Questions Week 2
Question: It's a warm summer day, and Anna is walking barefoot through a field. While walking, Anna accidentally steps on a wasp in the grass with her left foot. The wasp stings the bottom of her left foot, causing Anna to raise her left leg while simultaneously balancing on her extended right leg. What reflex caused her to react in this way? A. Crossed Extension Reflex B. Withdraw Reflex C. Stretch Reflex D. Pain Reflex
Correct Answer: A. Crossed Extension Reflex Explanation: The crossed extension reflex involves the flexion of the ipsilateral limb and the simultaneous extension of the contralateral limb; in other words, this reflex flexes one limb while extending and stabilizing the other one. The function of this reflex is to remove a lower limb from a painful stimulus, such as a wasp sting on the bottom of a foot. This reflex is meant to help prevent falls by shifting the weight of the body to the unaffected limb. This reflex will flex the lower limb that was impacted by the painful stimulus while extending, stabilizing, and transferring the weight of the body to the other lower limb.
Maria, an elderly woman fell on her arm. She experienced sensations of numbness and tingling down her right arm to her thumb. In order to locate an injury, the doctor used ??? to indicate the problem. A. Dura B. Dermatomes C. Spinothalamic Tract D. Upper Extremeties
Correct Answer: D A dermatome is an area of skin which is innervated by the cutaneous branches of a single spinal nerve. Upper extremeties consist of C5-T1, and lower extremeties consist of L1-S1. In this case the spinal nerves from C5-T1 have been affected.
Sara has recently been diagnosed with a tumor on her spinal cord. She notices an issue when she burns her left hand on the stove and does not even realize because she cannot feel the pain. Her symptoms also include losing the function in her right leg and foot. What spinal cord injury is Sara being diagnosed with? A. Central Cord Syndrome B. Anterior Cord Syndrome C. Cauda Equina Syndrome D. Brown-Sequard Syndrome
Brown-Sequard syndrome results in the loss of movement and proprioception on the same side below the lesion, but includes loss of sensation and pain on the contralateral side below the lesion. This syndrome is rare compared to other incomplete spinal cord injuries. Central Cord Syndrome is incorrect because there is loss of movement and sensation in the arms and hands. The anterior cord syndrome is incorrect because it is caused by a blood clot in the spinal cord, leading to loss of motor function, pain and temperature sensation. However, proprioception is still viable. Cauda equina syndrome is incorrect because the symptoms include bladder and bowel issues, and progressive loss of sensation in the lower extremities. These are all incomplete spinal cord injuries where some function will remain below the injury.
Which of the following innervates the upper back & arm? A. Brachial plexus B. Cervical plexus C. Lumbrosacral plexus D. Sacral plexus
A. The function of the brachial plexus is to provide nerve supply to the upper back & arm area. This plexus has 5 nerve branches: axillary, medial, musculocutaneous, ulnar, & radial. Each branch innervates a specific section of the arm.
How many neurons are involved in a stretch reflex a. 2 b. 10 c. 26 d. 31
Answer is a because it involves 2 neurons and does not involve the brain and only the spinal cord.
Which of these is not one of the 5 components of the reflex arc? a) Motor neuron b) Spinal neuron c) Sensory neuron d) Sensory receptor
Answer is b) Spinal neuron. There is no spinal neuron, only spinal cord and sensory or motor neuron.
Q: Which nerve is the both the longest and thickest nerve in the body? a. Axillary b. Sciatic c. Phrenic d. Femoral
A: b. Sciatic ; It is both the longest and thickest nerve of the body and is composed of two nerves: the tibial and common fibular nerves.
Elizabeth, a 70-year-old woman experiences a spinal cord injury as a result of falling. She experiences a loss of motor function, pain, and temperature sensation but still has preserved vibration and proprioception. Which of the following spinal cord injuries is Elizabeth suffering from? a. Complete Spinal Cord Injury b. Brown-Sequard Syndrome c. Central Cord Syndrome d. Anterior Cord Syndrome
ANSWER: D WHY?: As Elizabeth still has some function below the injury, she is not suffering from a complete spinal injury. Therefore, she must be suffering from some type of incomplete spinal cord injury; Brown-Sequard Syndrome, Central Cord Syndrome, or Anterior Cord Syndrome. The answer is D, Anterior Cord Syndrome, because the symptoms of this syndrome include loss of motor function, pain, and temperature sensation below the lesion. As well, in this syndrome, her proprioception and vibratory remain intact due to the sparing of the dorsal horn in this syndrome. Infarction, such as a blood clot is a main cause of this syndrome, which may have been caused by Elizabeth's fall.
