Neuro

Question 1

What is acetylcholine?

Answer 1

Acetylcholine (ACh) is a neurotransmitter between neurons and from neurons to effector cells.

Question 2

Function of Acetylcholine:

Answer 2

gets released into the synaptic cleft, due to the presence of action potential in the presynaptic neuron.

Question 3

what happens to acetylcholine when it enters the synaptic cleft?

Answer 3

It binds to acetylcholine gated Na+ channels, allowing sodium to enter the post synaptic cleft causing depolarisation and may lead to production of a action potential.

Question 4

How and why is acetylcholine degraded?

Answer 4

Acetylcholine is degraded by an enzyme call Acetylcholinesterase (AChE). This is to stop the transmission of action potentials when not required.

Question 5

What happens if acetylcholine isnt degraded?
(the continued production of Action Potentials)

Answer 5

Neutransmission will not stop. Acetylcholine may increase in concentration in the synpatic cleft, and lead to excessive synaptic transmission.

Question 6

What is a nerve agent?

Answer 6

Nerve agents are chemicals that interfere with the nervous system. Therefore it inhibits the breakdown of acetylcholine, a neurotransmitter used by the somatic and autonomic nervous systems.

Question 7

why might nerve agents cause uncontrolled skeletal muscle contraction and constriction of pupils?

Answer 7

In the somatic motor pathway, this will lead to excessive excitation of a muscle cell, causing uncontrollable contraction.

In the autonomic nervous system (the parasympathetic system) it will lead to pupil constriction.

Question 8

role of dorsal ramus:

Answer 8

carries info to the dorsal side of the body

Question 9

What is Peripheral nerve structure?

Answer 9

Nerves are wrapped in epinerium, fasicles are wrapped in perinerium, axons are wrapped in endonerium

Question 10

The ventral/anterior root contains what?

Answer 10

efferent axons

Question 11

what level does the spinal cord end?

Answer 11

L1

Question 12

What are the 3 white matter tracts in the brain?

Answer 12

Commissural , projection, association

Question 13

What are the commissural , assocation and projection tracts?

Answer 13

Commissural = axons crossing from 1 side to other side of the brain (coordinates RHS with LHS)

Projection = axons from cerebrum to other areas of central nervous system

Association = axons between areas on the same side of the cerebrum (long or short distance)

Question 14

what lobe is responsible for detecting vision?

Answer 14

occipital lobe

Question 15

the corpus callosum is an example of what?

Answer 15

A commissural tract

Question 16

What is the division between the cerebrum and cerebellum?

Answer 16

the transverse fissure

Question 17

what type of white matter communicates within the same hemisphere of the cerebrum?

Answer 17

Association tracts

Question 18

how do you measure action potential velocity?

Answer 18

Using conduction studies equation: velocity = distance/time

Question 19

what is somatic sensation?

Answer 19

the bodys ability to sense stimuli

Question 20

what are the 4 morphological types of sensory neurons?

Answer 20

Multipolar, bipolar , unipolar, anaxonic

Question 21

what is sensory signal transduction ?

Answer 21

Process of converting sensory signals from environment into electrical signals that can be transmitted and interpreted by the brain.

Question 22

4 types of general sensory receptor:

Answer 22

mechanoreceptor, nociceptors, thermoceptors, chemoreceptors

Question 23

What is a tonic receptor?

Answer 23

slow adapting receptors, that is continually active to reflect background level of stimulation. Frequency changes when stimulus intensity changes.

Question 24

what is a phasic receptor?

Answer 24

fast adapting receptor, that is normally silent, responds briefly to change, e.g touch and temperature.

Question 25

what are the following 4 types of information about a stimulus that are encoded by sensory systems?

Answer 25

1. modality - type of receptor activated
2. intensity - stimulus strength
3. duration - time period which stimulus exists
4. location - place in body where receptors are activated

Question 26

in the stretch reflex pathway, reciprocal inhibitory neurons are required in order to control the movement. TRUE OR FALSE?

Answer 26

FALSE - in the WITHDRAWAL reflex pathway, reciprocal inhibitory neurons are required in order to control the movement.