Physiology Study Guide 10: the Spinal Cord & Fiber Tracts1

Physiology Study Guide 10: The Spinal Cord & Fiber Tracts1

Steven A. Fink; Instructor

PHYSIOLOGY STUDY GUIDE 10:

THE SPINAL CORD & FIBER TRACTS

True/False

____ 1. Somatic motorneurons are affected by both pyramidal & extrapyramidal tract fibers from the brain.

____ 2.Nerve fiber tracts consist of bundles of myelinated axons ascending or descending within the CNS.

____ 3. Motorneurons leave the spinal cord via the dorsal (posterior) root of the spinal nerve.

____ 4. Proprioceptors are a type of somatic sensory neuron.

____ 5. The commissure that links the right & left hemispheres of the cerebrum together is called the cerebellum.

____ 6. Injury to the spinal cord could result in anesthesia above the level of the injury.

____ 7. Somatic motorneurons are affected by both excitatory & inhibitory influences.

____ 8. Based upon its name, the “Reticulospinal Tract” is probably an ascending fiber tract that conveys sensory information.

____ 9. In a man injured in an accident that completely severed his spinal cord at the level of T-12, you would expect an inability to voluntarily control urination or defecation.

____10. The corticospinal tract is a motor tract.

____11. All spinal nerves are called "mixed nerves" because they all contain both sensory and motor nerve fibers.

____12. The cell bodies of sensory neurons are located in the gray matter of the CNS.

____13. The cell bodies of autonomic motorneurons are located in the dorsal (posterior) root ganglia of the spinal nerves.

____14. Sensory nerve fibersenter the spinal cord through the anterior (ventral) root of the spinal nerve.

Multiple Choice

____15. A cluster of neuron cell bodies within the CNS is called a(n):
(a) nucleus
(b) effector
(c) ganglion
(d) commissure
(e) white matter

____16. The Pyramidal Tract fibers originate in the:

(a) Cerebral cortex

(b) Thalamus

(d) lateral gray horns of the Spinal cord

(e) Cerebellum

____17. An injury in a right cervical spinal nerve (Rt. C-3) would most likely produce:
(a) loss of sensation only at the 3rd cervical level on the right side
(b) paralysis of skeletal muscles only at the 3rd cervical level on

the right side

the right side
(d) loss of pain & temperature sensation on the right side of

the body at all levels below C-3
(e) paralysis of skeletal muscles on the right side of the body

at all levels below C-3

_____18. The Spinothalamic Tract conducts impulses related to:
(a) temperature & pain
(b) voluntary movement of skeletal muscles
(c) autonomic modulation of the visceral organs
(d) voluntary control of the Skeletal muscles
(e) subconscious shivering

____19. In the Dorsal (Posterior) White Column Tracts, the 1° (first-order) neuron synapses in the [see Lecture Outline, p. 79]

(a) thalamus

(b) medulla oblongata

(d) cerebral cortex

(e) spinal cord

____20. An injury to the Pyramidal Tract on the right side of the spinal cord at C-3 would most likely produce:
(a) loss of sensation only at the 3rd cervical level on the right side
(b) paralysis of skeletal muscles only at the 3rd cervical level on the

right side
(c) loss of both sensation & paralysis only at the 3rd cervical level on

the right side
(d) paralysis of all skeletal muscles on the right side of the

body at all levels below C-3
(e) loss of both sensation and paralysis of all skeletal muscles on the

right side of the body at all levels below C-3

____21. Spinal nerves are considered "mixed," which means that:
(a) they contain both nerves and tracts
(b) they contain both gray and white matter
(c) they contain both afferent ane efferent nerve fibers
(d) they use multiple types of neurotransmitters
(e) they contain dorsal and ventral roots

____22. The spinal cord passes through the ______of the vertebral column.
(a) foramen magnum
(b) lateral ventricle
(c) intervertebral foramen
(d) vertebral canal (foramen)
(e) central canal

____23. If the ventral (anterior) root of a spinal nerve was cut; there would be a loss on one side of ______at that level.
(a) sensation
(b) voluntary movement
(c) both (a) & (b) above
(d) impossible to predict

____24. Sensory neurons are also called:
(a) 1st order Neurons
(b) 2nd order Neurons
(c) 3rd order Neurons
(d) Interneurons
(e) Ganglia

