Chapter 13: Spinal Cord and Spinal Nerves Flashcards
Which of the three spinal meninges is the most superficial? a) Arachnoid mater b) Dura mater c) Meninx mater d) Pia mater e) Epi mater
b) Dura mater
Which of the structures listed below contains cerebrospinal fluid? a) Epidural space b) Subarachnoid space c) Dural space d) Meninx e) Pia mater
Answer: b) Subarachnoid space
Denticulate ligaments are thickenings of a) arachnoid mater. b) pia mater. c) dura mater. d) interstitial fluid. e) subdural space.
b) pia mater.
What spinal cord feature is the area where the nerves that supply the lower limb emerge? a) Lumbar enlargement b) Filum terminale c) Cauda equina d) Cranial nerve XII e) Cervical enlargement
a) Lumbar enlargement
Which of the following structures contains only sensory axons that conduct nerve impulses from sensory receptors in the skin, muscles and internal organs to the CNS? a) Spinal nerves b) Cauda equina c) Anterior root of spinal nerves d) Posterior root of spinal nerves e) Conus medullaris
d) Posterior root of spinal nerves
Which layer of protective connective tissue is the outermost covering surrounding a spinal nerve? a) dura mater b) pia mater c) endoneurium d) perineurium e) epineurium
e) epineurium
What type(s) of axons are wrapped in a protective endoneurium? 1. Myelinated 2. Unmyelinated 3. Only dendrites are surrounded by endoneurium a) 1 only b) 2 only c) 3 only d) Both 1 and 2 e) None of these choices
d) Both 1 and 2
Spinal nerves 1. Are parts of PNS. 2. connect the CNS to sensors and effectors in all parts of the body. 3. are named according to the region of the cord from which they emerge. a) 1 only b) 2 only c) 3 only d) both 1 & 3 e) 1, 2 & 3
e) 1, 2 & 3
Intercostal nerves a) are also known as cervical nerves. b) do not enter into a plexus and directly connect to the structures they supply. c) are found in the C6-T4 area of the vertebral column. d) extend through the sacrum. e) do not exist in humans.
b) do not enter into a plexus and directly connect to the structures they supply.
A man presents with median nerve palsy in his left hand. What is the most likely site of injury? a) Dorsal scapular nerve b) Intercostal nerve c) Lumbar plexus d) Median nerve e) Radial nerve
d) Median nerve
Which region of the spinal cord carries nerve impulses for proprioception? a) Posterior white column b) Anterior gray horn c) Anterior white column d) Lateral white column e) Dermatome tract
a) Posterior white column
Which white matter tracts of the spinal cord carry sensory information? a) Ascending tracts b) Descending tracts c) Integration tracts d) Columnar tracts e) Epidural tracts
a) Ascending tracts
Which type of descending motor pathway conveys nerve impulses that originate in the cerebral cortex and are destined to cause precise, voluntary movements of skeletal muscles? a) Indirect pathway b) Direct pathway c) Reflex arc d) Somatic arc e) Muscle spindle
b) Direct pathway
Which type of descending motor pathway originates in the brainstem and governs automatic movements that help regulate muscle tone, posture and balance? a) Indirect pathway b) Direct pathway c) Reflex arc d) Somatic arc e) Muscle spindles
a) Indirect pathway
Which of the following parts of a reflex arc monitors body conditions?
a) Sensory receptor
b) Integrating center
c) Motor neuron
d) Effector
e) Interneuron
a) Sensory receptor
Which of the following parts of a reflex arc receives sensory information and decides how to respond to a change in the body’s condition?
a) Sensory receptor
b) Sensory neuron
c) Motor neuron
d) Effector
e) Integration center
e) Integration center
Which of the following parts of a nervous reflex arc is usually a muscle or gland?
a) Sensory receptor
b) Sensory neuron
c) Motor neuron
d) Effector
e) Integration center
d) Effector
Which of the following parts of a reflex arc would have a cell body in the posterior root ganglion?
a) Sensory receptor cell
b) Sensory neuron
c) Motor neuron
d) Effector
e) Interneuron
b) Sensory neuron
A nerve impulse initiated at a muscle spindle has to travel through which of the following structures to get into the spinal column?
a) Anterior root of spinal nerve
b) Posterior root of spinal nerve
c) Tectospinal tract
d) Central canal
e) Lateral reticulospinal tract
b) Posterior root of spinal nerve
In response to a muscle being stretched, a muscle spindle initiates a somatic spinal reflex that causes
- contraction of the agonist muscle.
