PCOL M2 Flashcards

1
Q

EXPLAIN ORGANIZATION OF THE NERVOUS SYSTEM

A

IE AND EV to CNS = afferent
CNS TO IE AND EV = efferent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  • are electrically excitable cells that process and transmit information via an electrochemical process
A

NEURONS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  • Receive and integrate the input from other neurons and conduct this information to the cell body
  • May be hundreds in every neuron
A

DENDRITES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Carries the output signal of a neuron from the cell body, sometimes over long distances

A

AXONS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Only one in every neuron, but may branch distally to contact multiple targets

A

AXONS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Makes contact with other neurons at specialized junctions
- end part of neuron

A

AXON TERMINAL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

spaces between 2 neurons

A

synapses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

old english in uk and us singular and the plural form of [spaces between 2 neurons]

A

UK = synapse [singular]
synapses [plural]
US = ganglion [singular]
ganglia [plural]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

2 broad categories of Neuronal System in the CNS

A
  1. HIERARCHICAL SYSTEMS
  2. NONSPECIFIC OR DIFFUSE NEURONAL SYSTEM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  • Include all pathways directly involved in sensory perception and motor control
A
  1. HIERARCHICAL SYSTEMS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

o Information is processed sequentially by successive integrations at each relay nucleus on its way to the cortex

A
  1. HIERARCHICAL SYSTEMS sensory system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A lesion at any link incapacitate the system

A
  1. HIERARCHICAL SYSTEMS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Two types of cells (hierarchical)

A

 Relay or projection neurons
 Local Circuit neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

about Relay or Projection neurons

A

Relatively large
Axons emit collaterals that arborize extensively in the vicinity of the neurons

Excitatory

glutamate

Interconnecting pathways transmit signals over long distances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

About Local Circuit neurons

A

Small axons arborize in the immediate vicinity of the cell body

inhibitory

GABA or glycine

Recurrent feedback pathways Feed-forward pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  • Contain one of the monoamines (—-,—-,—-)
  • Pathways emanating from the reticular formation
  • Some peptide-containing pathways
  • Small, approximately 1500 on each side of the brain (rat)
  • Axons are very fine and unmyelinated
  • Neurotransmitters: —–
  • Receptors: —-
  • The system is implicated in functions such as sleeping and waking, attention, appetite, and emotional states
    Types of Ion-channel and Neurotransmitter Receptors in the CNS
A
  1. NONSPECIFIC OR DIFFUSE NEURONAL SYSTEMS
    * Contain one of the monoamines (dopa, SE, NE)
    * Neurotransmitters: Monoamines
    * Receptors: Adrenergic receptors (metabotropic)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

found in compact cell group called locus ceruleus located in the caudal pontine central gray matter

A
  • NE cell bodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

explain The synaptic transmission

A

1 synthesis
2 storage vesicle
3. Release
4. Postsynaptic receptors

in the 5 step depends
5. uptake then metabolism
or
5. diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain synaptic transmission of acetylcholine

A

asa pic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Explain synaptic transmission of norepinephrine

A

nasa pic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  • Provides a small depolarization
  • Due to the excitatory transmitter acting on an ionotropic receptor, causing an increase in cation permeability
  • Generally results from opening of Na+ channels
A

EXCITATORY POST SYNAPTIC POTENTIAL (EPSP)

22
Q
  • Provides a small local hyperpolarization
  • Propagated by inhibitory neurotransmitters
  • Generally results from opening of K+ and Cl- channels
A

INHIBITORY POST SYNAPTIC POTENTIAL (IPSP)

23
Q
  • Neurotransmitters are chemicals that take a nerve signal across the synaptic gap between a sending neuron, and a receiving one
A

NEUROTRANSMITTERS OF THE BRAIN

24
Q
  • Small molecule neurotransmitters
  • Mainly amino acids and amines
A
  1. The “classical“
25
Q
  • Relatively larger
  • The combination of two or more amino acids joined by peptide bonds
A
  1. The neuropeptide neurotransmitters
26
Q

AMINO ACID NEUROTRANSMITTERS Two categories:

A

*the acidic amino acid [glutamate]
*the neutral amino acids [glycine and GABA]

27
Q
  • Released into the synaptic cleft by Ca2+ -dependent exocytosis
  • Mediates excitatory post synaptic transmission
  • Activates both ionotropic and metabotropic receptors
A

GLUTAMATE - Vesicular glutamate transporter (VGLUT)
o Ionotropic receptors include;
* NMDA –R
* KA-R
* AMPA-R
o All are composed of four subunits

28
Q
  • GluA1–GluA4 subunits
  • Majority contain the GluA2 subunit and permeable to Na+ and K+ , but not to Ca2+
  • Some are present on inhibitory interneurons, lack the GluA2 subunit and are also permeable to Ca2+
A

GLUTAMATE Ionotropic receptors
 AMPA

29
Q
  • high levels in the hippocampus, cerebellum, and spinal cord
  • formed from a number of subunit combinations (GluK1–GluK5)
  • permeable to Na+ and K+ and in some subunit combinations can also be permeable to Ca2+
A

GLUTAMATE Ionotropic receptors
 KA (Kainate) Receptor

30
Q
  • present on essentially all neurons in the CNS
  • highly permeable to Ca2+ as well as to Na+ and K+ .
A

GLUTAMATE Ionotropic receptors
 NMDA

31
Q
  • two requirements for NMDA receptor channel opening:
A

o Glutamate must bind the receptor and
o the membrane must be depolarized

32
Q
  • G protein-coupled receptors that act indirectly on ion channels via G proteins
  • mGluR1–mGluR8 divided into 3 groups
A

GLUTAMATE Metabotropic receptors

33
Q
  • typically located postsynaptically
  • activate phospholipase C, leading to inositol trisphosphate mediated intracellular Ca2+ release
A

