What bone bears an upward protrusion?

The Axial Skeleton

A B
Maxilla anterior part of the hard palate
Ethmoid superior and medial nasal conchae formed from its projections, site of cribiform plate, bears an upward protrusion, the cocks comb, or crista galli
Temporal site of the mastoid process, site of styloid processes, middle ear found here

Has an upward protrusion called the Crista Galli?

Ethmoid Bone. The unpaired ethmoid bone is located at the midline within the central skull. It has an upward projection, the crista galli, and a downward projection, the perpendicular plate, which forms the upper nasal septum.

Which bone contains alveoli bearing teeth?

The alveolar process, which is also called the alveolar bone, is a thickened ridge of bone containing the sockets of the teeth or dental alveoli. It is located on the jaw bones which hold the teeth. The tooth-bearing bones are called the maxilla and the mandible.

What is the bat shaped bone on the floor of the cranium?

The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended.

What are the 8 bones of the skull?

There are eight cranial bones, each with a unique shape:

What are the four bones containing paranasal sinuses?

Paranasal sinuses are named after the bones that contain them: frontal (the lower forehead), maxillary (cheekbones), ethmoid (beside the upper nose), and sphenoid (behind the nose).

What 2 bones make up the nasal septum?

The Septum. The nasal septum is the key midline support structure of the nose and is composed of the quadrilateral cartilage, perpendicular plate of the ethmoid bone, and vomer bone (Figure 6-4).

Where is the ethmoid?

skull The ethmoid bone is a cube-shaped bone located in the center of the skull between the eyes. It helps form the walls of the eye socket, or orbital cavity, as well as the roof, sides, and interior of the nasal cavity.

What tiny bones bear tear ducts?

Specifically, the lacrimal bone helps form the nasolacrimal canal necessary for tear translocation. A depression on the anterior inferior portion of the bone, the lacrimal fossa, houses the membranous lacrimal sac. Tears or lacrimal fluid, from the lacrimal glands, collect in this sac during excessive lacrimation.

Is alveolar bone cancellous?

The trabecular bone contains cancellous bone, which is located between the alveolar bone proper in addition to the plates of cortical bone. The alveolar bone is located between two neighboring teeth is the interdental septum.

What type of bone is alveolar bone?

The alveolar process is the lining of the tooth socket and also known as the alveolus. While the alveolar process is made from compact bone, it can also be called the cribriform plate because it contains holes where Volkmann canals pass from the alveolar bone into the PDL.

What surrounds the Crista Galli?

The crista galli is the upper part of the perpendicular plate of the ethmoid bone of the skull. It rises above the cribriform plate. The falx cerebri (a fold of the dura mater surrounding the brain) attaches to the crista galli.

What does sphenoid bone mean?

Sphenoid bone: A prominent, irregular, wedge-shaped bone at the base of the skull. The sphenoid bone has been called the ‘keystone’ of the cranial floor because it is in contact with all of the other cranial bones.

Is the ethmoid bone a flat bone?

The bones that form the top and sides of the brain case are usually referred to as the “flat” bones of the skull. The brain case consists of eight bones. These include the paired parietal and temporal bones, plus the unpaired frontal, occipital, sphenoid, and ethmoid bones.

What does the sphenoid articulate with?

The sphenoid bone is a single bone, the body of which lies in the midline and articulates with the occipital bone and the temporal bones to form the base of the cranium.

What are the 22 bones of the skull?

The skull (22 bones) is divisible into two parts: (1) the cranium, which lodges and protects the brain, consists of eight bones (Occipital, Two Parietals, Frontal, Two Temporals, Sphenoidal, Ethmoidal) and the skeleton of the face, of fourteen (Two Nasals, Two Maxillae, Two Lacrimals, Two Zygomatics, Two Palatines, Two …

What are the 29 bones of the skull?

Head bones: The 29 head bones consist of 8 cranial bones, 14 facial bones, the hyoid bone, and 6 auditory (ear) bones. The 8 cranial bones are the frontal, 2 parietal, occipital, 2 temporal, sphenoid, and ethmoid bones.

What is appendicular bone?

The appendicular skeleton is one of two major bone groups in the body, the other being the axial skeleton. The appendicular skeleton is comprised of the upper and lower extremities, which include the shoulder girdle and pelvis.

What are the paranasal sinuses and orbits?

Paranasal sinuses are a group of four, paired, air-filled spaces that surround the nasal cavity (maxillary sinuses), above the eyes (frontal sinuses), between the eyes (ethmoid sinuses), and behind the eyes (sphenoid sinuses). … The frontal sinuses are superior to the orbits and are in the frontal bone.

What are the 4 paranasal sinuses where are they located and why are they important?

Paranasal sinuses are a group of four paired air-filled spaces that surround the nasal cavity. The maxillary sinuses are located under the eyes; the frontal sinuses are above the eyes; the ethmoidal sinuses are between the eyes and the sphenoidal sinuses are behind the eyes.

Which cranial bone contains sinuses?

The sphenoid bone is one of the most complex in the body due to its interactions with numerous facial bones, ligaments, and muscles. The body that forms the middle of the sphenoid bone articulates with the ethmoid and occipital bone and forms a key part of the nasal cavity; it also contains the sphenoidal sinuses.

What makes up the septum?

The nasal septum is the dividing wall between the right and left nasal cavities. The nasal septum is made up of cartilage and bone. The quadrangular cartilage makes up the front part of the nasal septum, and the ethmoid and vomer bones make up the paper-thin back part of the septum.

What 3 structures make up the nasal septum?

The basic components of the nasal septum are a quadrangular cartilage, perpendicular plate of ethmoid and the vomerine bone. The quadrangular lamina thickens at the upper region and is in continuity with the perpendicular plate of ethmoid making an osseo-cartilaginous continuity.

How is nasal septum formed?

The quadrangular cartilage, the vomer, the perpendicular plate of the ethmoid and aspects from the premaxilla and palatine bones form the nasal septum. Nasal scroll. Nasal subunits include the dorsum, sidewalls, lobule, soft triangles, alae, and columella.

What makes up the ethmoid bone?

The ethmoid bone consists of the cribriform plate, two ethmoid labyrinths, and the perpendicular plate. [2] The ethmoid bone encloses ethmoidal cells and is separated from the orbits by the lamina papyracea.

Is the nasal bone a flat bone?

Flat Bones Protect Internal Organs There are flat bones in the skull (occipital, parietal, frontal, nasal, lacrimal, and vomer), the thoracic cage (sternum and ribs), and the pelvis (ilium, ischium, and pubis). The function of flat bones is to protect internal organs such as the brain, heart, and pelvic organs.

What is the weakest part of the skull?

pterion Clinical significance The pterion is known as the weakest part of the skull. The anterior division of the middle meningeal artery runs underneath the pterion. Consequently, a traumatic blow to the pterion may rupture the middle meningeal artery causing an epidural haematoma.

What problems might a herniated disc cause quizlet?

What problems a herniated disc might cause? it might compressed a nerve leading to pain and possibly paralysis. Thoracic and sacral.

What bone is the most posterior?

The squamous part of the occipital bone is the most posterior and largest portion. It is the part of the bone that borders the parietal and temporal bone, and the posterior part of the foramen magnum. The outer squamous part contains several ridges or lines, crests, and prominences.

Which bone is described as a single irregular butterfly shaped bone forming the cranial floor?

Anatomical Structure. The sphenoid bone is said to be ‘butterfly-shaped’. It consists of a body, paired greater wings and lesser wings, and two pterygoid processes.