Anatomy Chapter 16: Spinal Cord and Spinal Nerves



Anatomy Chapter 16: Spinal Cord and Spinal Nerves

The Spinal Cord

* Provides a vital ___________ between the ___________and the rest of the ___________.

* Exhibits some functional ______________________from the brain.

* The spinal cord and its attached spinal ___________serve ___________important functions.

* pathway for ______________________and ___________impulses

* responsible for ______________________

Structure of the Spinal Cord

* A typical adult spinal cord ranges between _____and ___________ (cm) (16 to 18 inches) in length.

* Viewed in cross section, it is roughly ______________________, but slightly flattened both posteriorly and ______________________.

* Its external surface has two longitudinal ______________________.

* the posterior (or ___________) median sulcus, dips internally on the ___________________surface

* the anterior (or ___________) median fissure, is observed on its ______________________surface

Regions of the Spinal Cord

* The ______________________region is the ______________________-most region of the spinal cord.

* continuous with the _________________________________

* contains neurons whose ___________form the ______________________spinal nerves

* The ______________________region lies inferior to the ______________________region.

* attached to this region are the ______________________spinal ___________

* The ______________________region is a shorter segment of the spinal cord that

* contains the neurons for the lumbar ___________nerves

* The ______________________region lies inferior to the ______________________region and

* contains the neurons for the ______________________spinal nerves

* The ______________________region is the most inferior “___________” of the spinal cord.

* one pair of coccygeal spinal ______________________arises from this region.

Structure of the Spinal Cord

* The spinal cord is ______________________than the vertebral canal that houses it. _____________________________________________________________________________

* The ______________________inferior end of the spinal cord is called the ___________________ ______________ and it marks the official “___________” of the spinal cord proper.

* ______________________to this point, nerve roots (groups of axons collectively called the ___________ ___________) project inferiorly from the spinal cord.

* Within the cauda equina is the _________________________________, a thin strand of ___________mater that helps anchor the ___________medullaris to the ______________________.

Structure of the Spinal Cord

* The spinal cord is associated with ___________ pairs of spinal nerves that connect the ___________to muscles, receptors, and ___________.

* Each side of the spinal cord contains 8 cervical nerves (called ___________), 12 thoracic nerves (___________), 5 lumbar nerves (___________), 5 sacral nerves (___________), and 1 coccygeal nerve (___________).

Arrangement and Functions of the Spinal Meninges

* Are continuous with the ______________________meninges.

* Structures that encircle the spinal cord, listed from outermost to ______________________are:

- _________________________________

- ______________________space

- ___________mater

- ______________________space

- ______________________

- _________________________________space

- ___________mater

Location and Distribution of Gray Matter

* In the spinal cord, ___________ is centrally located.

* Its shape resembles a letter ___________ or a ______________________.

* The gray matter may be _________________________________into the following components:

- ______________________horns

- ______________________horns

- ______________________horns

- the gray _________________________________

Location and Distribution of White Matter

* The white matter of the spinal cord is ______________________to the gray matter.

* White matter on each side of the cord is also ______________________into three regions.

* A posterior ______________________lies between the posterior gray ___________on the posterior side of the cord and the posterior median ___________.

* The white matter region on each ______________________side of the spinal cord is the lateral __________________.

* The anterior ______________________is composed of tracts of white matter that occupy the space on each anterior side of the cord between the anterior gray horns and the anterior median ___________.

* The anterior ______________________are interconnected by the white ______________________.

Spinal Nerves

* ___________ pairs of spinal nerves connect the central nervous system to ______________________, glands, and ______________________

* Each spinal ___________is formed from the union of thousands of motor and sensory ___________.

* ___________axons originate from the ___________cord.

* Each anterior ___________and its corresponding posterior root ___________within the intervertebral foramen to become a spinal ___________.

* Contain both ___________axons and ______________________axons.

* Each spinal nerve is associated with the vertebra of the same ______________________.

Dermatomes

* A specific ______________________of skin supplied by a single ______________________nerve.

