HSSLIVE Plus One Zoology Chapter 9: Locomotion and Movement Notes

Chapter 9: Locomotion and Movement

Types of Movement in Animals

• Amoeboid Movement: Using pseudopodia (temporary projections)
• Ciliary Movement: Using cilia (short hair-like structures)
• Flagellar Movement: Using flagella (long whip-like structures)
• Muscular Movement: Using muscles attached to skeletal elements

Human Muscular and Skeletal System

Skeletal System

The human skeleton consists of 206 bones organized into:

• Axial Skeleton (80 bones): Forms the central axis
  • Skull (22 bones): Cranium, facial bones
  • Hyoid bone (1)
  • Vertebral column (26 bones): Cervical (7), thoracic (12), lumbar (5), sacrum (1), coccyx (1)
  • Sternum and ribs (25 bones)
• Appendicular Skeleton (126 bones): Limbs and girdles
  • Pectoral girdles (4 bones): Clavicles (2), scapulae (2)
  • Upper limbs (60 bones): Humerus, radius, ulna, carpals, metacarpals, phalanges
  • Pelvic girdle (2 bones): Hip bones
  • Lower limbs (60 bones): Femur, tibia, fibula, patella, tarsals, metatarsals, phalanges

Types of Bones

• Long Bones: Limb bones like femur, humerus
• Short Bones: Wrist (carpals), ankle (tarsals)
• Flat Bones: Skull bones, ribs, scapula
• Irregular Bones: Vertebrae, facial bones
• Sesamoid Bones: Within tendons (e.g., patella)

Bone Structure

• Outer Layer: Compact bone (dense, hard)
• Inner Layer: Spongy bone (porous)
• Central Cavity: Bone marrow (red marrow for blood cell formation, yellow marrow for fat storage)
• Covered by: Periosteum (fibrous membrane)
• Composition:
  • Organic matter (35%): Collagen (provides flexibility)
  • Inorganic matter (65%): Calcium phosphate, calcium carbonate (provides hardness)

Joints

Joints are junctions between bones that allow movement.

Types of Joints:

1. Fibrous Joints: Immovable (e.g., skull sutures)
2. Cartilaginous Joints: Slightly movable (e.g., pubic symphysis, intervertebral discs)
3. Synovial Joints: Freely movable
   • Ball and Socket: Hip, shoulder (all directions)
   • Hinge: Elbow, knee (one plane)
   • Pivot: Between atlas and axis (rotation)
   • Gliding: Between carpals, tarsals (sliding)
   • Saddle: Thumb-carpals (many directions)
   • Condyloid: Wrist (two planes)

Structure of Synovial Joint:

• Articular Cartilage: Covers bone ends
• Joint Cavity: Contains synovial fluid
• Synovial Membrane: Secretes synovial fluid
• Ligaments: Connect bones, provide stability
• Joint Capsule: Encloses joint

Muscular System

There are about 600 muscles in the human body, constituting about 40-50% of body weight.

Types of Muscles:

1. Skeletal Muscles: Attached to bones, voluntary control
2. Smooth Muscles: In internal organs, involuntary
3. Cardiac Muscle: Found only in heart, involuntary but rhythmic