Which nerve is the most important nerve of the cervical plexus? A. Intercostal nerve B. Phrenic nerve C. Sciatic Nerve D. None of the above
Answer- The answer B. The phrenic nerve is the major motor and sensory nerve of the diaphragm. The phrenic nerve originates from the C3-C5 nerve roots.
Ben's car accident left him with a spinal damage on the left side. He had a piece of the car get punctured to the back of his neck which left damage to the left side of his spinal cord. On the left side of his body, below the lesion, he is losing movement and proprioception. On the opposite side of the lesion, right side, he has lost sensation and pain. What type of syndrome is this? A. Anterior Cord Syndrome B. Brown-Sequard's syndrome C. Central Cord Syndrome D. Multiple sclerosis
Answer: B- Brown-Sequard's syndrome Reasoning: Brown Sequard's syndrome is an uncommon neurological disorder marked by a spinal cord injury. Below the lesion, this results in loss of movement and proprioception on the same side, which is called ipsilateral. In Ben's case, this is his left side. This will have an impact on ipsilateral loss of corticospinal and the dorsal column. Also, below the lesion, there will be loss of feeling and discomfort on the other side, known as contralateral. In Ben's case this is his right side. This syndrome is usually due to traumatic injury that only affects one side. Trauma, such as a puncture wound to the neck or back, is the most common cause of this condition.
Amy is at the stove in her kitchen cooking dinner. The burner is on and is preheating the pan. When Amy goes to grab the pan, she touches a part of the handle that was too close to the burner and burns her hand, causing her to drop the pan and pull her hand away. What kind of reflex did Amy perform? A. Withdrawal Reflex B. Stretch Reflex C. Crossed Extensor Reflex D. All the Above
Answer: A The Answer is A because the heat of the pan was painful stimulus to the sensory neuron which then relayed the message to the interneuron in the spinal cord to activate the motor neuron to remove her hand from the painful stimulus.
If a patient is having trouble breathing, what nerve could you expect to be impacted? A) Sciatic Nerve B) Phrenic Nerve C) Tibial Nerve D) Femoral Nerve
Answer: B) Phrenic Nerve. The phrenic nerve is located in the cervical plexus. It is the major motor and sensory nerve of the diaphragm and it is the major breathing muscle. If there is an issue with the phrenic nerve, an individual would have trouble breathing.
Which level of innervation is the major focus in Occupational Therapy evaluation? What parts of the body does this level innervate? a. Cervical Plexus; neck and shoulders b. Brachial Plexus; upper back and arm c. Brachial Plexus; lower back and lower limbs d. Sacral Plexus; buttocks, lower limbs
Answer: B. Brachial Plexus; upper back and arm. The brachial plexus is broken up between the upper back and arm. It carries movement and sensory signals from the spinal cord to the hands and arms. The nerves that make up the brachial plexus are the axillary, musculocutaneous, median, ulnar, and radial. It is the major focus of OT evluation.
Question: Brenda is walking home from school by the soccer field, when all of a sudden, a ball comes out of nowhere. Brenda's hands are full of books and without thinking she kicks the ball away from her face with her foot. What reflex did Brenda exhibit? a. Somatic reflex b. Crossed extensor reflex c. Stretch reflex d. All of the above
Answer: C. The answer is stretch reflex because Brenda had to act quickly to prevent harm. Because of this, the brain was not involved in her reflex and occurred completely within the spinal cord.
When a patient experiences Central Cord Syndrome there is often a loss of sensation and motion in__________ A) legs B) hands C) feet D) arms E) legs and feet F) arms and hands
Answer: F) Arms and hands. After a patient experiences central cord syndrome there is often a resulting loss of sensation and motion in the arms and hands not the legs and feet.