____25. The ______Tract relays sensory information about pain.
(a) Spinocerebellar
(b) Dorsal (Posterior) White Columns
(c) Corticospinal
(d) Extrapyramidal
(e) Spinothalamic

____26. Which nerve fiber tract relays orders from the Midbrain to the somatic motorneurons?
(a) Spinocerebellar
(b) Dorsal (White) Columns
(c) Corticospinal
(d) Extrapyramidal
(e) Spinothalamic

____27. The cell bodies of certain autonomic motorneurons are located in the ______of the spinal cord.
(a) dorsal (posterior) gray horns
(b) lateral gray horns
(c) ventral (anterior) gray horns
(d) dorsal (posterior) root (spinal) ganglia
(e) gray commissures

____28. Spinal nerves contain:

(a) axons of sensory nerve fibers & dendrites of motor nerve fibers

(b) axons of motor nerve fibers & dendrites of sensory nerve fibers

(d) dendrites & axons of motor nerve fibers

(e) none of the above

____29. Somatic motorneurons originate in the ______of the spinal cord.

(a) dorsal gray horns

(b) lateral gray horns

(d) dorsal white columns

(e) central canal

____30. Bundles of nerve fibers that cross from one side to the CNS to the

other side are called:
(a) ganglia
(b) fasciculi
(c) commisures
(d) Nodes of Ranvier
(e) astrocytes

____31. Most sensory information is transmitted to the ______of the brain before being relayed to the Cerebral Cortex.
(a) Cerebellum
(b) Midbrain
(c) Thalamus
(d) Hypothalamus
(e) Basal (Ganglia) Nuclei

____32. The visceral sensory neuron cell bodiesare located in the:

(a) dorsal (posterior) root ganglia

(b) ventral (anterior) gray horns

(d) dorsal (posterior) gray horns

(e) Thalamus

____33. The Dorsal (Posterior) White Column Fiber Tract transmits action potentials to:
(a) somatic motorneurons in the spinal cord
(b) interneurons in the cerebellum
(c) interneurons in the cerebral cortex
(d) interneurons in the thalamus
(e) interneurons in the spinal cord

___34. Which one of the following is located principally in the dorsal (posterior) gray horns of the spinal cord?
(a) the cell bodies of sensory neurons
(b) the cell bodies of somatic motorneurons
(c) the cell bodies of certain autonomic motorneurons
(d) the cell bodies of interneurons
(e) myelinated sensory fiber tracts

___35. Which one of the following lists the components of a Reflex Arc in the correct order of functioning?
(a) receptor, motorneuron, integrating center, sensory neuron, effector
(b) motorneuron, receptor, integrating center, sensory neuron, effector
(c) receptor, sensory neuron, effector, motorneuron, integrating center
(d) receptor, sensory neuron, integrating center, motorneuron, effector
(e) effector, sensory neuron, integrating center, motorneuron, receptor

___36. Bundles of myelinated axons in the spinal cord having a common origin & destination and relaying similar information/commands are called:
(a) tracts
(b) commissures
(c) ganglia
(d) nuclei
(e) meninges

___37. Each spinal nerve passes through an opening in the vertebral column called a(n):
(a) vertebral body
(b) intervertebral disc
(c) intervertebral foramen
(d) vertebral canal (foramen)
(e) central canal

____38. The 2nd order neurons of the Spinothalamic Tract decussate in the:
(a) spinal cord
(b) Medulla oblongata
(c) Thalamus
(d) Corpus Callosum
(e) Limbic System

Use the diagram below to answer the next 3 Multiple Choice Questions:

____39. The structure labeled (A) is:
(a) somatic sensory nerve fiber
(b) somatic motor nerve fiber
(c) visceral sensory nerve fiber
(d) autonomic motor nerve fiber
(e) ascending interneuron
(ab) descending interneuron

____40. The structure labeled (B) is:
(a) somatic sensory nerve fiber
(b) somatic motor nerve fiber
(c) visceral sensory nerve fiber
(d) autonomic motor nerve fiber
(e) ascending interneuron
(ab) descending interneuron

____41. The structure labeled (C) is:
(a) somatic sensory nerve fiber
(b) somatic motor nerve fiber
(c) visceral sensory nerve fiber
(d) autonomic motor nerve fiber
(e) ascending interneuron
(ab) descending interneuron