Ch.7-8 Powerpoint

• Axial Skeleton


  Forms the longitudinal axis of the body
• Parts of the Axial Skeleton


  • Skull
  • Vertebral column
  • Bony thorax

  
• Skull


  • Two sets of bones form the skull: Cranium bones enclose the brain, Facial bones
  • Hold eyes in anterior position
  • Allow facial muscles to express feelings
  • Bones are joined by sutures (immovable joints)
  • Only the mandible is attached by a freely movable joint

  
• Cranial bones


  • Frontal bone
  • Occipital bone
  • Ethmoid bone
  • Sphenoid bone
  • Parietal bones (pair)
  • Temporal bones (pair)

  
• 14 Facial bones

  • Maxillae (pair)
  • Palatine bones (pair)
  • Lacrimal bones (pair)
  • Zygomatic bones (pair)
  • Nasal bones (pair)
  • Vomer bone
  • Inferior nasal conchae (pair)
  • Mandible

  
• 4 Sutures

  • Coronal suture
  • Squamous suture
  • Sagittal suture
  • Lambdoid suture
• Paranasal sinuses


  Hollow portions of bones surrounding the nasal cavity
• Functions of paranasal sinuses

  • Lighten the skull
  • Amplify sounds made as we speak
• Hyoid bone


  • The only bone that does not articulate with another bone
  • Serves as a movable base for the tongue
  • Aids in swallowing and speech
• Vertebral column


  • Provides axial support
  • Extends from skull to the pelvis
  • 26 vertebral bones separated by intervertebral discs

  
• Regions of the vertebral column

  • 7 cervical vertebrae
  • 12 thoracic vertebrae
  • 5 lumbar vertebrae
  • Sacrum (formed by fusion of 5 vertebrae)
  • Coccyx (formed by fusion of 3–5 vertebrae)
• Primary curvatures


  • Spinal curvatures of the thoracic and sacral regions
  • Present from birth
  • Form a C-shaped curvature in newborns
• Secondary curvatures


  • Spinal curvatures of the cervical and lumbar regions
  • Develop after birth
  • Form an S-shaped curvature in adults
• Common features of vertebrae

  • Body (centrum)
  • Vertebral arch
  • Pedicle
  • Lamina
  • Vertebral foramen
  • Transverse processes
  • Spinous process
  • Superior and inferior articular processes
• Thoracic cage


  • Bony thorax that protects organs of the thoracic cavity
  • Consists of sternum, ribs, and thoracic vertebrae
• Types of ribs


  • True ribs (pairs 1–7)
  • False ribs (pairs 8–12)
  • Floating ribs (pairs 11–12)
• Appendicular Skeleton


  • Composed of 126 bones
  • Includes limbs (appendages), pectoral girdle, and pelvic girdle

  
• Pectoral girdle


  • Also called shoulder girdle
  • Composed of clavicle and scapula
  • Allows the upper limb exceptional flexibility
• Humerus


  • Forms the arm
  • Proximal end articulates with the glenoid cavity of the scapula
  • Distal end articulates with the bones of the forearm
• Bones of the forearm

  • Ulna
  • Radius
• Bones of the hand

  • Carpals
  • Metacarpals
  • Phalanges

  
• Pelvic girdle


  • Formed by two coxal bones
  • Composed of ilium, ischium, and pubis
• Pelvis


  Protects reproductive organs, urinary bladder, and part of the large intestine
• Female pelvis


  • Inlet is larger and more circular
  • Shallower, with lighter and thinner bones
  • Ilia flare more laterally
  • Sacrum is shorter and less curved
  • Ischial spines are shorter and farther apart, resulting in a larger outlet
  • Pubic arch is more rounded due to a greater angle
• Femur


  • The heaviest, strongest bone in the body
  • Proximal end articulates with the acetabulum of the coxal (hip) bone
  • Distal end articulates with the tibia in the lower leg
• Bones of the lower leg

  • Tibia
  • Fibula
• Bones of the foot

  • Tarsals
  • Metatarsals
  • Phalanges

  
• Arches of the feet

  Bones of the foot are arranged to form three strong arches: two longitudinal and one transverse