backflow of blood from the left ventricle into the atrium. They looked
like tough strings within the sheep heart specimen (Rizzo, 2015).
f. Describe the path that blood takes starting in the right atrium and ending in the
superior/inferior vena cava.
From the right atrium, the blood usually flows via the tricuspid valve into the right
ventricle. From the left ventricle through the pulmonic valve into the pulmonary artery towards
the lungs. The deoxygenated blood in the lungs is usually passed through tiny structures referred
to as alveoli where there is an exchange of oxygen and carbon dioxide via the capillary walls
(Denbow, 2015). When the blood gets full of oxygen, it moves back to the heart through the left
atrium. From there it passes via the mitral valve and into the left ventricle. The left ventricle
usually pushes the blood past the aortic valve into the aorta and hence out of the body to supply
blood rich in oxygen throughout the body. The blood from the whole parts of the body usually
returns to the heart via veins. That is the superior vena cava and then into the right atrium to start
the oxygenation process again (Allen & Harper, 2014).
2. Discuss your dissection of the respiratory system of the fetal pig by doing the following:
a. Compare the structure of the trachea to the structure of the esophagus.
Trachea and esophagus are usually part of the respiratory and digestive system
respectively. However, since they belong to different systems they perform different functions.
As an illustration, the trachea is generally surrounded by a ring-shaped cartilage that is hard to
keep it open all the time to facilitate gas exchange. On the other hand, the esophagus is usually
flexible to allow the foods and liquid movement. Accordingly, the trachea is defined by two parts

ANATOMY 5
that are the thoracic and the cervical (Roper & Voss, 2014). The esophagus possesses three parts
that is the thoracic, cervical and abdominal and hence extends from the lower side of the pharynx
to the cardiac opening of the stomach. The esophagus also has some constrictions at the places it
originates, and therefore food can lodge themselves within these areas (Allen & Harper, 2014).
The trachea usually has two parts while the esophagus has three parts.
b. Describe how the structures of the respiratory system (i.e., trachea, bronchi, and lungs)
relate to their functions.
Structures of the trachea, bronchi, and lungs were all within the fetal pig. The trachea is
rigid and hollow tube-like which when felt had several small hard rings surrounding it. This was
the cartilages which surround the trachea to keep it upright and patent for the gaseous exchange
(Scanlon & Sanders, 2014). The two Bronchi which are usually interlinked by the trachea could
be described as upside-down tree as they spread further into bronchioles in the lungs (Rizzo,
2015). In fetal pig, the left lung had three lobes while the right lung had four lobes. Accordingly,
the lungs of the fetal pig were dark pink to almost red and had a spongy texture because of
millions of alveoli which make up the surface area of the lungs (Denbow, 2015).
c. Describe the texture of the lungs.
I could describe the texture of the lungs as spongy. Accordingly, both the left and right
lungs were relatively light.
d. Describe the similarities and differences between the left lung and the right lung.
The lungs in the right side were shorter and broader while the left lung is long and
narrow. However, both of them usually facilitates gaseous exchange through millions of the
alveoli in each (Denbow, 2015).

ANATOMY 6
3. Discuss your dissection of the sheep kidneys and the urinary system of the fetal pig by
doing the following:
a. Compare the structure of the fetal pig kidneys to the structure of the sheep kidneys.
The structures of the kidneys of both the pig and sheep resembled each other. However,
the notable difference was their sizes. The kidneys in both specimens had common bean shaped
shape which appeared dense to touch (Roper & Voss, 2014). The Kidneys of the pig were
however located below the small and large intestine and were covered in a shining coating which
is called peritoneum which had to be dissected away from the kidney before it could be accessed.
Furthermore, both the kidneys had a visible renal artery, renal vein along with the ureter which
was attached.
b. Describe the location of the kidneys in the fetal pig.
The kidney was found in the abdominal cavity dorsal under the lining of the peritoneum
(Scanlon & Sanders, 2014).
c. Describe the path that urine takes to exit the body, starting in the kidney.
Urine usually starts from the kidney. It is the kidney that filters the blood wastes which
comes in form of urine. Urine however is termed as the mixture of water, urea, salts, ammonia,
and creatinine. When blood goes through the renal capillaries, it is then taken into structures
called the glomeruli which are just like a filter (Rizzo, 2015). However, its structure usually
allows the waste products, water, and salt to pass from the blood into a tiny channel called tubule
while keeping the blood cells along with protein in the bloodstream. There are over a million
nephrons in each kidney. Urine usually travels from the tubules through the ureters attached to
each kidney down to the bladder where the urine is stored until excretion. The body gets ride of
urine via the Urethra (Roper & Voss, 2014).

