Puzzle Piece 5: Skeletal System - Axial Skeleton

What is the total number of bones in an adult human skeleton?

206 bones.

How does the number of bones in children compare to adults?

Children have more bones as some fuse together during childhood and adolescence.

What are the two main divisions of the human skeleton?

Axial skeleton and appendicular skeleton.

What does the axial skeleton consist of?

Bones in the vertical central axis of the body, including the skull, hyoid bone, vertebral column, and thoracic cage.

What does the appendicular skeleton consist of?

Bones in the upper and lower limbs, and bones that connect the limbs to the axial skeleton.

How many bones are in the axial skeleton?

80 bones.

What are the components of the axial skeleton?

Cranial bones, facial bones, ear ossicles, hyoid bone, vertebral column, and thoracic cage.

What is the function of bones in the lower back and lower limbs?

They are thicker and stronger to support body weight.

What do surface markings on bones indicate?

They provide clues about their function, such as muscle attachment points.

What are cranial bones and how many are there?

Cranial bones encase the brain and there are 8 cranial bones.

List the paired cranial bones.

Parietal bones and temporal bones.

List the unpaired cranial bones.

Sphenoid bone, ethmoid bone, occipital bone, and frontal bone.

What is the coronal suture?

A suture that separates the frontal bone from the parietal bones.

What is the sagittal suture?

A suture that separates the right and left parietal bones.

What is the lambdoid suture?

A suture that separates the occipital bone from the parietal bones.

What is the squamous suture?

A suture that separates the temporal bone from adjacent bones.

What is the significance of sutures in the skull?

They are fibrous joints made of dense irregular connective tissue, providing strength.

What is the function of the frontal bone?

It forms the forehead and part of the bony orbits.

What is the supraorbital foramen?

A hole above each orbit that allows the passage of nerves and vessels.

What is the frontal sinus?

An air pocket space in the frontal bone that can lead to frontal sinusitis when inflamed.

Why is it important to associate bone features with their respective bones?

To avoid confusion and enhance understanding of skeletal anatomy.

What does the term 'foramen' mean?

It means hole.

What does 'supra' indicate in anatomical terms?

It indicates 'superior' or 'above'.

What does 'orbital' refer to in the context of bones?

It refers to the bony orbit surrounding the eye.

What is the function of the frontal sinus?

It is an air pocket space that can lead to frontal sinusitis when inflamed.

What type of bone is the frontal bone?

The frontal bone is categorized as a flat bone and a pneumatized bone due to the presence of the frontal sinus.

Where are the parietal bones located in relation to other cranial bones?

The parietal bones are found posterior to the frontal bone and anterior to the occipital bone.

What do the right and left parietal bones form?

They form the sides (lateral) and roof (superior) of the cranium and are separated by the sagittal suture.

What is the role of the occipital bone?

The occipital bone forms the back (posterior) and base of the cranium.

What are the features of the occipital bone?

The occipital bone features the foramen magnum, occipital condyle, hypoglossal canal, and jugular foramen.

What is the foramen magnum?

It is a large hole in the occipital bone that allows the brain stem to pass through.

What is the significance of the occipital condyle?

It is the smooth rounded surface of the occipital bone that sits on top of the first cervical vertebra (C1), also known as the atlas.

What does the hypoglossal canal serve as a pathway for?

It serves as a pathway for structures to reach underneath the tongue and is located superior to the occipital condyle.

What is the jugular foramen and its significance?

The jugular foramen is a shared feature between the occipital and temporal bones, serving as a passageway for the internal jugular artery and cranial nerves IX, X, and XI.

What bones form the cranium's base?

The occipital bone at the back and the temporal bone anterior to it.

What is the location and function of the temporal bones?

The temporal bones form the sides (lateral) and base of the cranium and are located close to the ears.

What are the distinct features of the temporal bone?

The temporal bone features the mastoid process, styloid process, zygomatic process, mandibular fossa, external acoustic meatus, internal acoustic meatus, and carotid canal.

What is the mandibular fossa and its importance?

The mandibular fossa articulates with the mandibular condyle of the mandible, forming the temporomandibular joint (TMJ), which is critical for jaw movement.

What is the external acoustic meatus?

It is the ear canal that faces the external environment and is related to hearing.

What does the carotid canal allow passage for?

The carotid canal allows the passage of the internal carotid artery.

What is the sphenoid bone known for?

The sphenoid bone is an irregular bone that touches all other cranial bones, earning it the nickname 'Keystone'.

What are the features of the sphenoid bone?

The sphenoid bone features the sella turcica, foramen rotundum, foramen ovale, foramen spinosum, optic canal, superior orbital fissure, and inferior orbital fissure.

What is housed in the sella turcica?

The sella turcica houses the pituitary gland, the major endocrine gland in the body.

What is the difference between a foramen and a fissure?

A foramen is a short hole, while a fissure is an elongated hole.

What cranial nerve passes through the optic canal?

The optic canal is the passageway for cranial nerve II (optic nerve).

What is the ROS sequence in relation to the sphenoid bone?

The ROS sequence refers to the foramen rotundum, foramen ovale, and foramen spinosum, which are passageways for branches of cranial nerve V (trigeminal nerve).

What type of bone is the ethmoid bone?

An irregular and pneumatized bone due to the presence of ethmoid air cells.

What structures does the ethmoid bone help form?

Part of the bony orbit, superior and middle nasal conchae, and the nasal septum with the vomer bone.

What is the function of the crista galli in the ethmoid bone?

It anchors the brain anteriorly.

What is the cribriform plate and its significance?

It is a passageway for the olfactory nerve (CN I).

What are the superior and middle nasal conchae?

