Human Anatomy and Physiology - Problem Drill 07: The Skeletal System Axial Skeleton

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1 Human Anatomy and Physiology - Problem Drill 07: The Skeletal System Axial Skeleton Question No. 1 of 10 Which of the following statements about the axial skeleton is correct? Question #01 A. The axial skeleton includes the vertebral column and the bones of the upper limbs. B. The major functions of the axial skeleton include protecting the brain and the organs of the thorax. C. The axial skeleton includes the bones of the skull and the pelvic girdle. D. The axial skeleton plays no role in the breathing cycle. E. Adjusting the position of the head and neck is not part of the function of the axial skeleton. The bones of the upper limbs are part of the appendicular skeleton. B. Correct! The major functions of the axial skeleton include protecting the brain and the organs of the thorax, providing surfaces for the attachment of muscles in the region, adjusting the position of the head and neck, and playing a role in the breathing cycle. The pelvic girdle is part of the appendicular skeleton. The axial skeleton does contribute to breathing. The first two cervical vertebrae facilitate the movements of the head and neck. The two major divisions of the skeletal system are the appendicular skeleton and the axial skeleton. The axial skeleton includes the bones of the skull, inner ear bones, vertebral column and the bones of the thorax. The major functions of the axial skeleton include: (1) protecting the organs in the thorax, as well as the brain, (2) providing surfaces for the attachment of muscles in the region, (3) adjusting the position of the head and neck, and (4) playing a role in the breathing cycle.

2 Question No. 2 of 10 What part of the vertebrae in the image below is labeled with the letter A? A Question #02 A. Spinous process. B. Transverse process. C. Vertebral body. D. Vertebral arch. E. One of the two spinous processes. The spinous process is the process at the most posterior part of the vertebra. B. Correct! The letter A identifies one of the two transverse processes. The vertebral body is the round, thick anterior portion of the vertebra. The vertebral arch is connected to a transverse process. The letter A identifies one of the two transverse processes. Spinous Process Transverse Process Vertebral Arch Vertebral Body Vertebral Foramen The vertebrae in the spinal column share some common structural features. The vertebral body is in contact with the intervertebral discs and transfers the weight along the axis and length of the spinal column. The vertebral arch protects a portion of the spinal cord and, from it, extends the spinous process and transverse processes. These processes function by providing muscle attachment points, as well as by playing a role in the articulation with rib bones. The spinal cord passes through the vertebral foramen in each vertebra, down the length of the spinal column.

3 Question No. 3 of 10 An individual is injured in a motor vehicle accident and the x-ray reveals a fracture of the patient s second cervical vertebra. Based on this information, which of the following would be correct? Question #03 A. The second cervical vertebra is known as the atlas. B. There is no risk of injury to the dens projection, as it is part of the first cervical vertebra. C. The second cervical vertebra has a process known as the dens projection that passes through a ligament opening in the atlas. D. The second cervical vertebra plays no role in the pivot movement of the head. E. The axis is fused with the 3 rd cervical vertebra by the age of 25. The second cervical vertebra is known as the axis. B. Incorrect! The dens projection originates at the second cervical vertebra and then passes cranially into the first cervical vertebra. C. Correct! The second cervical vertebra has a process known as the dens projection that passes through a ligament opening in the atlas. The ability of the head to pivot and rotate on the spinal column is due, in part, to the dens projection of the second cervical vertebra. The axis is fused with the atlas by adulthood. The cervical region of the spinal column contains two unique vertebrae, the Atlas C1 and the Axis C2. The occipital bone of the skull rests on and communicates with the first cervical vertebra C1. The arrangement of these first two vertebrae allows the rotation of the head on the spinal column. The Atlas C1 articulates with the occipital bone of the skull. This vertebra lacks a vertebral body, has oval articular facets, and has the largest vertebral foramen. The Axis C2 contains a dens or odontoid projection from the fusion of the first two cervical vertebrae. The dens projection passes through a ligament opening in the Atlas C1, which permits the skull to pivot relative to the rest of the spinal column. This fusion between C1 and C2 is not complete in children and, therefore, severe shaking can lead to dislocation and brain damage.

4 Question No. 4 of 10 Which region of the spinal column is highlighted in the image below? Question #04 A. The region of the spinal column with the largest vertebral bodies. B. Thoracic region. C. A region of the spinal column with no curve. D. Cervical region. E. Coccyx. A. Correct! The region of the spinal column identified in the image is the lumbar region, which contains vertebrae with the largest vertebral bodies. B. Incorrect! The thoracic region is made up of 12 vertebrae, which are adjacent to the cervical region. The spinal column region identified in the image forms an anterior curve. The cervical region is the first spinal column segment; the lumbar region is identified in the image. The coccyx is the most distal region of the spinal column; the lumbar region is identified in the image. 5 Lumbar Vertebrae There are 5 lumbar vertebrae, named L1 through L5. The lumbar have the largest vertebral body but the smallest vertebral foramen. These vertebrae, which form an anterior (lordotic) curve, are located in the small of the back and bear the most weight in the vertebral column. These vertebrae provide attachment points for lower back muscles. The true spinal cord ends at L2 in 98% of the human population.

