Bryan - Neurosciences - Winter 2010 - Midterm 1 Study

Front 1

What is a circumscribed collection of neurons in the CNS called? Outside the CNS?

Back 1

Nucleus
Ganglion

Front 2

Where does the spinal cord terminate in the dog? In the horse? How about humans?

Back 2

L6 - dog
S2 - horse
L2 - humans

Front 3

Where is CSF located with respect to the meninges?

Back 3

Subarachnoid space

Front 4

Where is the lumbar cistern in dogs? In cats? In the horse? Cow? Sheep? Pig?

Back 4

Dog/cat - L5/L6 (+/- 1)
All others - lumbosacral space

Front 5

In which of the 5 brain regions would the reticular formation be found?

Back 5

Mylencephalon, metencephalon, mesencephalon, diencephalon (?)

Front 6

In which of the 5 brain regions would the pineal gland, facial nerve, and olfactory bulb be found?

Back 6

Pineal - diencephalon
Facial - myelencephalon
Olfactory - telencephalon

Front 7

In which of the 5 brain regions would the oculomotor n., corpus callosum, lateral ventricles be found?

Back 7

Oculomotor - mesencephalon
corpus and ventricles - telencephalon

Front 8

In which of the 5 brain regions would the substantia nigra, red nucleus, and optic nerve be found?

Back 8

nigra and red - mesencephalon
Optic n. - diencephalon

Front 9

In which of the 5 brain regions would the hypothalamus, middle cerebellar peduncles, and fourth ventricle be found?

Back 9

hypo - diencephalon
peduncles - metencephalon
ventricle - metencephalon and mylencephalon

Front 10

In which of the 5 brain regions would the hippocampus, caudate nucleus, and cerebral peduncles be found?

Back 10

hippo and caudate - telencephalon
peduncles - mesencephalon

Front 11

What is the principal structure responsible for the blood/brain barrier? Blood/csf barrier? brain/csf barrier?

Back 11

Blood/brain - nonfenestrated capillaries
Blood/CSF - choroid epithelial tight junctions
Brain/CSF - ependymal cells and glial membrane

Front 12

Which structures comprise the limbic system?

Back 12

Amygdala, hippocampus, pyriform lobe, septal area, anterior nucleus of the thalamus

Front 13

Which spinal cord segments lie within the 5th lumbar vertebra of a dog?

Back 13

Caudal L7, S1 - S3

Front 14

Which spinal cord segments contain LMNs for the thoracic limb in the cat and dog?

Back 14

C6 - T1

Front 15

Which spinal cord segments supplies the pelvic limbs? How 'bout the pelvic cavity?

Back 15

Limbs - L4 - S2
Cavity - S1 - S3

Front 16

What are the three types of efferent neurons and what do they innervate?

Back 16

Alpha - sleketal muscle
Beta - smooth, cardiac muscle, and glands
Gamma - muscle spindle

Front 17

What is the rate of axonal regrowth? What is the critical timeframe of regrowth before a neuron will completely die?

Back 17

1mm/day or 1in/month
1 year is critical

Front 18

T or F
In a hyperpolarized neuron, membrane potential is more negative than the normal RMP.

Back 18

True!

Front 19

When a nerve cell becomes hyperpolarized, in what direction do K ions flow?

Back 19

Into the cell

Front 20

T or F:
Increasing stimulus strength to 5x over threshold increases the rate of depolarization and the amplitude of the signal.

Back 20

False! It does increase the depolarization rate but the amplitude (overshoot height) remains the same.

Front 21

What provides the electrostatic force keeping K ions within the cell?

Back 21

Protein anions within the cell.

Front 22

What two factors allow for cell repolarization after an AP is initiated?

Back 22

Close Na gates
Efflux of K

Front 23

What is the major cause of the rapid depolarization phase of an AP?

Back 23

Opening of Na gates (Na influx)

Front 24

What two factors determine the length constant of a nerve?

Back 24

Degree of myelination
Radius of fiber

Front 25

Which type of fiber conducts signals the fastest? Which is the slowest?

Back 25

A alpha (Ia and Ib)
C (pain fibers)

Front 26

Which type of fiber is most susceptible to local anesthetics? To hypoxia? To pressure?

Back 26

C - anesthetics
B - hypoxia
A - pressure

Front 27

Classify A, B, and C fibers by whether they are afferent or efferent.

Back 27

A - afferent and efferent
B - efferent
C - efferent and afferent

Front 28

What are some advantages of saltatory conduction in a mammal?

Back 28

Metabolic efficiency (use less ions)
Increase conduction speed (ion exchange only occurs at internodes)

Front 29

What is the main neurotransmitter used for nociception? What neurotransmitter inhibits it? What is this inhibition called?

Back 29

Substance P (inhibited by enkphalins through presynaptic inhibition)

Front 30

How is Ach inactivated in the synaptic cleft?

Back 30

Cholinesterase breaks it down into choline and acetate. These are resorbed by the presynaptic membrane.