Which of the following is true about the autonomic nervous system? a) It is under voluntary control and includes the somatic nervous system. b) It is under involuntary control and includes both the sympathetic and parasympathetic nervous systems. c) it is under voluntary control and only includes the parasympathetic nervous system. d) all of the above is true e) none of the above is true
Answer: The answer is "B". This is because the autonomic nervous system is responsible for involuntary control over actions that are considered to be physiological. Some of these actions include regulating heart rate (raising & lowering), digestion, rest, regulation of the bladder (relaxation & constriction), etc. Also, the ANS is broken down into two sub-categories: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system is responsible for physiological reactions regarding "fight or flight" and the parasympathetic nervous system is responsible for physiological reactions regarding "rest and digestion".
A boy broke his right arm while playing on a trampoline with his friends. When he gets to the hospital, the doctor finds that he cannot feel the sensation of a light pinprick on the outside of his right shoulder. What nerve is most likely damaged? a.) Sciatic nerve b.)Radial nerve c.) Axillary nerve d.) Ulnar nerve
Answer: The correct answer is C. Axillary nerve because this nerve innervates the deltoid and the teres minor. This part of the body is on the lateral side of ones shoulder which is where he cannot feel the prick. The radial and the ulnar nerve would effect the fingers and the hand. The sciatic nerve would effect the lower back and the leg.
Which of the following is the plexus which innervates the thigh, abdominal wall, groin, and psoas muscle? a. Brachial plexus b. Sacral Plexus c. Lumbosacral Plexus d. Cervical Plexus
Answer: The correct answer is C. Lumbosacral Plexus. While the other plexuses do innervate parts of the body as well, they do not innervate the thigh, abdominal wall, groin, and psoas muscle. The Cervical Plexus innervates the neck, ear, back of head, and shoulders while the Sacral Plexus innervates the buttock, lower limb, pelvic structures, and perineum. And lastly, the Brachial Plexus focuses on innervating the upper back and the arm. The Lumbosacral Plexus includes major nerves such as the femoral and obturator nerves and this plexus is considered to be a major focus of intervention for many Physical Therapists.
For an Anterior spinal cord syndrome what function(s) of the following remain intact? a. Pain b. Vibratory Sensation c. Motor function d. Proprioception e. Temperature
Answer? B. Vibratory sensation AND D. Proprioception A blood clot in the spinal cord can cause anterior cord syndrome. As a result, it is defined by a loss of motor function, pain, and temperature sensation below the lesion; nevertheless, proprioception and vibratory sensation remain intact due to the sparing of the dorsal horn.
All segments of the body contain dermatome distribution except? a. T1 b. C5 c. S1 d. C1
C1 is the correct answer beacause it does NOT contain dermatomes! UE dermatomes are typically from C5-T1 LE dermatomes are typically from L1-S1 T2-T12 dermatomes innervate the trunk
Sensory tracts carry ___ information to the brain while motor tracts carry ___ information to the PNS. a. ascending, descending b. descending, ascending c. efferent, afferent d. important, insignificant
Correct answer: (a). The sensory white matter tracts carry ascending sensory information up to the brain while the motor white matter tracts carry descending motor information down to the body or peripheral nervous system (PNS). The gray matter has ventral roots that contain motor (efferent) fibers and dorsal roots that contain sensory (afferent) fibers.
On a cold afternoon, Jennifer's mom makes her a cup of coffee. Jennifer sits down at the table to drink her coffee and reaches out to grab the mug. When she touches it, her hand immediately draws back in pain after contacting such a hot object. This is an example of the Withdrawal Effect. Which neuron(s) is involved in this particular reflex? a. Interneuron in the spinal cord b. Motor neuron c. Sensory neuron d. All of the above
Explanation: The answer is all of the above. When Jennifer's hand was exposed to the painful stimulus, in this case her hot cup of coffee, the sensory receptors were activated by this stimulation. The sensory neuron then synapsed with an interneuron that is located in the spinal cord. From there that interneuron synapsed with a motor neuron ultimately providing excitatory signals to the ipsilateral flexor muscle unit and resulting in her hand being pulled away from the hot stimulus.
