Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

2nd year mbbs > Neuro Physio > Flashcards

Neuro Physio Flashcards

(93 cards)

Start Studying
1
Q

What is Facilitation?

A

the enhancement of the response of a neuron to a stimulus following prior stimulation.
“the response is dependent on the frequency of stimulation and on neuromuscular facilitation”

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

Uni and bidirectional synapses?

A

The chemical synapse (most of the synapses in humans and all in cns ) is unidirectional (pulses are transmitted from the sending neuron to the receiving neuron) and only the electrical synapses are bidirectional through gap junctions. ( very few in cns mostly in smooth and cardiac muscles.

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

what are ionotropic and metabotropic receptors?

A

ionotropic receptors are typically ligand-gated ion channels, through which ions pass in response to a neurotransmitter (directly gate ion channels ), metabotropic receptors require G proteins and second messengers to indirectly modulate ionic activity in neurons.

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

inhibitory effect of acetylcholine?

A

some peripheral parasympathetic nerve endings i.e by vagus nerve in heart

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

Causes of synapse fatigue

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

spatial and temporal summation

A

Spatial summation occurs when stimuli are applied at the same time, but in different areas, with a cumulative effect upon membrane potential.
he effects of impulses received at the same place can add up if the impulses are received in close temporal succession. Thus, the neuron may fire when multiple impulses are received, even if each impulse on its own would not be sufficient to cause firing.

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

labeled line principle

A

Specificity of nerve fibres to transmit only one modality.

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

Max receptor potential amplitude?

A

100 mv

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

Rapidly aadapting/phasic/movement receptos?

A

PC adapts rapidly by either fluid redistribution or accomodation of tip of nerve fibre. some hair cells adapt within seconds and Meissner’s corpuscles. all the mechanoreceptors except a few adapt almost completely ( longest can take upto 2 days to adapt. )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Slowly adapting receptors/ tonic receptors?

A

Merkel’s discs and Ruffini endings, receptors of macula in vestibular apparatus, pain receptors, baroreceptors of arterial tree, chemoreceptors of carotid and aortic bodies and joint capsules and muscle spindle receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

nerve fibres type of golgi tendon organs

A

group 1b also k/a alpha type A fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

nerve fibres type of temp, pain and pricking pain

A

group 3 or delta type A

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

nerve fibres type of most discrete cutaneous tactile receptors and from flower spray nding of muscle spindles

A

group 2 also k/a beta and gamma type A

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

nerve fibres type of unmyelinated fibres carrying pain, temp, itch and crude touch sensations

A

group 4 also k/a type C fibers

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

nerve fibres type of annnulospiral endings of muscles spindles

A

group 1a also k/a alpha type A fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Amplifying divergence is characteristic of?

A

Corticospinal pathway supplying skeletal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Reverberatory/Oscillatory circuit?

A

caused by positive feedback within the neuronal circuit that feeds back to re-excite the input of the same circuit hence prolong the signal also results in rhythmical signals that last for life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

continual discharge caused by intrinsic neuronal excitabilty specially occur in neurons of?

A

Cerebellum and most of the interneurons of spinal cord

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

continuous touch receptors are?

A

EXPANDED TIP TACTILE RECEPTORS (MERKEL’S DISC GROUPED TOGETHER INTO DOME RECEPTOR innervated by a single large mylinated A-beta fibre ) also present on hairy parts of skin which DO NOT HAVE meissner corpuscles

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

Ruffinis ending receptors are present?

A

(DEEPER LAYERS OF SKIN) (HEAVY
PROLONGED TOUCH & PRESSURE) JOINT ROTATION. adapt slowly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Synaptic Delay?

A

SYNAPTIC DELAY
1. Transmission of impulse from pre to post synaptic Neuron time is required in process of Discharge of Neurotransmitter by pre synaptic membrane
2. Diffusion of Neurotransmitter in post synaptic membrane

  1. Action of Neurotransmitter on membrane receptor
  2. Action of receptor to increase membrane permeability
  3. Inward diffusion of Na to achieve threshold for AP
  4. Synaptic delay is about 0.5 milli seconds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Causes of synaptic Fatigue?

A

Exhaustion of neurotransmitter
- Progressive inactivation of post syn memb receptors
- Slow development of abnormal ionic concentration inside post synaptic neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Muscle sensory receptors?

A

Muscle Spindle: Detects length of the muscle & rate of change of length.

• Golgi Tendon Organ: Transmit information about tendon tension & rate of change of tension.

• These proprioceptors provide functional status

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are Ant Motor Neuron?