- relaxation of the antagonist muscle.
- contraction of the antagonist muscle.
- relaxation of the agonist muscle.
a) 1 only
b) 2 only
c) 3 only
d) 4 only
e) 1 and 2
e) 1 and 2
In response to a tendon being stretched excessively, a tendon organ initiates a somatic spinal reflex that causes
- contraction of the agonist muscle.
- relaxation of the antagonist muscle.
- contraction of the antagonist muscle.
- relaxation of the agonist muscle.
a) 1 only
b) 2 only
c) 3 only
d) 4 only
e) 3 and 4
e) 3 and 4
A somatic spinal reflex that involves one effector muscle being stimulated while the opposing muscle is inhibited is called _____ innervation.
a) reversal
b) relaxed
c) representative
d) reciprocal
e) relegated
d) reciprocal
Which of following is NOT a function of the spinal reflexes that use muscle spindles and tendon organs as sensors?
a) Awareness of muscle tension in body
b) Prevention of damage to muscles
c) Protection of spinal nerves
d) Prevention of damage to tendons
e) Maintenance of muscle tone
c) Protection of spinal nerves
A typical spinal nerve has how many connections to the spinal cord?
a) 1
b) 2
c) 3
d) 4
e) 5
b) 2
Which branch of a spinal nerve serves the deep muscles and skin of the posterior surface of the trunk?
a) Meningeal branch
b) Rami communicantes
c) Brachial plexus
d) Posterior ramus
e) Anterior ramus
d) Posterior ramus
The thoracic nerves are also called the
a) brachial nerves.
b) lumbar nerves.
c) sacral nerves.
d) cervical nerves.
e) intercostals nerves.
e) intercostals nerves.
Where is the subarachnoid space?
a) E
b) F
c) G
d) H
e) I
a) E
Where is the subdural space?
a) E
b) F
c) G
d) H
e) I
b) F
Where is the arachnoid mater?
a) E
b) F
c) G
d) H
e) I
d) H
Where is the pia mater?
a) E
b) F
c) G
d) H
e) I
c) G
Which layer is the dura mater?
a) E
b) F
c) G
d) H
e) I
e) I
Which of the labeled structures contains cerebral spinal fluid?
a) A
b) D
c) E
d) F
e) All of these choices
a) A
Which of the labeled structures carries exclusively sensory information towards the spinal cord?
a) B
b) C
c) F
d) G
e) H
a) B
Which of the labeled structures carries exclusively motor information away from the spinal cord?
a) B
b) C
c) F
d) G
e) H
b) C
Where is the pia mater?
a) D
b) E
c) F
d) G
e) H
b) E
Where is the posterior ramus?
a) B
b) C
c) G
d) H
e) None of these choices
c) G
Where is the epidural space?
a) A
b) D
c) E
d) F
e) G
d) F
Where is the anterior (ventral) root of a spinal nerve?
a) A
b) B
c) C
d) G
e) H
c) C
Where is the posterior median sulcus?
a) A
b) E
c) F
d) H
e) J
a) A
Where is the lateral white column?
a) C
b) D
c) G
d) H
e) I
b) D
Where is the anterior gray horn?
a) B
b) C
c) H
d) I
e) None of these choices
c) H
Where is the anterior white column?
a) B
b) C
c) H
d) I
e) J
d) I
Which portion of the spinal cord contains cell bodies and axons of interneurons as well as incoming axons of sensory neurons?
a) B
b) C
c) D
d) H
e) I
b) C
Which portion of the spinal cord contains the cell bodies of somatic motor neurons and motor nuclei?
a) B
b) C
c) D
d) H
e) I
d) H
Describe the cross-sectional anatomy of the spinal cord.