If a person was in a car accident resulting in an injury at C4 and the person lost all function below C4, the person is said to have a... a. Complete spinal cord injury b. Incomplete spinal cord injury c. A partial spinal cord injury d. No spinal cord injury
The answer is A because a complete spinal cord injury happens when sensation (which includes feeling, pain, and temperature) and movement are completely lost below the lesion. Since this patient lost all function below C4, it makes it a complete spinal cord injury.
Which plexus innervates the buttocks, pelvic structures, lower limbs and perineum? A. Lumbar Plexus B. Sacral Plexus C. Brachial Plexus D. Cervical Plexus
The answer is B. Sacral Plexus. The Sacral Plexus runs along the L4-S-4. This network of nerve fibers is located on the posterior part of the pelvic wall and supplies sensation of skin and muscles to the lower half of the body.
Which statement is false pertaining to white matter? A) Pathways decussate B) each column contains several fiber tracts that carry information C) Fibers run in one direction, ascending D) Most pathways consist of two or three neurons
The answer is C, Fibers run in one direction. This is false because pathways run in 3 directions, ascending, descending and transversely. It is important to know that sensory tracts have ascending information carry sensory input up to the brain and motor tracts have descending information that carry motor plans down the both. They also can run transversely.
At which innervation level are the deltoid and teres minor innervated? A. Median B. Radial C. Axillary D. Musculocutaneous
The answer is C: Axillary. The axillary nerve innervates the deltoid and teres minor. The median nerve branches to most of the forearm flexor muscles. The radial nerve essentially innervates all extensor muscles. The musculocutaneous nerve sends fibers to the biceps brachii and brachialis.
Marie decides to straighten her hair. She picks up the hair straightener not realizing that the straightener was already hot. Immediately she lets go and she starts to run cold water through her hand. What kind of reflex did she just experience? a. stretch reflex b. somatic reflex c.crossed extension reflex d. withdrawal reflex
The answer is D. The withdrawal reflex is associated with the removal of a limb or body part from a painful stimulus. The moment Marie's hand came in contact with the heat of the straightener she first had a sensory neuron that picked up the stimulation of pain. Afterwards it travels to an interneuron in the spinal cord which goes from one side of the spinal cord and synapses on a motor neuron. The motor neuron results in the action of taking away the hand from the pain source which was the hot straightener.
Stretch reflex is important for maintaining posture and balance. It involves the brain and spinal cord. a. True b. False
The answer is False. Stretch reflex only involves the spinal cord. The reflex loop explains how only two neurons from the spinal cord are involved. The sensory neuron that located in the muscle spindle confirms that stretch has occurred. It will then send this information to gray matter of the spinal cord and synapses directly on the motor neuron of the muscle body. The muscle will make adjustments to compensate for the stretch. Most sensory neurons do not pass directly through the brain, but synapse in the spinal cord. The reflex loop allows reflex actions to happen quickly seconds through the activation of spinal neurons. This allows no delay in routing other information to the brain.
The spinothalamic tract receives blood supply from which of the following? a. posterior communicating artery b. posterior spinal arteries c. anterior spinal arteries d. posterior communicating artery
The answer is c. Anterior spinal arteries because it supplies blood to the ventral part of the spinal cord where the spinothalamic tract is located.
Central cord syndrome results in the loss of motion in which of the following: a.) hands b.) arms c.) feet d.) A & B
The answer is d.) because Central Cord Syndrome results in the loss of motion in the upper extremities, which would be the hands and arms. The upper extremities are affected more than the lower extremities because the motor fibers for the upper extremities are towards the center of the spinal cord. The center of the spinal cord is where the damage or lesion is present in Central Cord Syndrome. Therefore, damage to the central cord affects the arms and hands more severely than the lower extremities. The nerves going to the legs are more toward the outside of the cord.
The sacral plexus L4-S4 innervates the A.Thigh, abdominal wall, groin and psoas muscle B. Buttock, lower limb, pelvic structures and perineum C. Neck, ear, back of head and shoulders D. Upper back and arm only
The answer is option B (buttock, lower limb, pelvic structures and perineum). The sacral plexus L4-S4 lies in the back of pelvis and includes the sciatic nerve.
