Neuro System Part1 Flashcards
1
Q
Difference between the CNS and PNS?
A
1) CNS - Brain and spinal cord
2) PNS - Includes cranial nerves (12 pairs), spinal nerves (31 pairs) and Pathways (afferent and efferent).
2
Q
Difference between Afferent and Efferent Pathways?
A
1) Afferent - Ascending/sensory to CNS
2) Efferent - Descending/motor, innervates effector organs
3
Q
2 branches of the PNS?
A
1) Somatic Nervous System - Receives sensory inputs from cutaneous sources. Controls voluntary skeletal muscle
2) Autonomic Nervous System - Receives input from internal visceral sources. Controls involuntary cardiac and smooth muscles.
4
Q
2 Branches of the Autonomic Nervous System?
A
1) Sympatheitic - Fight or flight
2) Parasympathetic - Rest and digest
5
Q
What are the 3 components of Neurons?
A
1) Cell Body (soma) - Have densely packed nuclei.
2) Dendrites - The receptive portion of the neuron.
3) Axons - Carry impulses away from cell body to end bulb.
6
Q
What are Ganglia and Plexuses?
A
Groups of cell bodies in the PNS.
7
Q
Where are neurotransmitters released?
A
into the synapse
8
Q
4 Characteristics of Axons?
A
1) Myelination - Lipid insulation via Schwann cells
2) Endoneurium - Connective tissue around axon
3) Neurilemma - Schwaan sheath
4) Saltatory conduction - Causes faster conduction down axon
9
Q
Myelinated A-delta Fibers vs. Un-myelinated C-fibers
A
1) Myelinated A-delta Fibers - Allows accurate localization of pain.
2) Un-myelinated C-fibers - Carries long-lasting, dull, burning, achy pain.
10
Q
4 Structural Classifications of Neurons?
A
1) Multipolar Neuron
2) Bipolar Neuron
3) (Pseudo)Unipolar Neuron
4) Anaxonic Neuron
11
Q
3 Functional Classifications of Neurons?
A
1) Sensory - Transmits sensory impulses to CNS via afferent pathway.
2) Associational/Interneurons - Transmits impulses from neuron to neuron
3) Motor - Transmits motor impulses from CNS to effector organ via efferent pathway.
12
Q
4 Types of Neuroglia (“nerve glue”)
A
1) Astrocytes - Forms the BBB
2) Microglia - Removes pathogen and debris in CNS
3) Ependymal - Line the cavities of the CNS and produce cerebrospinal fluid)
4) Oligodendrocytes - Deposits myelin within the CNS
13
Q
What are Schwaan Cells ?
A
Glial cells that form and maintain the myelin sheath in the PNS.
14
Q
What are Nodes of Ranvier?
A
Spaces between myelin sheaths that increase conduction velocity.
15
Q
What is Wallerian Degeneration?
A
Degeneration of an axon distal to a cut/crush. The axon portion will degenerate and disappear. The proximal portion regenerate but this process is limited to myelinated axons in the PNS only.
16
Q
2 types of conduction in a neuron down its axon?
A
1) Continuous Conduction - Non myelinated axon
2) Saltatory Conduction - Uses myelination
17
Q
Describe the “All or None Response” of a nerve impulse.
A
Action potential response occurs only when the stimulus is strong enough (above -55mv); if it is too weak, then the membrane remains unexcited.
18
Q
What happens during the Depolarization Phase of an Action Potential?
A
Start when Resting Membrane Potential (-70mv) receives a stimulus (above -55mv), then the voltage-gated Na2+/K+ channels open
19
Q
Voltage vs. Ligand gated ion channels
A
1) Voltage-gated ion channels - Open in response to voltage change.
2) Ligand-gated ion channels - Open in response to a ligand (neurotransmitter) binding to its receptor site (i.e. Ach).
20
Q
What is a synapse? What happens there?
A
The space between two adjacent neurons.
21
Q
Impulses are transmitted across the synapse by _______ and __________ conduction.
A
chemical and electrical
22
Q
In the Synapse, Impulses are transmitted by _________.
A
neurotransmitters
23
Q
Neurotransmitters are formed in the ______ neuron?
A
presynaptic
24
Q
Synaptic knobs or ________ store the neurotransmitters
A
End Bulbs
25
Neurotransmitters are released across the ________, which is the space between neurons.
synaptic cleft
26
How do Voltage-gated Calcium channels play a part in the release of neurotransmitter from the end of the presynaptic end bulb?
