LO5

• How is the skeletal system classified?

  - Axial skeleton (bones along the body's central axis: skull, vertebral column, and ribcage)

  - appendicular skeleton (limbs (arms and legs) and bones that connect them to axial skeleton (shoulder girdle and pelvic girdle))
• What are the main features of the sphenoid bone?

  Body, greater wings, lesser wings, sella turcica, sphenoidal sinuses, pterygoid process, foramina
• Name the bones that form the orbital foramen.

  Sphenoid bone (lesser wing), frontal bone (superior part of orbital foramen)
• Foramen


  round or oval opening through a bone
• Crest


  A raised or prominent part of the edge of a bone
• Ramus


  armlike bar
• Process


  any bony prominence
• Condyle


  A round, protruding part at the end of a bone
• What are the functions of paranasal sinuses?

  - Lighten the skull

  - Enhance resonance of voice

  - Moistening and warming air

  - Protection (cushioning of impt. structures)

  - Immune defense (sinuses produce mucus, which traps and removes bacteria)
• List three major differences between the male and female skulls.


  - Size and shape: male skulls are larger and have wider/broader features

  - Male skulls tend to have more prominent and pronounced brow ridges (supraorbital ridge) compared to female skulls

  - Male skulls tend to have larger and more square-shaped/skull mandibles
• Foramen magnum


  opening through which the spinal cord passes from the brain into the spinal canal.
• Foramen ovale


  one of the several foramina (openings) in the skull that allows for the passage of nerves, specifically the mandibular nerve
• Jugular foramen


  passage for several important structures, including the internal jugular vein
• Stella turcica


  contains the pituitary gland
• Optic canal


  passage for the optic nerve
• Mastoid process


  attachment site for several muscles of the neck and head
• Mental foramen


  allows for the passage of blood vessels and nerves that supply sensation to the chin and lower lip
• Mandibular foramen


  point of entry for the inferior alveolar nerve and blood vessels, which supply sensation to the lower teeth and gums
• Superior orbital fissure


  passageway for several important structures, including nerves that control eye movement
• Dens


  pivot point around which the atlas and the skull rotate
• Cribriform plate


  contains perforations for olfactory nerve fibers, transmitting smell sensations from the nose to the brain
• What are the primary and secondary curvatures of the vertebral column?

  Primary curvature: Thoracic and sacral curvature

  Secondary curvature: cervical and lumbar curvature
• Scoliosis


  abnormal lateral curve
• Kyphosis


  hunchback
• Lordosis


  swayback
• What are floating ribs, false ribs and true ribs?


  True ribs: 1st-7th- directly attach to the sternum

  False ribs: 8th-12th- One common attachment to sternum only

  Floating ribs: 11th and 12th- not attach directly to the sternum
• What are the main differences between a male and female pelvis?


  - Pelvic inlet is wider in female pelvis

  - Pubic arch bigger in males than in females

  - Thicker bones in males due to testosterone

  - Acetabula is smaller in females than males

  - Coccyx is more movable/straight in females, and less movable/curves ventrally in males
• What structural feature allows more mobility in the shoulder (relative to the hip)?

  The bone and socket cavity is a lot more shallow relative to the hip. The acetabulum is a lot deeper. The shoulder also has fewer ligaments than the hip. In general, mobility and stability are inversely related, so the as stability goes up, mobility goes up, and vice versa.
• What are the main structures of the coxal bone?

  Ilium: forms the superior region of the hip bone and joins the pubis

  Ischium: forms the posterior and inferior section of the hip bone

  Pubis: forms the front part of pelvic girdle
• Which bones form the pelvic girdle?


  The two hip bones (each hip bone is composed of three fused bones: the ilium, ischium, and pubis), sacrum, and coccyx form the pelvic girdle
• Describe the general structure of an intervertebral disc.

  - Nucleus pulposus: Inner gelatinous nucleus that gives the disc its elasticity and compressibility

  - Anulus fibrosis: Outer collar composed of collagen and fibrocartilage
• How are joints classified?

  Functional vs. structural classifications
• What are the structural classifications of joints?

  fibrous, cartilaginous, synovial
• fibrous joints, characteristics

  - Bones joined by dense fibrous connective tissue

  - No joint cavity

  - Most are synarthrotic (immovable)

  - Three types: sutures, syndesmosis, gomphosis
• cartilaginous joints, characteristics

  - Boned united by cartilage

  - No joint cavity

  - Two types: synchondrosis, symphysis
• synovial joints, characteristics

  - All are diarthrotic

  - Include all limb joints; most joints of the body

  Distinguishing features:

  1. Articular cartilage: hyaline cartilage

  2. Joint (synovial) cavity: small potential space

  3. Articular (joint) capsule

  4. Synovial fluid

  5. Reinforcing ligaments

  6. Rich nerve and blood vessel supply
• Friction reducing structures of synovial joints


  - Bursae: flattened, fibrous sacs containing synovial ligaments, muscles, skin, tendons or bones

  - Subacromial bursa

  - Tendon sheath: elongated bursa that wraps completely around
• Stabilizing Factors at Synovial Joints

  - Shapes of articular surfaces (minor role)

  - Ligament number and location (limited role)

  - Muscle tone, which keeps tendons that cross the join taunt

  --> Extremely important in reinforcing shoulder and knee joints and arches of the foot
• Muscle attachments across a synovial joint (2)

  - Origin- attachment to the immovable bone

  - Insertion- attachment to the movable bone
• List the functional classifications of joints. What characterizes each?


  Functional Classifications are based on amount of movement allowed by the joint.

  
  

  Three functional classifications:

  - Synarthroses: immovable

  - Amphiarthrosis: slightly movable

  - Diarthroses: freely movable