* All spinal nerves except for ___________ innervate a segment of skin, and so each of these nerves is associated with a ______________________.

* The skin of the body may be ______________________into sensory segments that collectively make up a _________________________________map.

Nerve Plexuses

* A network of _________________________________anterior rami of ___________nerves.

* Anterior ___________of most spinal nerves form nerve ______________________on both the right and left sides of the body.

* Nerve plexuses then split into multiple “___________” nerves that ______________________various body structures.

* Principal plexuses are the ______________________plexuses, ______________________plexuses, ______________________plexuses, and ______________________plexuses.

Reflexes

* ______________________, ______________________, _____________________________reactions of muscles or ______________________to a stimulus.

* All reflexes have similar ______________________.

- a ______________________is required to initiate a response to ______________________input

- a ___________response requires that few neurons be involved and synaptic delay be ___________

- an ______________________response occurs the same way ______________________

* An involuntary response requires no ___________or pre-______________________of the reflex activity.

* Reflexes are usually not ______________________.

* ______________________of the stimulus occurs ___________the reflex action has been completed, in time to correct or ___________a potentially ______________________situation.

Components of a Reflex Arc

* The neural “______________________” of a single reflex.

* Always begins at a ______________________in the ___________.

* Communicates with the ___________.

* Ends at a peripheral effector (muscle or ___________) cell.

Ipsilateral and Contralateral Reflex Arcs

* _________________________________is when both the receptor and effector organs of the reflex are on the same ___________of the spinal ___________.

* for example, an ______________________effect occurs when the muscles in your ___________arm contract to pull your ___________hand away from a hot object

* _________________________________is when the sensory impulses from a receptor organ ___________over through the spinal cord to activate effector organs in the ___________________limb.

* for example, ______________________effect occurs when you step on a ___________object with your left foot and then contract the muscles in your ___________leg to maintain balance as you withdraw your ___________leg from the damaging object

Monosynaptic Reflexes

* The ______________________of all reflexes.

* _________________________________are not involved in processing this reflex.

* The ___________________ (knee-jerk) reflex is a monosynaptic reflex that physicians use to assess the functioning of the ______________________cord.

* By tapping the patellar ______________________with a reflex hammer, the muscle ______________________in the quadriceps muscles are ______________________.

* Produces a noticeable ___________of the leg.

Polysynaptic Reflexes

* Have more ______________________neural pathways that exhibit a number of ___________involving interneurons within the reflex arc.

Because this reflex arc has more ______________________, there is a more prolonged ___________between stimulus and ___________.

See over(

Be able to fill in and describe this figure on the exam

[pic]

Stretch Reflexes

* _________________________________reflex that monitors and regulates skeletal muscle ___________.

* When a stimulus results in the ______________________of a muscle, that muscle reflexively ______________________.

* The ____________________ (knee-jerk) reflex is an example of a ______________________reflex.

* The stimulus (the ___________on the patellar ______________________) initiates contraction of the ______________________femoris muscle and extension of the ___________joint.

Golgi Tendon Reflex

* Prevents skeletal muscles from ______________________excessively.

* ________________tendon organs are nerve endings located within tendons near a muscle–tendon ______________________.

* activation of the Golgi tendon organ signal ______________________in the spinal cord, which in turn inhibit the actions of the ______________________neurons

The associated muscle is allowed to ___________, thus protecting the muscle and ______________________from excessive ______________________damage.

Reflex Testing in a Clinical Setting

* Reflexes can be used to ___________specific muscle groups and specific spinal nerves or ______________________of the spinal cord.

* Consistently ______________________reflex response may indicate ______________________to the nervous system or ___________.

* A reflex response may be normal, ______________________, or ______________________.

