Chapter 3 Brainstem Anatomy, Topography, and Functional Levels

1. Chapter 3 Brainstem Anatomy, Topography, and Functional Levels

4. The brainstem: midbrain, pons, medulla oblongata

5. Midbrain Tentorial notch

6. clivus foramen magnum posterior anterior

8. 3rd ventricle Cerebral aqueduct 4th ventricle central canal Open part Closed part

9. Medulla oblongata: Contains centers associated with: equilibrium audition deglutition coughing vomiting salivation tongue movements respiration circulation

10. Pons: Contains centers associated with: mastication eye movements facial expression blinking salivation equilibrium audition

11. Midbrain: Contains centers associated with: auditory reflexes visual reflexes pupillary reflexes

14. ventral surface of medulla Fig. 3-3

15. ventral surface of pons transverse bands Cerebellar angle junction Fig. 3-3

16. Basilar artery Vertebral artery

17. ventral surface of midbrain (anterior part of cerebral peduncle) Fig. 3-3

18. dorsal surface of closed medulla Fig. 3-4

19. Floor of 4th ventricle: (see Fig. 3-4) caudal part is formed by posterior surface of rostral medulla

20. Floor of 4th ventricle: rostral part is formed by posterior surface of pons

21. motor structures are more medial; sensory structures are more lateral

23. Fig. 5-3 Motor cranial nerves

25. ventral surface of medulla (cranial rootlets) Fig. 3-3

26. ventral surface of pons transverse bands Cerebellar angle junction Fig. 3-3

27. ventral surface of midbrain CN’s I and II connect to the forebrain (anterior part of cerebral peduncle) Fig. 3-3

29. Myelin-stained brainstem cross sections: Rostral part of closed medulla (at dorsal column nuclei)

30. { the dorsal column nuclei Fig. 3-6 Rostral part of closed medulla

31. Caudal part of open medulla (at hypoglassal and vagal nuclei)

32. hypoglossal nucleus nucleus ambiguus Fig. 3-7 Caudal part of open medulla (at hypoglossal and vagal nuclei)

33. Rostral part of open medulla (at lateral aperture)

34. acoustic tubercle (opens into subarachnoid space) Inferior cerebellar peduncle Fig. 3-8 Rostral part of open medulla (at lateral aperture)

35. Caudal pons (at abducens and facial nuclei)

36. Facial nucleus Fig. 3-9 Caudal pons (at abducens and facial nuclei)

37. Middle pons (at trigeminal nuclei)

38. Middle pons (at trigeminal nuclei)

39. Rostral pons (at decussation of trochlear nerves)

40. (emergence) Rostral pons (at decussation of trochlear nerves)

41. Caudal midbrain (at inferior colliculus)

42. Trochlear nucleus Caudal midbrain (at inferior colliculus)

43. Rostral midbrain (at superior colliculus)

44. CNIII fibers Rostral midbrain (at superior colliculus)

45. corpora quadrigemina (for reflex movements of eyes, head, and neck)

46. Inputs and outputs of the Brainstem Reticular Formation Fig. 20-2

47. Functions of the reticular formation: 1. Integrates of cranial nerve reflexes 2. Helps in conduction and modulation of slow pain 3. Influences voluntary movements 4. Regulates autonomic nuclei 5. Is associated with diffuse modulating systems 6. Integrates basic functions (respiration, sleep) 7. Activates the cerebral cortex * * Ascending Reticular Activating System Fig. 20-9

48. Fig. 20-1

50. Chapter 3 know the location of the brainstem and the locations where it is continuous with the forebrain and the spinal cord know the functional centers contained within the midbrain, pons, and medulla know the locations of the tectum and tegmentum of the brainstem know the anterior surface features of the medulla know the anterior surface features of the pons know the anterior surface features of the midbrain know the posterior surface features of the closed medulla know the parts of the brainstem that form the floor of the 4th ventricle know the posterior surface features seen in the floor of the 4th ventricle know the posterior surface features of the midbrain know the points of attachment or emergence of the cranial nerves III-XII know the cross section levels of the brainstem where the nuclei of the motor cranial nerves are found