What are some of the responsibilities of the parasympathetic nervous system? a. Reduces heart rate b. increase salvia production c. stimulates the activity of the pancreas d. all of the above
The answer to this question is D. all of the above. The parasympathetic nervous system is responsible for the "rest and digest" actions of the body, such as reducing ones heart rate, increasing salvia production and stimulating the activity of the pancreas.
Alex, a teenager is involved in a serious car accidents and receives an injury to his neck. He still maintains some functions. Which would be the most common diagnosis? A. Complete SCI B. Anterior Cord Syndrome C. Central Cord Syndrome D. Brown-Sequard Syndrome
The answer to this would be C. Central Cord Syndrome. Alex does not not completely loss all sensation below the lesion from the accident. When looking at central cord syndrome that commonly comes from trauma to the neck, like Alex received.
The nerves roots from C5 through T1 contribute to the: a. Cervical plexus b. Brachial plexus c. Lumbosacral plexus d. Sacral plexus
The correct answer is B. The brachial plexus is formed by the nerves among C5 through T1, however C4 and T2 also contribute to this plexus. The brachial plexus is responsible for the innervation of the upper back and the arm and is very important for movement of the upper extremities.
Malcolm was on the rugby team at his university. A few weeks ago, during practice, he sustained a hyperextension injury to his neck. The athletic trainer on duty stated that he complained of numbness and a tingling sensation in his arms, hands, and fingertips. Malcolm was immobile before emergency medical services were called and were able to stabilize his cervical spine with a collar. He was rushed to the hospital for care and for further assessment. Today, he is in rehabilitation. He complains of neck stiffness and feels weakness in his arms but is able to walk. What was Malcolm's diagnosis? a. Anterior Cord Syndrome b. Spinal Stenosis c. Stroke d. Central Cord Syndrome
The best and correct answer is d. Central Cord Syndrome. Central Cord Syndrome is an incomplete spinal cord injury caused by trauma to the cervical spine, or the neck. Therefore, the answer could not be Anterior Cord Syndrome which is caused by trauma to the anterior 2/3 portion of the spine. The injury is considered "incomplete" given the fact that Malcolm and other patients are never completely paralyzed following the trauma. The injury sustained by Malcolm caused numbness in his upper extremities and essentially made him immobile until medical professionals were able to stabilize his cervical spine and were able to help him regain mobility, making d. the correct answer.
What is the function of white matter in the spinal cord ? a. Axon that allow the communication of information b. Map the sensory nerves on the skin that connect to spinal nerve c. Maintaining posture and balance d. Somatic reflexes
The correct answer is "a. Axon that allow the communication of information". The white matter has the sensory and the motor tract. The sensory tract is responsible for ascending information up to the brain. The Motor tract is responsible for descending motor plans down the body.
What spinal segment is not associated with a dermatome distribution? a. C2 b. C1 c. L1-S1 d. T2-T12
The correct answer is "b. C1". C1 is the only spinal segment that does not include a dermatome distribution. The body includes 30 dermatomes, which includes one less spinal nerve than normal. Dermatomes transmit sensations, where sensory nerves originate from a single spinal nerve root. Dermatomes do not include the C1 spinal nerve because this specific spinal nerve does not have a sensory root. Therefore, dermatomes are begun at C2. Dermatomes are used on a mapping for the use of comparing regions of altered sensation.
What segment of the body does not have dermatome distribution? a. C1 b. C5-T1 c. L1-S1 d. T2-T12
The correct answer is A, C1. Dermatomes are an area of skin innervated by the cutaneous branches of a single spinal nerve. Typically, C1 spinal nerve does not have a sensory root. All segments besides C1 have dermatome distribution.
Which two receptors are matched correctly: A) thermorecpetors are for temperature B) proprioceptor are for smell c) Chemoreceptors are for vision d) photoreceptors are for movement
The correct answer is A. This is the correct answer because thermoreceptors are what our body uses to feel temperature and tells you when something is hot. Proprioceptrs are used to determine light which would be the correct pairing instead of smell. Chemoreceptors are used for chemcials. Photoreceptors are used to deterime light and not movement. So this leaves A as the only correct pairing.
