Class 10 - The Skeletal System Flashcards
Bones found in the axial skeleton (6)
- Skull
- Vertebrae
- Sternum
- Ribs
- Sacrum
- Hyoid
Bone groups found in the appendicular skeleton (4)
- Pectoral girdle (clavicle, scapula)
- Upper extremity (humerus, radius, ulna, carpals)
- Pelvic girdle (hip bone, sacrum)
- Lower extremity (femur, patella, tibia, fibula, tarsals)
Average number of bones of adult and at birth
Adult: ~206
At birth: ~270, decrease with fusion (e.g. ilium, ischium, and pubis—>hip bone)
The skull + 6 cavities
22 bones joined by sutures (immovable joints).
- Cranial cavity - encloses brain
- Orbits - eye sockets
- Nasal cavity
- Oral cavity
- Middle and inner ear cavities
- Paranasal sinuses
4 sinuses + 2 purposes
- Frontal
- Sphenoid
- Ethmoid
- Maxillary
Purposes:
A. Lighten skull
B. Add resonance to voice
Foramina (sing: foramen)
Holes that allow passage for nerves and blood vessels
2 major categories of skull bones
- Cranial (enclose brain)
- Facial
Meninges
Membranes that separate brain from bones. Dura mater is thickest one.
Foramen magnum
Inferior opening of cranium where brain and spinal cord meet
2 parts of cranium
- Calvaria (skullcap)
- Base (floor)
3 paired depressions of cranial base (skull-cranium-base) + what part of brain they contain
- Anterior cranial fossa - frontal lobe of brain
- Middle cranial fossa - temporal lobes
- Posterior cranial fossa - cerebellum
What are the eight ( 6 unique) cranial bones?
(skull-cranium)
- Frontal (1)
- Parietal (2)
- Temporal (2)
- Occipital (1)
- Sphenoid (1)
- Ethmoid (1)
Frontal bone + 4 characteristics
Forms forehead and part of roof of cranium.
- Coronal suture - posterior boundary of frontal bone
- Supraorbital margin - ridge of bone deep to eyebrow
- Supraorbital foramen
- Glabella - smooth area above root of nose
Parietal bones + 4 sutures + 2 features
4 sutures:
1. Sagittal suture
2. Coronal suture
3. Lambdoid suture
4. Squamous suture
Features:
A. Parietal foramen
B. Superior and inferior temporal lines (attachment of temporalis muscle)
4 parts of temporal bones (skull-cranium-temporal)
- Squamous part
- Tympanic part
- Mastoid part
- Petrous part