Define reflex:
Rapid, predictable, involuntary motor responses to stimuli; they are mediated over neural pathways called reflex arcs.
Name five essential components of a reflex arc
Receptor, sensory neuron, integration center, motor neuron, and effector.
In general, what is the importance of reflex testing in a routine physical examination?
Reflex testing is an important diagnostic tool for assessing the condition of the nervous system. Distorted, exaggerated, or absent reflex response may indicate degeneration or pathology of portions the the nervous system, often before other signs are apparent.
Reflexes classified as somatic reflexes include a
Abdominal reflex, achilles reflex, corneal reflex, crossed-extensor reflex, gag reflex, patellar reflex, and plantar reflex.
Of these, the simple stretch reflexes are _______ and ________ , and the superficial cord reflexes are _________ and __________.
Achilles reflex and patellar reflex; corneal reflex and plantar reflex.
Reflexes classified as autonomic reflexes include ________ and _________.
Ciliospinal reflex and pupillary light reflex.
Name two cord-mediated reflexes
Patellar reflex and cross-extensor reflex
Name two somatic reflexes in which the higher brain centers participate
Superficial cord reflexes and pupillary light reflexes
Can the stretch reflex be elicited in a pithed animal (that is, an animal in which the brian has been destroyed)?
Yes
Explain
Even without the brain a stretch reflex only needs an afferent control center, and motor fibers to be elicited. These components still stay intact if the brain has been destroyed.
Trace the reflex arc: naming efferent and afferent nerves, receptors, effectors, and integration centers, for the two reflexes listed:
Patellar reflex:
Hit patellar tendon to excite the muscle spindles of quadriceps. Femoral nerve - afferent nerve - to - integration centers - L2 through L4 from thereto - efferent nerve - femoral back to quads - effector - to make the contraction. Also sends impulse to hamstrings - effector - to provide resistance.
Trace the reflex arc: naming efferent and afferent nerves, receptors, effectors, and integration centers, for the two reflexes listed:
Achilles reflex:
Hit achilles tendon, goes to CNS through the sciatic nerve - afferent- from there it travels to interneurons in the spinal cord - integration center- S1 through S2. From there to alfa motor neurons - efferent nerve - tibial nerve from the sciatic nerve to go to the gastrocnemius - effector.
Three factors that influence the rapidity and effectiveness of reflex arc were investigated in conjunction with patellar reflex testing - mental distraction, effect of simultaneous muscle activity in another body area, and fatigue.
Which of these factors increases the excitatory level of the spinal cord?
muscle activity
Which factor decreases the excitatory level of the muscles?
Fatigue
When the subject was concentrating on an arithmetic problem, did the change noted in the patellar reflex indicate that the brain activity is necessary for the patellar reflex or only that i may modify it?
No effect; it does not involve the brain
Name the division of the autonomic nervous system responsible for each of the reflexes listed:
ciliospinal reflex
Sympathetic
Salivary reflex
Sympathetic
Pupillary light reflex
Parasympathetic
The pupillary light reflex, the crossed-extensor reflex, and the corneal reflex illustrate the purposeful nature of reflex activity. Describe the protective aspect of each.
Pupillary light reflex
To protect and help control the eyes from the damage of different lights.
Corneal reflex
To protect the eyes from foreign bodies and lights
Crossed-extensor reflex
To help protect and maintain balance when a withdraw reflex occurs at another part of the body. Helps so you will not hurt yourself when a reflex occurs.
Was the pupillary consensual response contralateral or ipsilateral?
Contralateral
Why would such a response be of significant value in the particular reflex?
Helps to even out the light rays making it less stressful for the affected eye.
Differentiate between the types of activities accomplished by somatic and autonomic reflexes.
Somatic includes all pathways that are voluntary, and autonomic includes all pathways that are involuntary actions.
13. (the box to be filled in)
Micturition
Organ involved: bladder/ureters
Receptors stimulated: stretch receptors
Action: sensation to urinate
Hering-Breuer
Organ involved: lungs
Receptors stimulated: stretch receptors - pulmonary
Action: inspiration/inhalation without over stretching the lungs
Defecation
Organ involved: mouth, pharynx, esophagus, stomach, small & large intestines, and all digestive organs.
Receptors stimulated: stretch receptors
Action: stool passage
Carotid sinus
Organ involved: carotid & common carotid arteries, heart, blood vessels
Receptors stimulated: beroreceptors
Action: control of blood pressure by regulating changes in hear rate
How do basic and leaned or acquired reflexes differ?
Basic reflexes are inherited - born with them.
Learned/acquired reflexes are not inherited - not born with them.
Name at least three factors that may modify reaction time to a stimulus.
Illness, age, and fatigue.
In general, how did the response time for the leaned activity performed in the laboratory compare to that for the simple patellar reflex?
learned reflexes are not as fast as basic reflexes.
Did the response time without verbal stimuli decrease with practice?
Yes
Explain the reason for this
Because it is being leaned/stored by repetition.
Explain, in detail, why response time increased when the subject had to react to a word stimulus.
Because it distracts, it makes the reflexes slow down, the body can't go as fast with two as it can with one.
19. BIOPAC -
I didn't do this one.
Hope everything here helped you. Please leave feedback and rate my note cards.