The spinal cord is slightly flattened in its anterior-posterior dimension. It has two grooves: anterior median fissure and shallower posterior median sulcus. The central canal contains CSF. The gray commissure surrounds the central canal, and forms the cross bar of the H. It contains the axons that connect the two sides of the gray horns (anterior, posterior, lateral). White matter surrounds the gray and is subdivided into columns (anterior, posterior, lateral). The anterior white commissure is anterior to the gray commissure.
Describe the gross external anatomy of the spinal cord.
The spinal cord is roughly cylindrical, but slightly flattened anterior/posterior. It extends from the medulla to the superior border of L2. The length ranges from 42-45 cm and is approximately 2 cm in diameter. There is a cervical enlargement from C4-T1 and a lumbar enlargement from T9-T12. The conus medullaris is the tapered inferior end. The filum terminale is an extension of the pia mater that anchors the cord to the coccyx. The cauda equina is the roots of spinal nerves angling inferiorly in the vertebral canal from the end of the spinal cord. 31 pairs of spinal nerves leave the cord at regular intervals through the intervertebral foramina.
Name and describe the locations of the four major plexuses of spinal nerves.
Cervical: alongside C1 through C4; 2. Brachial: inferior and lateral to C4 through T1 and superior to rib, posterior to clavicle; 3. Lumbar: lateral to L1 through L4 passing obliquely
posterior to psoas major and anterior to quadratus lumborum; 4. Sacral: L4-S3; anterior to sacrum.
Identify and describe the function of each of the components of a spinal reflex arc.
- Receptor: responds to specific changes in body conditions by producing graded potential; 2. Sensory neuron: conducts impulse from receptor to integrating center in gray matter of spinal cord; 3. Integrating center: site of synapse between sensory and other neurons; decision-making area in gray matter of spinal cord; 4. Motor neuron: conducts impulse from integrating center to effector; 5. Effector: is the structure that promotes change in body conditions by responding to motor nerve impulse, such as a muscle or a gland.
Which of the following structures is labeled B in the diagram?
a) Lumbar enlargement
b) Cervical enlargement
c) Conus medullaris
d) Cauda equina
e) Obturator nerve
b) Cervical enlargement
Which of the following structures is labeled D in the diagram?
a) Lumbar enlargement
b) Cervical enlargement
c) Conus medullaris
d) Cauda equina
e) Obturator nerve
a) Lumbar enlargement
Which of the following structures is labeled G in the diagram?
a) Lumbar enlargement
b) Cervical enlargement
c) Conus medullaris
d) Cauda equina
e) Obturator nerve
d) Cauda equina
The structure labeled A in the diagram belongs to which group of spinal nerves?
a) cervical nerves
b) thoracic nerves
c) lumbar nerves
d) sacral nerves
e) coccygeal nerves
a) cervical nerves
The structure labeled F in the diagram belongs to which group of spinal nerves?
a) cervical nerves
b) thoracic nerves
c) lumbar nerves
d) sacral nerves
e) coccygeal nerves
c) lumbar nerves
The structure labeled I in the diagram belongs to which group of spinal nerves?
a) cervical nerves
b) thoracic nerves
c) lumbar nerves
d) sacral nerves
e) coccygeal nerves
e) coccygeal nerves
Which of the following nerves is labeled A in the diagram?
a) phrenic nerve
b) ulnar nerve
c) intercostal nerve
d) femoral nerve
e) tibial nerve
a) phrenic nerve
Which of the following nerves is labeled D in the diagram?
a) phrenic nerve
b) ulnar nerve
c) intercostal nerve
d) femoral nerve
e) tibial nerve
c) intercostal nerve
Which of the following nerves is labeled E in the diagram?
a) phrenic nerve
b) ulnar nerve
c) intercostal nerve
d) femoral nerve
e) tibial nerve
d) femoral nerve
Which of the following nerves is labeled B in the diagram?
a) phrenic nerve
b) axillary nerve
c) intercostal nerve
d) femoral nerve
e) common fibular nerve
b) axillary nerve
The nerve labeled A in the diagram arises from which plexus?
a) cervical plexus
b) brachial plexus
c) lumbar plexus
d) sacral plexus
e) coccygeal plexus
a) cervical plexus
The nerve labeled B in the diagram arises from which plexus?
