Chapter 7 - Lab

1. Chapter 7 - Lab The Skeletal System: The Axial Skeleton

2. I. Bone Surface Markings A. Depressions and Openings 1. Fissure – narrow slit between adjacent parts of bones through which blood vessels or nerves pass

3. 2. Foramen – opening through which blood vessels, nerves, or ligaments pass

4. 3. Fossa – shallow depression

5. 4. Sulcus – furrow along a bone surface that accommodates a blood vessel, nerve, or tendon

6. 5. Meatus – tubelike opening

7. B. Processes 1. Condyle – large, round protuberance at the end of a bone

8. 2. Facet – smooth flat articular surface

9. 3. Head – Rounded articular projection supported on the neck (constricted portion) of a bone

10. 4. Crest – prominent ridge or elongated projection

11. 5. Epicondyle – projection about a condyle

12. 6. Line – long, narrow ridge or border (less prominent than a crest)

13. 7. Spinousprocess – sharp, slender projection

14. 8. Trochanter – very large projection

15. 9. Tubercle – small, rounded projection

16. 10. Tuberosity – large, rounded, usually roughened projection

17. II. Cranial Bones A. Frontal Bone • Forms the forehead, the roofs of the orbits • The right and left sides are united after birth by the metopic suture, which disappears between the ages of six and eight

18. Frontal squama Supraorbital margin Supraorbital foramen (notch)*†

19. B. Parietal Bones (2) • Form the greater portion of the sides and roof of the cranial cavity • Contains many protrusions and depressions on the internal surfaces that accommodate blood vessels

20. C. Temporal Bones (2) • Form the inferior lateral aspects of the cranium

21. The zygomatic processarticulates with the temporal process of the zygomatic bone forming the zygomatic arch

22. The mandibular fossaand articular tuberclearticulate with the mandible to form the temporomandibular joint Mandibular fossa Articular tubercle

23. Temporal squama Mastoid portion Mastoid process External auditory meatus Styloidprocess

24. The temporal squama forms the temple • The mastoid process serves as an attachment for several neck muscles • the mastoid portion directs sound waves into the external auditory meatus • The styloidprocess serves as a point of attachment for muscles and ligaments of the tongue and neck

25. The internal auditory meatusallows the passage of the facial (VII) and vestibulocochlear (VII) nerves

26. Carotid foramen† Stylomastoidforamen† Jugular foramen†

27. The petrous portion houses the internal and middle ear

28. D. Occipital Bone • Posterior part of the cranium

29. Hypoglossal canal Hypoglassal canal † †

30. The foramen magnum† is the site where the medulla oblongata connects with the spinal cord • The occipital condyles articulate with vertebra and allow you to nod • The external occipital protuberance is an attachment place to a ligament that extends to the seventh cervical vertebra to help support the head

31. E. Sphenoid Bone • Lies at the middle part of the base of the skull

32. Articulates with all the other cranial bones, holding them together • Resembles a butterfly 1. 2. 3. • The sellaturcica is the body of the sphenoid bone • 3 parts: tuberculumsellae, hypophysealfossa, dorsum sellae

33. * Optic Foramen*† †

34. The sphenoidal sinus drains into the nasal cavity • The greater and lesser wings form parts of the floor of the cranium • The optic foramen*† allows passage of the optic (II) nerve into the orbit • The superior orbital fissure* allows blood vessels and cranial nerves through • the pterygoidprocesses provide muscle attachment to help move the mandible • The foramenovale†, foramenlacerum†, and foramrotundum† all allow the passage of nerves and arteries (p.208)

35. Optic foramen*† Superior orbital fissure*

36. F. Ethmoid Bone • Located on the midline in the anterior part of the cranial floor medial to the orbits • Major superior supporting structure to the nasal cavity

37. Cribriform plate with Olfactory foramina† Superior nasal concha Lateral mass Middle nasal concha

38. The cribriform plate forms the roof of the nasal cavity • The olfactory foramina† allow the passage of olfactory nerves • The crista galli serves as a point of attachment for the membranes that separate the two sides of the brain • The perpendicular plate forms the superior portion of the nasal septum • The lateral masses, superior nasal concha, and middle nasal concha help to cleanse inhaled air

39. III. Facial Bones A. Nasal Bones (2) • Form the bridge of the nose

40. B. Maxillae (2) • Form the upper jaw bone • Articulates with every bone of the face except the mandible

41. Each maxilla contains a large maxillary sinus that empties into the nasal cavity • The palatine process forms ¾ of the hard palate, or bony roof of the mouth which separates the nasal cavity from the oral cavity • The alveolar process contain sockets for the maxillary teeth

42. Incisive foramen Intraorbital foramen† Inferior orbital fissure†

43. C. Zygomatic Bones (2) • Cheekbones • Temporal processarticulates with the zygomatic process of the temporal bones in the zygomatic arch

44. D. Lacrimal Bones (2) • Smallest bones of the face • The lacrimal fossa* hold the lacrimal sac that gathers tears and passes them into the nasal cavity

45. E. Palatine Bones • Forms the back of the hard palate by horizontal plates

46. F. Inferior Nasal Conchae • Helps the conchae of the ethmoid bone to swirl the filter air before it passes into the lungs

47. G. Vomer • Forms the inferior portion of the nasal septum

48. H. Mandible • Lower jawbone • Largest and strongest facial bone • Consists of a curved body, and two perpendicular rami that are met at the angles Condylar process †

49. The condylar process, mandibular notch, and coronoid process articulate with the temporal bones in the temporomandibular joint • The alveolar process contain sockets for the mandibular teeth • Mental foramen† and mandibular foramen†

50. IV. Sutures • Immovable joints that hold most skull bones together A. Coronal • Unites the frontal bone and both parietal bones