Occipital Bone Flashcards

Examine the occipital bone's four parts, foramen magnum, occipital condyles, muscle attachments, cranial articulations, and neurovascular landmarks.

Card 1 of 30Question

Where is the occipital bone located?

At the posterior and inferior aspects of the cranium, forming the back of the skull and much of the posterior cranial fossa.

In This Section

1. Where is the occipital bone located?

At the posterior and inferior aspects of the cranium, forming the back of the skull and much of the posterior cranial fossa.

2. What are the four anatomical parts of the occipital bone?

The squamous part, basilar part, and two lateral parts.

3. Which opening separates the four parts of the occipital bone?

The foramen magnum.

4. Which major neural structure passes through the foramen magnum?

The medulla oblongata, which continues inferiorly as the spinal cord.

5. Which arteries pass through the foramen magnum?

The vertebral arteries and the anterior and posterior spinal arteries.

6. Which cranial nerve roots ascend through the foramen magnum?

The spinal roots of the accessory nerve (cranial nerve XI).

7. What are the occipital condyles?

Paired convex articular projections on the inferior surface of the lateral parts of the occipital bone.

8. Which vertebra articulates with the occipital condyles?

The atlas, or first cervical vertebra (C1).

9. What type of synovial joints are the atlanto-occipital joints?

Condylar, or ellipsoid, synovial joints.

10. What movements occur primarily at the atlanto-occipital joints?

Flexion and extension of the head, with limited lateral flexion.

11. Which canal passes through the occipital bone superior to each occipital condyle?

The hypoglossal canal.

12. Which cranial nerve passes through the hypoglossal canal?

The hypoglossal nerve (cranial nerve XII).

13. What is the condylar canal?

A variable canal posterior to the occipital condyle that may transmit a condylar emissary vein.

14. What is the basilar part of the occipital bone?

The portion situated anterior to the foramen magnum that joins the body of the sphenoid bone.

15. What is the clivus?

A sloping internal cranial surface formed by the basilar occipital bone and sphenoid body, supporting the brainstem.

16. What is the pharyngeal tubercle?

A midline projection on the inferior surface of the basilar occipital bone that anchors the pharyngeal raphe.

17. What is the external occipital protuberance?

A palpable midline bony prominence on the external surface of the occipital squama.

18. What is the inion?

The most prominent point of the external occipital protuberance.

19. What is the external occipital crest?

A median ridge extending inferiorly from the external occipital protuberance toward the foramen magnum.

20. Which ligament attaches to the external occipital protuberance and external occipital crest?

The ligamentum nuchae.

21. What are the three principal paired nuchal lines of the occipital bone?

The highest, superior, and inferior nuchal lines.

22. Which muscles attach along the superior nuchal line?

The trapezius, sternocleidomastoid, splenius capitis, and occipitalis muscles.

23. Which suboccipital muscles attach to the inferior nuchal line?

The rectus capitis posterior major and rectus capitis posterior minor muscles.

24. What is the internal occipital protuberance?

A midline prominence on the internal occipital surface near the confluence of the dural venous sinuses.

25. What is the internal occipital crest?

A median ridge extending from the internal occipital protuberance toward the foramen magnum, providing attachment for the falx cerebelli.

26. Which dural venous sinuses produce grooves on the internal surface of the occipital bone?

The superior sagittal, transverse, sigmoid, and occipital sinuses.

27. What are the cerebral and cerebellar fossae of the occipital bone?

Paired internal depressions that accommodate the occipital cerebral lobes and cerebellar hemispheres, respectively.

28. Which bones articulate with the occipital bone?

The two parietal bones, two temporal bones, sphenoid bone, and atlas.

29. Which suture connects the occipital bone to the parietal bones?

The lambdoid suture.

30. What is the lambda on the posterior aspect of the skull?

The junction of the sagittal and lambdoid sutures, corresponding to the posterior fontanelle in infants.