Skeletal System Flashcards
What is the anatomical position?
Head, feet, and palms facing forward.
What are the two skeleton divisions?
Axial and Appendicular Skeleton.
What does the Axial skeleton system consist of?
Skull
Hyoid bone
Vertebral column
Thoracic Cage
What does the appendicular skeleton consist of?
Limbs and bones that attach them to axial skeleton called girdles.
Pectoral and pelvic girdle.
How many groupings does the skull have and how many bones for each grouping?
3 main groupings.
Cranium (8 bones)
Facial Bones (14 bones)
Auditory ossicles (6 bones, 3 on each side)
What are the 8 bones in the cranium?
1 frontal 2 parietal 2 temporal 1 sphenoid 1 ethmoid 1 occipital
What are the 14 facial bones?
2 nasal 2 maxillae 2 zygomatic 2 lacrimal 2 palatine 2 inferior nasal conchae 1 vomer 1 mandible
What is the 3 vertebrae by region?
Cervical (7), Thoracic (T12), Lumber (L5).
What is the typical vertebral structure?
Body Spinous Process Transverse processes (2) - Lateral bone projections Laminae (2) - Connects the two processes Pedicles (2) - Connects body to transverse process Vertebral foramen - Opening for spinal cord Superior and Inferior Articular Processes - With Facets = Articular Surfaces - Articulate w/ Vertebrae above and below Intervertebral foramina - Exit for spinal nerves
What are the two atypical cervical vertebrae and their characteristics?
C1 and C2.
C1 = atlas
- No body and spinous process
- Allows nodding motion
C2 = axis
- Dens = odontoid process
- Allows shaking motion
Which way is the cervical and lumbar curved? What are the abnormal curvatures?
Concave posteriorly.
Curves laterally = Scoliosis
Exaggerated thoracic curve = Kyphosis
Exaggerated lumbar curve = Lordosis
What does the thoracic cage consist of?
Ribs and the sternum.
What and how many parts does the sternum consist of?
3 parts.
Manubrium = Superior
Body = middle
Xiphoid process = Inferior
What are the characteristics of the ribs?
Articulates with thoracic vertebrae.
7 pairs = true ribs
- Attaches directly to sternum via costal cartilage
5 pairs = false ribs (T8 - 12)
- Attach indirectly to sternum via costal cartilage (8 - 10) or not at all (11 - 12 are embedded into muscle)
What does the pectoral girdle consist of?
Clavicle and scapula.
What does the clavicle articulate with?
The clavicle articulates with the manubrium of the sternum and the acromion process of the scapula.
What are the characteristics of the scapula?
Located on the spine
Has 3 parts: Acromion process Glenoid fossa/cavity - Articulates with head of humerus Coracoid process - Attaches muscles for arm and chest
What does the pelvic girdle consist of?
Has two os coxae (hip bones) that have 3 bones:
Ilium = Articulates with sacrum Ischium = Most inferior part Pubis = Left and right joined by pubic symphysis
What are the 3 joints in pelvic girdle?
Pubic symphysis Sacroiliac joint - Sacrum and ilium Acetabulum - Articulates with head of femur - All 3 bones of ox coxae join here
What do long bones consist of?
Diaphysis = shaft Epiphyses = proximal and distal extremities Epiphyseal plate = Used for bone growth (length) Epiphyseal line = Replaces plate with bone when fully complete - Diaphysis and epiphysis meet here Medullary cavity - Red marrow in child, yellow in adult Periosteum - External surface Endosteum - Lines medullary cavity and canals Articular cartilage - Prevents friction between bones
What are the two bone types?
Spongy bone and Compact bone.
What are the characteristics of spongy bone?
No osteon
Have trabeculae (irregularly aranged lamellae)
Canalicular connect osteocytes in lacnunae
Found in flat and irregular bones
Long bones
Spaces containing bone marrow
What are the characteristics of compact bone?
Surface of all bones
Composed of osteons
What do osteon compose of?
Lamellae
- Arranged in concentric circles
Lacunae (w/ osteocytes)
- Between lamellae
Canaliculi
- Channels that connect osteocytes to blood supply and to other osteocytes
Central (Osteonic) Canal
- Blood vessels and nerves
Perforating (Interosteonic) Canals
- Perpendicular to central canal
- Carry blood supply from periosteum to central canals and medullary cavity