Review Questions

1. What provides a vital link between the brain and the rest of the body

2. The spinal cord exhibits some functional independence from the brain; True (A) or False (B)

3. The spinal cord and its attached spinal nerves serve what two important functions

4. A typical adult spinal cord is approximately how long?

5. What is the shape of the spinal cord when viewed in cross section?

6. The external surface of the spinal cord has what two longitudinal depressions

7. What is the superior-most region of the spinal cord

8. The cervical region of the spinal cord is continuous with what structure superior to it?

9. Which major region of the spinal cord is shortest?

10. What spinal cord region is the most inferior “tip” of the spinal cord

11. What is the relationship between the length of the spinal cord and the length of the vertebral column?

12. What is the tapering inferior end of the spinal cord that marks the official “end” of the spinal cord proper

13. What nerve roots project inferiorly from the spinal cord but are still housed in the vertebral canal?

14. What is a thin strand of pia mater that helps anchor the conus medullaris to the coccyx

15. The spinal cord is associated with 31 pairs of spinal nerves that connect the CNS to

16. The spinal meninges are continuous with the cranial;

17. Structures that encircle the spinal cord, listed from outermost to innermost are

18. Where, in the spinal cord, is the gray matter located?

19. The shape of the gray matter in the spinal cord resembles;

20. The gray matter may be subdivided into what components

21. The _______ of the spinal cord is external to the gray matter

22. What lies between the posterior gray horns on the posterior side of the cord and the posterior median sulcus

23. The white matter region on each lateral side of the spinal cord is the

24. What is composed of tracts of white matter that occupy the space on each anterior side of the cord between the anterior gray horns and the anterior median fissure

25. The anterior funiculi are interconnected by what structure?

26. 31 pairs of spinal nerves connect the central nervous system to

27. Each spinal nerve is formed from the union of thousands of motor axons only; True (A) or False (B)

28. From where do motor axons originate?

29. Each anterior spinal root and its corresponding posterior root unite within the intervertebral foramen to become a

30. Spinal nerves contain both motor axons and sensory axons; True (A) or False (B)

31. Each spinal nerve is associated with the vertebra of the same

32. What is a specific segment of skin supplied by a single spinal nerve

33. All spinal nerves except for C1 innervate a segment of;

34. The skin of the body may be divided into sensory segments that collectively make up a

35. What is a network of interweaving anterior rami of spinal nerves

36. Nerve plexuses then split into multiple ___________ that innervate various body structures

37. What are the principal nerve plexuses?

38. What is a rapid, automatic, involuntary reactions of muscles or glands to a stimulus

39. All reflexes have similar properties; True (A) or False (B)

40. What are the three reflex properties?

41. Reflexes are usually suppressed; True (A) or False (B)

42. What is the neural “wiring” of a single reflex?

43. Where do reflex arcs always begin?

44. What are the components of a reflex arc?

45. What type of reflex arc occurs when both the receptor and effector organs of the reflex are on the same side of the spinal cord?

46. When the muscles in your left arm contract to pull your left hand away from a hot object, this is an example of a;

47. What type of reflex arc occurs when the sensory impulses from a receptor organ cross over through the spinal cord to activate effector organs in the opposite limb

48. When you step on a sharp object with your left foot and then contract the muscles in your right leg to maintain balance as you withdraw your left leg from the damaging object, this is an example of a;

49. What is the simplest of all reflexes

50. What is a monosynaptic reflex that physicians use to assess the functioning of the spinal cord

51. What happens when the patellar ligament is hit with a reflex hammer

52. What would be indicated if the patellar reflex did not occur?

53. What reflexes have more complex neural pathways that exhibit a number of synapses involving interneurons within the reflex arc

54. Why is there is a more prolonged delay between stimulus and response in a polysynaptic reflex?

55. What is a monosynaptic reflex that monitors and regulates skeletal muscle length

56. The patellar (knee-jerk) reflex is an example of a stretch reflex; True (A) or False (B)

57. The stimulus (the tap on the patellar tendon) initiates contraction of what muscle (group)

58. What type of reflex prevents skeletal muscles from tensing excessively

59. What are nerve endings located within tendons near a muscle–tendon junction

60. What are the 3 levels of reflex response?

Essays;

Tell me as much as you can about stretch reflexes.

Be able to fill in and describe this figure on the exam

[pic]

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download