Match the following neurons/ cells to its corresponding description. 1. spinal glycinergic inhibitory interneurons 2. directly innervate the skeletal muscle fibers 3. where almost all sensory signals from spinal nerves or signals from the brain are transmitted first A. Anterior Motor Neurons B. Interneurons C. Renshaw Cells D. A & B E. A & C

1. C 2. A 3. B Source: Guyton (Chapter 55)

S1_L1: Reflexes Flashcards by MindMed Official

This is an involuntary motor output and nearly instantaneous movement in response to a stimulation.

Reflex

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TRUE OR FALSE: Reflexes are symmetrical. It does not receive nor need conscious thought.

A. Both statements are true
B. Both statements are false
C. Only the 1st statement is true
D. Only the 2nd statement is true

A. Both statements are true

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Reflex responses happen (1)_______ to prevent us from being (2)_______

automatically
harmed

NOTE: it is for self-preservation

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Reflexes are (1)_______ and can be modified to perform (2)_______ tasks and maintain (3)_______

adaptable
motor
balance

Source: Ganong (Chapter 12)

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Determine the number of synapses of a reflex

ankle reflex
stretch reflex
deep tendon reflexes
withdrawal reflex
triceps reflex

A. Monosynaptic reflex
B. Polysynaptic reflex

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This is the basic unit of integrated reflex activity

Reflex Arc

Source: Ganong (Chapter 12)

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An activity in the reflex arc generates (1)_______ action potentials in the (2)_______ nerve

all-or-none
afferent

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TRUE OR FALSE: Reflex activity is specific in that a particular stimulus elicits a particular response. Ascending inputs from higher brain regions play an important role in modulating and adapting spinal reflexes.

A. Both statements are true
B. Both statements are false
C. Only the 1st statement is true
D. Only the 2nd statement is true

Source: Ganong (Chapter 12)

C. Only the 1st statement is true

Note: It is descending inputs

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Activity in the reflex arc starts in a (1)______ with a (2)______

sensory receptor
receptor potential

Source: Ganong (Chapter 12)

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TRUE OR FALSE: The number of action potentials is proportional to the size of the receptor potential.

True

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Somatic reflex - involve the (1) _______ muscles, while autonomic reflex - involve the (2)_______ muscles

skeletal
smooth

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_______ is the integrative area for the cord reflexes

Cord gray matter

Source: Guyton (Chapter 55)

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TRUE OR FALSE: When tendon reflex are tested, limbs on each side should be flexed to 90 degrees and strike for 5 times.

False

It must only be placed in identical positions and elicited in the same manner.

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TRUE OR FALSE: Receptor potential’s magnitude is proportional to the strength of the stimulus

True

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Tendon reflexes are elicited because of change in (1)_____ or (2)_____ tension in a muscle

length
tension

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You tested a pt’s knee jerk with him sitting on the edge of a bed, with his feet dangling. With a reflex hammer, you tap his patellar tendon. As a result, his leg kicked out, then immediately came to a rest.

What grade will this response be given?

2+ (normoreflexia)

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You tested a pt’s knee jerk with him sitting on the edge of a bed, with his feet dangling. With a reflex hammer, you tap his patellar tendon. As a result, his leg kept swinging out repetitively.

What grade will this response be given?

NOTE: This is a very brisk, with clonus response (repetitive jerky movement noted after elicitation of reflex)

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You tested a pt’s knee jerk with him sitting on the edge of a bed, with his feet dangling. With a reflex hammer, you tap his patellar tendon. However, tghe leg does not respond.

What grade will this response be given?

0 (areflexia)

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TRUE OR FALSE: Tendon reflexes can excite either GTO or muscle spindle, or both at the same time

True

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Match the following neurons/ cells to its corresponding description.

located in the anterior horns of the spinal cord
present in all areas of the cord gray matter
small and highly excitable, often exhibiting spontaneous activity and capable of firing as rapidly as 1500 times per second

A. Anterior Motor Neurons
B. Interneurons
C. Renshaw Cells
D. A & B
E. A & C

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Match the following neurons/ cells to its corresponding description.

spinal glycinergic inhibitory interneurons
directly innervate the skeletal muscle fibers
where almost all sensory signals from spinal nerves or signals from the brain are transmitted first

A. Anterior Motor Neurons
B. Interneurons
C. Renshaw Cells
D. A & B
E. A & C

Source: Guyton (Chapter 55)

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Interconnections among the (1)_____ and (2)______ are responsible for most of the integrative functions of the spinal cord

interneurons
anterior motor neurons

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What are the 2 types of anterior motor neurons?

alpha motor neurons and gamma motor neurons

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type A alpha (Aα) motor nerve fibers innervate (1)______ fibers, while type A gamma (Aγ) motor nerve fibers innervate (2)_______ fibers

extrafusal
intrafusal

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Intrafusal fibers constitute the middle of the _______, which helps control basic muscle tone.

muscle spindle

This is when the stimulation of each motor neuron tends to inhibit adjacent motor neurons

Lateral inhibition

Which of these utilizes lateral inhibition? A. Anterior Motor Neurons B. Interneurons C. Renshaw Cells

C. Renshaw Cells

These fibers run from one segment of the cord to another and provide pathways for the multi segmental reflexes

Propriospinal Fibers

What tract carry instantaneous information from both the muscle spindles and the Golgi tendon organs directly to the cerebellum?

