Chapter 8: The Skeletal System Flashcards
2 Regions of Skeletal System
Axial
Appendicular
How many Bones?
Infant?
206
infant:270
Sesamoid Bones
form within some tendons in response to strain
Sutural Bones
extras bones in skull
Condyle
rounded knob
Head
expanded end of a bone
Process
any bony prominence(projection)
Tubercle
small rounded process
Spine
Sharp, narrow process
Fossa
Shallow and broad depression or basin
Passages and Cavities
Canal
Foramen
Sinus
Canal
Tubular Passage
Foramen
hole through a bone
Sinus
air filled space in a bone
Skull
Most complex part of the skeleton
Contain: Cranial Cavity Orbits-eye sockets Nasal Cavity Paranasal Sinuses Oral cavity Middel & Inner ear cavities
Cranial Bones(8)
Enclose the Brain Sphenoid Temporal(2) Ethmoid Parietal(2) Occipital Fromen Magnum Frontal
Fromen Magnum
large whole where spinal cord meets the brain
Frontal Bone
extends from inside eye orbits to coronal suture
forms anterior wall(FROEHEAD)
Parietal Bones(2)
Form most roof and walls of cranium
bordered by 4 sutures
Temporal Bones(2)
forms lower wall and part of floor
Occipital Bone
forms rear skull and part of base
contains foramen magnum
Sphenoid Bone
forms lower front wall and part of base
butterfly shaped, back of eyes
Ethmoid Bone
Between eyes, superior half of nasal septum
forms upper base
Facial Bones(14) ZIP LVN MM
lie anterior to the cranial cavity
Zygomatic(2) Inferior Nasal(2) Palatine(2) Lacrimal(2) Vomer(1) Nasal(2) Maxillae(2) Mandible
Maxillae(2)
Largest facial bones(form upper jaw)
extend from teeth to eye orbits
Palatine Bone(2)
L shaped, located in the posterior nasal cavity
under vomer, behind maxilla
Zygomatic Bones(2)
From Angles of the cheeks
extend halfway to ear
Lacrimal Bones(2)
Part of the medial wall of eye orbits
smallest bone in the skull(tear ducts)
Nasal Bones(2)
form bridge of nose
Inferior Nasal Conchae(2)
behind nose, under ethmoid bone
Vomer(1)
inferior half of the nasal septum
Mandible(1)
Strongest bone in the skull- LOWER JAW
Foramina
holes that allows passage for nerves and blood vessels
4 types of Paranasal Sinuses
FEMS
Frontal
Ethmoid
Maxillary
Sphenoid
Characteristics of Paranasal Sinuses
Lined by mucous membranes, air filled
add resonance to voice
Lighten Skull
Auditory Ossicles
3 in each ear, they make up ear cavity
malleus, incus, and stapes
Hyoid Bone
U shaped, between chin and larynx
attachment for muscles that control tongue, mandible and larynx
When do Bones Fuse
in the first 2 years
not fused at birth
Fontanelles
space between unfused cranial bones
contain fibrous membrane, and allow shifting of bones during birth and growth
Skull Growth during Childhood
more rapid then rest of skeleton
- 1/2 adult size by 9 months
- Final size at 8 or 9 yrs
Vertebral Column supports…
Skull and Trunk
Vertebral Column provides attachment for…
limbs-thoracic cage-postural muscles
Vertebral Column consists of…
chain of 33 vertebrae with intervertebral discs of fibrocartilage
5 groups of Vertebrae
Thoracic Lumbar Cervical Coccygeal Sacral
Cervical #
Neck, 7 vertebrae
Thoracic #
Chest, 12 vertebrae
Lumbar #
Lower Back, 5 verterae
Sacral #
Base of Spine, 5 fused vertebrae
Coccygeal #
Tailbone, 4 fused vertebrae
What has a C shaped spine
Newborns- till about age 3
Monkeys, apes, and other four legged animals
4 Bends in a S Shaped Spine
Cervical- Neck
Thoracic- Chest
Lumbar- Lower back
Pelvic- Tailbone
Causes of Spine Curvatures
disease- weakness- paralysis of trunk muscles- poor posture- pregnancy
Scoliosis
most common– abnormal lateral deviation
Kyphosis
hunchback/ widows hump–result of osteoporosis
Lordosis
swayback/ exaggerated lumbar curvature–due to large abdominal weight(pregnancy, obesity)
Body of Vertebra
spongy bone(w/ red marrow) covered in shell of compact bone *weight bearing portion
Vertebral Foramina
collectively form canal for spinal cord
Spinous Process
projects from arch, visible under skin
Intervertebral Discs
Gelatinous pad covered in fibrocartilage that binds vertebrae- helps absorb shock and support weight
Herniated Disc
(ruptured of slipped)-puts painful pressure on spinal nerve or cord
Cervical Vertebrae
small, light
Function: supports the head, allows for movement
Spinous process:forked
Thoracic Vertebrae
correspond to 12 ribs
Function: support the thoracic cage
Spinous Process: pointed, angled downward
Body: slightly heart shaped
Lumbar Vertebrae
thick, stout body W/ blunt/squarish process
Function: support abdominal cavity; resist twisting of spine
