Week 2 - Skeletal System Flashcards
What are the parts of the Skeletal system?
- Bones
- Cartilage
- Joints
- Ligaments
What are the subdivisions of the skeleton?
- Axial
2. Appendicular
List the functions of the bones
- Support the body
- Protect soft organs
- Allow movement
- Store minerals and fats
- Blood cell formation (hematopoiesis)
How many bones does the adult skeleton have?
206
Describe the basic types of bones
- Compact
- Homogeneous
- Dense outer layer
- Spongy
- Porous. Filled with red or yellow bone marrow
- Small needle-like pieces of bone
What are the classifications of bones and give 1 example?
- Irregular
- E.g. skull
- Flat
- Skull
- Long
- Humerus
- Short
- Carpals
Describe the gross anatomy of a long bone (part 1)
- Diaphysis
- Is the tubular shaft
- Composed of compact bone
- Epiphysis
- End of the bone
- Composed of spongy bone
- Periosteum
- Outside covering of Diaphysis
- Perforating (Sharpey’s) fibers
- Attaches Periosteum to underlying bone
- Arteries
- Supplies bones with nutrients
- Endosteum
- Covers the trabeculae of spongy bone
Describe the gross anatomy of bone (part 2)
- Articular cartilage
- Covers external surface of epiphysis
- Decreases friction
- Epiphyseal plate
- Flat plate of hyaline cartilage
- Seen in young bones
- Epiphyseal line
- Remnant of epiphyseal plate
- Seen in adult bones
- Marrow (medullary) cavity
- A shaft which contains yellow marrow (mostly fat) in adults
Describe the microscopic anatomy of bone
- Osteon (Haversian system)
- A unit of bone (shaped like an optic fibre cable) with central canal and matrix rings
- Central (Haversian) canal
- Is the opening of the Osteon. The hollow part of an optical fibre cable
- Carries blood vessels and nerves
- Perforating (Volkmann’s) canal
- Perpendicular to central canal
- Carries blood vessels and nerves
- Lacuane
- Cavities containing bone cells (Osteocytes)
- Arranged in rings called lamellae
- Canaliculi
- Tiny canals found from the central canal to the lacunae
- Connects bone cells to a nutrient supply
Identify the types of bone cells
- Osteogenic cells
- Divides stem cells with periosteum and endosteum
- Osteoblasts
- Bone-forming cells
- Osteoclasts
- Giant bone-destroying cells
- Osteocytes
- Mature bone cells
Describe the formation of bone
In embryos, it’s mostly hyaline cartilage then it gets replaced with bone
Describe the process of Ossification
Epiphyseal plates permit lengthwise growth of bone.
New cartilage is continously formed and old cartilage becomes OSSIFIED. Meaning it’s decayed, opening up a medullar cavity. Bone takes it place through osteoblasts
Remodelling continues in response to
- Blood calcium levels
- Pull of gravity and muscles on skeleton
What are the types of bone fractures?
- Closed (simple). Doesn’t penetrate the skin
2. Open (compound). Pierces the skin
Describe the axial skeleton
- Forms the longitudinal axis of the body
- Divided into 3 regions:
- Skull
- Vertebral column
- Bony thorax
Name the cranial bones in the skull
- Frontal bone
- Parietal bones
- Temporal bones
- Occipital bone
- Sphenoid bone
- Ethmoid bone
Describe the vertebral column
- Composed of 24 single vertebral bones separated by discs
- 7 cervical vertebrae are in the neck
- 12 thoracic vertebrae are in the chest
- 5 lumbar vertebrae are in the lower back
- Provides attachment for muscle and ribs
- Protects spinal cord
Describe the different spinal curvatures and explain how they differ from one another
- Scoliosis
- Kyphosis
- Lordosis
Describe the sacral and coccygeal vertebrae
The sacral is the fusion of 5 vertebrae
The coccyx is the fusion of 3 - 5 vertebrae. The “tailbone”
Describe the thoracic and lumbar vertebrae
The thoracic articulates with the ribs, is body-heart shaped and is a long spinous process
The lumbar is massive kidney-shaped bodies and a prominent spinous processes for muscle attachment
Name the components of the thorax and their pair numbers
Firstly, the thorax is a cage which protects organs
Consists of the:
1. Sternum
2. Ribs
- True ribs (pairs 1-7)
- False ribs (pairs 8-12)
- Floating ribs (pairs 11-12)
3. Thoracic vertebrae
(There is diagram on S36 showing location of the true, false and floating ribs)
What segments is the Appendicular skeleton composed of?
It’s composed of 126 bones
- Limbs (appendages)
- Pectoral girdle
- Pelvic girdle
Identify the bones that form the pectoral girdle
- Clavicle - collarbone
2. Scapula - shoulder blade
Identify the bones of the upper limbs
The humerus forms the arm. Permits proximal & distal end articulation
The forearm has 2 bones
1. Ulna
- It's the medial bone
2. Radius
- Lateral boneDescribe the bones in the hand
Carpals - the wrist. Is 8 bones arranged in 2 rows of 4 bones
Metacarpals - palm. 5 per hand
Phalanges - fingers and thumb. 14 in each hand
Identify the bones of the pelvic girdle
It’s composed of 3 fused bones
- Ilium
- Ischium
- Pubis
- Sacrum
Identify the gender differences between the pelvis
- The female pelvis is lighter, thinner, and shallow
- The female pelvic inlet is larger and more oval
- The female ilia flare more laterally
- The female sacrum is shorter and less curved
- The female ischial spines are shorter and farther apart; thus the outlet is larger
- The female pubic arch is more rounded because the angle of the pubic arch is greater
Identify and describe the bones in the lower body
- Femur - thigh bone
- Heaviest & strongest bone
- Permits proximal and distal end articulation - Tibia - shinbone
- Larger than femur
- More medially oriented
- Permits proximal end articulation - Femur
- Thin stick shape
- Lateral to tibia
Identify the bones of the foot
Tarsals which consist of 7 bones (the 2 largest being the calcaneus and talus)
Metatarsals (of which are 5) form the sole of the foot
Phalanges - 14 bones
Identify the functional classification of joints
Synarthroses
– Immovable joints
Amphiarthroses
– Slightly moveable joints
Diarthroses
– Freely moveable joints
Identify the structural classification of joints
Fibrous joints
– Generally immovable
Cartilaginous joints
– Immovable or slightly moveable
Synovial joints
– Freely moveable
Describe fibrous joints
Are held by dense connective tissue Types 1. Sutures - Immobile 2. Syndesmoses - Limited/no movement 3. Interosseous membrane - Slight movement
Describe cartilaginous joints
2 types
- Synchrondrosis - Immobile
- Symphysis - Slightly movable
Describe synovial joints
Separated by joint cavity
Seen in the carpals and in the elbow
