Lab: Exercise 8: The Axial Skeleton
The vertebral column consists of _______ single vertebrae
24
How many lumbar vertebrae are there?
5
How many cervical vertebrae are there?
7
List the important markings of the maxillae
Alveolar process Palatine processes
True or False The first seven pairs of ribs are called floating ribs because they have only indirect cartilage attachments to the sternum
False The first 7 pairs of ribs are called true ribs and they have a direct attachment to the sternum by their own costal cartilages
Ribs 8 - 12 are called ______ ______ because these ribs have indirect cartilage attachments to the sternum
False Ribs
Lacrimal Bone
Fingernail-sized bones forming a part of the medial orbit walls between the maxilla and the ethmoid. Each lacrimal bone has an opening that serves as a passageways for teas.
The sternum is attached to the:
First 7 pairs of ribs
Ribs pairs 11 - 12 are called ______ ______ that have no sternal attachment
Floating Ribs
Large opening in base of occipital that allows the spinal cord to join with the brain
Foramen Magnum
List the important markings of the occipital bone:
Foramen Magnum Occipital Condyles
Opening posterior to the sella turcica that allows a branch of cranial nerve V to pass
Foramen Ovale
Palatine Processes of Maxillae
Form the anterior hard palate
Anterior portion of cranium; forms the forehead, superior part of the orbit, and anterior part of cranial floor
Frontal Bone
Occurs where the parietal bones meet the occipital bone posteriorly
Lambdoid Suture
How many thoracic vertebrae are there?
12
Zygomatic Process
A bridgelike projection that joins the zygomatic bone (cheekbone) anteriorly. Together these two bones forms the zygomatic arch.
Sella Turcica
A saddle-shaped region in the sphenoid midline that nearly encloses the pituitary gland
Inferior margin containing sockets (alveoli) in which teeth lie
Alveolar Process of the Maxillae
Sacrum: The winglike ______ articulate laterally with the hip bones, forming the sacroiliac joints
Alae
Optic Canal
Allows the optic nerve (cranial nerve II) to pass
Superior margin of mandible; contains sockets for the lower teeth
Alveolar Process of Mandible
Frontal Bone
Anterior portion of cranium; forms the forehead, superior part of the orbit, and anterior part of cranial floor
The ______ (C1) lacks a body, and tis lateral processes contain large depressions o their superior surfaces that receive the occipital condyles of the skull. This joint enables you to nod
Atlas
This joint enables you to nod yes
Atlas
______ _______ is made up of three parts: The skull The vertebral column The bony thorax
Axial skeleton
The ______ (C2) acts as a pivot for rotation of the atlas (and skull) above. Its large vertical process, the dens, acts as the pivot point.
Axis
Sphenoid Bone
Bat-shaped bone forming a lateau across the width of the skull. The sphenoid bone can be seen in its entire width if the top of the cranium is removed
Lesser Wings
Bat-shaped portions of the sphenoid anterior to the sella turcica.
Vomer
Blade-shaped bone in median plane of nasal cavity that forms most of the nasal septum
Choose the correct term: The body/spinous process of a typical vertebra forms the rounded, central portion that faces anteriorly in the human vertebral column.
Body
Structure of a Typical Vertebra Rounded central portion of the vertebra; faces anteriorly in the human vertebral column
Body
List the important markings of the mandible:
Body Ramus Alveolar Process
What are the common features of all vertebrae?
Body Vertebral Arch Vertebral Foramen Transverse Processes Spinous Process Superior and inferior articular processes
Horizontal portion; forms the chin
Body of the mandible
Cribriform Plates
Bony plates lateral to the crista galli through which olfactory fibers pass to the brain from the nasal mucosa
The ______ ______ is composed of the sternum, ribs, and thoracic vertebrae
Bony thorax
The axial skeleton is made up of the skull, the vertebral column, and the:
Bony thorax
External Acoustic Meatus
Canal leading to eardrum
The ______ results from the fusion of three to five small, irregularly shaped vertebrae
Coccyx
What are the two major regions of the intervertebral discs?
Central gelatinous regioni that behaves like a fluid and An outer ring of tough collagen fibers that stabilize the disc
The transverse processes of the ______ vertebrae contain foramina through which the vertebral arteries pass superiorly to the brain. Any time you see these foramina in a vertebra, you can be sure that it is a ______ vertebra
Cervical
The vertebral foramen of these vertebrae is triangular and the spinous process is short and often bifid, or split into two branches
Cervical Vertebrae
Structure of a Typical Vertebra Vertebral Arch:
Composed of pedicles, laminae, and a spinous process, it represents the junction of all posterior extensions from the vertebral body
What shape is the bony thorax?
