Chapter Three Skeletal System

The skull is a complex structure. There are 8 cranial bones and 14 facial bones in the skull. From the anterior view most of the facial bones can be seen and some of the cranial bones are visible too. The bone that makes up the forehead and extends beyond the eyebrows is the frontal bone. This bone forms the upper rim of the orbit, which is a socket that encloses the eye. In the back of the orbit is the sphenoid bone and the lateral walls of the orbit are composed of the zygomatic bones. The bridge of the nose consists of the paired nasal bones and just lateral to them are the two maxillae. These bones hold the upper teeth. The lower teeth are held by the mandible. Inside the nasal cavity two projections can be seen. These are the inferior nasal conchae. The wall that divides the nasal cavity is the nasal septum and it consists of two bones, the ethmoid bone and the vomer. Along the side of the skull are the temporal bones, located posterior to the zygomatic bones. Label the major bones of the skull and color them in. As you color in the skull try to use the same color for the same bone on different pages. This will help you associate the same bone with various views from which it can be seen.

Frontal Bone

Answer Key: a. Orbit, b. Frontal bone, c. Temporal bone, d. Sphenoid bone, e. Nasal bone, f. Zygomatic bone, g. Nasal septum, h. Maxilla, i. Mandible

Many bones seen from the anterior view can also be seen from the lateral view. The frontal bone is joined to the parietal bones by the coronal suture. The parietal bones span much of the cranium and articulate with the occipital bone at the lambdoid suture. There is a posterior extension of the occipital bone known as the external occipital protuberance. The exterior aspect of the temporal bone is seen from the lateral view and many of the significant features such as the mastoid process, external acoustic meatus, and styloid process are visible. On the side is the elongated zygomatic process. The temporal bone articulates with other cranial bones by the squamous suture. The bone anterior to the temporal bone is the sphenoid bone. It is a bone that is found in the middle of the skull. The nasal bone is visible from the lateral view and its relationship with the maxilla can be seen here. Behind the maxilla is the lacrimal bone which houses the nasolacrimal canal, a duct that drains tears from the eye into the nose. The mandible articulates with the rest of the skull at the mandibular condyle. A depression in front of the condyle is the mandibular notch and the anterior section of bone in front of the notch is the coronoid process. Label the major features of the skull seen in lateral view and color each bone a different color.

Details of the mandible can be seen in the isolated bone. In addition to the features of the mandible listed above, find the mandibular foramen and the mental foramen of the mandible. These are holes for the passage of nerves and blood vessels. The main portion of the mandible is the body and the upright part is the ramus. The angle is the posterior junction of these two parts. The teeth are located in alveoli and the small segments of bone between the teeth are the alveolar processes. Label the features of the mandible.

External Occipital Protuberance

Answer Key: a. Coronal suture, b. Parietal bones, c. Zygomatic process, d. Temporal bone, e. Squamous suture, f. Lambdoid suture, g. External occipital protuberance, h. Occipital bone, i. Mastoid process, j. External acoustic meatus, k. Styloid process, I. Mandible, m. Maxilla, n. Zygomatic bone, o. Nasal bone, p. Lacrimal bone, q. Sphenoid bone, r. Frontal bone, s. Coronoid process, t. Mandibular foramen, u. Mandibular notch, v. Mandibular condyle, w. Ramus, x. Angle, y. Body, z. Mental foramen

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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Responses

  • Charles
    Where is the lambdoid suture located?
    8 years ago
  • christian
    Where is the coronal suture located?
    8 years ago
  • cormac
    What is the suture that separates the lambdoid and sagittal bone?
    8 years ago
  • CRAIG
    What bone makes up the lower rim of the eye orbit and the side and bottom of the nose?
    7 years ago
  • Albertino
    How many bones are there in spinal cordexact &correct answer?
    5 years ago
  • della
    How many facial bones are there?
    2 years ago
  • Ottavio
    What bonen makes up the lower rim of the eye orbit and the side and the bottom of the nose?
    2 years ago

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