Dorsal spinocerebellar tracts

TRUE OR FALSE: Both the GTO and muscle spindle are almost entirely for the purpose of extrinsic muscle control. These operate almost completely at a subconscious level. A. Both statements are true B. Both statements are false C. Only the 1st statement is true D. Only the 2nd statement is true

D. Only the 2nd statement is true *intrinsic muscle control

Determine whether the description is for a muscle spindle or for GTO. 1. excitatory in nature 2. inhibitory in nature 3. sensitive to stretch 4. sensitive to tension or rate of change of tension 5. distributed all throughout the muscle belly A. Muscle Spindle B. Golgi Tendon Organ

1. A 2. B 3. A 4. B 5. A

The following statements are true about muscle spindles, EXCEPT: A. Deeply ingrained with nerve endings B. Spindle-like or fusiform-shaped muscle sensory receptor C. Send information to the nervous system about muscle length or rate of change of length D. Central portion functions as a sensory and motor receptor E. None of the above

D. Central portion functions as a sensory and motor receptor NOTE: Only as a sensory receptor

TRUE OR FALSE: Muscle spindles provide information on joint position.

True NOTE: This is because changes in muscle length are associated with changes in joint angle Source: Ganong (Chapter 12)

The central portion of the muscle spindle is _____ A. Contractile B. Non-contractile

B. Non-contractile

What are the 2 types of sensory endings at the central receptor area of the muscle spindle?

1. Primary afferent ending/Annulospiral ending 2. Secondary afferent ending/FlowerSpray ending

Determine the type of sensory endings at the central receptor area of the muscle spindle. 1. Type II fibers 2. Encircles the central portion of intrafusal fibers 3. Faster nerve conduction velocity 4. Excited by both the nuclear bag intrafusal fibers and the nuclear chain fibers 5. Only excited by the nuclear chain fibers A. Annulo-spiral ending B. Flower-Spray ending

1. B 2. A 3. A 4. A 5. B

How fast is the nerve conduction velocity of the annulo-spiral endings?

70-120m/s

What kind of nerve fibers do the annulo-spiral endings ahve?

Type Ia fibers

TRUE OR FALSE: Both branches of the annulo-spiral endings innervate the nuclear bag and nuclear chain.

False. NOTE: One branch innervates nuclear bag. The other branch innervates nuclear bag and nuclear chain.

Determine the muscle spindle intrafusal fiber. 1. has 2 subtypes: dynamic and static 2. one to three in each spindle 3. three to nine in each spindle 4. innervated by type Ia and II 5. nuclei aligned in a chain throughout the receptor area A. Nuclear bag muscle fibers B. Nuclear chain fibers

1. A 2. A 3. B 4. B 5. B

The polar ends of a muscle spindle is contractile because of the presence of (1)____ and (2)_____ filaments.

1. actin 2. myosin

Gamma efferent fibers are _____ A. Inhibitory B. Excitatory C. Both

B. Excitatory

Stretching the muscle spindles (1)______ the rate of firing, whereas shortening the spindle (2)_______ the rate of firing

1. increases 2. decreases

TRUE OR FALSE: Spindles can send to the spinal cord either positive signals to indicate stretch or negative signals to indicate that the muscle is unstretched

True

Determine the response of the muscle spindle receptor. 1. Slow lengthening/stretching of muscle 2. Degree of muscle contraction remains constant 3. When lengthening stops, there’s an extra rate of smaller static responses 4. Elicited by signals from annulospiral/primary ending only 5. Stimulated by rapid stretch or unstretch A. Static Response B. Static Response

1. A 2. A 3. B 4. B 5. B

Static response responds to (1)_____ of receptor, while dynamic response responds to the (2)_____ of (3)_____ of receptor length

1. length 2. rate 3. change

Determine the response of gamma motor nerves. 1. excites mainly the nuclear bag intrafusal fibers 2. excites mainly the nuclear bag intrafusal fibers A. Gamma-dynamic (gamma-d) B. Gamma-static (gamma-s)

1. A 2. B

TOPIC: Myotatic reflex The stimulus that initiates this reflex is (1)______ of the muscle, and the response is (2)______ of the muscle being stretched.

