Exam 3 Flashcards
(205 cards)
1
Q
The 6 Roentgen Signs
A
Location
Number
Shape
Size
Opacity
Margination
2
Q
The 5 Radiographic Opacities (from least to most dense)
A
Air
Fat
Fluid/water/soft tissue
Bone
Metal
3
Q
CNS components
A
Brain
Spinal cord
Neural components of the eye
4
Q
PNS components
A
Nerves
Peripheral ganglia
Neuromuscular junctions
5
Q
Input zone
A
Receives incoming signals from other neurons/cells or the environment
Dendrites, cell body, nucleus
6
Q
Trigger zone
A
AKA integration zone
Initiates action potentials, where decision to produce a neural signals is made
Axon hillock
7
Q
Conducting zone
A
Conducts action potentials in undiminishing fashion, often over long distances
Axon
8
Q
Output zone
A
Releases neurotransmitter that influences other cells, where transmission of information occurs
Axon terminals
9
Q
Unipolar neuron
A
One single neurite emerges from soma and divides into 2 branches: central (axon) and peripheral (dendrites)
Rounded soma, sensory ganglia of spinal nerves (dorsal root ganglia) and some cranial nerves
10
Q
Bipolar neuron
A
A neurite emerges from each end of the soma (2 processes)
Elongated soma, retinal bipolar, sensory cochlear, vestibular ganglia, olfactory epithelium
11
Q
Multipolar neuron
A
Many neurites emerging from soma (one axon, many dendrites)
Most common classification in CNS
Cerebellar cortex: Purkinje
Brain cortex: pyramidal
Spinal cord: motor neuron
12
Q
Anterograde transport
A
Slow, kinesin
Herpes virus travels from dorsal root ganglia to skin and mucosa during lytic cycle
Feline herpesvirus type 1 (FHV-1)
13
Q
Retrograde transport
A
Fast, dynein
Neurotropic viruses and other pathogens use this route to reach soma
Herpes, rabies, polio, tetanus toxin
14
Q
Electrical synapse
A
Bidirectional action potential
Gap junctions
15
Q
Chemical synpase
A
Calcium channels cause synaptic vesicles to release neurotransmitters, binding of neurotransmitters to ligand-gated ion channels
16
Q
Steps 1 and 2 of chemical synapse
A
Action potentials arrive at axon terminal and voltage-gated calcium channels (VGCC) open
17
Q
Steps 3 and 4 of chemical synapse
A
Calcium enters the cell and signals to vesicles
18
Q
Step 5 and 6 of chemical synapse
A
Vesicles move to the membrane and once docked, release neurotransmitters by exocytosis
19
Q
Steps 7 and 8 of chemical synapse
A
Neurotransmitter diffuses across synaptic cleft and binds to receptors (anesthesia/analgesics inhibit this step)
20
Q
Astrocyte
A
Most abundant cell (~40% CNS)
Astrocytic end-feet - expansions of the astrocyte ending process
Secrete ECM proteins that provide physiological support
Implicated in neurogenesis, cell migration, development, and regeneration
21
Q
Microglia function and clinical implication
A
Phagocytic scavenger, highly motile, synaptic pruning, responsive to injury/infection/electric activity
Clinical implication: diabetic neuropathy from hyperactive microglia
22
Q
Oligodendrocyte function and clinical implication
A
Provides myelin, axonal metabolic support
Clinical implication: canine distemper virus (CDV) - demyelination in cerebellum affecting motor coordination
23
Q
Ependymal cells function and clinical implication
A
Conforms the neuroepithelial lining of the CNS ventricular system, CSF production
Clinical implication: hydrocephalus secondary to ependymal lining of inflammation
24
Q
CNS glial cells
A
Astrocytes, microglia, oligodendrocytes, ependymal cells
25
PNS glial cells
Satellite and Schwann cells
26
CNS myelination patterns
One oligodendrocyte to several axons
No basal lamina or supporting connective tissue
No oligodendrocyte cytoplasm
Large perinodal space
27
PNS myelination patterns
One Schwann cell to one axon
Basal lamina and connective tissue
Schwann cell cytoplasm
Small perinodal space
28
PNS large axons
Ensheathed and myelinated
Individual Schwann cell per internode
29
PNS small axons
Ensheathed but NOT myelinated
