Axial skeleton Flashcards
How many bones are in the axial skeleton and what are the main groupings?
80 bones. Skull, Spine, chest, and hyoid
How many bones are in the skull?
22 + 6 ear ossicles.
How many bones are there in each region of the skull
-8 cranial bones
-14 facial bones
-Top part of the skull
-Cavity that holds the eyes and their appendages
-Calvaria
-Orbit
What are the cranial bones and how many are there of each?
-Frontal bone (1)
-Parietal bones (2)
-Occipital bone (1)
-Temporal bones (2)
-Sphenoid bone (1)
-Ethmoid bone (1)
Forehead bone, forms the upper part of the eye socket
Frontal bone
What are these and where are they found?
1. Superior boundary of the orbit
2. ridge superior to the eye socket
3. slight depression the joins the brow ridge
4. rounded elevation on the frontal bone
5. sinus within the frontal bone
Features of the frontal bone.
1. Supraorbital margin
2. Superciliary arch
3. Glabella
4. Frontal eminence
5. Frontal sinus
Form the top sides of the cranium
Parietal bones
- Slight eminence in the center of each parietal bone
Feature of the parietal bone.
1. Parietal eminence
Forms the back of the skull
Occipital bone
What are these and where are they found?
1. Rounded knobs that form a joint with the first cervical vertebrae
2. Opening where the spinal chord enters the cranium
3. Bony prominence in the middle of the occipital bone where the posterior wall meets the base of the skull
Features of the occipital bone.
1. Occipital condyles
2. Foramen magnum
3. External occipital protuberance
Inferior and lateral portion of the cranium
Temporal bones
What are these the divisions of and where?
1. Squamous portion
2. Petrous portion (what does this house?)
Temporal divisions.
1. Anterior/ superior
2. Posterior/ inferior. Houses the inner eat components and the Carotid canal
The passageway in the temporal bone which the inner carotid artery passes
Carotid canal
What are these and how many?
1. Hammer shaped bones
2. Anvil shaped bones
3. Stirrup shaped bones
Inner ear ossicles
1. Malleus (2)
2. Incus (2)
3. Stapes (2)
What are these and where are they found?
1. Projection at the base of the temporal bone
2. The depression in the temporal bone into which the condyle of the mandible fits
3. the lateral, outer opening of the ear or auditory canal
4. process projecting from the lower squamous portion articulating with the temporal process on the zygomatic bone forming the zygomatic arch
Features of the temporal bones.
1. Mastoid process
2. Mandibular fossa
3. External auditory meatus
4. Zygomatic process
Forms the central part of the cranial floor
Sphenoid bone
What are these and where are they found?
1. Depression in the floor of the sphenoid bone (contains the pituitary gland)
2. Sinuses within the sphenoid bone
Features of the sphenoid bone
1. Sella turcica
2. Sphenoidal sinuses
Anterior skull bone that forms parts of the cranial floor, nasal septum, and parts of the nasal cavity
Ethmoid bone
What are these and where are they found?
1. Forms the roof of the nasal cavity
2. Anterior triangular wedge projecting superiorly into the cranial cavity
3. Flat plate extending from under the cribriform plate
4. Sinuses within the ethmoid bone
Features of the ethmoid bone.
1. Cribriform plate
2. Crista galli
3. Perpendicular plate
4. Ethmoid sinuses
What are the facial bones and how many are there of each?
-Nasal bones (2)
-Lacrimal bones (2)
-Zygomatic bones (2)
-Palatine bones (2)
-Maxillary bones (2)
-Vomer (1)
-Inferior nasal conchae (2)
-Mandible (1)
Form the upper part of the bridge of the nose
Nasal bone
Inner-cranial bone that forms the medial wall of the eye socket
Lacrimal bones
Cheek bones
Zygomatic bones
What is this and where is it found?
1. Projection that articulates with temporal bone at the zygomatic process forming the zygomatic arch
Feature of the zygomatic bones.
1. Temporal process
Form the posterior roof of the mouth and part of the nasal cavity and eye orbit
Palatine bones
-upper jawbone forming part of the roof of the mouth, the floor and side walls of the nasal cavity, and the floor of the orbit
-Nasal spine ofc the ___ marks the base of the nose
-Frontal process of the ___ forms the lateral boundary of the nose
Maxillary bones
What are these and where are they found?
1. Bony blade-like process on the nasal surface of the maxilla that connect with the palatine bone
2. Thick ridges of bone that contain the tooth sockets
3. Sinuses within the maxillary bones
Features of the Maxillary bones.
1. Palatine process
2. Alveolar process
3. Maxillary sinuses
Ridges in the wall of the nasal cavity
Inferior nasal conchae
Forms the posterior portion of the nasal septum
Vomer
Lower jawbone
Mandible
What are these and where are they found?
1. Where the left and right side of the mandible meet
2. Thick ridges of bone that contain the tooth sockets
Features of the mandible.
1. Mental eminence
2. Alveolar process
What are these the divisions of?
-Ramus (vertical process)(coronoid process is an attachment point for masseter and temporalis muscles: Mandibular condyle articulates with the temporal bone)
-Angle
-body
Mandible
What is the bone and how many are there?
-U-shaped bone in the neck
-Anchor for the tongue
-Unarticulated
Hyoid bone (1)
What are the bones of the vertebral column and how many are there?
Vertebral column (26)
-Cervical vertebrae (7)
-Thoracic vertebrae (8)
-Lumbar vertebrae (5)
-Sacrum (1)
-Coccyx(1)
-Most superior 7 vertebrae
-C1-C7
-C1 = Atlas
-C2 = Axis
Cervical vertebrae
-12 bones between the cervical and lumbar vertebrae
-T1-T12
Thoracic vertebrae
-Most inferior vertebrae
-Connect to the sacrum
-L1-L5
Lumbar vertebrae
Bone of the lower vertebral column between L5 and the coccyx
Sacrum
Last bone of the vertebral column
Coccyx
What is the bone and how many are there?
Breastbone
-Manubrium
-Body
-Xiphoid process
Sternum
-Superior portion
-Main portion
-Small, inferior portion that points downward
What are the bones in the ribs and how many are there?
Ribs (24 / 12 pairs)
-True ribs (14 / 7 pairs)
-False ribs (10 / 5 pairs)
What are these?
-14 bones, 7 pairs
-Connect to the spine posteriorly
-Connect directly to the sternum anteriorly
True ribs
What are these?
-10 bones, 5 pairs
-Ribs 8-10 connect to the spine posteriorly and the costal cartilage anteriorly
-Ribs 11-12 are “floating ribs” that connect to the spine posteriorly and have no attachment anteriorly
False ribs
