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Flashcards in Cellular organization & neurochemistry Deck (64):
1

Dilated pupils, elevated pulse & BP, dry skin & hyperthermia, delirium are all symptoms associated with an overload of which type of medication?

Anticholinergics

2

Antipsychotic drugs block DA transmission in which dopaminergic tract?

Mesolimbic

3

Atrophy of the distal part of neurons after being severed from the proximal part

Wallerian degeneration

4

Cell bodies of seratonergic neurons are found in & around the

Raphe nuclei

4

Catecholamines

DA, NE, and epinephrine

5

Depletion of norepinephrine results in

Decreased sympathetic activity (orthostatic hypotension, sleep disturbances, depression)

5

Cell death through inflammatory response

Necrosis

6

Dopamine producing cells are located in the

Midbrain (substantia nigra pars compacta, ventral tegmentum)

7

Dysfunction of GABA is implicated in which conditions?

Huntington's (lack of inhibition of BG), tetanus & strychnine poisoning (impair presynaptic GABA release), stiff-person syndrome

8

Describe the structure of neuronal membranes

Phospholipid membrane bilayer with "head" that contains phosphorus (polar & hydrophilic) & two "tails" that are lipid molecules (nonpolar & hydrophobic)

8

Enhanced GABA activity produces what kind of effects?

sedative, anxiolytic, anticonvulsant

9

Excess norepinephrine results in

Increased sympathetic activity (e.g., tremor, bronchodilation)

9

Endorphins

Peptide hormones synthesized in the brain that bind to opiate receptors; reduce the sensation of pain & affect emotions

10

Four nucleotide bases

Adenine, thymine, guanine, cytosine

11

Which neurotransmitter opens Cl- channels & closes CA++ channels, hyperpolarizing cells?

GABA

12

Excitotoxicity

Cell death by calcium flooding; occurs when concentrations of excitatory amino acids (glutamate) exceed the ability of uptake mechanisms to remove them (e.g., HD, epilepsy, stroke, hypoxia, TBI)

13

Which neurotransmitter is involved in regulation of mood, memory, hormones, blood flow, new learning, attention switching, & motor behavior?

Norepinephrine

14

Glutamate is implicated in

Plasticity, learning, & memory

15

Groups of ribosomes used for protein synthesis

Nissl bodies

16

Which neurotransmitter is involved in regulating mood, eating, sleeping, temp, sex, aggression, arousal, & pain?

Serotonin

16

Histamine is concentrated in the

Hypothalamus

17

How are the catecholamines synthesized?

L-Tyrosine => L-Dopa => dopamine => norephinephrine => epinephrine

18

How is serotonin involved in sleep?

Activity of serotonin-producing cells reaches highest level during arousal, drops to quiescent levels during slow-wave sleep, & disappears during REM sleep

19

How is acetylcholine synthesized?

Formed by combo of acetyle CoA + choline, in presence of enzyme choline acetyltransferase, action is terminated by cholinesterase

20

Low serotonin is associated with

Depression, anxiety, OCD, PD, AD

21

Solvents that readily permeate the nervous system & damage lipid-rich myelin, causing neuropathy & encephalopathy, are called

Lipophilic

22

Membrane potential is the property of what 2 opposing forces?

1. Force of diffusion - molecules distribute themselves equally throughout the medium in which they're dissolved 2. Force of electrostatic pressure - particles with the same kind of charge repel; different charges attract

23

Membrane-bound structures important in packaging peptides & proteins (including NTs) into vesicles

Golgi apparatus

26

Mesolimbic pathway

Ventral tegmental area => amygdala/limbic system

27

Which type of glial cells undergo rapid proliferation in response to tissue destruction, act as scavengers & metabolize tissue debris?

Microglia

28

Nigrostriatal pathway

Substantia nigra => D2 receptors of striatum Decreased DA here = rigidity, tremor, akinesia Excess => dyskinesia

29

Pathway of norepinephrine

Locus ceruleus (pons) & lateral tegmentum => cerebral cortex, limbic system, RAS, spinal cord

30

Physiological roles of endorphins

Pain perception, stress, respiratory regulation, temp control, tolerance development (opioids)

32

Relatively refractory period

State in which axon membrane is hyperpolarized, and a new action potential can be induced by only if the intensity of the stimulus is higher than that which initiated the 1st action potential

33

Removal of dead cells by mitochondria, microglia, & astrocytes

Phagocytosis

34

Programmed gene-directed cell death

Apoptosis

35

Serotonin is increased by what drugs?

SSRIs, tricyclics, MDMA (ecstacy), LSD

36

Scarring associated with hyperplasia glial overgrowth/replacement of cell bodies by glial cells

Gliosis/sclerosis

37

Spatial summation

Impulses in 2 excitatory fibers cause 2 synaptic depolarizations at about the same time that together reach firing threshold; they sum over space to fire a target neuron

38

System of transport for materials within a neuron, may be used for structural support

Microfilaments/neurotubules

39

Sodium-potassium pump

Continuously pushes Na+ out of the cell, exchanges 3 Na+ for every 2 K+

39

Serotonin is synthesized from

Tryptophan

40

Temporal summation

Occurs when a burst of action potentials reaches a nerve fiber terminal; the serious of impulses in one excitatory fiber can sum over time to fire a target neuron, even thought each individual EPSP wouldn't do it

41

System of tubes for transport of materials within cytoplasm

Endoplasmic reticulum

41

Take up glucose & break it down for energy

Mitochondria

42

What are some of the known functions of glutamate NMDA receptors?

Memory, migration of embryonic neurons, excitotoxic neuron death

44

What happens during an action potential?

Once the threshold of excitation is reached, Na+ gates open, allowing Na+ into the cell & depolarizing it. K+ gates are then opened, allowing K+ out of the cell and repolarizing it.

45

What are the main functions of astrocytes?

1) Provide support to BBB 2) Maintain local ionic & pH balance between neurons 3) Deliver energy to neurons 4) Regulate & coordinate neuronal firing

46

What is acetylcholine's role in the CNS?

Influences alertness, attention, & memory Decreased acetylcholine fx in AD

48

What is the average resting membrane potential of neurons?

~ -70mV

49

What is the only low-molecular-weight amine transmitter substance that is not an amino acid or derived directly from one?

Acetylcholine

52

What is the principal inhibitory neurotransmitter in the brain?

GABA

53

What is the principle excitatory neurotransmitter in the brain?

Glutamate

54

What is the only transmitter to be synthesized in vesicles?

Norepinephrine

55

When a neuron is at resting potential, what ions are primarily in the intracellular fluid?

K+

56

When a neuron is at resting potential, what ions are primarily in the extracellular fluid?

Cl- and Na+

57

Which glial cells form myelin in the CNS? PNS?

CNS - oligodendrocytes PNS - Schwann cells

58

Where are endorphins found in the brain?

Primarily in the pituitary, lesser amounts also present in the hypothalamus & other regions of the brain involved in pain perception

59

Which glial cells swell in response to brain injury?

Astrocytes

60

Which neurotransmitter is found at the neuromuscular junction?

Acetylcholine

61

Which toxin prevents the release of acetylcholine?

Botulism toxin

62

Cluster of neurons in the dorsal pons situated on the floor of the 4th ventricle that contains over 1/2 of the norepinephrine neurons in the CNS; neurons are activated during states of heightened vigilance & may be more involved in affective disorders

Locus ceruleus

63

Which glial cells line the brain ventricles & central canal of the spinal cord, assisting with the secretion/circulation of CSF?

Ependymal cells

64

Which dopaminergic pathway is implicated in the negative symptoms of psychosis?

Mesocortical