One Schwann cell per several axons
Ex: postganglionic axons of autonomic ganglia, small sensory neurons
30
Meninges
Triad of membranes enveloping the CNS for protection
(dura mater, arachnoid mater, pia mater)
31
Ventricles
From Latin "ventriculus"
Small chamber or cavity within a bodily organ
Literally "little belly" (venter = belly)
32
Dura mater
"Tough mother"
Outermost membrane, fibroelastic cells, permeable to fluid
33
Arachnoid mater
"Spider-like mother"
Flat cells, impermeable to fluid
Arachnoid trabeculae, arachnoid space (CSF), arachnoid villi (CSF reabsorption into venous circulation)
34
Pia mater
"Tender mother"
Innermost membrane, flat cells, fully envelops CNS following its contour
35
CSF function
Clear, colorless, low protein fluid that surrounds and permeate entire CNS for protection and nourishment
Continual turnover (~3-4/day) partially regulated by osmotic pressure
36
CSF production
Choroid plexus (lateral and fourth ventricles)
37
CSF circulation
Subarachnoid space
Third ventricle, to mesencephalic aqueduct, to choroid plexus fourth ventricle, to median aperture, to central canal and subarachnoid space
38
CSF absorption
Venous sinuses, arachnoid villi to dorsal (superior) sagittal sinus
39
Ganglion/ganglia
Cluster of neuron cell bodies
40
Nerve
Bundle of axons
41
Fascicles
Myelinated axons, unmyelinated axons
Myelin sheath
Schwann cells
Endoneurium, endoneurial capillaries
Perineurium
Connective tissue
42
Extrafascicular
Adipose tissue
Blood vessel
Epineurium
43
Dorsal root ganglia (DRG)
Sensory ganglia or intervertebral ganglia
Pseudounipolar neurons organized in clusters
Myelinated axons between clusters
Sensory neurons surrounded by many satellite cells and basal lamina
44
Sympathetic ganglia
Paravertebral ganglia
Multipolar neurons
Less organized than DRG
Unmyelinated axons loosely cross between neurons
45
The central nervous system (CNS) is comprised of the cerebrum, spinal cord, and neural components of the...
Eye
46
Chemical synapse includes multiple steps for its completion from the moment that the action potential reaches the presynaptic terminal to the neurotransmitter binding to the receptors at the postsynaptic terminal, including
a. Ca2+ binding to dynein and kinesin
b. Ca2+ entry through VGCC
c. Ca2+ intake through synaptic cleft
d. Ca2+ release from neurotransmitter vesicles
Calcium entry through VGCC
47
Tanycytes are specialized ependymal cells with basal membrane protrusions that surround the blood vessels mostly at the
a. central canal
b. fourth ventricle
c. lateral ventricles
d. third ventricle
Third ventricle
48
Neuroinvasion of neurotropic viruses, like rabies, herpes, and tetanus, reach the soma via ____. Some of these viruses, like FHV-1 could remain quiescent during resurface during the lytic phase via ____.
Retrograde transport
Anterograde transport
49
Cerebrospinal fluid is an ultrafiltration of blood serum with equal osmolarity and sodium milliequivalents but,
a. higher glucose
b. higher potassium
c. lower pH
d. lower water present
Lower pH
50
Higher protein content in the CSF is the clinical implication when ultrafiltration fails to occur at the
Blood-CSF barrier
51
External hydrocephalus is the result of a disruption in the one-way-valve system that allows drainage of CSF (higher to lower pressure) from CNS back into systemic circulation. This disruption occurs at the
a. arachnoid villi
b. blood-brain barrier
c. blood-CSF barrier
d. retina-CSF barrier
Arachnoid villi
52
The ___ is the most restrictive physiologic barrier in any organism
Blood-brain barrier
53
What do you think is the condition of Oreo and Kahlua and its underlying cause?
Congenital malformation that interferes with CSF flow causing internal hydrocephalus
54
Arachnoid mater consists of the spongy arachnoid trabeculae, the arachnoid space filled with CSF, and arachnoid villi that pass through the dura into the venous sinuses and the pia mater is...