1. stretch 2. contraction

This pathways allows a reflex signal to return with the shortest possible time delay back to the muscle after excitation of the spindle

Monosynaptic pathway

Arrange the monosynaptic pathway in correct sequence. 1. spinal cord 2. muscle 3. sensory receptor 4. afferent neuron 5. efferent neuron

34152

In the monosynaptic pathway, most fibers do not reach level of the (1)______ but at level of (2)______. It is faster than (3)______.

1. cerebrum 2. spinal cord 2. polysynaptic reflex

This is the stretch reflex of the quadriceps femoris muscle, because the tap on the tendon stretches the muscle

Knee jerk reflex

Determine the kind of stretch reflex. 1. Elicited by the continuous static receptor signals transmitted by both primary and secondary endings. 2. Signals transmitted by primary sensory endings of the muscle spindles 3. Caused by rapid stretch or unstretch, sudden stretch of muscle spindles 4. The reflex functions to oppose sudden changes in muscle length 5. Causes the degree of muscle contraction to remain reasonably constant A. Static Stretch Reflex B. Dynamic Stretch Reflex

1. A 2. B 3. B 4. B 5. A

This is the ability to prevent oscillation or jerkiness of body movements.

Damping/Smoothing

_________ consists of a netlike collection of knobby nerve endings among the fascicles of a tendon. This is encapsulated muscle sensory receptor through which muscle tendon fibers pass

Golgi Tendon Organ (GTO)

The GTO has a local cord signal excites a single inhibitory interneuron that inhibits the (1)_______. It directly inhibits the (2)________ without affecting adjacent muscles

1. anterior motor neuron 2. individual muscle

The GTOs uses what type of nerve fibers?

Type Ib

This stimulated by increased tension in the connecting muscle, signals are transmitted to the spinal cord to cause reflex effects in the respective muscle

Golgi Tendon Reflex

This stimulated by increased tension in the connecting muscle, signals are transmitted to the spinal cord to cause reflex effects in the respective muscle

Golgi Tendon Reflex

When tension is so great, inhibitory effect can lead to sudden and instantaneous relaxation of the whole muscle. What reaction is being referred by the statement above?

Lengthening reaction

When tension is so great, inhibitory effect can lead to sudden and instantaneous relaxation of the whole muscle. What reaction is being referred by the statement above?

Lengthening reaction

GTO inhibits the muscle contraction, therefore it _______ the muscle

lengthens

TRUE OR FALSE: The lengthening reaction is a protective mechanism to prevent tearing of the muscle or avulsion of the tendon from its attachments to the bone

True

The golgi tendon reflex is ______ A. Excitatory B. Inhibitory C. Both

B. Inhibitory

TRUE OR FALSE: The Golgi Tendon Reflex provides a positive feedback mechanism that prevents the development of too much tension on the muscle. It equalizes contractile forces of the separate muscle fibers A. Both statements are true B. Both statements are false C. Only the 1st statement is true D. Only the 2nd statement is true

D. Only the 2nd statement is true NOTE: It is a negative feedback. Fibers that exert excess tension become inhibited by the reflex. Fibers that exert too little tension become more excited because of the absence of reflex inhibition

This is a stretch reflex that causes the agonist muscle to contract and simultaneously causes antagonist to relax. It often exist between the muscles on the two sides of the body

Reciprocal Inhibition

This is a neuronal circuit that causes this reciprocal inhibition

Reciprocal innervation

This reflex is elicited most powerfully by stimulation of pain endings. It is also called nociceptive reflex or pain reflex.

Flexor Reflex

TRUE OR FALSE: The flexor reflex pass directly to the anterior motor neurons. It has one reciprocal inhibition circuit to enable for muscle withdrawal. A. Both statements are true B. Both statements are false C. Only the 1st statement is true D. Only the 2nd statement is true

B. Both statements are false NOTE: Pathways for eliciting the flexor reflex do not pass directly to the anterior motor neurons but instead pass first into the spinal cord interneuron pool of neurons. Diverging circuits to spread the reflex to the necessary muscles for withdrawal

TRUE OR FALSE: A weak stimulus causes one quick flexion movement. A strong stimulus causes prolonged flexion and sometimes a series of flexion movements. A. Both statements are true B. Both statements are false C. Only the 1st statement is true D. Only the 2nd statement is true

A. Both statements are true

Circuits to cause (1)_______ that lasts many fractions of a second after the stimulus is over. Because of this, reflex can hold the irritated part away from the stimulus for (2)____ to (3)_____ seconds after the irritation is over.

1. afterdischarge 2. 0.1 3. 3

This is when part of the body other than the limbs is painfully stimulated, the part will be withdrawn from the stimulus. What reflex is this?