Front 31

Where are electrical synapses found?

Back 31

Eye and cerebral cortex; also invertebrates

Front 32

What is the major difference between an EPP and an EPSP.

Back 32

An EPP occurs within a muscle cell while an EPSP occurs at a synaptic cleft.

Front 33

T or F:
An EPP is actually made up of multiple (sometimes hundreds) of MEPPs.

Back 33

True!

Front 34

How does an IPSP make a neuron less able to fire an AP? (i.e. what subcellular mechanisms are involved)?

Back 34

Increase permeability of K and Cl
Hyperpolarize the cell

Front 35

What NT is released by Renshaw cells? By preganglionic sympathetic neurons? At the neuromuscular endplate?

Back 35

Glycine
Ach
Ach

Front 36

Which NT is antagonized by LSD? An axo-axonic inhibitory neurotransmitter? The most common excitatory NT?

Back 36

Serotonin
GABA or Enkephalin
Glutamate

Front 37

Which NT is associated with addiction? Produced by Substantia nigra? Antagonized by strychnine?

Back 37

Dopamine
Dopamine
Glycine

Front 38

Which neurotansmitter is the postganglionic sympathetic NT? Is made by raphe nuclei? Is associated with the locus ceruleus?

Back 38

NE
Serotonin
NE

Front 39

Which NT is associated with the hippocampus and alzheimers? The NT of pain fibers? Released by substantia gelatinosa cells?

Back 39

Ach
Substance P
Enkephalin

Front 40

Which NT is inhibited by botulism toxin? Has gallamine as an agonist?

Back 40

Ach
Ach

Front 41

Where does botulism toxin have its effect?

Back 41

Binds to Ca preventing Ach release at NM junction

Front 42

What is the difference between strychnine and tetanus toxins?

Back 42

Both affect Renshaw cells. Tetanus inhibits the Renshaw cells, causing Ach release and muscular contraction. These lesions are irreversible.
Strychnine is a glycine antagonist, preventing the renshaw cells from signalling leading to constitutive Ach secretion. This is reversible

Front 43

How does Atropine work?

Back 43

Blocks Ach at postsynaptic receptor

Front 44

What are the nondepolarizing NM blocking agents and how do they work?

Back 44

Curare and Gallamine
competes with Ach for receptors

Front 45

Which drug is condemned for use on horses? What does this drug do? Can animals given this drug feel pain?

Back 45

Succinylcholine is a depolarizing NM blocker.
Does not deaden pain.

Front 46

Name some cholinesterase inhibitors. Which are irreversible?

Back 46

Neostigmine
Physostigmine
parathion (irreversible)
malathion (irreversible)
dichlorovos (irreversible)
nerve gas (irreversible)

Front 47

Which drugs impact GABA and how?

Back 47

Valium - increase GABA effectiveness
Ivermectin - GABA agonist

Front 48

Which receptors convey unconscious proprioception? To where do they send their information?

Back 48

muscle spindle and golgi tendon organs send info to the cerebellum

Front 49

Compare/contrast lesions of UMNs and LMNs.

Back 49

Both lack voluntary movement.
UMNs have reflex; LMNs have no reflex.

Front 50

How is the excitatory state of LMNs modulated?

Back 50

Through EPSPs and IPSPs. Increased EPSPs = excitation; increased IPSPs = attenuation.

Front 51

Which of the following species has flow from the basilar artery contributing to the brain arterial supply?
Horse, dog, cow, sheep, cat

Back 51

Horse and dog

Front 52

Which space in the brain does NOT produce CSF?

Back 52

Cerebral aqueduct

Front 53

Which spinal cord segments originate under L3? Under L5?

Back 53

L3 - L3 and cranial L4
L5 - Caudal L7, S1 - S3

Front 54

Which spinal cord segments originate under L4? L6?

Back 54

L4 - caudal L4, L5, L6, cranial L7
L6 - Ca 1-5

Front 55

Spinal cord segments T2 - L3 are responsible for which region(s) of the body? How about C1 - C5?

Back 55

Sympathetic outflow and muscles of respiration.
Neck meat.

Front 56

What are the 5 segments or zones of neurons? Which are graded in their response?

Back 56

Receptive (graded)
trigger zone
conductile
transmissive (graded)
trophic

Front 57

T or F:
An EPP always results in depolarization.

Back 57

True!

Front 58

What is the formula for length constant? Which factor is important in mammals? In invertebrates?

Back 58

((membrane resistance x radius)/(2 x axoplasm reistance))^0.5

Mammals modulate membrane resistance while invertebrates change radius.

Front 59

Give examples of presynaptic inhibition.

Back 59

Enkaphalins (from substantia gelatinous cell) inhibit substance P release (from nocioceptive fiber).

GABA inhibits DA release.

Front 60

Name a phasic receptor and a tonic receptor.

Back 60

Phasic - pacinian corpuscle
Tonic - joint receptor

Front 61

What is the rate-limiting step in catecholamine synthesis?

Back 61

Tyrosine Hydroxylase