Nervous System Flashcards
What is the function of the nervous system
system processes information from the internal and external environments, using sensory receptors. Usually, it then sends signals encoding this information to the brain, which processes the information to determine an appropriate response. Finally,
nerve impulses
electrical signals transmitted by neurons
neurons
nerve cells
axon
carries nerve impulses to other cells
what structures make up the central nervous system
brain and spinal cord
what structures make up the peripheral nervous system
nerves that connect the CNS to the rest of the body
What does the somatic system do?
The somatic nervous system controls activities that are under voluntary control, such as turning a steering wheel.
What does the autonomic system do?
The autonomic nervous system controls activities that are not under voluntary control, such as digesting a meal. The autonomic nervous system has two main divisions: the sympathetic division (which controls the fight-or-flight response during emergencies), the parasympathetic division (which returns the body back to routine day-to-day operations)
How can you examine the nervous system
1) mental status: will, emotion, thought process, reasoning, intellect, memory-check history
2) cranial nerves: supply motor and sensory to face and head
3) motor nerves: strength, movement, balance, and gait
4) sensory nerves- pain, light touch, sharp/dull
5) deep tendon reflexes- reflex arc to test motor and sensory nerves
what is the protective layer of the brain called
3 layers; meninges, spaces between these layers contain cerebrospinal fluid that cushions and nourishes the brain and spinal cord
c1-c8 nerves (supply to…?)
arm
t1-t12 nerves (supply to…?)
thorax
L1-L5 and s1-s5 nerves (supply to…?)
buttocks and legs
what is the parasympathetic system also called
rest and digest
what is the sympathetic system also called
flight or fight
list 12 cranial nerves
olfactory (smell)
optic (sight)
oculomotor (eye movement)
trochlear (eye movement)
trigeminal (provide sensory information to the face, chewing)
abducens (eye movement)
facial (face movement, taste, sensory info for ears)
acoustic (hearing and balance)
glossopharyngeal (enables swallowing, sends nerve impulses to mouth)
vagus (regulates internal functions, such as digestion and hr)
accessory (moves your deltoids and moves your neck and head)
hypoglossal (tongue movement)
how can you test the sensory system
pain-use a sharp object (end of paper clip or broken tongue depressor), ask the patient if they feel sharp or dull
temperature- often omitted if pain is intact, use 2 test tubes filled with hot and cold water
position- grab the big toe and manually move it up and down for the patient to tell you the position
vibration- place a vibrating tuning fork over the big toe, stop the vibration and the patient will tell you if they can’t feel it vibrating anymore
light touch- touch lightly with a wisp of cotton or hand, compare both sides and see if the patient can feel it
deep tendon reflexes
- stretch reflex
- involuntary response (quick response involving only a few neurons- sensory and motor)
- represent the simplest unit of sensory and motor functions
- tapping the tendon activates sensory fibres to travel to the spinal cord which arc back around to create a motor response
grading for deep tendon reflexes
4+ - very brisk, hyperactive reflex
3+ - more active than normal, slightly hyperreflexic
2+- normal reflexes
1+- somewhat diminished, low normal
0+- no response, absent
ALS and MS can cause hyperreflexic patients, whereas damage to the nervous system can cause hypoflexic
reflex tendons
biceps reflex: c5: flex arm at elbow and strike on thumb, watch for elbow flexion or contraction of bicep tendon
brachioradialis reflex: c6: hand partly pronated, striking eat radius with flat edge to watch for flexion and aspiration of forearm
triceps reflex: c7, flex the arm at the elbow, strike the triceps tendon above the elbow to find evidence of muscle contractions of the triceps
patellar reflex: L4- sitting or supine, knee flexed, tap the patellar tendon below the patella to check for contraction of quads
achilles reflex- s1- sitting of prone, slightly dorsiflex at the angle to check for plantar flexion of the ankle
examination of mental status
wetrim , look at the patients grooming and hygiene, mannerisms and behaviour, concentration and judgement, and mood
examination of Motor system
posture, tics or tremors, look at muscle girth for evidence of atrophy, muscle strength oxford
- coordination (checking for balance)
rapid alternating movement-supination pronation on thighs, run heel down shin to the big toe with eyes closed
point to point movements- touch nose then finger
gait- heel to. toe, heel and toe walking, hop on 1 foot
what causes red eyes in pictures, and how do cameras that flash continuously before taking the picture prevent red eyes?
A sudden flash doesn’t let your pupil react to the light, and the light reflects to the retina which makes the eye appear red (as the back of the eye has blood-choroid)
having the camera flash before a bunch of times helps prep your eyes, the pupils contract and take in less light, as a result less light is reflected and don’t appear red