As the impulse travels down the axon of the presynaptic neuron, voltage-gated calcium channels open up and calcium enter the cell, which binds to vesicles containing neurotransmitters. These vesicle then release their content to the synaptic cleft via exocytosis.
27
3 types of Synapses?
1) Nerve to nerve
2) Nerve to gland
3) Nerve to muscle (NMJ)
28
What is the Sarcoplasmic Reticulum? What does it do?
Structure in muscle cells that is similar to the ER, it stores Ca++ and is responsible for the Excitation-Contraction Coupling Mechanism?
29
Characteristics of the Sarcoplasmic Reticulum?
1) Impulse travels along sarcoma
2) Causes extrusion of Ca++
3) Ca++ initiates cross bridging
30
What are the steps of the biomechanics of contraction?
1) At rest, tropomyosin covers troponin binding sites
2) Ca++ released from SR binds to troponin causing troponin causing tropomyosin to move
3) Actin binding site exposed
4) Myosin head binds & flexes
5) Filaments slide past each other
31
Characteristics of cardiac muscle contraction?
Contraction in the heart requires extracellular Ca++ and is controlled by autonomic nerves and Beta adrenergic agonist.
32
Characteristics of smooth muscle contraction?
Smooth muscles require extracellular Ca++ for contraction and is controlled by autonomic nerves and hormones.
33
Briefly explain the role of the following Neurotransmitters?
1) Acetylcholine - skeletal muscle contraction, sweating, other neurons of PNS & brain
2) Glutamate - learning and memory and pain
3) GABA - inhibitory
4) Endorphins/Enkephalins - endogenous opioid
5) SubstanceP - Stimulates pain signals
34
Valium MOA?
Valium is a GABA agonist - enhancing its inhibitory effect (anxiety, insomnia, seizures).
35
Briefly explain the role of the Neurotransmitter Serotonin?
-Mental functions, circadian rhythms, mood, and sleep/wakefulness, anxiety
36
What are SSRIs?
Selective Serotonin Re-uptake Inhibitors such as Paxil, Prozac and Zoloft.
37
What is the job of the the 3 Catecholamines?
1) Epi and Norepi - regulate organ function and some brain functions (fight or flight responses)
2) Dopamine - plays a role in Parkinson's
38
Effects of the neurotransmitters on the post-synaptic neurons?
1) Excitatory Stimulus - Depolarizes the post synaptic neuron
2) Inhibitory Stimulus - Hyperpolarizes the postsynaptic neuron
39
Which neurotransmitters are excitatory and which one are inhibitory?
1) Acetylcholine - E and I (Nicotinic receptor are E and Muscarinic are Both)
2) Norepi - E and I (alpha1 receptors are E and alpha2 receptors are I)
3) Serotonin - I
4) Dopamine - E
5) GABA - I
6) Glutamate - E
7) Endorphins - I
8) SubdtanceP - E
40
All Muscarinic Receptors are G-coupled protein receptors, mediating cellular responses through 2nd messenger cascades. What are the 5 subtypes, which are excitatory or inhibitory, and where are they located?
1) M1 - Excitatory in the CNS
2) M2 - Inhibitory in cardiac muscle
3) M3 - Excitatory in Smooth muscle
4) M4 - Inhibitory in CNS
5) M5 -Excitatory in CNS
41
What binds to Cholinergic Receptors?
Acetylcholine
42
What are the two types of Cholinergic Receptors?
1) Muscarinic
| 2) Nicotinic
43
Describe Nicotinic Receptors?
Nicotinic Receptors are ligand-gated ion channels. When Ach bind its receptor, this allows the entry of sodium ions.
44
Describe the different types of Nicotinic receptors?
1) N1 or Nm - Excitatory at the NMJ
| 2) N2 or Nn - Excitatory at the ANS, CNS, and adrenal medulla
45
What are the 3 types of Adrenergic Receptors and there subtypes?
1) Alpha - alpha1 and alpha2
2) Beta - beta1 and beta2
3) Dopamine
46
Where are alpha1 receptors located?
Located posynaptically on effectors organs
47
What happens when Alpha1 receptors are binded?
1) Pupils dilate
2) Blood vessels constrict
3) Bladder tone increases (decreasing urine output)
* can't see can't pee, can't spit can't shit*
48
(T/F?) Mydriasis (pupil dilation) is mediated by both Alpha1 and Alpha2 receptors?