In regards to innervation levels of the hand and arm, which one of these answers innervates the deltoid and teres minor? A. Axillary B. Median C. Radial D. Ulnar
The correct answer is A. Axillary. The median branches to most of the flexor muscles of the forearm, radial innervates essentially all extensor muscles, and the ulnar supplies the flexor carpi ulanris and part of the flexor digitorum profundus .
What neurons are associated with the crossed extension reflex? A. Interneurons B. Sensory Neurons C. Motor Neurons D. None of the above
The correct answer is A: Interneurons because they cross the midline of the spinal cord and a crossed extension reflex allows our body to compensate for one side for stimulus on another. Without the interneurons we wouldn't be able to compensate for the one side.
Which plexus is home to the sciatic nerve? A. Brachial Plexus B. Sacral Plexus C. Lumbrosacral Plexus D. Cervical Plexus
The correct answer is B Sacral Plexus. The sciatic nerves is the longest and thickest nerve that is part of the Sacral Plexus. The sciatic nerve is composed of 2 nerves, the tibial nerve and the common fibular or peroneal nerve. The Sacral Plexus innervates the buttock, lower limb, pelvic structures, and the perineum.
On a hike with her family, a woman suddenly falls and severely extends her neck upon hitting the ground. What injury may be the most common for an accident such as this? a. Incomplete spinal cord injury b. Central cord syndrome c. Anterior cord syndrome d. Brown Sequard syndrome
The correct answer is B, Central cord syndrome. Central cord syndrome is a type of incomplete spinal cord injury. These types of injuries leave some function remaining below the level of injury. More specifically, central cord syndrome is a common cervical spine injury, usually due to some sort of trauma to the neck. This is especially common with hyperextensions that may lead to spinal cord impingement. Central cord syndrome can potentially lead to a loss of motion and sensation in the hands and arms.
Intercostal nerves supply muscles of the: A. ribs B. all of the above c. back D. anterolateral thorax E. abdominal wall
The correct answer is B, all of the above. Intercostal nerves supply muscles of the abdominal wall, back, ribs, and anterolateral thorax.
A fresh batch of cookies was just taken out of the oven. Joey a young child, goes over to the hot pan to take a cookie and quickly pulls away without grabbing one. Which of Joey's reflexes caused him to pull away? A. Withdrawal Reflex B. Somatic Reflex C. Crossed Extensor Reflex
The correct answer is B. Somatic Reflex because he had the ability to pull away from a hot object before he even sensed the heat. Some skeletal muscle movements do not require Joey's conscious thought, such as pulling away from a hot object. This would not be withdrawal reflex because he did not physically touch the hot object so he did not experience a painful stimulus. This is also not crossed extensor reflex because none of Joey's lower limbs were involved.
What is the name of the plexus that innervates the buttocks, lower limbs, pelvic structures, and perineum? What major nerve is found here? A. Cervical plexus and phrenic nerve B. Sacral plexus and sciatic nerve C. Sacral plexus and obturator nerve D. Brachial plexus and phrenic nerve
The correct answer is B. The sacral plexus is the particular plexus that concerns the butt, lower limbs, pelvis (sacrum), and perineum. This plexus is located posteriorly since it deals with aspects of the posterior body. The sciatic nerve is the major nerve found here and is the largest nerve in the body. A good way to remember this is to think of how sciatic nerve pain affects the lower spine and the back of either or both of the legs. Sciatic can be defined as related to or close to the hip. The other answers are not correct because the cervical plexus concerns the neck, ear, back of head, and shoulders, and the brachial plexus concerns the upper back and arm. Lastly, it could not be C because while the first part is correct, the obturator nerve is located in the lumbrosacral plexus.