Innermost layer that fully envelops CNS parenchyma following its contour
55
Node of Ranvier features
No myelin
VGSC
Na+/K+ ATPase
Na+/Ca2+
56
Juxtaparanode features
VGKC
High myelin content
57
Paranode features
Paranodal loops
58
Internode features
High myelin content
59
____ have clusters of unipolar neurons with higher density of satellite cells per neuron and bundles of myelinated axons around neurons' clusters, while the ____ have scattered multipolar neurons with unmyelinated axons loosely crossing across neuron and are surrounded by a capsule and adipose tissue
a. basal ganglia, paravertebral ganglia
b. dorsal root ganglia, parasympathetic ganglia
c. paravertebral ganglia, intervertebral ganglia
d. sensory ganglia, sympathetic ganglia
Sensory ganglia
Sympathetic ganglia
60
Dysfunctional ion channels either genetic or acquired, could disturb channel function by altering voltage sensitivity, chemical interaction, and even mechanical perturbation. These disorders are collectively known as
Channelopathies
61
The outer zones of neural tissue in the CNS that contains neuronal cell bodies, aka gray matter, are
Cerebral and cerebellar cortices
62
The ____ are bundles of axons in the CNS, while they are classified as ____ in the PNS
Tracts
Nerves
63
High frequency transducers
Use linear array
Advantages: imaging small parts (thyroid), better resolution
Disadvantages: poor penetration
64
Low frequency transducers
Use curved array
Advantages: better depth penetration (horses, cows, large dogs), deeper margins of structures
Disadvantages: resolution is decreased
65
Gold standard transducers
Use a tightly curved array
Blended probes are cutting edge in technology and incorporate multiple frequency crystals which work in conjunction
Good depth penetration and spatial resolution
66
Echogenic
Having/producing echoes
Something is bright
67
Isogenic
Having some echo/brightness
Shades of gray
68
Anechoic
Free/devoid of echoes
(ex: urine, bile)
69
How is depth calculated
Distance = rate * time / 2
Rate is fixed (1540 m/s), time calculated by machine
70
Ultrasound signal propagation speed (slowest to fastest)
Air (331 m/s)
Water (1540 m/s)
Liver tissue (1549 m/s)
Kidney tissue (1561 m/s)
Bone (4080 m/s)
71
Shorter wavelength
Higher resolution
Lower depth
72
Higher wavelength
Lower resolution
Higher depth
73
Determinants of image quality
Frequency of transducer
Number of crystals in transducer
Machine quality
Patient size, shape, type of examination
74
Attenuation
Absorption (heat)
Scattering (not mapped, useless)
Reflection (mapped)
75
Acoustic impedance
Resistance for propagation of sound waves
Aids in ability to distinguish each organ
76
Tissues with high acoustic impedance
Difficult to image
Ex: stones/mineral (ultrasound waves cannot penetrate)
77
Larger differences in acoustic impedance at interfaces
Causes more reflection
Echogenic interface (white)
Cannot see deep to the interface (bone, gas)
78
Smaller differences in acoustic impedance at interfaces
Allows for sound to pass between tissues (liver to kidney)
79
Reverberation artifact
Sound bouncing back and forth between 2 strong reflectors (discrete bands)
"Dirty" acoustic shadowing from small reflectors (few reflectors create multiple regular lines on screen)
Ex: gas, skin surface, mineral (rare)
Synonyms: comet tail, ringdown, regular arrangement of echoes
80
Dirty shadowing
Distal to gas
Gas mixed with mucous, gas in colon
Inhomogeneous due to multiple reflectors (soft tissue gas interference, 99% of beam is reflected)
81
Clean (hard) shadowing
Distal to mineral
Calculus (urinary or biliary), bone (skeletal or ingested)
Hyperechoic interface with trapezoidal anechoic region in far field, bright white interface with black distally
Watch focus settings
Usually between soft bone/mineral interface
82
Acoustic enhancement
Through transmission artifact, increased echogenicity distal to anechoic (fluid-filled) structure, black with brightness deep, fluid-filled structures
Ex: cysts, gallbladder, urinary bladder, peritoneal fluid
83
Edge shadowing artifact
Ultrasound beam strikes curved surface, beam either bent inward or outward
Refraction may be convergent or divergent
Results in lack of echoes returned to transducer from line of sight
Ex: kidney, bladder, cystic structures
84
Mirror image artifact
Results in mirror image across a strong reflector
Sound beam is reflected 3 times then mapped image is projected deeper than it actually is (mismapped)
Improper depth settings on machine
85
Useful artifacts
Acoustic shadowing (clean - bone mineral, dirty - gas)
Acoustic enhancement
86
Useless artifacts
Mirror image
Edge shadowing
87
The parasympathetic nervous system influences function in all of these organs EXCEPT
a. heart
b. pupillary smooth muscles
c. salivary glands
d. adrenal glands
Adrenal glands
88
Paravertebral or chain ganglia contain the cell bodies of what kind of neurons
a. parasympathetic postganglionic nerves
b. sympathetic preganglionic nerves
c. sympathetic postganglionic nerves
d. parasympathetic preganglionic nerves
e. spinal afferent neurons
Sympathetic postganglionic nerves