True
49
Where are Alpha2 adrenergic receptors located and what are their purpose?
Located on both presynaptic and postsynaptic cells and are responsible for mediating feedback inhibition.
50
What happens when Alpha2 receptors are binded?
1) Inhibit NE from adrenergic neurons
2) Inhbit Ach from cholinergic neurons
3) Inhibit Insulin release
51
What is Yohimbne? How does it work?
Yohimbine is an Alpha2 receptor blockade. It increases NE and stimulates cardiac beta1 and peripheral vascular alpha1 receptors (usually used to treat ED).
52
Where are Beta1 receptors found?
Mainly found in the heart and kidneys
53
What happens when Beta1 receptors are binded?
1) Increased chronotropy (HR @ SA node)
2) Increased Inotropy (force of contraction)
3) Increased AV-node conduction velocity
4) Increased renin release (decreases urine output)
54
Where are Beta2 receptors located and what do they do there?
1) Lungs - Bronchodilation
2) Baldder - Detrusor muscle relaxation
3) Eyes - accommodation and flow of aqueous humor
4) GI - decreased peristalsis
5) Liver - Glucogenesis and glycogenesis
6) Vascular Smooth Muscle - While alpha1 vasoconstrictor, beta vasodilator in muscle and liver, because you need these organs for fight or flight
7) Uterus - Increases Tocolysis (premature labor) terbulataline
55
Main purpose of Beta2 agonist drugs? examples?
Used to treat Asthma and COPD.
| i.e. Albuterol, salmeterol, formeterol and terbulataline
56
Types of NMJ Blocking agents used in Anesthesia?
1) Non-depolarizing - Act by completely binding to aCH receptors (i.e. pancuronium, vecuronium, and rocuronium).
2) Depolarizing - Depolarizes motor end-plate making the muscle no longer responsive to Ach. (i.e. succinylcholine).
57
How do Inhibitory Neurotransmitters work?
They cause the postsynaptic neuron to hyper polarize and become less likely to fire, which decreases synaptic transmission. i.e. GABAa binds to its receptors an causes Cl- ions to flow into the cell, causing hyper polarization.
58
Which Anesthetics works by potentiating hyper polarization?
1) Propofol - Binds to GABAa receptors, holds Cl- ion channels open to allow influx of Cl- ions .
2) Lidocaine injection - Sodium channel blocker, prevents Na+ from entering nerve cell to transmit a signal.
59
Functions of the Medulla Oblongata?
Regulates breathing, HR and BP, Coughing, swallowing, vomiting, and sneezing
60
Functions of the Pons?
- Relays Signals
| - Respiratory Centers that assist the medulla
61
Function of the Substantia Nigra?
Production of Dopamine - Low levels = Parkinson's disease. high levels = wooden chest syndrome (in rapid anesthesia induction with fentanyl).
62
Cerebral Peduncles Function?
Fibers that connect upper and lower parts of the brain
63
What is the meaning of Corpora Quadrigemina? Which structures of the brain does it include?
It means "4 small bodies". It includes:
1) Superior Colliculi - reflex movements of head and eyes in response to visual stimuli.
2) Inferior Colliculi - reflex movements of the head and trunk in response to auditory stimuli.
64
What is Wooden Chest Syndrome?
A rare side effect of rapid induction with Fentanyl (6-7mcg/kg) or other synthetic opioid that causes increased dopamine and decreased GABA levels, leading to increased muscle tone and chest wall rigidity. It is reversible with naloxone.
65
Function of the Thalamus?
Thalamus is composed of two bodies connected by the intermediate mass and is the "grand central relay center" for signals (except smell) to the cerebral cortex.
66
Function of the Hypothalamus?
Controls homeostasis, pituitary gland - connected by the infundibulum, mamalary bodies for smell and taste functions, optic chiasim where optic nerves cross.
67
Function of Epithalamus?
- contains pineal gland
| - biological clock
68
Function of the Cerebellum?
- Muscle synergy
| - maintenance of balance and posture
69
Which part of the brain is known as the Motor Strip and the Sensory Strip?
