Intro to the CNS

Question 1

what are the 3 basic functions of the nervous system

Answer 1

1. sensory input: neurons collect info about external environment and internal conditions of body
2. integration: neurons that receive the sensory input, analyze it and make decisions about appropriate response to make
3. motor output: neurons that carry out instructions that result from integration by impulses sent to various effector organs that include muscles + glands

Question 2

what is unique about the neuron cell biology (4)

Answer 2

1. non-mitotic
2. mature but have some plasticity
3. cell body is main machinery site
4. dendrites are specialized processes that form axon and synaptic terminals

Question 3

how is the function of neurons regulated

Answer 3

mechanical, chemical, photon

1. alter sensitivity to ion flux
2. influenced by ion channels
3. alters impulse transmission

Question 4

what are the features of neurons and their function being dependant on the environment

Answer 4

ion flux requires controlled environment

tight blood brain barrier

various cell types support neurons

Question 5

what are neuroglia

Answer 5

supportive cells

help neurons function efficiently

have immune function

many different types

Question 6

what is the ependymal

Answer 6

structural and functional

specialized epithelial cells form boundary of ventricles

involved in cerebrospinal fluid production

Question 7

what is the hierarchical organization of the nervous system

Answer 7

a sensory input may be simple or complex

sensory inputs and motor outputs are communicated to different levels of the spinal cord via specific tracts

Question 8

what are the types of sensory inputs

Answer 8

simple or complex

—A simple monosynaptic reflex arc is a local event within the spinal cord

—A more complex response e.g. correcting balance may involve more that one level of the spinal cord

Question 9

what are the types of nerves

Answer 9

PNS nerves (sensory + motor)

spinal cord (processing + integration)

brainstem (processing + integration)

brain (processing + integration)

Question 10

what does the motor system control

Answer 10

voluntary movement

reflex response

posture

gait

Question 11

how does a signal from the motor system cause a response

Answer 11

divided into the upper motor neuron (UMN) and lower motor neuron (LMN)

planned movement is conceived in the forebrain and transmitted to effector muscles via UMN then LMN

Question 12

what are the neurological signs of forebrain dysfunction (6)

Answer 12

mentation: normal, obtuned or stupor (less likely)

change in behaviour can be reported

seizures can be reported

contralateral proprioceptive deficits

contralateral menace response absent

circling towards the side of lesion

Question 13

what are the neurological signs of cerebellar dysfunction (4)

Answer 13

mentation: normal

hypermetria, dysmetria (ipsilateral)

intention tremors

can have head tilt (contralateral)

Question 14

what are the neurological signs of brain stem dysfunction (4)

Answer 14

mentation: normal, obtunded, stupor or coma

head tilt and wide base stance

cranial nerves III-XII can show deficits

ipsilateral proprioceptive deficits