89
The autonomic outflow from the sacral spinal cord contains what kind of neurons
a. parasympathetic postganglionic nerves
b. sympathetic preganglionic nerves
c. sympathetic postganglionic nerves
d. parasympathetic preganglionic nerves
e. spinal afferent neurons
Parasympathetic preganglionic neurons
90
Some of the nerves that innervate lymph nodes have been determined to be adrenergic. This would suggest that
a. the parasympathetic nervous system may influence lymph node activity
b. the sympathetic nervous system must act to enhance lymph node activity
c. the parasympathetic nervous system has no effect on lymph node activity
d. the sympathetic nervous system may influence lymph node activity
The sympathetic nervous system may influence lymph node activity
91
Prevertebral ganglia contain the cell bodies of which kind of neuron
a. parasympathetic postganglionic nerves
b. sympathetic preganglionic nerves
c. sympathetic postganglionic nerves
d. parasympathetic preganglionic nerves
e. spinal afferent neurons
Sympathetic postganglionic nerves
92
The autonomic outflow from the lumbar spinal cord contains what kind of neurons
a. parasympathetic postganglionic nerves
b. sympathetic preganglionic nerves
c. sympathetic postganglionic nerves
d. parasympathetic preganglionic nerves
e. spinal afferent neurons
Sympathetic preganglionic neurons
93
The synapse between the preganglionic and postganglionic neuron in the parasympathetic nervous system is found in the
a. terminal ganglia
b. paravertebral ganglia
c. prevertebral ganglia
Terminal ganglia
94
CT advantages/disadvantage
High detail cross-sectional images, minimal anatomic superimposition, ability to reformat to view anatomy in any plane or 3D
Dense tissues appear brighter
95
MRI advantages/disadvantages
Not reliant on differences in tissue densities, relies on magnetic properties of molecules (must have magnetic moment/NMR signal)
Image production based on RF signal produced after relaxation from high energy to low energy state
96
Cytotoxic edema
Cell swelling from ischemia
Na/K pump dysfunction
Intracellular
Gray and white matter
97
Hydrostatic edema
Transependymal fluid transit
Obstructive hydrocephalus
Extracellular
98
Vasogenic edema
Disruption of blood-brain barrier (loosening of tight junctions)
Extravasation of high protein edema
Extracellular
White matter distribution
99
Window
Contrast control
Narrow window increases contrast, wide window increases gray scale
100
Level
Brightness control
High level best for seeing bone, medium level best for soft tissues, low level best for lung
101
T1 images
Relaxation of protons after RF pulse to the longitudinal axis
Bright tissue: fat, contrast
Dark tissue: water/fluid/edema, bone
102
T2 images
Relaxation of protons after RF pulse to the transverse axis
Bright tissue: fat, water/fluid/edema
Dark tissue: bone
103
T1 pulse sequences
Good anatomical image but poor distinction between gray and white matter
104
T2 and FLAIR
Good for identifying edema and other fluids
T2: fluid has high signal density (appears white)
FLAIR: pure water appears black, "dirty" water appears white, good for detecting subtle and periventricular edema
105
T2 gradient echo
Sensitive for detection of hemorrhage and degradation products
106
kVp
Controls energy or imaging characteristics of X-rays produced
Affects overall exposure and how beam interacts with tissues
107
mAs
Total number of X-rays produced during exposure
108
Photoelectric absorption/effect (PE)
Good
Detection of different tissues
Increasing atomic number - decreasing beam energy
Results in complete absorption of X-ray without forward scatter, happens most commonly when X-ray energy is close to electron binding energy
Increase radiographic contrast by decreasing kVp
109
Compton scatter
Bad
Degradation of image quality (blurry)
Decreasing atomic number - increasing beam energy
Results in scattering of X-ray beam, higher energy photons result in more forward scatter that can hit detector and decrease radiographic quality
110
kVp manipulation
Lower kVp = lower exposure, higher contrast
Higher kVp = higher exposure, lower contrast
111
mAs manipulation
Double the mAs = double the radiation exposure
Decrease mAs = decrease exposure/darkness
Increase mAs = increase exposure/darkness
112
How kVp and mAs relate
Increasing/decreasing the kVp by 15% results in the same change in film exposure as halving or doubling the mAs
113
Technique for imaging thorax
Rads should be taken at end inspiration (very short time)
Short exposure times needed to freeze motion
kVp should be high, except in small patients
114
Technique for imaging abdomen
High contrast is helpful
Exposures can be made between expiration and next inspiration
Longer exposure times up to 0.1 sec are better tolerated
kVp should be kept as low as possible
115
2 key hallmark features of malignancy
Local tissue invasion
Metastatic disease - gold standard diagnosis for malignancy, can arise at any time over the course of a malignant tumor
(Primary, recurrent, and metastatic tumors)
116
Why is metaplasia concerning for a premalignant condition?
