CH7 Flashcards
Axial Skeleton
80 bones
includes the the skull (cranial bones and facial bones), the vertebral column, the hyoid bone (floating bone in throat), the sternum, and the ribs.
Protects spinal cord, brain and visceral organs
Appendicular Skeleton
126 bones
consists of the bones of the upper limbs, the lower limbs, the pectoral girdle, and the pelvic girdle.
Facilitates movement
What bones dose the vertebral column consist of?
24 vertebrae + sacrum and coccyx
Cervical
C1-C7, 7 bones
7am
Thoracic
T1-T12, 12 bones
* Spinous process is long and overlap next inferior vertebrae (looks like an elephant trunk)
* Articulation sites - facets for rib attachment
12pm lunch
Lumbar
L1-L5, 5 bones
* Strongest, largest, thick body and short, rounded spinous process
* Takes on the weight of the body
5pm dinner
Sacrum
- Formed from the fusion of 5 sacral vertebrae, whose lines of fusion are indicated by the transverse processes
- Fuses between 13-30 yr old
Coccyx
Formed by the fusion of 4 small coccygeal vertebrae
Special features of C21 C2 (and movements)
- C1 (Atlas) - does not have a body or spinous process. Helps with head rotation nodding
- C2 (Axis) - has upward projection dens, helps with head rotation shaking head no
- They both help with head rotation (nodding, shaking head no)
Differentiate b/t cranial bones and facial bones
Cranial bones compose the top and back of the skull and protect the brain. The facial bones are made up of the eye sockets, nose and jaw - involved in sensory function
True ribs
ribs directly attached; ribs 1-7
False ribs
not attached/or indirectly attached by costal cartilage; 8-12
Floating
don’t directly attach to sternum; 11-12
* Originates to thoracic verterbral column
Common foramens of skull
Mental foramen (chin), mandibular foramen, supraorbital (above eye), infraorbital (below eye), magnum foramen (passageway for spinal cord)
Hyoid bone
- Located in the upper neck (throat).
- Does not join another bone.
- Provides attachment for muscles that act on the tongue, larynx, and pharynx.
- It aids in tongue movement and deglutition (swallowing)
Paranasal Sinuses
- Paranasal sinuses are cavities in the skull lined with mucous membranes.
- Helps with resonating speech. (speech changes when we have a cold/sinuses)
- Paranasal sinuses include: Frontal, Sphenoid, ethmoid, maxillae
Sinusitis
sinuses are inflamed because of allergies or infection
Nasal septum
Nasal septum divides nasal cavity into left and right sides
* Formed by the perpendicular plate of the ethmoid bone and vomer bone
Septal cartilage
fills the gap between and extends into the nose
Deviated septum
difficulty breathing, obstructs nasal airway
Hard palate
separates the oral cavity from the nasal cavities, forming the floor of the nasal cavity and the roof of the oral cavity
* comprised of two facial bones: the palatine process of the maxilla and the paired palatine bones
Intervertebral discs
padding b/t each vertebrae. Disc consists of fibrous outer layer called the annulus fibrosus and a gel-like center called the nucleus pulposus
Intervertebral foramen
exit for spinal nerve
Annulus Fibrosis
Outer portion of disc. Tougher layer
Nucleus Pulposus
Inner portion; composed of water, collagen, and proteins
Bone formation
ossification
Fontanelles
Soft spots of a newborn skull that are not fully ossified, filled with fibrous connective tissue
* Allows for continued growth of skull after birth
2 major fontanelles
Anterior and Posterior fontanelle
Anterior
The anterior fontanelle remains soft until about 18 months to 2 years of age
Posterior
junction of the 2 parietal bones and the occipital bone. Closes first (before anterior fontanelle) closure happens during the first several months (of an infant’s life)
Bones make up eye socket
7 bones that make up the orbit
Frontal, sphenoid, zygomatic, maxilla, nasal, lacrimal, ethmoid, palatine bones
Osteoblasts
secrete osteoid and stimulate calcium phosphate deposition. Create new bone tissue, strengthen bones, and repair breaks
Osteocytes
mature bone cells that maintain the matrix and initiate remodeling maintain bone health
Osteoclasts
large, multinucleated cells that break down bone matrix, comes from bone marrow
Chondrocytes
the cells responsible for cartilage formation and part of ossification
Shoulder girdle
consists of the clavicle and scapula, which serve to attach the upper limb to the sternum of the axial skeleton
Parts of the clavicle
- Medial - sternal attachment that attaches to the manubrium (sternum) and first rib
- Middle - most common fracture site. Caused by direct hit or FOOSH- fall on outstretched hand
- Lateral - acromial end, attaches to acromion head of scapula
Skull bone sutures
immovable joints, found between the skull bones (holding skull bone stogether)
4 Main Sutures:
Coronal: separates Frontal and Parietal bones
Sagittal: separates the two parietal bones
Lamboid: between the occipital and parietal bones
Squamous: between the temporal and Parietal bones
Zygomatic arch
Formed jointly by zygomatic process of temporal bone and temporal process of zygomatic bone
Part of your cheekbone that sits underneath temples
Temporal bone
contains the squamous, mastoid and zygomatic portions of the temporal bone
Sphenoid
connects all cranial bones and has multiple openings for the passage of nerves and blood vessels
* Forms anterior walls and floor of middle cranial fossa
Key stone bone
Ethmoid
unpaired and located at the midline of skull
Has an upward projection the crista galli and a downward projection the perpendicular plate
Cribriform plates
form the roof of nasal cavity and portion of anterior cranial fossa floor
Bony structures that protect the eyeball
Supraorbital margin, nasal bone, zygomatic process
Herniated disc
- Protrusion of the nucleus pulpsus (within the vertebral disc).
- Typically happens by bending anteriorly and laterally forward, causing additional pressure and squeezing on the vertebral disc. Nucleus Pulposus pops out putting pressure on the spinal nerve. Causing pain!
- Typically this occurs at the L3-L4 level
Curvatures of the spine
- Primary curvatures - thoracic and sacrococcygeal
- Secondary curvatures- cervical and lumbar
Abnormal curvatures of the spine
- Scoliosis - abnormal lateral bending of vertebral column
- Kyphosis - excessive curvature of upper thoracic spine
- Lordosis - excessive curvature in lumbar region
- Osteoporosis - age-related disorder that causes gradual loss of bone density and strength. Can cause kyphosis
Fetal development of curvatures
- The fetus of a baby has one curvature (anteriorly concave curve)
- Baby: at 5 months old a baby can hold its head up (with no head lag). Cervical Curvature develops.
- Lumbar curve develops as walking begins.
- The four normal curves are fully developed by 10 years old.
foramen magnum
largest hole - allows access for spinal cord to the brain
Sinus cavities
Frontal, sphenoid, ethmoid, maxillary
Mandible
Mental foramen, mandibular condyle, notch, coronoid process, mandibular foramen
Supraspinous ligament
runs down spinous processes
Thoracic Cage
Manubrium, sternum body, xiphoid process
