Skeletal System
Biology · कंकाल तंत्र · 14 facts
Human skeleton: 206 bones in adults; 270 in babies(fuse later)
Skull: 22 bones; protects brain
Vertebral column(backbone): 33 vertebrae; protects spinal cord
Rib cage: 12 pairs of ribs; protects heart and lungs
Femur(thighbone): longest and strongest bone in body
Stapes(stirrup) in ear: smallest bone in body
Joints: fixed(skull), hinge(elbow,knee), ball-and-socket(shoulder,hip)
Cartilage: flexible connective tissue; nose, ear, joints
Ligaments connect bone to bone; Tendons connect muscle to bone
Bone marrow: produces RBC, WBC, platelets
Calcium+Vitamin D essential for strong bones; deficiency=rickets/osteoporosis
3 types of muscles: skeletal(voluntary), smooth(involuntary), cardiac(heart)
Hyoid bone: only bone not connected to any other bone(in throat)
Muscles work in pairs: biceps(flexor) and triceps(extensor)