1. Internal Organs EQ. 5.00 – Standard: Understand equine anatomy
Objective 5.03: Understand the internal organs of equine.

2. Organs of Thoracic Cavity
Area between the neck and abdomen
Ribs form the sides of the thoracic cavity.
The organs of the thoracic cavity include the circulatory and respiratory systems.
Major organs include:
Heart: lies towards the bottom of the thoracic cavity and to the left of the center.
Lungs: lie to the sides and behind the heart and fill most of the thoracic cavity

3. Thoracic Cavity Functions of organs in thoracic cavity:
The heart pumps blood throughout the horse’s body.
The lungs exchange oxygen and carbon dioxide between the blood and the air.

4. Location of thoracic cavity

5. Abdominal Cavity
Extends from just behind the thoracic cavity to the pelvic region
Diaphragm - A body partition of muscle and connective tissue; separates the abdominal and thoracic cavities.

6. Major Organs in A.C.
Liver – Large organ extending all the way across the abdominal cavity
Spleen and Stomach – Lie behind the liver and in front of the small and large intestine
Kidneys – Lie on each side of the backbone and under the ribs in the loin area of the horse

7. Functions of A.C.
Liver metabolizes several nutrients, detoxifies (removes the poison) many drugs and poisons and stores some nutrients.
The spleen and stomach are part of the gastrointestinal tract and function in the digestion and utilization of food.
The kidneys remove wastes from the boy and conserve fluids and important components of the blood.

8. Organs of Pelvic Cavity
Continuous with the abdominal cavity
Rectum – The terminal portion of the intestine, which continues from the abdominal cavity to the pelvic cavity
Urinary Bladder – Lies within the pelvic cavity and extends into the abdominal cavity when full

9. Organs of Pelvic Cavity
Major organs include:
Male reproductive organs which lie toward the back and at the base of the pelvic cavity; OR,
Female reproductive organs extending from the back of the cavity to near the abdominal cavity.

10. Pelvic Cavity

11. Functions of P.C.
The rectum is the terminal portion of the intestine and serves as the exit part for solid waste.
The urinary bladder collects liquid waste.
Horse reproductive organs will be covered.