NEURONES Flashcards
1
Q
Neurones are —— cells
A
Nerve cells
2
Q
Neurones are said to evolve from?
A
primitive neuroeffecfor cells
3
Q
Cns+pns= how many neurones
Cns=how many neurones
How many brain cells
A
trillions of neurones
100 billion neurones
25 billion brain cells
4
Q
Brain and spinal cord are continuous with each other at ——-
A
Foramen magnum
5
Q
List the 3 layers of meninges that surround brain and spinal cord
A
Outer dura matter
Middle arachnoid
Inner pia
6
Q
What fills the subarachnoid space
A
CSF
7
Q
Which is more , glial cells or neurons and by how much
A
Glial cells
10-50 times
8
Q
Mention 2 unique things found in the soma of a neurone
A
Nissl bodies
Neurofibrils
9
Q
What isn’t in the soma of a neurone
A
Centrosome- they can’t divide
10
Q
Nissl bodies
Eosinophilic or basophilic
A
Basophilic
11
Q
Parts of a neurone where nissl bodies can be found
A
Soma and dendrites only
12
Q
Function of nissl bodies
A
Protein synthesis, they have ribosomes
13
Q
Nissl bodies have —— appearance after staining
A
Tigroid appearance
14
Q
Which part of a neuron can neurofibrils be found?
A
Every part of a neurone
15
Q
Nodes of ranvier lack——
A
Myelin
16
Q
Size of some Lengthof dendrite Length of axon Size of nodes of ranvier Distance between 2 nodes of ranvier
A
5-100um Few 100um Few um to 1m 1um 1mm
17
Q
Mention 2 areas with very long axons
A
Pyramidal tracts-corticospinal
Peripheral nerves-nerve to limb(like sciatic nerve)
18
Q
Myelin is a ____-_____
A
Protein-lipid
19
Q
- produces myelin in cns
- produces myelin in pns
A
Oligodendrocytes
Schwann cells
20
Q
Myelin. Continuous or not continuous
A
Not continuous
21
Q
Veins drain nerves through ——?
A
Cerebrospinal fluid
22
Q
Speed of myelinated nerve is — times that of unmyelinated nerve
A
50 times
23
Q
Neuroglial cells
Excitable or non-excitable
A
Non-excitable
24
Q
Common site of tumors in a nervous system
A
Neuroglial cells
25
```
Function of
Astrocytes
Ependymal cells
Oligodendrocytes
Microglia cells
```
Tight junctions to give Blood-brain barrier;regulate the extra cellular composition of the CSF
Form choroid plexus that secrete CSF; they also line the brain ventricles and spinal cord canal
Produce myelin and supportive function
Specialized macrophages
26
Functions of neuroglial cells of pns
Satellite cells
Schwann cells or neurolemmocytes
Surround cell body or soma
Produce myelin
27
Schwann can produce myelin to surround how many axons?
Just 1
28
4 zones of a nerve fiber
Receptor or dendritic zone
Initial segment
Axonal zone
Terminal zone
29
Pseudounipolar
Bipolar
Multipolar
Soma is attached to the side(cutaneous nerve)
Soma is in the middle (auditory neuron)
Soma is at the dendritic end
30
Relationship between diameter of a fiber, velocity of conduction, duration of spike, and duration of refractory period
Increase diameter-increase velocity-reduced spike time-reduced refractory period
31
Which fiber is most,less, and least susceptible to
Cocaine
Pressure
Hypoxia
Cocaine- most(C), less(B), least (A)
Pressure-most(A), less(B), least(C)
Hypoxia- most(B), less(A), least(C)
32
Which FIBER is for motor-muscle
A gamma
33
Which fiber is for pain, cold,touch
A delta
34
Which fiber is for touch, pressure motor
A beta
35
Which fiber is for proprioception and somatic motor
A alpha
36
Which fiber is for preganglion autonomic reflexes
B fiber
37
Gray matter is made up of
Nerve cell bodies and proximal parts of a nerve cell
38
White matter is made up of
Remaining part of nerve fiber besides the cell body and proximal part
39
Location of gray and white matter in brain and spinal cord
Brain: white inside;gray outside
| Spinal cord: white outside;gray inside
40
Bundle of nerve fiber is called,
A fasiculus
41
Each nerve fiber is covered by?
The whole nerve is covered by ,
Endoneurium
Epineurium
42
```
Define
Axoplasm
Axolemma
Axis cylinder
Neurilemma
```
Cytoplasm of an axon
Continuation of cell membrane of soma
Axoplasm+axolemma
Covering of axis cylinder
43
What is responsible for the white color of nerves
Myelin sheath
44
Unmyelinated and myelinated fibers have Schwann cells
| T/F
T
45
AKA of neurilemma
Sheath of Schwann/ neurilemmal sheath
46
Nucleus of the internode is located-?