1) Motor Strip - Precentral gyrus in the frontal lobe
| 2) Sensory Strip - Sensory is the parietal lobe
70
Function of the following anatomies in the Cerebral Cortex:
1) Primary Motor Area
2) Somatosensory
3) Brocca's Speech Area
4) Wernicke's Area
5) Premotor Cortex
1) Primary Motor Area - Initiates impulses to skeletal muscles
2) Somatosensory - Impulses from touch, proprioception (joints) pain and temperature
3) Brocca's Speech Area - Initiates impulses that result in speech (left hemisphere)
4) Wernicke's Area - Recognizes spoken words and translates words.
5) Premotor Cortex - Learned repetitious, and patterned motor skills.
71
Functional differences between the two cerebral hemispheres?
1) Left Hemisphere - Receives somatic sensory signals from and controls the right side of the body.
2) Right Hemisphere - Receives somatic sensory signals from and controls the left side of the body.
72
Reticular Formation (Reticular Activating System)?
Keeps us conscious and alert.
73
Function of the Limbic System?
It is the "Emotional Brain"
| - it helps to establish memories, gives visceral response to emotions, and elicits the fear response via the amygdala.
74
Characteristics of Cerebrospinal Fluid?
1) CSF is a clear, colorless fluid similar to plasma and interstitial fluid.
2) Contains glucose, protein, albumin, electrolytes,
3) pH = 7.3
4) Produced by the choroid plexuses and is composed of ependymal cells
5) It is reabsorbed through the arachnoid villi
75
Major differences between composition of CSF and Plasma?
1) CSF: K+ = 2.2mEq/L, pH = 7.3, Protein = 35, glucose = 35
| 2) Plasma : K+ = 4.5mEq/L, pH = 7.4, Protein = 7000, glucose = 90
76
What are the following values for CSF:
1) Volume
2) Specific Gravity
3) Pressure
4) Production
1) Volume - ~150mL
2) Specific Gravity - 1.002 to 1.009
3) Pressure - 5-15mmHg
4) Production - Produced by the ependymal cells in the choroid plexus (in all 4 ventricles) at a rate of 30mL/hr
77
Intracranial Pressure (ICP) Characteristics?
1) Normal 5-15mmHg
2) Cerebral HTN = >20mmHg
3) ICP measured by Intraventricular catheter, subdural bolt, or a catheter placed over the convexity of the cerebral cortex.
4) ICP measurement is indicated with a GCS score < or = to 7
78
Which structures will the needle pass through with the following approaches :
1) Midline
2) Paramedial
1) Midline - Suprspinousc & interspinous ligaments and ligamentum flavum,
2) Paramedial - Ligamentum flavum
79
What is Bratson's Plexus?
Epidural veins located mostly in anterior epidural space (Batson’s Plexus).
80
What is a Nerve Plexus?
When the Ventral rami branch and anastomose repeatedly to form 5 nerve plexuses.
81
Name and describe the 5 Nerve Plexuses?
1) Cervical (in neck, C1 to C5) - Supplies neck and phrenic nerve to the diaphragm.
2) Brachial (in armpit, C5 to T1) - Supplies upper limb and some of the shoulder and neck.
3) Lumbar (in low back, L1 to L4) - Supplies abdominal wall, anterior thigh and genitals.
4) Sacral (in pelvis, L4,L5, & S1 to S5) - Supplies remainder of lower trunk and lower limb.
5) Coccygeal (S4 & S5 and coccygeal nerves)
82
Function of the following Nerves:
1) Supraventricular Nerves
2) Phrenic nerve
1) Supraventricular Nerves - Innervates skin over upper chest shoulders.
2) Phrenic nerve - Diaphragm
83
What are dermatomes?
Each spinal nerve receives sensory input from a specific area of skin called a dermatome. A total loss of sensation requires anesthesia of 3 successive spinal nerves.
84
(T/F?) Spinal nerves are mixed nerves, meaning they are both sensory and motor neurons).
True
85
Function of the following anatomical structures:
1) Anterior Spinothalmic Tract
2) Lateral Spinothalmic Tract
3) Posterior (dorsal) Column
4) Lateral Corticospinal
1) Anterior Spinothalmic Tract - Vague touch
2) Lateral Spinothalmic Tract - Pain and temperature
3) Posterior (dorsal) Column - Fine touch, two-point discriminatin and proprioception.
4) Lateral Corticospinal - Precise voluntary movements from cerebral cortex down spinal cord to muscles.