Group I receptors

34
Q
  • typically located on presynaptic nerve terminals and act as inhibitory autoreceptors
  • Activation causes the inhibition of Ca2+ channels, resulting in inhibition of transmitter release
  • Are activated only when the concentration of glutamate rises to high levels during repetitive stimulation of the synapse
  • Activation also causes the inhibition of adenylyl cyclase and decreases cAMP generation
A

Group II and group III receptors

35
Q
  • inhibitory neurotransmitters typically released from local interneurons
A

GABA and GLYCINE

36
Q
  • spinal cord and brainstem
  • selectively permeable to Cl− .
  • Strychnine selectively blocks glycine receptors
A

o Glycine

37
Q
  • throughout the CNS
A

o GABA

38
Q
  • Ionotropic receptor that are selectively permeable to Cl-
  • Mediate fast component of IPSP
A

 GABA A

39
Q
  • Metabotropic receptors, selectively activated by Baclofen
  • Inhibit Ca+2 channel or activate K+ channel
  • Also inhibit adenylyl cyclase and decrease cAMP generation
A

 GABA B

40
Q
  • ——- responses are mediated by both muscarinic and nicotinic receptors
  • Muscarinic effects are slower than nicotinic effects
  • CNS responses are mostly mediated by G-protein coupled muscarinic receptors
  • Degraded by cholinesterases
A

ACETYLCHOLINE

41
Q
  • Most noradrenergic neurons are located in the locus caeruleus or the lateral tegmental area of the reticular formation
  • An amine, excitatory transmitter of the brain and smooth muscle
  • All receptors are metabotropic
  • Hyperpolarizes the neuron by increasing potassium conductance via the Alpha-2 receptor
  • Enhances excitatory inputs in most areas of the CNS by both indirect and direct mechanisms
A

NOREPINEPHRINE

42
Q
  • Induce arousal, heighten mood
  • Impaired monoamine (NE, SE and Dopa) neurotransmission has been associated with depression
  • Drugs that induce monoamine release are indicated for attention deficit disorder and narcolepsy
A

NOREPINEPHRINE

43
Q

involves disinhibition

A

o Indirect mechanism

44
Q

involves blockade of potassium conductance

A

o Direct mechanism

45
Q
  • Synthesized from dopa
  • Degraded by Monoamine oxidase A (MAO-A) in the brain and MAO-B outside the CNS and by catechol-O-methyl transferase (COMT)
  • Receptors are:
    o D1–like (D1 and D5 ); and
    o D2 -like (D2 , D3 , D4 )
    o all are metabotropic
  • Major pathways are the projection linking the substantia nigra to the neostriatum and the projection linking the ventral tegmental region to limbic structures, particularly the limbic cortex
  • Generally exerts a slow inhibitory action on CNS neurons [containing substantia nigra neurons, where D2-receptor activation opens potassium channels via the Gi coupling protein ]
A

DOPAMINE

46
Q
  • Important dopaminergic pathways
A

o Nigrostriatal pathway (from the substantia nigra to striatum)
o Neurons of the chemoreceptor trigger zone (CTZ) of the medulla – controls vomiting
o Projections from the hypothalamus to the intermediate lobe of the pituitary – thought to regulate prolactin release

47
Q
  • Result from overstimulation of dopamine receptors
A

Psychoses

48
Q
  • Caused by too little dopaminergic input from the substantia nigra into the striatum
A

Parkinson’s disease

49
Q
  • Formed from tryptophan (hydroxylated, then decarboxylated)
  • Released from inhibitory neurons
  • Stimulates 5HT receptors (more than a dozen)
    o All receptors are metabotropic, except 5HT3 (ionotropic)
  • Has inhibitory actions in most areas of the CNS
  • Has been implicated in the regulation of virtually all brain functions, including;
    o perception, mood, anxiety,
    o pain, sleep, appetite,
    o temperature,
    o neuroendocrine control, and
    o aggression
  • Depression, Attention Deficit Disorder and Headaches have been attributed to serotonergic imbalances
A

5-hydroxytryptamine (5-HT, serotonin)

50
Q
  • Exclusively made by neurons in the tuberomammillary nucleus (TMN) in the posterior hypothalamus
  • Modulate arousal, attention, feeding behavior, and memory
  • Receptors are H1 to H4
    o all are metabotropic
  • Centrally acting antihistamines are generally used for their sedative properties
  • Antagonism of H1 receptors is a common side effect of many drugs including some tricyclic antidepressants and antipsychotics
A

HISTAMINE

51
Q
  • Generally packaged in large, dense core vesicles
  • Released neuropeptides may act locally or may diffuse long distances and bind to distant receptors
  • Most ——- receptors are metabotropic and primarily serve modulatory roles in the nervous system ———-
  • Implicated in a wide range of CNS functions including;
    o reproduction,
    o social behaviors,
    o appetite,
    o arousal,
    o pain,
    o reward, and
    o learning and memory
    o Opioid peptides
    o Neurotensin
    o Substance P
    o Somatostatin
    o Cholecystokinin
    o Vasoactive Intestinal Polypeptide (VIP)
    o Neuropeptide Y
    o Thyrotropin-releasing hormone (TRH)
    o The Opioids
  • Endorphins, enkephalins and dynorphins are opiate receptor agonists
  • All opioid receptors are metabotropic
     Mu, kappa, delta
  • In times of stress and pain, endogenous peptides act at opiate receptors (to relieve pain) Neuropeptides
A

Neuropeptides

52
Q
  • Released from primary sensory neurons in the spinal cord and brainstem and causes a slow excitatory postsynaptic potential
  • Plays an important role in transmitting pain stimuli
A

Substance P