Skeletal+Anatomy+LAB

Skeletal Anatomy Overview

Focus: ANSC 2350 Lab Week 3

Types of Bones

  • Gross Classification:

    • Long bones: Typically longer than they are wide, they include the humerus and femur and are crucial for movement.

    • Short bones: As wide as they are long; examples include the carpals and tarsals, providing stability and support while allowing for some motion.

    • Flat bones: These bones have a flattened shape and include the skull and ribs, serving protective roles and providing surfaces for muscle attachment.

    • Sesamoid bones: Small, round bones embedded in tendons, they reduce friction and improve the mechanical advantage of muscles; an example is the patella (kneecap).

    • Irregular bones: Bones that do not fit into the other categories; examples include vertebrae and many facial bones, designed for complex shapes and varying functions.

    • Pneumatic bones (avian): These are lightweight bones containing air spaces; they help reduce the overall weight of birds, aiding in flight.

Skeleton Structure

Axial Skeleton:

  • Consists of the skull, vertebral column, ribs, and sternum.

  • Key Components:

    • Skull: Divided into facial bones and cranial bones, it protects the brain and supports the structure of the face.

    • Vertebrae: Composed of cervical (Atlas & Axis), thoracic, lumbar, sacral, and caudal vertebrae, which provide structural support and protect the spinal cord.

    • Sternum: A flat bone that lies in the midline of the thoracic skeleton and serves as an attachment for ribs through cartilage.

    • Ribs: Curved bones that form the ribcage, protecting the heart and lungs while allowing breathing movements.

Appendicular Skeleton:

  • Comprises the bones of the limbs and girdles.

  • Important Bones:

    • Forelimb: Humerus (upper arm), scapula (shoulder blade), ulna and radius (forearm), carpals (wrist), and metacarpals (hand).

    • Pelvic Limb: Femur (thigh), patella (kneecap), tibia and fibula (lower leg), tarsals (ankle), and metatarsals (foot).

Specific Bone Features

Vertebral Column Anatomy:

  • A typical vertebra includes:

    • Spinous process: A bony projection off the posterior of the vertebra, providing attachment points for muscles.

    • Transverse process: Lateral projections that also serve as muscle attachment sites and contribute to the structure of the vertebral joints.

    • Vertebral foramen: The opening that houses the spinal cord.

    • Body: The anterior portion, which bears the weight and serves as a shock absorber.

  • Types of Vertebrae:

    • Cervical: Seven vertebrae in the neck region, including Atlas (C1) and Axis (C2), which allow for head rotation and flexion.

    • Thoracic: Twelve vertebrae connected to the ribs, providing stability for the upper body.

    • Lumbar: Five larger vertebrae in the lower back, designed to support more weight and allow for bending movements.

Skull Anatomy

  • Components of Axial Skeleton:

    • Frontal: The bone forming the forehead region.

    • Parietal: Located on the top of the skull, involved in protecting the brain.

    • Facial bones: Include the nasal bones, maxillae, zygomatic bones, which form the structure of the face.

    • Temporal: Houses structures of the inner ear and contributes to the sides of the skull.

    • Lacrimal: Small bones forming part of the eye socket.

    • Nasal: Form the bridge of the nose.

Understand equine and bovine skull differences.

  • Equine skulls tend to be longer and more elongated, while bovine skulls are broader and have a more pronounced sinus structure, impacting their feeding and sensory perception.

Pelvic and Thoracic Limbs

  • Anatomy of horse and ox limb structures includes specific adaptations suited to their lifestyles; horses have long limbs for speed, while oxen have stockier limbs for strength and endurance.

  • Comparison of digits and metacarpals across species: Horses have a single dominant digit (hoof), while oxen have cloven hooves with two functional digits, reflecting their evolutionary adaptations for different environments.

Practical Application

  • Memorization of pelvic bone parts and species comparison:

    • Conducting observational studies of calcaneus, tarsals, metatarsals, and phalanges in humans, dogs, and horses aids in understanding functional anatomy and variations among species.