Between myelin sheath and neurilemma
47
Cns have neurilemma
| T/F
F. So they use oligodendrocytes
48
Cohnheim’s areas or fields
In some muscle fibers, some of the myofibrils are arranged in groups
49
A in A band stands for
I in I band stands for?
Anisotropic band: light gets refracted to different directions
Isotropic band:light is refracted at the same angle
50
Myosin has - light chains and -heavy chains
4 light; 2 heavy
2 heavy forms the tail
2 light forms each head
51
There’s myosin head in the H zone
| T/F
F.
52
```
Who has longer chronaxie
Adults or infants
Red muscles or pale muscles
Cold blooded or warm blooded animals
High temperature or low temperature
Paralyzed muscle or normal muscle
```
```
Infants
Pale muscles
Cold blooded
Low temperature
Paralyzed muscle
```
53
Differentiate between
| Summation, superimposition and beneficial effect
second stimulus is applied during contraction period, or during second half of latent period;one curve
second stimulus falls during relaxation period of first twitch;2 curves;second Is greater
second stimulus falls after the relaxation period of the first curve; 2 curves;second is greater
54
```
Tetanus and fatigue in
Skeletal
Cardiac
Smooth
Nerve
```
S: possible;possible
C:not; not
Smooth: possible: not
N:no clue; not
55
Chemical process of relaxation of skeletal muscle
| Active or passive
Active. It’s physical process is passive
56
Ph changes during contraction of skeletal muscle
Before: slightly alkaline
Start: acidic (atp breaks)
Middle: alkaline(atp forms back)
End: acidic(lactic acid formation
57
End plate potential
| Propagative or non-propagative
Non propagative
58
Function. And origin of bungarotoxin
Deadly snakes
Blocks acetylcholine receptors
59
Function of Succinylcholine and Carbamylcholine
Act like ACH and keeps the muscle in a depolarized state
60
Function of Botulinum Toxin
Prevents release of Ach from the presynaptic terminal
61
Smooth muscle spike potential doesn’t reach isoelectric base
| T/F
T
62
Muscular dystrophy involves the nervous system
| T/F
F. It doesn’t
63
Describe:
Hypertonicity
Hypotonia
Increased muscle tone;no stretch
| Decreased muscle tone;too much stretch
64
Kernicterus is caused by?
Brain damage by jaundice in infants
65
Myotonia is ?
Continuous contraction; delayed and slow relaxation
66
Terminal knobs are usually involved with with what?
| Excitatory or inhibitory function
Excitation
67
Terminal waves or coils or free endings without nerve are usually involved with with what?
Excitatory or inhibitory function
Inhibitory function
68
3 examples of calcium channel blockers
Nifedipine
Verapamil
Diltaziem
69
Functions of A alpha fibers
Proprioception and somatic motor functions
70
Functions of Abeta fibers
Touch, pressure, motor
71
Which sensory receptor has its own motor supply
Muscle spindle
72
Function of Agamma fibers
Motor to muscle spindles
73
Function of Adelta
Pain cold touch
74
Sympathetic function of C nerve fiber
Post ganglionic sympathetic
75
Dorsal root function of C nerve fibers
Pain, temperature, some mechanoreceptors, reflex responses
76
Origin of 1a sensory fibers
Muscle spindle annulospiral ending
77
Origin of sensory fiber 1b
Golgi tendon organ
78
Another name for primary and secondary sensory nevers endings are?
Annulospiral; flower-spray spiral
79
Origin of 111 sensory fibers
Pain and cold receptors, some touch receptors
80
Origin of IV sensory fibers
Pain, temperature, dorsal rootC receptors
81
Stretch of muscle annulospiral spindle causes?
Stretch of golgi tendon organ causes?
Contraction
| Relaxation
82
Axons end in ——- that are also a less ——-
Terminal buttons
Axon telodendria
83
Local responses are graded
| T/F
T
84
Local responses can’t be summated.
| T/F
F
85
AP can be measured with ——
| RMP can be measured with ——
ERM or IRM
| ERM
86
Difference between IRM and ERM?
Erm gives an approximate value of the time course
87
Why is a spark produced at 15mV when generating AP in a nerve cell
The depolarization from 7-15mV is too rapid
88
In cardiac action potential, what marks the end of phase 2?
Closure of Ca channels
89
When does SA node depolarize ?
When Ca is entering in cardiac AP
90
Difference between the repolarization phase in cardiac and skeletal AP
Cardiac-rapid
| Skeletal-slow