A college football player comes into the ER following a play gone wrong, causing him to be tackled by a player with his head pushed back, landing with his neck hyperextended. He is stating he cannot feel anything on the upper portion of his body, particularly his arms and hands. What spinal cord injury is this player most likely suffeirng from? A: anterior cord syndrome B: central cord syndrome C: posterior cord syndrome D: brown-sequard syndrome
The correct answer is B: central cord syndrome. Central cord syndrome is a result of some form of injury to the cervical spinal cord which results in loss of function and sensation in the hands and arms rather than the legs like most SCIs that cause forms of paralysis. Due to the hyperextension of the players neck when he was tackled and fell on the field, this is why he was diagnosed with central cord syndrome over any other incomplete SCI.
Kelly has been experiencing numbness in the anterior side of her legs, as well as her toes and decided to see the doctor. Which dermatome will the doctor find damaged or affected? A. Cervical B. Thoracic C. Lumbar D. Sacral
The correct answer is C. Lumbar. Dermatomes are areas of skin supplied by peripheral nerve fibers originating from a single dorsal root ganglion. The lumbar region of the spine (L1-L5) is responsible for most of the lower extremity including the anterior side of the thigh, knee, leg, and toes.
he most important nerve of the cervical plexus (C1-C4) is: a. Femoral Nerve b. Sciatic Nerve c. Phrenic Nerve d. Obturator Nerve
The correct answer is C. Phrenic Nerve. This nerve is the major motor and sensory nerve for the diaphragm, a major breathing muscle of the body. A lack of innervation to this nerve results in the loss of muscle contraction of the diaphragm causing difficulty breathing.
Which of these statements is NOT true regarding stretch reflexes? A. It is known as the knee jerk reaction B. It maintains balance and posture C. It involves two neurons D. It involves the brain and spinal cord
The correct answer is D because a stretch reflex only occurs within the spinal cord and the brain has no role. C is incorrect because both the sensory and motor nerves are involved when a stretch reflex occurs. B is incorrect because the reflex functions to maintain the muscle at a constant length and strength. A is incorrect because the knee-jerk reaction typically occurs when the tendon of the muscle is tapped.
What acts as protection for the spinal cord? A) Bone B) Meninges C) CSF D) All of the above
The correct answer is D) All of the above. The spinal cord runs through the center of each vertabrae, which are protective bones. Meninges are layers of connective tissue membranes known as the dura layer, the arachnoid layer, and that pia layer which cover the spinal cord. Cerebrospinal fluid (CSF) reduces brain weight, prevents crushing, and maintains chemical stability.
Which of the following is NOT a component of a reflex arc: a) motor neuron b) effector organ/tissue c) sensory receptor d) dura mater
The correct answer is D. Dura mater is the most external layer of tissue that covers the spinal cord. It is one of three layers that makes up the spinal cord's meninges. It is not one of the components of a reflex arc. The reflex arc components consist of a sensory receptor, which is a nerve or a specialized tissue at the end of a sensory neuron that responds first to a stimulus, a sensory neuron, which may act as the sensory receptor, the spinal cord or brain tissue, a motor neuron, and an effector organ or tissue that responds to the message from the motor neuron. Because dura mater is not related to the reflex arc, it is the correct answer.
You have a patient who has suffered from a stroke. You notice most of their impairments are on the left side of their body; therefore, you can indicate the stroke happened on which hemisphere of the brain? a. Right hemisphere b. Both hemispheres c. Strokes do not occur in the brain d. Left hemisphere
The correct answer is a. Right hemisphere. In brain and spinal cord communication, information crosses over before it reaches the cortex itself. The left hemisphere controls the right side of the spinal cord as the right hemisphere controls the left side of the spinal cord. If you are observing a patient that has just had a stroke and has impairments on their left side, we can infer the blood clot was located on the right hemisphere of the brain.
When performing a stretch reflex is the brain involved? a. True b. False
The correct answer is b. False. The stretch reflex does not involve the brain because it happens without conscious thinking or planning, it only occurs within the spinal cord. It involves the sensory and motor neuron and happens very quickly anywhere from 20ms to 40ms. It is important for maintaining our posture and balance.
Which is NOT correct about white matter? a. Pathways are paired and decussate b. Each spinal nerve connects to the spinal cord via two medial roots c. Sensory tracts ascend information, motor tracts descend information d. Fibers can move ascending, descending, and transversely
The correct answer is b. each spinal nerve connects to the spinal cord via two medial roots because that is correct about grey matter. Pathways for white matter are on each side of the spinal cord or brain and the pathways cross-over one another. White matter moves in the three directions, ascending, descending, and transverse, where sensory information is brought up from the body into the brain and motor information is brought from the brain into the body.
The medial portion of your calf is mapped by which dermatome? a. L5 b. S1 c. L4 d. T12
The correct answer is... L4. The Lower Extremity (LE) is typically mapped from L1-S1. It is possible that a muscle crosses multiple dermatomes and be innervated by several motor nerves depending on the muscle's size, but in the case of specifically the medial side of your calf, the dermatome is L4.
Which of these is NOT an effect of anterior cord syndrome? A) Loss of motor function B) Loss of pain sensation C) Loss of temperature sensation D) Loss of proprioception
The correct answer is: D. Anterior cord syndrome is an incomplete spinal cord injury caused by an infarction (blood clot) in the spinal cord. As a result, there is a loss of motor function, pain, and temperature sensation below the lesion. However, both proprioception and vibratory sensation are preserved as the dorsal horn/dorsal column is still intact. Dorsal columns mediate sensory modalities of cutaneous touch discrimination and proprioception, which is perception or awareness of the position or awareness of the position and movement of the body.
Testing reflexes are extremely important in detecting both absent, reduced, delayed, and exaggerated reflexes that could be a sign of spinal cord injuries, spinal stenosis, demyelination or other abnormal responses. Which statement below represents the correct order of a reflex arc in response to a stimulus? a) motor neuron, spinal cord/brain tissue, effector organ/tissue, sensory receptor, sensory neuron b) motor neuron, effector organ/tissue, sensory neuron, sensory receptor, spinal cord/brain tissue c) sensory receptor, sensory neuron, spinal cord/brain tissue, motor neuron, effector organ/tissue d) sensory receptor, spinal cord/brain tissue, sensory neuron, effector organ/tissue, motor neuron
The correct answer to this question is C) sensory receptor, sensory neuron, spinal cord/brain tissue, motor neuron, effector organ/tissue. The reason this is the correct answer is because the reflex arc responds to a stimulus in the particular pattern that first alerts the sensory receptor. The sensory receptor is the first structure/ nerve that responds to the stimulus. After the sensory receptor is alerted, the sensory neuron also responds. After the sensory neuron responds, the sensory information is sent to the spinal cord/brain tissue. Next, the spinal cord relays the infomration to the motor neuron of the muscle which then produces a response or reflex. For example, when looking at the stretch reflex, we can see the relfex arc present in the reflex loop of a stretch reflex. First, the muscle spindle contains sensory neurons which senses a stretch in the muscle. After this, the information is then sent to the spinal cord's gray matter. Next, the the information synapses to the motor neuron and the muscle responds to control the reflex. We can see reflexes occur in our every day life, if we touched something hot, we have somatic responses that do not involve our conscuious control of our muscles. This allows us to pull away from the hot object.
Aaron is a baseball player who suffered a spinal cord injury during a car accident in his off season. One of his goals is to get back to participating in simple tasks on his baseball team such as catching the ball. After his accident he has been experiencing sensations of tingling and numbness within his hand hindering him from his ideal performance. Which part of Aarons spinal cord may be injured causing his sensations in his hand? a. Corticospinal tract b. Ventral roots in the gray matter c. Motor tracts in white matter d. Sensory tract in white matter
The correct answer would be D. Sensory tract in white matter. This answer is correct since white matter is the aspect of the spinal cord which conveys the communication of information in the body. The white matter is then separated into different tracts containing various information and messages. The motor tract in white matter communicates the performance of activities. This also means that the motor tract brings information down into the body to produce movement. The other part is the sensory tract which communicates ascending information bringing sensations into the brain. Damage to the sensory tract would be responsible for Aaron's lack of sensation within his hand and his experience of tingling and numbness. His sensations come from damage to the sensory tract within the white matter of his spinal cord initially caused by the trauma from his accident. The other answers are incorrect since A and B are responsible for the delivery of motor functioning. C is incorrect since it has similar functioning with communicating motor information from the brain to produce performance just within white matter.
