neurology and animal responses Module 5

Question 1

outline 5 features of the sensory neuron

Answer 1

short dendrites
long dendron
short axon
cell body in middle
myelinated

Question 2

outline 4 features of a motor neuron

Answer 2

many short dendrites
long axon
cell body to one side
myelinated

Question 3

outline 3 features of the relay neuron

Answer 3

many short dendrites
short axon
cell body in middle

Question 4

where are relay neurons found

Answer 4

CNS (brain and spinal chord)

Question 5

where are motor and sensory neurons found

Answer 5

PNS

Question 6

what is a similarity between a motor neuron and a sensory neuron

Answer 6

myelination + both found in PNS

Question 7

what is a similarity between relay neuron and motor neuron

Answer 7

many short dendrites

Question 8

what are the 4 stages of an action potential, what is the voltage at these stages

Answer 8

Stimulus (-70 mV)
depolarisation (-55 mV)
repolarisation (30mV)
hyperpolarisation (-80mV)
resting potential (-70mV)

Question 9

what is the effect of nicotine on synaptic transmission

Answer 9

mimics the effect of Ach and so can bind to cholinergic receptors in the brain

Question 10

what is the effect of curare on synaptic transmission and the body

Answer 10

blocks receptors at neuromuscular junctions so muscles can’t be stimulated - causes paralysis.

Question 11

what is the effect of opiods on synaptic transmission

Answer 11

blocks Ca2+ receptors meaning fewer vesicles fuse with the pre synaptic membrane, less neurotransmitter released.

Question 12

what is the name of the enzyme that breaks down Ach in a neuromuscular junction

Answer 12

acetylcholinesterase

Question 13

give an example of an excitatory neurotransmitter

Answer 13

Glutamate

Question 14

give an example of an inhibitory neurotransmitter

Answer 14

Gaba

Question 15

what is a sarcomere

Answer 15

basic functional unit of a muscle fibre

Question 16

what is the sarcolemma

Answer 16

plasma membrane around fibres

Question 17

what is the sarcoplasmic reticulum

Answer 17

endoplasmic reticulum in sarcomere

Question 18

what is a myofibril

Answer 18

long cylindrical organelles - made of actin and myosin

Question 19

What is the I band

Answer 19

light band - made of actin filament only

Question 20

what is the H zone

Answer 20

made of myosin only

Question 21

what is the A band

Answer 21

dark band - overlap of myosin and actin

Question 22

what is the Z line

Answer 22

marks the end of the sarcomere

Question 23

what is the M line

Answer 23

middle of myosin filament

Question 24

what happens to the various regions and lines when a muscle fibre contracts

Answer 24

A band stays the same length
I band gets shorter
H zone gets shorter

Question 25

what is skeletal muscle, give 3 features

Answer 25

-found in muscle fibres

• under conscious control
• contracts quickly but fatigues quickly
• multinucleated

Question 26

what is smooth muscle, give 3 features

Answer 26

found in walls of internal organs eg. gut and blood vessels

-uninucleated
- fibres are spindle shaped
- contracts slow,doesn’t fatigue

Question 27

what is cardiac muscle, give 4 features

Answer 27

found in walls of heart

-myogenic
-connected by intercalated discs
-muscle fibres are branched
- uninucleated + rythmical contraction