S1_L1: Reflexes Flashcards
This is an involuntary motor output and nearly instantaneous movement in response to a stimulation.
Reflex
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
Reflex responses happen (1)_______ to prevent us from being (2)_______
- automatically
- harmed
NOTE: it is for self-preservation
Reflexes are (1)_______ and can be modified to perform (2)_______ tasks and maintain (3)_______
- adaptable
- motor
- balance
Source: Ganong (Chapter 12)
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
- A
- A
- A
- B
- A
This is the basic unit of integrated reflex activity
Reflex Arc
Source: Ganong (Chapter 12)
An activity in the reflex arc generates (1)_______ action potentials in the (2)_______ nerve
- all-or-none
- afferent
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
Activity in the reflex arc starts in a (1)______ with a (2)______
- sensory receptor
- receptor potential
Source: Ganong (Chapter 12)
TRUE OR FALSE: The number of action potentials is proportional to the size of the receptor potential.
True
Somatic reflex - involve the (1) _______ muscles, while autonomic reflex - involve the (2)_______ muscles
- skeletal
- smooth
_______ is the integrative area for the cord reflexes
Cord gray matter
Source: Guyton (Chapter 55)
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.
TRUE OR FALSE: Receptor potential’s magnitude is proportional to the strength of the stimulus
True
Tendon reflexes are elicited because of change in (1)_____ or (2)_____ tension in a muscle
- length
- tension
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)
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?
4+
NOTE: This is a very brisk, with clonus response (repetitive jerky movement noted after elicitation of reflex)
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)
TRUE OR FALSE: Tendon reflexes can excite either GTO or muscle spindle, or both at the same time
True
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
- E
- B
- B
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
- C
- A
- B
Source: Guyton (Chapter 55)
Interconnections among the (1)_____ and (2)______ are responsible for most of the integrative functions of the spinal cord
- interneurons
- anterior motor neurons
What are the 2 types of anterior motor neurons?
alpha motor neurons and gamma motor neurons
type A alpha (Aα) motor nerve fibers innervate (1)______ fibers, while type A gamma (Aγ) motor nerve fibers innervate (2)_______ fibers
- extrafusal
- intrafusal
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.
- excitatory in nature
- inhibitory in nature
- sensitive to stretch
- sensitive to tension or rate of change of tension
- distributed all throughout the muscle belly
A. Muscle Spindle
B. Golgi Tendon Organ
- A
- B
- A
- B
- 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?
- Primary afferent ending/Annulospiral ending
- Secondary afferent ending/FlowerSpray ending
Determine the type of sensory endings at the central receptor area of the muscle spindle.
- Type II fibers
- Encircles the central portion of intrafusal fibers
- Faster nerve conduction velocity
- Excited by both the nuclear bag intrafusal fibers and the nuclear chain fibers
- Only excited by the nuclear chain fibers
A. Annulo-spiral ending
B. Flower-Spray ending
- B
- A
- A
- A
- 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.
- has 2 subtypes: dynamic and static
- one to three in each spindle
- three to nine in each spindle
- innervated by type Ia and II
- nuclei aligned in a chain throughout the receptor area
A. Nuclear bag muscle fibers
B. Nuclear chain fibers
- A
- A
- B
- B
- B
The polar ends of a muscle spindle is contractile because of the presence of (1)____ and (2)_____ filaments.
- actin
- 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
- increases
- 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.
- Slow lengthening/stretching of muscle
- Degree of muscle contraction remains constant
- When lengthening stops, there’s an extra rate of smaller static responses
- Elicited by signals from annulospiral/primary ending only
- Stimulated by rapid stretch or unstretch
A. Static Response
B. Static Response
- A
- A
- B
- B
- B
Static response responds to (1)_____ of receptor, while dynamic response responds to the (2)_____ of (3)_____ of receptor length
- length
- rate
- change
Determine the response of gamma motor nerves.
- excites mainly the nuclear bag intrafusal fibers
- excites mainly the nuclear bag intrafusal fibers
A. Gamma-dynamic (gamma-d)
B. Gamma-static (gamma-s)
- A
- 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.
- stretch
- 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.
- spinal cord
- muscle
- sensory receptor
- afferent neuron
- 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)______.
- cerebrum
- spinal cord
- 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.
- Elicited by the continuous static receptor signals transmitted by both primary and secondary endings.
- Signals transmitted by primary sensory endings of the muscle spindles
- Caused by rapid stretch or unstretch, sudden stretch of muscle spindles
- The reflex functions to oppose sudden changes in muscle length
- Causes the degree of muscle contraction to remain reasonably constant
A. Static Stretch Reflex
B. Dynamic Stretch Reflex
- A
- B
- B
- B
- 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
- anterior motor neuron
- 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.
- afterdischarge
- 0.1
- 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)_______
- tension
- agonist
- 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)________
- lower
- 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)_______.
- antagonists
- 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
- dorsiflexion
- 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.
5
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