A

Larger neurons located in the anterior horns of the spinal cord.
■ They give rise to the nerve fibers that leave the cord by way of the anterior roots & directly innervate the skeletal muscle fibers.
■ They are of two types:
■ Alpha Motor Neurons
■ Gamma Motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Alpha Motor Unit innervate?
Stimulation of single alpha motor neurons excites group of muscle fibers known as MOTOR UNIT.
26
Renshaw cells and their role?
Each alpha neuron gives off collateral before it leaves the spinal gray matter which makes synaptic contact with a small cell present in ventral horn called Renshaw cell ■ These Renshaw cells are inhibitory cells that cause inhibition of surrounding motor neurons to sharpen or focus its signals. This phenomenon is known as Recurrent Inhibition or Lateral inhibition by Renshaw Cells
27
Primary ending of sensory innervation of muscle spindle?
They are present in central receptor area of the spindle Type 1a fiber These fibers make direct connection with α motor neurons innervating the same as well as synergistic muscle. These endings are stimulated by sustained stretch of the muscle as well as brief stretch as by tapping over the muscle’s tendon called Tonic and Phasic stretch reflex respectively. velocity of transmission: 70 to 120 m/sec
28
Secondary ending of sensory innervation of muscle spindle?
■ These give rise to group II fibers; 8 micrometers in diameter ■ These are relatively slow conducting ■ These nerve fibers make connections with the α motor neurons of the muscle from which they arise ■ These are best stimulated by sustained stretch called Tonic stretch reflex ■ Discharge frequency is related to length of the fibers
29
Static response of muscle spindle:
■ Response of both the primary & secondary endings. ■ When the muscle is stretched slowly, sensory endings continue to transmit signals for several minutes. This is called static response of the muscle spindle.
30
Static response of muscle spindle:
■ Response of both the primary & secondary endings. ■ When the muscle is stretched slowly, sensory endings continue to transmit signals for several minutes. This is called static response of the muscle spindle.
31
Dynamic response of muscle spindle:
■ Response of the primary ending but not the secondary ending. ■ The primary ending is stimulated strongly when there is sudden change in length of the spindle. ■ Thus primary ending detects the rapid rate of change in spindle length.
32
Static and dynamic gamma fibres
■ Gamma motor nerve fibers control intensity of static & dynamic response. ■ Gamma dynamic fibers excites mainly nuclear bag intrafusal fibers. ■ Gamma static fibers excite nuclear chain fibers. ■ The simplest manifestation of muscle spindle is muscle stretch reflex.
33
Stretch Relfex
How a stretch reflex works: – Stretch activates the muscle spindle – Group II sensory neurons synapse directly with  motor neurons in the spinal cord –  motor neurons cause the stretched muscle to contract ■ All stretch reflexes are monosynaptic and ipsilateral
34
low frequency vibrations stimulate?
Meisnner corpuscles which are slow adapting than PC
35
cold receptors?
TYPE A DELTA FIBERS (20 M/SEC)
36
Define Amorphosynthesis
A medical condition where the patient is unaware of somatic sensations from one side of the body, usually a sign of lesion in the left parietal lobe ( somatosensory association area )
37
Warm receptors
TYPE C (0.4 -2 M/SEC)
38
Dorsal column damage signs
ATAXIA PATIENT CANNOT PERCEIVE POSITION OR MOVEMENT OF LEGS VISUAL CLUES HELP MOVEMENT LOSS OF INFORMATION FROM MUSCLES AND JOINTS PATIENT DOES NOT KNOW ABOUT POSITION & MOVEMENTS OF IPSILATERAL LIMBS BELOW THE LEVEL OF LESION WITH CLOSED EYES PATIENT UNABLE TO TELL WHERE LIMB OR PART OF LIMB IS PLACED IF U DORSIFLEX THE BIG TOE, UNABLE TO TELL WHETHER UPWARD OR DOWNWARD DIRECTION IMPAIRED MUSCULAR CONTROL MOVEMENTS ARE JERKY
39
What is neospinothalamic tract?
PAIN):TYPE A DELTA FIBERS ENTER THE DORSAL HORN IN LAMINA MARGINALIS.
40
PALEOSPINOTHALMIC TRACT( FOR SLOW PAIN):