a) cervical plexus
b) brachial plexus
c) lumbar plexus
d) sacral plexus
e) coccygeal plexus
b) brachial plexus
Which nerve labeled in the diagram does NOT arise from any plexus?
a) A
b) B
c) D
d) E
e) G
c) D
Which nerves labeled in the diagram form the sciatic nerve?
a) B and C
b) A and B
c) F and G
d) E and F
e) D and E
c) F and G
Which of the following is a virus infection of the peripheral nervous system caused by herpes zoster, a virus that also causes chickenpox?
a) areflexia
b) shingles
c) poliomyelitis
d) amyotrophic lateral sclerosis
e) menigitis
b) shingles
Which of the following is a degenerative disease of the spinal cord?
a) amyotrophic lateral sclerosis
b) shingles
c) poliomyelitis
d) areflexia
e) all of these are degenerative diseases of the spinal cord
a) amyotrophic lateral sclerosis
Describe the basic anatomy of a spinal nerve plexus.
Axons from the anterior rami of spinal nerves do not go directly to the body structures they supply. Instead, they form networks called plexuses on both the left and right sides of the
body by joining with various numbers of axons from anterior rami of adjacent spinal nerves. Thus, the nerves that emerge from a plexus and innervate body organs contain nerve fibers from multiple spinal nerves.
Which of the following regions of the spinal cord contains a conspicuous enlargement?
a) filum terminale
b) cervical region
c) thoracic region
d) sacral region
e) coccygeal region
b) cervical region
The area of the skin that provides sensory input to the CNS via one pair of spinal nerve is called
a) a dermatome.
b) a microtome.
c) perineurium.
d) a fascicle.
e) an epitome.
a) a dermatome.
Discuss the clinical significance of dermatomes.
Knowing which spinal cord segments supply each dermatome makes it possible to locate damaged regions of the spinal cord. If the skin in a particular region is stimulated but the sensation is not perceived, the nerves supplying that dermatome are probably damaged.
A severed obturator nerve will lead into paralysis of which region of the body?
a) Cervical
b) Thoracic
c) Lumbar
d) Thigh
e) Arms
d) Thigh
During childbirth, anesthesia is administered into the epidural space of the spinal column between which of the following vertebrae?
- L4 and L5
- T3 and T4
- S4 and S5
- C3 and C4
a) 1 only
b) 2 only
c) 3 only
d) 4 only
e) Both 1 and 4
a) 1 only
Which of the following spinal nerves DOES NOT travel through an intervertebral foramen to reach its destination?
a) cervical spinal nerve 1
b) thoracic spinal nerve 12
c) lumbar spinal nerve 2
d) sacral spinal nerve 1
e) cervical spinal nerve 7
a) cervical spinal nerve 1
The cell bodies of the sensory neurons that carry information from the periphery to the spinal cord are located in the
a) anterior white commissure.
b) central canal.
c) lateral gray horn.
d) posterior root ganglion.
e) posterior gray horn.
d) posterior root ganglion.
Which of the following lists the connective tissue coverings of the axons, fascicles, and entire nerve in the correct order?
a) endoneurium, perineurium, epineurium
b) endoneurium, epineurium, perineurium
c) perineurium, epineurium, endoneurium
d) epineurium, endoneurium, perineurium
a) endoneurium, perineurium, epineurium
Which of the following is NOT a common characteristic of dermatomes?
a) Can be used clinically to determine area of spinal cord damage
b) Each dermatome is only served by a single spinal nerve
c) Complete anesthesia of a single dermatome often requires blocking three adjacent spinal nerves
d) Dermatomes are designated based on the cranial or spinal nerve that serves that area of the skin
e) The dermatome serving the face is supplied by the trigeminal cranial nerve
b) Each dermatome is only served by a single spinal nerve
Which of the following is NOT a characteristic of the spinothalamic tract?
a) Begins in the spinal cord
b) Terminates in the thalamus
c) Found in the white matter of the spinal cord
d) Carries motor information down the cord
e) Is composed of multiple axons carrying information in the spinal cord
d) Carries motor information down the cord