Structures in the lateral aspects of the nasal cavity that aid in swirling air.

What forms the superior aspect of the nasal septum?

The perpendicular plate of the ethmoid bone.

What can happen if the ethmoid sinus becomes inflamed?

It can lead to ethmoid sinusitis.

How many facial bones are there, and what are the unpaired ones?

There are 14 facial bones; the unpaired ones are the mandible and vomer.

What is unique about the mandible bone?

It is the only movable bone in the face.

What features are associated with the mandible bone?

Mental foramen and mandibular foramen for CN V, and the mandibular condyle which forms the TMJ.

What is the function of the inferior nasal concha?

It forms the third bump in the nasal cavity and is a paired irregular bone.

What is the shape and function of the vomer bone?

It is an unpaired, flat bone that forms the inferior portion of the nasal septum.

What is the maxilla and its significance?

A paired, irregular, pneumatized bone that forms part of the bony orbit and upper jaw.

What does the palatine bone contribute to?

It forms the posterior portion of the hard palate and a tiny part of the bony orbit.

What is the zygomatic bone commonly known as?

The cheekbone.

What is the temporal process of the zygomatic bone?

It connects with the zygomatic process of the temporal bone to form the zygomatic arch.

What does the lacrimal bone form?

The medial aspect of the bony orbit, lacrimal fossa, and nasolacrimal canal for tears.

What is the nasal bone's function?

It forms the bridge of the nose.

What is unique about the hyoid bone?

It is the only bone in the body that does not connect to any other bone.

What shape is the hyoid bone, and what are its features?

It has a U-shape with greater and lesser horns.

What controls the movement of the hyoid bone?

Muscles involved in talking and swallowing.

What are the ear ossicles?

They are the smallest bones in the body, consisting of the malleus, incus, and stapes.

What are the smallest bones in the human body?

The ear ossicles, with the stapes being the smallest.

Where are the ear ossicles located and what is their function?

They are found in the middle ear and are responsible for amplifying sound waves.

What is the composition of the vertebral column?

The vertebral column is composed of cervical vertebrae (7), thoracic vertebrae (12), lumbar vertebrae (5), sacrum (5 fused), and coccyx (3-5 fused).

What are the four natural curves of the vertebral column?

Cervical, thoracic, lumbar, and sacral/coccygeal.

What are the benefits of the natural curves of the vertebral column?

They increase flexibility, strength, and shock absorption.

What are the three types of abnormal curvatures of the spine?

Scoliosis (lateral bending), kyphosis (excessive upper thoracic bend), and lordosis (excessive lumbar curvature).

What are the common features of cervical, thoracic, and lumbar vertebrae?

Each vertebra has a spinous process, transverse process, vertebral foramen, body (centrum), and articular facets.

What is the orientation of the spinous process in vertebrae?

The spinous process is always posterior.

What is the function of the body (centrum) of a vertebra?

The body always faces anteriorly and is close to the center of the body.

What is the transverse process of a vertebra?

A process that sticks out horizontally to the sides.

What is the vertebral foramen?

A hole in the middle of a vertebra.

What are articular facets and their role in vertebrae?

Facets used in the articulation between vertebrae; superior and inferior articular facets articulate with adjacent vertebrae.

What is the intervertebral disk?

A disk located between the bodies of two adjacent vertebrae.

What forms the vertebral canal?

The alignment of the vertebral foramen.

What is the role of spinal nerves in relation to the vertebral column?

Spinal nerves exit the spinal cord by passing through intervertebral foramen between adjacent vertebrae.

How many cervical vertebrae are there and where are they located?

There are 7 cervical vertebrae (C1 to C7) located in the cervical (neck) region.

What is unique about C1 (Atlas)?

It does not have a spinous process or body and allows for the yes motion of head movement.

What is the atlanto-occipital joint?

The joint between C1 (Atlas) and the occipital bone that allows for head nodding.

What is the function of C2 (Axis) in the vertebral column?

C2 has an odontoid process (dens) that articulates with C1 and allows for the no motion of head movement.

What is the atlanto-axial joint?

The joint between C1 (Atlas) and C2 (Axis) that allows for rotational head movement.

Why is there no intervertebral disc between C1 and C2?

Intervertebral discs are found between the bodies of two adjacent vertebrae, and C1 and C2 do not have bodies.

What is the significance of C1 in relation to the skull?

C1, named Atlas, supports the skull, resembling a globe, similar to the figure from Greek mythology who carried the world.

What is the function of C2, also known as Axis?

C2 allows for rotation around an axis, enabling the 'NO' motion of the head.

What unique feature is found in cervical vertebrae, except for C7?

A bifid spinous process, which is a spinous process divided into two.

Why is C7 clinically significant?

C7 has the largest spinous process, serving as a landmark for locating other vertebrae in the column.

What is the purpose of the transverse foramen in cervical vertebrae?

The transverse foramen allows passage for vertebral blood vessels.

How many thoracic vertebrae are there and what is their location?

There are 12 thoracic vertebrae (T1 to T12) located at the level of the thorax.

What structure do the thoracic vertebrae help form?

The thoracic cage, in conjunction with the ribs and sternum.

What are the specific bone features of thoracic vertebrae?

They have superior costal facets, inferior costal facets, and transverse costal facets for rib articulation.

How does a rib articulate with a thoracic vertebra?

The head of the rib articulates with the body of the thoracic vertebra at the superior and inferior costal facets, while the tubercle articulates with the transverse coastal facet.

What are the lumbar vertebrae characterized by?

Large bodies that support the weight of the upper body.

How many lumbar vertebrae are there?

There are 5 lumbar vertebrae (L1 to L5).