Withdrawal reflex

TRUE OR FALSE: The withdrwal reflex is a monosynaptic reflex.

False. It is polysynaptic

Phis is properly part of the withdrawal reflex that when a strong stimulus is applied to a limb, the response includes not only flexion and withdrawal of that limb but also extension of the opposite limb.

Crossed Extensor Reflex

This is also known as the inverse stretch reflex

Autogenic Inhibition

What is the receptor for autogenic inhibition?

Golgi tendon organ

When there is an increase (1)______, the GTO senses it and causes the (2)______ muscle to (3)_______

1. tension 2. agonist 3. relax

TRUE OR FALSE: The harder a muscle is stretched, the stronger is the reflex contraction. However, when the tension becomes great enough, contraction suddenly ceases and the muscle relaxes A. Both statements are true B. Both statements are false C. Only the 1st statement is true D. Only the 2nd statement is true

A. Both statements are true

TRUE OR FALSE: When the muscle is relaxed, it can stretch more

True

These are very old reflexes that is usually exhibited by newborns and infants

Primitive Reflexes

TRUE OR FALSE: Having normal primitive reflexes in adulthood is normal

False These reflexes should be supressed

What lobe gradually suppresses the function of primitive reflexes?

Frontal lobe

This is a learned response performed to a signal that was previously associated with an event of consequence.

Conditioned Reflex

This maneuver will heighten (exaggerate) lower limb tendon reflexes by countering some of the normal descending inhibition the brain sends to the reflex arc.

Jendrassik Maneuver

TRUE OR FALSE: Jendrassik Maneuver is part of the deep tendon reflex assessment

False

___________ is when more alpha motor neurons are excited and is responsible for the increased firing leading to exaggerated response

Subliminal fringe

The motor system can be divided into (1)______ and (2)________

1. lower 2. upper motor neurons

The following are s/sx of UMNL, EXCEPT: A. hypertonia B. hyperreflexive C. hypertonicity D. spasticity E. None of the above

E. None of the above

In UMNL, when the descending cortical fibers are damaged, the inhibition of the (1)______ is absent. The result is repetitive, sequential contraction of flexors and extensors, also known as (2)_______.

1. antagonists 2. clonus

An abnormal plantar extensor reflex happens during an UMNL. What is this reflex?

Babinski sign

A (+) Babinski sign shows of a (1)______ of the great toe and (2)_____ of the other toes when the lateral aspect of the sole of the foot is scratched

1. dorsiflexion 2. fanning

This is a form of muscle hypertonicity that offers increased resistance to stretch involving primarily the flexors in the upper limb and extensors in the lower limb and may be associated with muscle weakness

Spasticity

TRUE OR FALSE: Amyotrophic lateral sclerosis (ALS) is an UMNL.

False It is a disease that leads to lower motor neuron damage

Lower motor neurons are located _____ the dorsal root ganglion

below

Lower motor neurons are located _____ the dorsal root ganglion

below

Lower motor neurons are located _____ the dorsal root ganglion

below

This is the ability of muscle to resist stretch. It is assessed by passively moving the extremity

Muscle tone/ tonus

This term is used when a muscle’s resistance to stretch is high because of hyperactive stretch reflexes.

Hypertonic/Spastic muscle

This is the occurrence of regular, repetitive, rhythmic contractions of a muscle subjected to sudden, maintained stretch. It is also described as the oscillation of muscle jerks.

Clonus

Sustained clonus with _____ or more beats is considered abnormal.

TRUE OR FALSE: The higher center control of the brain can inhibit reflex

True

TRUE OR FALSE: The patellar reflex is an example of a monosynaptic reflex

True

TRUE OR FALSE: Jendrassik Maneuver should be performed by the patient during DTR assessment

False

TRUE OR FALSE: The Golgi Tendon Organ is purely inhibitory

True

TRUE OR FALSE: The presence of palmomental reflex in adults is always a red flag

False

TRUE OR FALSE: The central portion of the muscle spindle can contract and be stimulated by stretch

False

TRUE OR FALSE: Dynamic Stretch Reflex is stimulated by rapid stretch or unstretch

True

TRUE OR FALSE: Hacking of the patellar tendon is an example of autogenic inhibition

False

Which of the following can result to increase jump height (based from your knowledge of stretch reflex)? A. Immediately jumping without bending the hips and knee B. Squatting for 10 secs then jump C. Quick bending the hip and knee prior to jumping D. All of the above E. None of the above

C. Quick bending the hip and knee prior to jumping

Isometric contraction of the hamstring for 6 seconds following by stretch for 30 seconds will result in an increased hip flexion ROM due to _____. A. Autogenic Inhibition B. Reciprocal Inhibition

A. Autogenic Inhibition