5 Question No. 5 of 10 The sternum is part of the ribcage, which houses and protects the heart and lungs. Which of the following statements about the sternum is correct? Question #05 A. The sternum is made up of 2 separate bones that fuse by the age of 25 years. B. The xiphoid process is attached to the diaphragm. C. The body of the sternum is attached to the costal cartilages from the rib pairs 1 through 10. D. The sternum is attached through costal cartilages to all 12 pairs of ribs. E. The xiphoid process articulates with the clavicles. The sternum is made up of 3 separate bones that fuse by the age of 25. B. Correct! The xiphoid process is attached to the diaphragm. The body of the sternum is only attached to the costal cartilages from rib pairs 2 through 10. The sternum, as a whole, is attached to the first 10 pairs of ribs. The first part of the sternum, which is the manubrium, articulates with the clavicles. The sternum is a 3-component bone that forms the anterior midline of the thoracic wall. The three components are the manubrium, body and xiphoid process. These 3 bones do not fuse until at least 25 years of age. The manubrium articulates with the clavicle bones and costal cartilages and contains a jugular notch. The body of the sternum is attached to the costal cartilages from the rib pairs 2 through 10. However, the 8th, 9th and 10th pairs of ribs are not directly attached to the sternum but rather through an attachment with the 7th pair of ribs. The xiphoid process is attached to the diaphragm and the rectus abdominis muscle.

6 Question No. 6 of 10 Which bone of the skull is labeled in the image below? Question #06 A A. The basilar bone. B. The occipital bone. C. The sphenoid. D. The temporal bone. E. The sella turcica portion of the occipital bone. The letter A in the image is labelling the occipital bone. B. Correct! The letter A is labelling the occipital bone of the skull. The sphenoid bone is anterior to the occipital bone; the letter A is pointing to the occipital bone. The temporal bone is part of the floor of the skull; however, the letter A is pointing to the occipital bone. The sella turcica is part of the sphenoid. Occipital Bone The cranial vault, or fossa, houses the brain and changes in size as the skull grows. The foramen magnum is an opening in the occipital bone through which the medulla oblongata of the spinal cord passes. This is the route through which the central nervous system exits the skull and becomes the spinal cord.

7 Question No. 7 of 10 The orbit of the eye is made up of a number of bones. The orbit contains the eye, muscles, vessels and ocular fat. Which of the following is correct? Question #07 A. The bones of the eye orbit include the lacrimal bone and the temporal bone. B. There are a total of 9 bones that make up the orbit of the eye. C. The ethmoid bone is part of the eye orbit. D. The bones of the eye orbit include the lacrimal bone and the parietal bone. E. The superior orbital fissure is a fissure of the zygomatic bone. The lacrimal bone is part of the eye orbit; however, the temporal bone is not. B. Incorrect! There are a total of 7 bones that make up the eye orbit. C. Correct! The ethmoid bone is one of the 7 bones that make up the orbit of the eye. The lacrimal bone is part of the eye orbit, but the parietal bone is not. The superior orbital fissure is a foramen in the skull, which lies between the wings of the sphenoid. There are a total of seven bones that articulate to form the eye orbit. The bones are the: frontal, lacrimal, ethmoid, zygomatic, maxillary, palatine and the sphenoid. Contained within the orbit are the eyeball, ocular musculature, nerves and blood vessels. There are a number of nerves that pass through the superior orbital fissure, including: superior division of the oculomotor nerve, trochlear nerve, abducens nerve, and the sympathetic fibers from the cavernous plexus.

8 Question No. 8 of 10 Which of the following statements about the zygomatic bone is correct? Question #08 A. The zygomatic bone is the smallest bone of the skull. B. There is only a single zygomatic bone on the skull. C. The zygomatic bone is not part of the eye orbit. D. The zygomatic bones articulate with the maxilla, temporal bone, sphenoid and frontal bone. E. None of the answers are correct. The lacrimal bones are the smallest bones in the skull and are located in the anterior of the medial wall of the eye orbit. B. Incorrect! The skull contains a left and right zygomatic bone. The zygomatic bones contribute to the inferior wall of the eye orbit. D. Correct! The zygomatic bones form the arches of the cheeks, and these bones articulate with the maxilla, temporal bone, sphenoid and frontal bone. There is a correct answer option above. The zygomatic bones form the arches of the cheeks, and these bones articulate with the maxilla, temporal bone, sphenoid and frontal bone. A foramen on the anterior surface of each bone houses a sensory nerve that innervates the cheek. These bones also contribute to the inferior wall of the eye orbit.

9 Question No. 9 of 10 Which part of the lower jaw bone is labeled in the image below? A Question #09 A. Coronoid process. B. Angle. C. Rami. D. Mental protuberance. E. Alveolar part. A. Correct! The arrow is pointing to the coronoid process. B. Incorrect! The angle of the mandible is on either side at the base. The arrow is pointing to the coronoid process. The mental protuberance is located at the anterior and inferior portion of the mandible. The alveolar portion of the mandible is located at the anterior gum line. The mandible, or lower jaw bone, has a structure that contains a variety of surfaces. Each ramus of the mandible meets the body at the angle of the mandible. In addition to supporting the teeth in the mandibular body, the head articulates with the temporal bone to form the temporomandibular joint. The temporalis muscle inserts in the mandible at the coronoid processes. The alveolar part of the mandible is a thickened portion that contains the roots of the teeth.

10 Question No. 10 of 10 Which of the following statements about the temporomandibular joint is correct? Question #10 A. The temporomandibular joint is made up of the zygomatic bone and the frontal bone. B. The condyle of the mandible makes up part of the temporomandibular joint. C. There are no ligaments associated with the temporomandibular joint. D. The temporomandibular joint contains no cartilage. E. None of the answers is correct. The temporal bone along with the mandible makes the temporomandibular joint that facilitates jaw movement. B. Correct! The temporomandibular joint includes the condyle of the mandible and a disc of cartilage. The lateral ligament is associated with the temporomandibular joint. The temporomandibular joint involves the association of the condyle of the mandible and a disc of cartilage. One of the answers is correct above. The temporal bones articulate with the zygomatic bone to make the arches of the cheeks. The temporal bone along with the mandible makes the temporomandibular joint that facilitates jaw movement. The majority of the abnormality in the joint is between the condyle of the mandible and the disc of cartilage; this produces the click or pop sound.