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
3 features of squamous part of temporal lobe
(skull-cranium-temporal-squamous part)
- squamous suture
- Zygomatic process
- Mandibular fossa
2 features of tympanic part of temporal bones
(skull-cranium-temporal-tympanic part)
- external acoustic meatus (ear canal)
- Styloid process (muscle attachment)
4 features of mastoid part of temporal bone
(skull-cranium-temporal-mastoid part)
- Mastoid process
- Mastoid notch
- Stylomastoid foramen
- Mastoid foramen
3 features of petrous part of temporal bone
(skull-cranium-temporal-petrous part)
- Internal acoustic meatus
- Carotid canal
- Jugular foramen
7 features of occipital bone
(skull-cranium-occipital)
- Foramen magnum
- Basilar part
- Occipital condyles
- Condylar canals
- Hypoglossal canal
- External occipital protuberance
- Superior/inferior nuchal lines
Sphenoid bone structure + 10 features
(skull-cranium-sphenoid)
Median body and greater and lesser wings.
- Optic canal
- Anterior clinoid processes
- Superior orbital fissure
- Sella turcica
- Foramen rotudum
- Foramen ovale
- Foramen spinosum
- Foramen lacerum
- Posterior nasal apertures
- Medial/lateral pterygoid plates
3 major portions of ethmoid bone
(skull-cranium-ethmoid)
- Perpendicular plate
- Cribriform plate
- Ethmoidal labyrinth
14 facial bones (8 unique)
- Maxillae (2)
- Palatine (2)
- Zygomatic (2)
- Lacrimal (2)
- Inferior nasal conchae (2)
- Nasal (2)
- Vomer (1)
- Mandible (1)
6 features of maxillae
(skull-facial-maxillae)
- Alveolar processes
- Alveoli
- Infraorbital foramen
- Inferior orbital fissure
- Palatine processes (hard palate)
- Incisive fossa
9 features of the mandible
(skull-facial-mandible)
- Body/ramus/angle
- Mental symphysis
- Mental protuberance
- Mental foramina
- Alveolar processes (between teeth)
- Condylar process (TMJ)
- Coronoid process
- Mandibular notch
- Mandibular foramen
7 (but list 2) bones associated with the skull but not part of it
- 6 Auditory ossicles
- Hyoid bone
Sesamoid + sutural bones
Sesamoid - Bones that form within tendons (patella)
Sutural - Extra bones which develop along suture lines.
4 fontanelles of infant brain + 2 purposes
- Anterior
- Posterior
- Sphenoid
- Mastoid
A. Allow shifting of head bones during brain growth
B. Allow for passage of head through birth canal