Organization of Nervous System, Synapses and Transmitters

Question 1

CNS vs PNS

Answer 1

CNS: Encephalon (brain, brainstem, cerebellum), spinal cord
PNS: Peripheral nervous system (sensory and motor)

Question 2

What does the autonomic nervous system control?

Answer 2

Autonomic functions (heart rate, respiratory rate, digestion, urination…)

Question 3

What are the two systems that make up the ANS

Answer 3

Sympathetic nervous system: increases activity of autonomic functions

Parasympathetic nervous system: decreases the activity of autonomic functions

Question 4

Where do the ANS signals originate from?

Answer 4

The brainstem

Question 5

Name the 3 major levels of the CNS

Answer 5

Cortical level, subcortical level and the spinal cord level

Question 6

What does the spinal cord level contain?

Answer 6

Walking circuits
Circuits for reflexes
Circuits for body support (extensors)
Circuits for reflexes that control organ functions

Question 7

What does the subcortical level contain?

Answer 7

Brainstem (medulla and pons), mesencephalon, hypothalamus, thalamus, cerebellum, and basal ganglia

Question 8

What does the subcortical level control?

Answer 8

subconscious body activities: arterial pressure, respiration, equilibrium, body temperature, hormonal regulation

Question 9

What is vagal shock?

Answer 9

loss of consciousness due to lack of blood going to the brain

Question 10

T/F the stimulation of the sympathetic nervous system is what produces vagal shock

Answer 10

False, the parasympathetic nervous system is responsible for vagal shock

Question 11

Is the cortical level the superficial layer of the grey or white matter?

Answer 11

Grey matter

Question 12

What are the functions of the cortical level?

Answer 12

Information processing, memory storage, decision making, thought process

Question 13

What is the cerebral cortex made up of?

Answer 13

Grey matter

Question 14

Where is the information in the somatosensory system transmitted to?

Answer 14

spinal cord, reticular substance, cerebellum, thalamus, cerebral cortex

Question 15

What is the main function of the somatosensory system?

Answer 15

To transmit somatic information from the receptors to the CNS

Question 16

What does the motor system control?

Answer 16

Skeletal muscle contraction, smooth muscle contraction (internal organs), the activity of exocrine & endocrine glands

Question 17

In which direction does a signal travel through a neuron?

Answer 17

Cell body (soma) to the dendrites to the axon

Question 18

Name the four types of neurons

Answer 18

Unipolar neuron
Multipolar neuron
Pseudo-unipolar neuron
Bipolar neuron

Question 19

Where are unipolar neurons found?

Answer 19

Photoreceptors in the retina

Question 20

Describe a unipolar neuron

Answer 20

Dendrite & axon are on the same side

Question 21

Describe the multipolar neuron

Answer 21

Has several dendrites and one axon
Most common cell type (motoneuron, purkinje cell)

Question 22

Where are pseudo-unipolar neurons found?

Answer 22

They are the sensory neuron in the spinal cord

Question 23

What do pseudo-unipolar neurons develop from?

Answer 23

From bipolar neurons

Question 24

Where are bipolar neurons found?

Answer 24

in the eyes, the retina, inner ear & olfactory

Question 25

Describe the bipolar neuron

Answer 25

One main dendrite and one axon

Question 26

How is information transmitted within the neuron?

Answer 26

By action potentials

Question 27

Where do APs start?

Answer 27

Axon hillock

Question 28

How is information communicated between neurons?

Answer 28

By synapses

Question 29

Describe the role of Ca2+

Answer 29

Ca2+ enters the cell and causes neurotransmitters to be released form vesicles; amount of neurotransmitters released is directly related o the number of Ca2+ ions that enter

Question 30

What is a synonym for neurotransmitter?

Answer 30

Ligand

Question 31

What does the type of neurotransmitter based on?

Answer 31

The action on the postsynaptic neuron

Question 32

What are the two types of neurotransmitters?

Answer 32

Excitatory: Excite postsynaptic neuron Inhibitory: Inhibit postsynaptic neuron

Question 33

Name the excitatory neurotransmitters

Answer 33

Glutamate: Used in every part of the brain and spinal cord Dopamine: Motor behavior + pleasures + emotional arousal Norepinephrine: Sleep patterns + focus Acetylcholine: Activates skeletal muscle Serotonin: Mood + appetite + sleep + memory + learning

Question 34

Name the inhibitory neurotransmitters

Answer 34

GABA: used in every part of the brain, balancei n our system, many sedative drugs act by enhancing the effect of GABA

Question 35

What does GABA stand for

Answer 35

Gamma- amino butyric acid

Question 36

What are the 4 mechanisms of neurotransmitters release?

Answer 36

1. AP arrives at presynaptic terminal 2. Local depolarization opens voltage-gated Ca2+ channels and Ca2+ ions flow into terminal 3. Ca2+ ions trigger the fusion of synaptic vesicles with the presynaptic membrane 4. Release of the transmitter into the synaptic cleft

Question 37

Name the two types of receptors on the postsynaptic membrane

Answer 37

Ionotropic receptor Metabotropic receptor

Question 38

Which receptors are slow/fast acting?

Answer 38

Ionotropic = fats acting (lets ions flow inside Metabotropic = slow acting (second messenger activator

Question 39

What are the two types of ion channels in ionotropic receptors?