Chapter 12 Flashcards
What are the divisions of the skeleton? What does each make up?
- axial: 80 bones; head, neck, and trunk
- appendicular: 126 bones; extremities and bones that attach them
- ex. shoulder, pelvis, clavicle
What are the two divisions of the skull?
- facial: 14 bones
- cranial: 14 bones
What are the functions of the skull?
- to protect and support the brain and special sense organs
- muscle attachment: 1. moves part of the head and 2. facial expression
- allows entrance of respiratory and digestive tract
- houses many smaller cavities
What cavities does the skull form?
-cranial cavity breaks down into: nasal cavity, orbits, paranasal sinuses
Which cavities house organs involved in hearing and equilibrium?
- cochlea
- semicircular canals
- vestibule
What bones make up the cranial group? Function
- frontal (1)- forms the forehead
- parietal (2)- sides and rood of cranial cavity
- temporal (2)- forms lateral aspects and floor of cranium
- occipital (1)- forms the posterior part and most base of the cranium
- sphenoid (1)- lies at the middle part of the base of the skull
- ethmoid (1)- located on the midline in the anterior part of the cranial floor medial to the orbits
What bones make up the facial group? Function
- nasal bone (2): forms bridge of the nose
- maxillae: upper jawbone and hard palate
- zygomatic bone (2): cheek bones
- lacrimal bone (2): medial wall of each orbit
- palatine bone (2): posterior portion of hard palate
- inferior nasal conchae: form part of the inferior lateral wall of the nasal cavity
- vomer: inferior portion of nasal septum
- mandible: lower jaw
- nasal septum: divides nasal cavity into r and l
- orbits: eye sockets
What bones make up the orbit?
- frontal bone
- sphenoid bone
- zygomatic bone
- nasal bone
- lacrimal bone
- ethmoid bone
- palatine bone (not seen)
What is the only moveable skull bone? What does it articulate with? What are its processes?
- mandible
- temporal bone and maxilla
- coronoid process: attachment to temporal muscle
- condylar process: in jaw joint
What is a foramen?
-openings for blood vessels, nerves, or ligaments
What are the unique features of the skull?
- sutures
- paranasal sinuses
- fontanels
What is a suture?
-an immovable joint that holf most skull bones together
What are the important sutures and where are they?
- coronal: unites frontal and parietal
- sagittal: unites parietals
- lambdoidal: unites occipital and parietal and temporal
- squamous: unites parietal and temporal
What is a paranasal sinus?
- cavity within the cranial and facial bones near the nasal cavity
- decrease skull weight
What are the important sinuses?
- frontal sinus
- sphenoidal sinus
- maxillary sinus
- ethmoidal air cells
What is a fontanel? Function?
-areas of unossified tissue
What does a fontanel become?
-a suture
What is the function of a fontanel?
- provides flexibility to the fetal skull
- allows skull to change shape as it passes through birth canal
What are the important fontanels?
- anterior fontanel
- posterior fontanel
- posterolateral fontanel
- anterolateral fontanel
What is the pterion?
- where many of the sutures meet
- weakest part of the skull
What is the hyoid bone? Unique? Function?
- the u-shaped bone in the neck
- does not articulate with any other bone
- supports tongue
- provides attachment sites for some muscles of the tongue, pharynx, and neck
- helps keep larynx open at all times
What are the other names for the vertebral column?
- spine
- backbone
- spinal column
What are the functions of the vertebral column?
- protect the spinal cord
- support the head
- point of attachment for ribs, pelvis, and muscles
- permits forward, backward, and sidewise movement
How many vertebrae are there? Each region
- 24 total
- 7 cervical
- 12 thoracic
- 5 lumbar
- 1 sacrum (5 fused)
- 1 coccyx (4-5 fused)
What are the curves of the vertebral column? Function?
- cervical and lumbar are anterior curves
- thoracic and sacrum/coccyx are posterior curves
- increase column strength
- maintain balance and upright position
- shock absorbers
What are the exaggerations of those curves?
- lordosis: lumbar are far anterior
- kyphosis: thoracic are far posterior
- scoliosis: moved left to right rather than front to back
What are the functions of each vertebral region?
- cervical: contains the dens which allows the head to rotate
- thoracic: articulates with the ribs
- lumbar: provides attachment of the large back muscles
- sacrum: strong foundation for the pelvic girdle
- coccyx: tailbone
What are the three general components of a vertebra?
- body: weight bearing
- vertebral arch: surrounding spinal cord
- several processes: point of attachment for muscles
What are intervertebral discs? Function?
- cartilage between the bodies of adjacent vertebrae
- forms strong joints
- permits various movements
- shock absorbers
What is the atlas?
- the first cervical vertebra
- big hole
What is the axis?
-the second cervical vertebra
What is the unique process of the axis? Function?
- has the dens
- allows the head to rotate
What are the three components of the thorax?
- sternum
- ribs
- costal cartilage
What is the sternum and what is it made up of?
- breastbone
- manubrium, body, and xiphoid process
How many ribs are there?
-12 pairs
What are true ribs?
-pairs 1-7: attaches directly to the sternum via costal cartilage
What are false ribs?
- pairs 8-12
- pairs 8-10: their cartilage attaches to the cartilage above
What are floating ribs?
-pairs 11-12: they do not attach to the sternum in any way
What is the function of costal cartilage?
-hyaline cartilage that contributes to the elasticity of the thoracic cage