Cone-shaped
Located where the parietal bones articulate with the frontal bone
Coronal Suture
Eight bones make up the ______, which encloses and protects the brain
Cranium
Bony plates lateral to the crista galli through which olfactory fibers pass to the brain from the nasal mucosa
Cribriform plates
Vertical projection to which the dura mater (outermost membrane covering the brain) attaches
Crista Galli
List the important markings of the ethmoid bone:
Crista Galli Cribriform Plates Superior and middle nasal conchae
Irregularly shaped bones anterior to the sphenoid. Forms the roof of the nasal cavity, upper nasal septum, and part of the medial orbit walls
Ethmoid Bone
_______ Bone: Crista Galli Cribriform Plates Superior and middle nasal conchae
Ethoid
Canal leading to eardrum
External Acoustic Meatus
Portions of the sphenoid seen exteriorly on the lateral aspect of the skull, anterior to the temporal bones. Form part of the orbit of the eyes.
Greater Wings
List the important markings of the Sphenoid Bone:
Greater wings Sella turcica Lesser Wings Foramen ovale Optic Canal Superior orbital fissure
The thoracic cage protects the:
Heart and Lungs
Body of the Mandible
Horizontal potion; forms the chin
The ______ bone is not really considered or counted as a skull bone. Located in the throat above the larynx, it is the point of attachment for many tongue and neck muscles. It is horseshoe-shaped with a body and two pairs of horns, or cornua
Hyoid
Alveolar Process of Maxillae
Inferior margin containing sockets (alveoli) in which teeth lie
Temporal Bone
Inferior to parietal bone on lateral part of the skull
Where is the hyoid bone located?
In the throat above the larynx, it is the point of attachment for many tongue and neck muscles
Thin curved protruding medially from the lateral walls of the nasal cavity; serve the same purpose as the nasal conchae of the ethmoid bone
Inferior Nasal Conchae (Turbinates)
Define: Sutures
Interlocking joints
The individual vertebrae are separated by pads of fibrocartilage, ______ ______, that absorb shocks while providing the spine flexibility
Intervertebral Discs
Ethmoid Bone
Irregularly shaped bone anterior to the sphenoid. Forms the roof of the nasal cavity, upper nasal septum, and part of the medial orbit walls.
Fingernail-sized bones forming a part of the medial orbit walls between the maxilla and the ethmoid. Each of these bones has an opening that serves as a passageways for tears
Lacrimal Bone
Foramen Magnum
Large opening in base of occipital that allows the spinal cord to join with the brain
The 12 thoracic vertebrae (T1 through T12) have a ______ body than the cervical vertebrae
Larger
Zygomatic Bone
Lateral to the maxillae; forms the part of the face commonly called the cheekbone, and part of the lateral orbit
Bat-shaped portions of the sphenoid anterior to the sella turcica
Lesser Wings
What is the function of the paranasal sinuses?
Lighten facial bones and may act as resonance chambers for speech
Coronal Suture
Located where the parietal bones articulate with the frontal bone
These vertebrae have massive bocklike bodies and short, thick, hatchet-shaped spinous processes extending directly backward. Because the lumbar region is subjected to the most stress, these are also the sturdiest o the vertebrae
Lumbar
Choose the correct term: The lower jawbone, or maxilla/mandible, articulates with the temporal bones i the only freely moveable joint in the skull
Mandible
Only the _______, or lower jawbone, is attached to the rest of the skull by a freely movable joint
Mandible
The lower jawbone; articulates with the temporal bones in the only freely movable joints of the skull
Mandible
_______ Body Ramus Alveolar Process
Mandible
The ______ looks like the knot of a tie; ir articulates with the clavicle laterally
Manubrium
The sternum is a result of the fusion of three bones - from superior to inferior:
Manubrium Body Xiphoid Process
Rough projection inferior and posterior to external auditory meatus; an attachment site for muscles.
Mastoid Process
Two bones fused in a median suture; form the upper jawbone and part of the orbits. All facial bones, except the mandible, join the maxillae. Thus they are the main, or keystone, of the face
Maxillae
_______ Alveolar Process Palatine Pcesses
Maxillae
What are the four skull bones that contain sinuses?
Maxillary Sphenoid Ethmoid Frontal
What is the largest of the paranasal sinuses?
