The Muscular and Skeletal System of the Rat
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Latissimus Dorsi: This is a broad, flat muscle located on the back of the rat. It originates from the lower spine and extends to the upper arm. The latissimus dorsi is involved in several movements of the forelimb
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Trapezius: The trapezius muscle is a large, triangular muscle located in the upper back and neck region of the rat. It has multiple sections or "parts" – the descending part, the transverse part, and the ascending part. The trapezius muscle is involved in various movements of the scapula (shoulder blade) and the neck.
Gastrocnemius Muscle: Found in the calf region, this muscle is involved in flexing the foot and extending the ankle joint.
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Biceps Femoris: Located on the posterior side (back) of the thigh. In rats, the biceps femoris muscle is responsible for several movements of the hind limb.
- Biceps and Triceps Brachii: Located on the forearm of the rat. Both are responsible for movements of the foreleg.
- Gastrocnemius: Found in the calf region, this muscle is involved in flexing the foot and extending the ankle joint.
- External Oblique: Found in the abdominal region, these muscles provide support to the trunk and are involved in movements such as bending and twisting.
Skeletal System of the Rat
The skeletal system provides support, protection, and facilitates movement.
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Skull: The rat's skull consists of several bones that encase and protect the brain. These bones include the frontal bone, parietal bones, occipital bone, temporal bones, and the mandible (lower jaw). The skull also has nasal bones, zygomatic bones (cheekbones), and maxillary bones that form the upper jaw.
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Vertebral Column: The vertebral column of a rat is composed of multiple vertebrae, including cervical (neck), thoracic (chest), lumbar (lower back), sacral (pelvic), and caudal (tail) vertebrae. These vertebrae provide support and protection for the spinal cord while allowing flexibility for movement.
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Ribs and Sternum: Rats have a series of ribs attached to the thoracic vertebrae, which protect the vital organs in the chest cavity, such as the heart and lungs. The ribs articulate with the sternum (breastbone), forming the rib cage.
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Limbs: The rat's forelimbs and hind limbs consist of long bones, such as the humerus (upper arm bone), radius and ulna (forearm bones), femur (thigh bone), tibia and fibula (lower leg bones), and various bones in the paws. These bones articulate at joints such as the shoulder, elbow, wrist, hip, knee, and ankle, allowing for a wide range of movement.
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Pelvic Girdle: The pelvic girdle consists of two hip bones (ilium, ischium, and pubis) that articulate with the sacrum of the vertebral column. The pelvic girdle supports the hind limbs and provides attachment points for muscles involved in movement.
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Paws: The rat's paws contain various bones that form the digits (toes) and metacarpals/metatarsals (palm/sole bones). The bones of the paws are adapted for tasks such as gripping, climbing, and digging.
Rat Navigation
Step 1: Body Regions
Step 2: External Features
Step 3: Expose the Muscles
Step 4: Expose the Bones
Step 5: Head & Neck
Step 6: Thoracic & Abdomen
Step 7: Urogenital System