THE FIBERS FROM TYPE C FIBERS PASS IN LAMINA 2 & 3 , THEN TO LAMINA 5. IT PASSES THROUGH ANTERIOR COMMISSURE TO THE OPPOSITE SIDE. TERMINATE IN BRAIN STEM, INTRALAMINAR NUCLEI OF THALAMUS, TECTAL AREA, PERIAQUEDUCTAL GREY AREA.
41
what is ALLODYNIA?
SOMEONE WHO FEELS PAIN FROM NON-PAINFUL STIMULI. INDIVIDUALS WITH ALLODYNIA, HOWEVER, FEEL PAIN WHEN SOMETHING IS ORDINARILY PAINLESS.
42
types of hyperalgesia?
PRIMARY HYPERALGESIA: DUE TO INCREASED SENSITIVITY OF PAIN RECEPTORS. EG. SUN BURN SECONDARY HYPERALGESIA: FACILITATION OF SENSORY TRANSMISSION
43
Herpes Zoster is infection of?
Dorsal root ganglion
44
Components of analgesia system
it HAS THREE COMPONENTS: PERIAQUEDUCTAL GRAY AND PERIVENTRICULAR AREAS RAPHE MAGNUS NUCLEUS AND NUCLEUS RETICULARIS PARAGIGANTOCELLULARIS PAIN INHIBITORY COMPLEX IN DORSAL HORN OF SPINAL CORD
45
NEUROTRANSMITTERS OF ANALGESIC SYSTEM
Enkephalins & Serotonin. ACHIEVES PRESYNAPTIC INHIBITION BY BLOCKING CALCIUM cHANNELS IN THE MEMBRANES OF THE NERVE TERMINALS TO INHIBIT TRANSMITTER RELEASE. ANALGESIA SYSTEM CAN INHIBIT PAIN TRANSMISSION AT RETICULAR NUCLEI IN THE BRAIN STEM AND IN THE INTRALAMINAR NUCLEI IN THE THALAMUS.
46
define brain's opiate system and its components
OPIATE LIKE SUBSTANCES WITH IN THE CNS PROVIDES THE EXTREME DEGREE OF ANALGESIA. THEY INCLUDE : BETA ENDORPHIN (IN HYPOTHALAMUS AND PITUITARY) ENKEPHALIN (MET AND LEU-ENKEPHALIN) FOUND IN BRAIN AND SPINAL CORD DYNORPHIN. (IN BRAIN AND SPINAL CORD) ALL ARE THE BREAK DOWN PRODUCTS OF PROTEINS WHICH ARE PROOPIOMELANOCORTIN, PROENKEPHALIN AND PRODYNORPHIN.
47
reffered pain segment of Heart?
C3- T5
48
PACINIAN CORPUSCLES function?
detect pressure and high frequency vibration, presnt superficially imediately below skin and deeper in tissue
49
reffered pain segment of stomach?
7 TO 9TH THORACIC segment
50
brainstem & cerebellar vault headache
SUBTENTORIAL PAIN STIMULI CAUSE OCCIPITAL HEADACHE REFERRED TO THE POSTERIOR PART OF THE HEAD. SUPPLIED BY 9, 10 AND 2ND CERVICAL NERVES
50
intracranial headache types
HEADACHE OF MENINGITIS HEADACHE CAUSED BY LOW CSF PRESSURE. MIGRAINE HEADACHE ALCOHOL HEADACHE
51
HAIR END ORGAN function?
(MOVEMENT OF OBJECTS and initial touch ON SKIN) adapts readily
52
cerebral vault headache
STIMULATION OF PAIN RECEPTORS ABOVE TENTORIUM ARE REFERRED TO THE FRONTAL HALF OF THE HEAD SUPPLIED BY 5TH CRANIAL NERVE.
53
Intracranial causes of headache?
TUGGING ON THE VENOUS SINUSES DAMAGING THE TENTORIUM STRETCHING THE DURA TRAUMATIZING, STRETCHING AND CRUSHING STIMULUS TO THE BLOOD VESSELS OF THE MENINGES
54
Acupuncture relief pain by?
local lateral inhibition by stimulating large type A Beta sensory fibers of peripheral tactile receptors of same body area, and also by psychogenic stimulation of central angelia system.
55
lower brain centers send signals to which layers of cortex?
Layers I and II receive diffuse, nonspecific input signals from lower brain centers
55
which cerebral layers send axons to cerebral cortex?
The neurons in Layers II and III send axons - the cerebral cortex
56
layer 5 send fibers to?
Generally larger and project to more distant areas, such as to the basal ganglia, brain stem and spinal cord.
56
thalamus recieve signals from cerebral cortex through which layer?
Layer VI, especially large numbers of axons extend to the thalamus, providing signals from the cerebral cortex
57
function of phosphoinositides?
they are phosphorylated form of phosphotidylinositol. Play role in lipid signalling, cell signalling and membrane trafficking
58
ceramide?
sphingosine + 1fatty acid. ceramide + phosphoryl choline = sphingomyelin.
59
polar head of sphingophospholipids?
phosphate-alcohol
60
most abundant phospholipid in myelin?
Plasmalogen
60
what are Plasmalogens?
type of ether phospholipid. ether linkage at C1 indtead of ester
61
glucocerebrosides location?
generally present in all non neuronal cells of cns. specific function in cm of macrophages
62
Galactocerebrosides location?
exclusively in cm of brain cells.
63
sulfated galactosylceramides / sulfatides location?
nerve tissue and kidney
64
65
65
65
66
67
67
68
68
69
70
71
71
72
73
74
74
75
75
76
76
77
78
78
79
80

2nd year mbbs (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions