Skeletal System

 

Skeletal System

Overview

The skeletal system provides structure, support, and protection to the body, stores minerals (like calcium), and produces blood cells in bone marrow. It consists of 206 bones (in adults), cartilage, ligaments, and joints.

Anatomy

Key components:

• Axial Skeleton: Skull, vertebral column (cervical, thoracic, lumbar, sacral, coccyx), rib cage (12 pairs of ribs, sternum).
• Appendicular Skeleton: Upper limbs (humerus, radius, ulna, carpals, metacarpals, phalanges), lower limbs (femur, tibia, fibula, tarsals, metatarsals, phalanges), pectoral girdle (clavicle, scapula), pelvic girdle (ilium, ischium, pubis).
• Bone Types: Long (e.g., femur), short (e.g., carpals), flat (e.g., skull), irregular (e.g., vertebrae), sesamoid (e.g., patella).

Recommended Visuals:

• A labeled diagram of the full skeleton (front and back views).
• Close-up of the skull showing cranial bones (e.g., frontal, parietal, occipital) and facial bones (e.g., mandible, maxilla).
• Vertebral column with labeled regions (7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 4 coccyx).
• Source: “Netter’s Atlas of Human Anatomy” or free resources like Kenhub.com.

Memory Codes

1. Cranial Bones (8): "PEST OF 6"
   • Parietal, Ethmoid, Sphenoid, Temporal, Occipital, Frontal (6 sounds like "six").
   • Note: 2 parietal and 2 temporal are paired.
2. Vertebral Column (7-12-5-5-4): "Breakfast, Lunch, Dinner"
   • 7 cervical (morning), 12 thoracic (noon), 5 lumbar (evening), 5 sacral, 4 coccyx (fused).
3. Carpal Bones (8): "Some Lovers Try Positions That They Can’t Handle"
   • Proximal row: Scaphoid, Lunate, Triquetrum, Pisiform.
   • Distal row: Trapezium, Trapezoid, Capitate, Hamate.

Questions

Multiple-Choice:

1. How many bones are in the adult human skeleton?
   • A) 200 B) 206 C) 210 D) 212
     Answer: B) 206
2. Which bone is classified as a sesamoid bone?
   • A) Femur B) Patella C) Scapula D) Mandible
     Answer: B) Patella

Short-Answer:

1. Name the three types of vertebrae and how many of each are present in the human body.
   Answer: Cervical (7), Thoracic (12), Lumbar (5).
2. What is the function of the red bone marrow?
   Answer: Produces red blood cells, white blood cells, and platelets.

Long-Answer:

1. Describe the structure and function of the axial skeleton, including its major components and their roles in the body.
   Answer: The axial skeleton includes the skull, vertebral column, and rib cage. The skull protects the brain and supports facial structures. The vertebral column (33 vertebrae) supports the body, protects the spinal cord, and allows flexibility. The rib cage (12 pairs of ribs, sternum) shields the heart and lungs and aids in breathing.