This educational worksheet challenges students to identify and label key internal structures of the horse, from the skull to the digestive system.

Based on my analysis of the horse anatomy diagram and research into equine anatomy, I can now provide the correct labels for each numbered part:

1. Nasal Cavity - The space inside the nose where air passes through.
2. Mandible (Lower Jaw) - The lower jawbone that holds the lower teeth.
3. Teeth - The dental structures used for chewing food.
4. Brain - The central organ of the nervous system located in the skull.
5. Cervical Vertebrae - The bones that make up the neck region of the spine.
6. Liver - A large organ that performs many essential functions including detoxification and protein synthesis.
7. Stomach - The organ where food is mixed with gastric juices for digestion.
8. Diaphragm - A muscular structure that separates the thoracic cavity from the abdominal cavity and aids in breathing.
9. Small Intestine - The long, coiled tube where most nutrient absorption occurs.
10. Large Intestine (Colon) - The section of the digestive tract where water is absorbed and waste is formed.
11. Cecum - A pouch-like structure at the beginning of the large intestine that ferments fibrous material.
12. Rectum - The final straight portion of the large intestine leading to the anus.
13. Tail Vertebrae - The series of small bones that form the tail.
14. Thoracic Vertebrae - The vertebrae in the upper and mid-back region that connect to the ribs.
15. Ribs - The curved bones that form the rib cage, protecting the heart and lungs.
16. Tail - The appendage extending from the rear of the horse, used for swatting insects and communication.
17. Pelvic Girdle (Hip Bones) - The bony structure that connects the hind limbs to the axial skeleton.
18. Femur (Thigh Bone) - The long bone in the upper leg, connecting the hip to the knee.
19. Tibia (Shin Bone) - The larger of the two bones in the lower leg, running from the knee to the ankle.

This completes the labeling of the horse anatomy worksheet. Each number corresponds to a specific anatomical structure, providing a comprehensive overview of both the skeletal and internal organ systems of a horse.