Bio 2401: Chapter 13 Review

Sciatic

As the ________ nerve approaches the knee, it divides into two branches, the fibular nerve and the tibial nerve.

B) sciatic

Each of the following nerves originates in the lumbar plexus, except the ________ nerve. A) saphenous B) sciatic C) femoral D) obturator E) genitofemoral

Might be unable to breathe on his own

If a person has a crush injury to the C3-C5 spinal segments, you would expect that he _________.

Reverberation

In ________, axon collaterals extend back toward the source of the impulse and further stimulate the earlier neurons.

Divergence

In ________, one neuron synapses on several postsynaptic neurons.

Monosynaptic

In a(n) ________ reflex, a sensory neuron synapses directly on a motor neuron.

L1

In an adult, the conus medullaris is found at about the level of vertebra ______.

C) ascending tracts

Mary is in an automobile accident and suffers a spinal cord injury. She has lost feeling in her lower body. Her doctor tells her that swelling is compressing a portion of her spinal cord. Which part of her cord is likely to be compressed? A) the anterior gray horns B) the anterior gray commissures C) ascending tracts D) descending tracts

Cervical

Muscles of the neck and shoulder are innervated by spinal nerves from the ________ region.

D) white columns.

Nerve tracts or fasciculi make up the ______. A) central canal. B) posterior gray horns. C) gray commissures. D) white columns.

Subarachnoid

Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the _______ space.

Perineurium

The layer of connective tissue that surrounds a fascicle within a peripheral nerve is the _____.

Axons of sensory neurons; axons of motor neurons

The dorsal root of a spinal nerve contains _________ and ventral root contains _______.

Coccygeal ligament

The dura mater tapers inferiorly to form the ________.

Nerve cell bodies

The gray horns of the spinal cord contain mainly ______.

Endoneurium

The layer of connective tissue that surrounds individual axons within a peripheral nerve is termed the _________.

Paraplegia

The loss of feeling and movement of the legs is termed ________.

Rami communicantes

The white ramus and the gray ramus collectively are called the ________.

Axons of sensory

The dorsal root contains ________ neurons.

Cell bodies of sensory neurons

The dorsal root ganglia mainly contain _______.

Plexus

A complex, interwoven network of nerves is called a(n) ________.

Spinal nerve

A dorsal and ventral root of each spinal segment unite to form a __________.

Muscle weakness or paralysis

A viral disease that destroys the cells of the anterior gray horn will cause _____.

Polysynaptic

A(n) ________ reflex has at least one interneuron placed between the sensory and motor neurons.

Obturator nerve

Adductors of the hip is innervated by __________ nerve.

4

After age ________ the vertebral column continues to elongate, but the spinal cord itself does not.

C) are found in tendons.

All of the following are true of muscle spindles, except that they A) are found within skeletal muscle. B) consist of specialized fibers called intrafusal fibers. C) are found in tendons. D) are the receptor for the stretch reflex. E) are innervated by gamma motor neurons.

Cannot be modified by the brain

All of the following are true of neural reflexes, except that they _________.

A) are arranged according to dermatomes.

All of the following are true of polysynaptic reflexes, except that they A) are arranged according to dermatomes. B) are intersegmental in distribution. C) involve reciprocal innervation. D) have reverberating circuits that prolong the reflexive motor response. E) involve pools of interneurons.

D) gray commissures.

Axons crossing from one side of the spinal cord to the other within the gray matter are found in the A) anterior gray horns. B) lateral gray horns. C) posterior gray horns. D) gray commissures. E) white commissures.

A) loss of sensation in his torso

Bill contracts a viral disease that destroys cells in the posterior gray horns in his spinal cord. As a result, which of the following would you expect? A) loss of sensation in his torso B) inability to breathe C) problems with moving his arms D) uncontrollable sweating of his feet

Pia mater

Blood vessels that supply the spinal cord run along the surface of the __________.

Subarachnoid

Blood vessels traveling within the ________ space deliver oxygen and nutrients to the spinal cord.

Subarachnoid

Cerebrospinal fluid flows within the __________ space.

Dura mater, arachnoid mater, and pia mater.

Describe the 3 meninges _________.

Spinal tap

During the procedure known as a(n) ________, a needle is inserted into the subarachnoid space in the inferior lumbar region.

E) all of the above

In meningitis, A) inflammation of the meninges occurs. B) bacteria can be the cause. C) viruses can be the cause. D) CSF flow can be disrupted. E) all of the above

C) columns.

In the spinal cord, white matter is separated into ascending and descending tracts organized as ______. A) nuclei. B) ganglia. C) columns. D) nerves. E) horns.

A polysynaptic reflex

In which of the following would the delay between stimulus and response be greater?

Brachial

In which plexus does the ulnar nerve arise?

Sympathetic nerves

Postganglionic fibers of the autonomic nervous system that innervate internal organs do not rejoin the spinal nerve but form ______________.

Innate

Reflexes based on synapses formed during development are ________ reflexes.

E) whether they are sensory or motor.

Reflexes can be classified according to all of the following, except A) their development. B) where information processing occurs. C) the motor response. D) the complexity of the neural circuit. E) whether they are sensory or motor.

Ipsilateral; contralateral

Reflexes that activate muscles on the same side of the body as the stimulus are called ________. Reflexes that activate muscles on the opposite side of the body as the stimulus are called ________.

