Bone Anatomy: Axial Skeleton Flashcards
Total number of bones in the axial skeleton
80 bones
Total number of bones in the skull
22 bones [8 acts as the braincase, 14 are facial bones]
Total number of bones in the auditory ossicles
6 bones
Total number of bones in the vertebral column
22 bones [7 in the cervical vertebrae, 12 in the thoracic vertebrae, 5 in the lumbar vertebrae, the other 2 being the sacrum and the coccyx]
Total bones in the thoracic cage
25 bones [24 consists the ribs, the other 1 is the sternum which is comprised of 3 parts]
Alternate name for the braincase or skull
Neurocranium
It encloses the cranial cavity; covers and protects the fragile brain tissue
Skull, braincase, neurocranium
The parietal and lateral walls of the cranium; coronal suture
Parietal bone (paired)
Lies inferior to the parietal bone; squamous suture
Temporal bone (paired)
Forehead, bony projections under the eyebrow, part of the eye’s orbit
Frontal bone
Inferior and posterior bone of the cranium; lambdoid suture
Occipital bone
Butterfly-shaped bone that spans the width of the skull
Sphenoid
Irregularly shaped bone that lies anterior to the sphenoid bone
Ethmoid
Alternate name for the facial bones
Viscerocranium
It consists of 14 bones; 13 solidly connected, 1 movable (mandible). It holds the facial muscles in place. It is joined together by sutures (interlocking, immovable)
Facial bones, Viscerocranium
Upper jaw, main bones of the face; carries the upper teeth
Maxillae bones (2)
Lies posterior to the palatine provesses of the maxilla
Palatine bones (2)
Cheekbones
Zygomatic bones (2)
Bones forming part of the medial wall of each orbit
Lacrimal bones (2)
Bones forming the bridge of the bone
Nasal bones (2)
Thin curved bones projecting from the lateral wall of the nasal cavity
Inferior Nasal Conchae (2)
Single jone in the median of the nasal cavity
Vomer bone
Lower jaw: only freely movable joint of the face
Mandible
Unpaired, U-shaped bone; not part of the skull & has no direct bong attachment to the skull or any other bones.
Provides attachment to tongue muscles; elevates the larynx during speech and swallowing
Hyoid bone
form a flexible, bony bridge that transmits vibrations
Auditory Ossicles
3 parts of the auditory ossicles
Malleus (hammer), Incus (anvil), Stapes (stirrup)
Central axis of the skeleton, consists of 26 individual bones, has 5 regions
Vertebral Column
C1-C7, curved anteriorly
very small bodies (except atlas)
Cervical vertebrae bones
Bone in the cervical vertebrae which hold the head, allows head to move up and down
Atlas
Bone in the cervical vertebrae that allows for rotation to occur, and lets the head to move left to right
Axis
T1-T12, curved posteriorly
long, thin spinous processes extra facets (because of the ribs)
Thoracic vertebrae bones
L1-L5; curved anteriorly
large, thick bodies & heavy, rectangular transverse & spinous process
Lumbar vertebrae bones
The other 2 bones in the vertebral column
Sacrum (S1-S5) & Coccyx
It protects the vital organs within the thorax. It prevents the collapse of the thorax during respiration.
Rib cage
How many pairs of ribs does a normal person have?
12 pairs [1-7 true ribs, 8-12 false ribs, 11-12 floating ribs)
Ribs that are attached directly to the sternum
True ribs (1-7)
Ribs that do not attach directly to the sternum
False ribs (8-12)
Ribs that do not attach to the sternum
Floating ribs (11-12)
Breastbone, resembles a sword, is divided into three parts
Sternum
Three parts of the sternum
Manubrium
Body
Xiphoid process
A depression bet, the ends of the clavicles where they articulate with the sternum
Jugular notch
A slight elevation felt at the junction of the manubrium and the sternum; important landmark because it identifies the 2nd rib
Sternal angle
The most superior part of the sternum and has a trapezoid shaoe
Manubrium
The largest part of the sternum, its shape is flat and elongated
Body of the sternum
The smallest and most inferior part of the sternum
Xiphoid process