ANATOMY 7
4. Discuss your dissection of the components of the endocrine system of the fetal pig by
doing the following:
a. Describe the endocrine organs that are located in the throat region (e.g., function and
appearance).
The thyroid and thymus glands are the organs which are found within the throat. The
thyroid gland found above the trachea in fetal pig was oval with a dark red appearance. The
function of the thyroid gland is usually to maintain basic metabolic rate along with production of
thyroxin. On the other hand, the thymus gland in the pig is located above the heart. The thymus
gland was whitish and had two lobes (Scanlon & Sanders, 2014).
b. Describe three endocrine organs that are located in the abdominal or pelvic cavities.
The Endocrine gland organs within the abdominal cavity are pancreas, adrenal glands
together with the testicles. The pancreas was small and had the texture of small pebbles.
However, it was located behind the stomach. The pancreas had a grey to whitish color (Scanlon
& Sanders, 2014).
The adrenal glands in pig were tiny and were located anterior to the kidney. Furthermore,
they had an oval shape and were very light. Last but not least, testicles were situated on the fetal
pig. They were near the anus and surrounded by the sac called scrotum.
5. Discuss your dissection of the digestive system of the fetal pig by doing the following:
a. Describe the significant digestive organs, including their name, location, relative size,
and physical characteristics (e.g., color, shape, texture).
The stomach, esophagus, small intestine along with large intestine are the major digestive
organs of the fetal pig. The function of the stomach is usually to store around one to two litres of

ANATOMY 8
food for digestion. Furthermore, the stomach lining produces rennin which coagulates milk
proteins. I saw the esophagus at the back of the pig’s trachea which was very small and flexible
tube whitish in color. It usually links the stomach and hence was found in the abdominal cavity
to the right slightly under the liver. Accordingly, I dissected the pyloric sphincter which was
found underneath the stomach and leads to the small intestine. This usually prevents backflow of
food and has thicker layers (Reece & Rowe, 2017).
The small intestine appeared to possess many loops than large intestine, pink to whitish
and very smooth from outside. The inside of the small intestine had projections. This is where
the absorption of nutrients usually takes place. On the other hand, the large intestine was darker
in color. It was around one meter long and around 10cm wide. Its main function is to absorb
water, minerals and salt. Accordingly, the large intestine had few loops as compared to those in
the small intestine and had a rigid appearance. I then moved to the anus where the fecal matter
moves out of the body (Roper & Voss, 2014).
b. Describe the accessory digestive organs, including their name, location, relative size, and
physical characteristics (e.g., color, shape, texture).
I would describe the accessory organs of the digestive system as Teeth, tongue, salivary
glands, pancreas, liver along with the gallbladder. However, every organ usually plays a function
within the digestive system. The tongue was not easily accessible since the jaws were tightly
closed. However, the tongue is used in digestion to push food towards the back of the throat
(Scanlon & Sanders, 2014).
During dissection I saw three salivary glands in the fetal pig which includes the parotid
gland, the mandibular gland along with the sublingual gland. The pancreas gland in pig was
small and grey to white located just under the liver. Pancreas usually produces insulin. The liver

ANATOMY 9
was large and dark in color. The liver had a very dense texture and took the significant portion of
the abdominal cavity (Reece & Rowe, 2017). The function of the liver is usually to process the
nutrients absorbed from the small intestine along with secretion of bile into the small intestine
for fat digestion. Lastly, the gallbladder was under the liver. It is a small sac which appeared dark
green. The gallbladder usually holds bile which is produced in the liver.

ANATOMY 10
References
Allen, C., & Harper, V. (2014). Fetal pig dissection: a laboratory guide (No. Ed. 3). John Wiley
& Sons Ltd.
Denbow, D. M. (2015). Gastrointestinal anatomy and physiology. In Sturkie's Avian Physiology
(Sixth Edition) (pp. 337-366).
Reece, W. O., & Rowe, E. W. (2017). Functional anatomy and physiology of domestic animals.
John Wiley & Sons.
Rizzo, D. C. (2015). Fundamentals of anatomy and physiology. Cengage Learning.
Roper, C. F., & Voss, G. L. (2014). Guidelines for taxonomic descriptions of cephalopod
species.
Scanlon, V. C., & Sanders, T. (2014). Essentials of anatomy and physiology. FA Davis.