Descending motor tracts that excite the motor neurons that activate forearm and hand muscles also send excitatory impulses to motor neurons lower down the spinal cord. These EPSPs spatially summate with the excitatory inputs from the muscle spindles to quadriceps motor neurons, bringing the quadriceps neurons to threshold, and thus generate a brisk "knee jerk" response.

Sometimes, when it is difficult to initiate a knee-jerk reflex by tapping the patellar tendon, a patient will be asked to voluntarily make a fist. Then the reflex will be easily evoked. What does this illustrate about the relation between voluntary and involuntary reflex movement?

Reciprocal inhibition

Spinal interneurons inhibit antagonist motor neurons in a process called ________.

Leg

Spinal nerves from the sacral region of the cord innervate the ________ muscles.

Ventral

Suppose that you feel something brushing against your abdomen. The sensory information would be carried to the spinal cord over a ________ ramus.

Ventral ramus

The ______ innervates the ventrolateral body surface, structures in the body wall, and the limbs.

Phrenic

The ________ nerve, which arises in the cervical plexus, innervates the diaphragm.

Sympathetic

The ________ nervous system stimulates the arrector pili muscles and gives you "goosebumps."

Dorsal ramus

The ________ of each spinal nerve innervates the skin and muscles of the back.

Crossed extensor

The ________ reflex complements the flexor reflex by activating contralateral muscles.

Epidural space

The ________ separates the dura mater from the walls of the vertebral canal.

Somatic motor nuclei

The anterior horns of the spinal cord contain mainly ______.

E) phrenic.

The brachial plexus gives rise to all of the following nerves, except the A) radial. B) median. C) ulnar. D) musculocutaneous. E) phrenic.

Plexus

The complex, interwoven network formed by contributions from the ventral rami of neighboring spinal nerves is termed a(n) ________.

Quadriplegia

The condition in which a person loses all feeling and movement of the arms and legs due to spinal cord injury is termed ________.

Intersegmental reflex arcs

The most complicated spinal reflexes are called ________.

Phrenic

The nerve crucial for breathing that originates within the cervical plexus is called the ________ nerve.

Reflex arc

The neural "wiring" of a single reflex is called a(n) ________.

Epineurium

The outermost connective-tissue covering of nerves is the ______.

Horns

The outward projections from the central gray matter of the spinal cord are called ______.

Sensory nuclei

The posterior horns of the spinal cord contain mainly ______.

B) gray rami communicantes.

The postganglionic fibers that connect an autonomic ganglion in the thoracic or lumbar region with the spinal nerve and contain postganglionic fibers that innervate glands in the body wall or limbs are A) white rami communicantes. B) gray rami communicantes.

A) white rami communicantes.

The preganglionic fibers that connect a spinal nerve with an autonomic ganglion in the thoracic and lumbar region of the spinal cord and carries visceral motor fibers that are myelinated form the A) white rami communicantes. B) gray rami communicantes.

Tendon

The reflex that prevents a muscle from exerting too much tension is the ________ reflex.

Dermatome

The specific strip of skin that is innervated by a specific spinal nerve is called a(n) ________.

31

The spinal cord consists of five regions and ________ segments.

True

The spinal cord is part of the central nervous system. T/F

Medulla cone (conus medullaris); Cauda equina; Filum terminal

The structures of the spinal cord seen in the lumbar region include ______, _____, and ____.

Brachial

The ventral rami of spinal nerves C5 to T1 contribute fibers to the ________ plexus.

D) myelinated and unmyelinated axons.

The white matter of the spinal cord is mainly A) unmyelinated axons. B) neuroglia. C) Schwann cells. D) myelinated and unmyelinated axons. E) nodes of Ranvier.

Collateral

Unpaired sympathetic ganglia are called ________ ganglia.

A reflex arc is the wiring pattern of neurons that underlie a particular reflex. A reflex arc consists of three elements at the minimum: (1) a sensory receptor and neuron to carry afferent information to the CNS; (2) an excitatory synapse on a motor neuron; (3) the motor neuron to generate an action potential and conduct the impulse to an effector such as a skeletal muscle motor unit.

What is a reflex arc? What components must be present to qualify?

The dorsal roots contain axons of sensory neurons, so input from those afferents within the severed root would not be transmitted to the CNS and thus this lesion would result in a complete loss of feeling from the body region served by the afferent fibers in that dorsal root.

What would happen if the dorsal root of a spinal nerve were completely transected?

B) 11 thoracic spinal nerves

Which of the following associations is incorrect? A) 8 cervical spinal nerves B) 11 thoracic spinal nerves C) 5 lumbar spinal nerves D) 5 sacral spinal nerves E) 1 coccygeal spinal nerve

Why you close your eyes when you sneeze

Which of the following is not true about a positive Babinski reflex?

E) all of the above

Which of the following is true regarding an epidural block? A) It is commonly used as a method of pain control during labor and delivery. B) It affects only the spinal nerves in the immediate area of the injection. C) It can provide sensory and motor anesthesia, depending on the anesthetic selected. D) It can provide mainly sensory anesthesia, depending on the anesthetic selected. E) all of the above

He has a damaged left femoral nerve. This nerve also supplies sensory innervation to the skin on the anteromedial surface of the thigh and medial surfaces of the leg and foot, so he will also experience numbness in those regions.

While playing football, Ramón is tackled hard, and as he tries to get up, he finds that he has difficulty flexing and adducting his left thigh and extending his left leg. Which nerve innervating the lower limb may be damaged, and how would the damage affect sensory perception in Ramón's left leg?

Somatic

________ reflexes activate skeletal muscles.