Maxillary Sinus
Sacrum: The ______ ______ ______ is a remnant of the spinous processes of the fused vertebrae
Median sacral crest
Palatine Bone
Paired bones posterior to the palatine processes; form the posterior hard palate nad part of the orbit
Small rectangular bones forming the bridge of the nose
Nasal Bone
Styloid Process
Needlelike projection inferior to external auditory meatus that serves as an attachment point for muscles and ligaments of the neck. This process is often broken off demonstrations skulls.
_______Bone: Foramen Magnum Occipital Condyles
Occipital
The most posterior bone of cranium: forms the floor and back wall. Joins the sphenoid bone anteriorly
Occipital Bone
Rounded projections lateral to the foramen magnum that articulate with the first cervical vertebra (atlas)
Occipital Condyles
Squamous Suture
Occurs where each parietal bone meets each temporal bone, on each lateral aspect of the skull
Sagittal Suture
Occurs where the left and right parietal bones meet superiorly
Lambdoid Suture
Occurs where the parietal bones meet the occipital bone posteriorly
What are the 8 cranial bones?
One frontal bone Two parietal bones Two temporal bones One occipital bone One sphenoid bone One ethmoid bone.
Structure of a Typical Vertebra Vertebral Foramen:
Opening enclosed by body and vertebral arch through which the spinal cord passes
Foramen Ovale
Opening posterior to the sella turcica that allows a branch of cranial nerve V to pass
Allows the optic nerve (cranial nerve II) to pass
Optic Canal
Structure of a Typical Vertebra Superior and inferior articular processes:
Paired projections lateral to the vertebral foramen that enable adjacent vertebrae to articulate with one another
Paired bones posterior to the palatine processes; form the posterior hard palate and part of the orbit
Palatine Bone
Forms the anterior hard palate
Palatine Processes of the Maxillae
Posterior and lateral to the frontal bone, forming sides of cranium
Parietal Bone
Greater Wings
Portions of the sphenoid seen exteriorly on the lateral aspect of the skull, anterior to the temporal bones. Form part of the orbits of the eyes
Parietal Bone
Posterior and lateral to the frontal bone, forming sides of cranium
Twelve pairs of ______ form the walls of teh thoracic cage
Ribs
The joint between C1 and C2 allows you to:
Rotate your head from side to side to indicate "no"
Mastoid Process
Rough projection inferior and posterior to external auditory meatus; an attachment site for muscles
Structure of a Typical Vertebra Body:
Rounded central portion of the vertebra; faces anteriorly in the human vertebral column
Occipital Condyles
Rounded projections lateral to the foramen magnum that articulate with the first cervical vertebra (atlas)
The vertebral canal continues inside the sacrum as the ______ ______ and terminates near the coccyx in the ______ ______
Sacral Canal Sacral Hiatus
Sacrum: The paired ______ ______ are additional evidence that the sacrum is formed of separate fused vertebrae and serve as passageways for blood vessels and nerves.
Sacral foramina
The ______, formed from the fusion of five vertebrae, is the posterior border of the pelvis. Superiorly it articulates with L5, and inferiorly connects with the coccyx.
Sacrum
Occurs where the left and right parietal bones meet superiorly
Sagittal Suture
What are the four major sutures?
Sagittal Suture: Occurs where the left and right parietal bones meet superiorly Coronal Suture: Located where the parietal bones articulate with the frontal bone Squamous Suture: Occurs where each parietal bone meets each temporal bones, on each lateral aspect of the skull. Lambdoid Suture: Occurs where the parietal bones meet the occipital bone posteriorly
A saddle-shaped region in the sphenoid midline that nearly encloses the pituitary gland.