86
What are the 12 Cranial Nerves?
| Mneumonic - Old owls on tree tops are forever viewing green valleys and hills
1) Olfactory
2) Optic
3) Oculomotor
4) Troclear
5) Trigeminal
6) Abducens
7) Facial
8) Vestibulocochlear
9) Glossopharyngeal
10) Vagus
11) Accessory
12) Hypoglassal
87
Distribution and Action of the Occulomotor Nerve?
1) Distribution - Levator palpeerde superioris; 4 extrinsic eye muscles (inferior oblique, superior rectus, medial rectus, inferior rectus); colliery muscle (intrinsic eye muscle); iris muscles of the eye (intrinsic eye muscle).
2) Movement of eyelid and eyeball, accommodation of lens and pupillary constriction.
88
Distribution and Action of the Trigeminal Nerve?
1) Ophthalmic, maxillary, and mandibular branch
| 2) Cutaneous sensations from ophthalmic, maxillary, and mandibular areas; chewing
89
Distribution of the Abducens Nerve?
Lateral rectus muscle of eyeballs
90
Distribution and Action of the Glossopharyngeal Nerve?
1) Posterior 1/3 of tongue; pharyngeal muscles; parotid gland, carotid receptors
2) Taste; swallowing and speech, secretion of saliva, Chemo/baro receptors.
91
Distribution and Action of the Vagus Nerve?
1) Pharyngeal muscles and epiglottis, smooth muscles of thorax and GI tract, cardiac muscle, carotid receptors.
2) Taste and somatic sensation from pharynx and epiglottis, swallowing, coughing, voice production, smooth muscle contraction of GI tract, slowing of HR, secretion by digestive glands, chem/baro receptor.
92
Action of the Accessory Nerve?
Movement of head and shoulders
93
What is Bell's Palsy
Damage to cranial nerve VII (Facial Nerve) that manifests in the following:
1) Inability to wrinkle brow
2) Drooping eyelid and inability to close eye
3) Inability to puff cheeks
4) Drooping mouth, inability to smile/pucker
5) Loss of taste and decreased salvation
94
What is a Cholinesterase?
The enzyme that removes Ach from the synaptic cleft of NMJs.
95
How do inhibit the cholinesterase enzyme?
Anticholinesterases such as Neostigmine, edrophonium, and pyridostigmine
96
Two types of Alpha adrenergic receptors?
1) Alpha1 - Excitatory stimulation
| 2) Alpha2 - Inhibitory stimulation
97
Three types of Beta Adrenergic Receptors?
1) Beta1 - Increases HR and contractility and increases renin release from kidneys.
2) Bet2 - Bronchoconstriction
3) Beta3 - Mediates lipolysis; unregulated in CVD.
98
What are the effects of sympathetic stimulation on the following organs:
1) Pancreas
2) Adipose Tissue
3) Kidneys
4) Eyes
5) Lungs
6) Intestines
7) Uterus
8) Coronary Arterioles
1) Pancreas - Inhibit insulin via A2 receptor
2) Adipose Tissue - Lipolysis and breakdown of triglycerides via B3 receptors
3) Kidneys - Release of renin via B1 receptors
4) Eyes - Pupil dilation via A1
5) Lungs - Airway dilation via B2
6) Intestines - decreased motility and tone via B2 and contraction of sphincters via A1
7) Uterus - Inhibits contraction of non pregnant uterus via B2
8) Coronary Arterioles - Vasoconstriction via A1, and vasodilation via B2
99
Which A1 blocker is used for HTN?
Daxazosin/Phentalomine
100
1st, 2nd and 4th steps of Cerebrospinal Fluid Flow?
1) CSF secreted by choroid plexus into each ventricle
2) CSF flows through inter ventricular foramina into third ventricle (Foramen of Monroe)
4) CSF flows down cerebral aqueduct to 4th ventricle (Aqueduct of Sylvius)
101
Axon Hillock
Cone shaped area of neuron where the body joins the axon
102
Basal Ganglia
Fine motor control of the brain
103
Hippo Campus
memory and learning
104
Terbutaline
B2 agonist used as a tocolytic agent (anti-contraction medication for pregnant women)
105
Amygdala
Emotion, appetite, pain and stress response
106
Functions of the following brain lobes:
1) Frontal
2) Temporal
3) Occipital
4) Parietal
1) Frontal - Cognition and motor
2) Temporal - Auditory and speech
3) Occipital -Sight
4) Parietal - Sensory