Sella Turcica
The discs and the S-shaped or springlike construction of the vertebral column help prevent ______ to the head in walking and running and make the body trunk ______
Shock Flexible
Structure of a Typical Vertebra Spinous Process:
Single posterior projection from the vertebral arch
Needlelike projection inferior to external auditory meatus that serves as an attachment point for muscles and ligaments of the neck. This process is often broken off demonstration skulls
Styloid Process
The _______ is composed of two sets of bones: The cranial bones and The facial bones
Skull
Nasal Bone
Small rectangular bones forming the bridge of the nose
_______ Bone: Greater wings Sella turcica Lesser wings Foramen ovale Optic Canal Superior Orbital Fissure
Sphenoid
Bat-shaped bone forming a plateau across the width of the skull. The sphenoid bone can be seen in its entire width if the top of the cranium is removed
Sphenoid Bone
Structure of a Typical Vertebra Single posterior projection from the vertebral arch
Spinous Process
Occurs where each parietal bone meets each temporal bone, on each lateral aspect of the skull
Squamous Suture
The ______ forms most of the sternum
Sternum
The ______, a typical flat bone, is a result of the fusion of three bones - from superior to inferior, the manubrium, body, and xiphoid process
Sternum
The bony thorax is composed of the:
Sternum Ribs Thoracic Vertebrae
Transmits cranial nerves III, IV, and VI to the eye
Superior Orbital Fissure
Structure of a Typical Vertebra Paired projections lateral to the vertebral foramen that enable adjacent vertebrae to articulate with one another
Superior and inferior articular processes
Thin, delicately coiled plates of bone extending medially from the ethmoid into the nasal cavity. The conchae increase the surface area of the mucosa that covers them, thus increasing the mucosa's ability to warm and humidify incoming air. They are located behind, and are obscured by, the nasal bones
Superior and middle nasal conchae
Alveolar Process of the Mandible
Superior margin of mandible; contains sockets for the lower teeth
All of the bones of the skull are joined by interlocking joints called:
Sutures
The human ______ is a remnant of the tail that other vertebrates have
Tailbone
_______ Bone: Zygomatic Process External acoustic meatus Styloid process Mastoid process
Temporal
Inferior to parietal bone on lateral part of the skull
Temporal Bone
All ribs articulate posteriorly with the vertebral column at two locations:
The body and transverse processes of the thoracic vertebrae
The skull is composed of two sets of bones:
The cranial bones and The facial bones
The axial skeleton is made up of three parts:
The skull The vertebral column The bony thorax
Mandible
The lower jawbone; articulates with the temporal bones in the only freely movable joints in the skull
Occipital Bone:
The most posterior bone of cranium: forms the floor and back wall. Joins the sphenoid bone anteriorly
Inferior Nasal Conchae (Turbinates)
Thin curved protruding medially from the lateral walls of the nasal cavity; serve the same purpose as the nasal conchae of the ethmoid bone
Superior and Middle Nasal Conchae
Thin, delicately coiled plates of bone extending medially from the ethmoid into the nasal cavity. The conchae increase the surface area of the mucosa that covers the,, thus increasing the mucosa ability to warm and humidify incoming air. They are located behind, and are obscured by, the nasal bones
The ______ vertebrae articulate with the corresponding ribs
Thoracic
The bony thorax is also referred to as the:
Thoracic Cage
In these vertebrae, the body is somewhat heart shaped, with two small articulating surfaces, or costal facets, on each side (one superior, the other inferior) that articulate with the heads of the corresponding ribs. The vertebral foramen is oval or round, and the spinous process is long, with a sharp downward hook.
Thoracic Vertebrae
These vertebrae form the thoracic part of the spine and the posterior aspect of the bony thoracic cage (rib cage). They are the only vertebrae that articulate with the ribs
Thoracic Vertebrae
Superior orbital fissure
Transmits cranial nerves III, IV, and VI to the eye
Structure of a Typical Vertebra Two lateral projections from the vertebral arch
Transverse Processes
The first seven pairs of ribs are called ______ ______ because the attach directly to the sternum by their "own" costal cartilages
True Ribs
Maxillae
Two bones fused i the median suture; form the upper jawbone and part of the orbits. All facial bones, except the mandible, join the maxillae. Thus they are the main, or keystone bones of the face.
Structure of a Typical Vertebra Transverse Processes:
Two lateral projections from the vertebral arch
What are the smallest, lightest vertebrae?
Typical cervical vertebrae (C3 through C7)
Structure of a Typical Vertebra Composed of pedicles, laminae, and a spinous process, it represents the junction of all posterior extensions from the vertebral body
Vertebral Arch
Structure of a Typical Vertebra Opening enclosed by the body and vertebral arch through which the spinal cord passes
Vertebral Foramen
Ramus of the Mandible
Vertical extension of the body on either side
Crista Galli
Vertical projection to which dura mater (outermost membrane covering of the brain) attaches.
Blade-shaped bone in median plane of nasal cavity that forms most of the nasal septum
Vomer
The ______ ______, at the inferior end of the sternum, lies at the level of the fifth intercostal space.
Xiphoid Process
A bridgelike projection that joins the zygomatic bone (cheekbone) anteriorly. Together these two bones form the:
Zygomatic Arch
Lateral to the maxillae; forms the part of the face commonly called the cheekbone and part of the lateral orbit
Zygomatic Bone
A bridgelike projection that joins the zygomatic bone (cheekbone) anteriorly. Together these two bones form the zygomatic arch.
Zygomatic Process
List the important markings of the temporal bone:
Zygomatic process External acoustic meatus Styloid process Mastoid process