Cells that are not programmed to be in a certain area experience altered differentiation and new cues that can change how they grow
Persistent insults drive growth cues leading to neoplasia
117
Anisocytosis vs. anisokaryosis
Variation in cell size/shape vs. variation in nuclear size/shape
118
Monomorphism vs. pleomorphism
In homogeneous cell populations
Cells look the same vs. cells vary in appearance
119
Anaplasia
Loss of features associated with differentiation of certain cell types
Hard to identify what type of cell is present
120
Initiation
Start of neoplastic pathway
Disturbance of cell growth (cell proliferation/mutagenesis)
Initiating genetic lesions establish genetic and population instabilities that predispose cells to additional mutations - selective survival and eventual transformation to malignancy
IRREVERSIBLE
121
Promotion
Something has to happen that favors outgrowth of initiated cell
Results in localized signaling that allows initiated cell to "out-grow" physiologic non-initiated cells
Cell would stop responding to signaling if stimulus removed - REVERSIBLE
122
Progression
To transform from benign to malignant
Tumor progresses into cancer
Involves accumulation of additional mutations and/or continued selection of initiated cell (as in promotion)
123
Adenoma vs. carcinoma in situ vs. carcinoma
Benign epithelial tumor vs. non-invasive epithelial neoplasm that has both benign and malignant features (cellular atypia but intact basement membrane) vs. malignant epithelial tumor
124
Epithelial tumors
"Structures" - large polygonal cells with defined cell borders
Arranged in sheets, tubules, acini, glands
Benign: adenoma (may be pedunculated - stalk, ex: polyp or papilloma)
Malignant: carcinoma - Scirrhous response, reactive tissue stroma (scar forming against cancer), necrosis (umbilication/ulceration)
125
Mesenchymal tumors
Connective tissue produces stroma
Spindle-shaped cells
Arranged in streams, fascicles, bundles
Usually higher N:C ratio
Muscle, fibroblasts (collagen), adipose tissue, bone, cartilage
Blood and lymph vessels - endothelial cells
126
Round cell tumors
Hematopoietic tissue
Individualized cells within tumor, cells are round to polygonal, N:C ratio variable, cells often infiltrate into adjacent tissue
No stroma/matrix, lack orderly arrangement
127
How mesenchymal tumors are classified
1st part is cell origin
Benign ends in __oma (ex: fibroblast - fibroma, fat cell - lipoma, endothelial cell - hemangioma, bone - osteoma, cartilage - chondroma)
Malignant ends in __sarcoma (ex: fibrosarcoma, liposarcoma, hemangiosarcoma, etc.)
128
How is cancer-associated vasculature different than normal?
Vascularization critical for tumor growth
Small localized tumors secrete signaling molecules to blood vessels through simple diffusion
Tumors encourage angiogenesis (blood vessels to grow across basement membrane) to allow growth/spread
129
Why is the lung such a common site for metastatic disease?
Intricate capillary network, small blood vessels
Tortuosity causes tumor to get stuck, thin walls allows for easy escape from blood supply and set up as a new tumor in tissues
130
Carcinomatosis
Unique form of metastasis, direct-implanting or seeding of surface by malignant cells
Usually occurs in malignant epithelial tumors
Cells arrive by exfoliation and implanting on adjacent surfaces rather than by vascular route
131
G1/S checkpoint
Major checkpoint in cell cycle
Did DNA get completely synthesized, and are there any errors in synthesis?
If error passes, gets locked into the gene
132
G2/M checkpoint
Second checkpoint in cell cycle
More concerned with making sure that the number of chromosomes are correct and properly formed
DNA now compacted into chromosomes, making it harder to detect mutations than in open chromatin
133
Tumor suppressor genes controlling cell cycle
p53: guardian of the genome, upregulates expression of gene p21 (CDKi) to slow down cell cycle (can also upregulate GADD45 - DNA damage repair, and Bax - apoptosis)
Rb: retinoblastoma
134
Oncogene
Promotes cell survival and proliferation
Often a "normal" protein (ex: c-Myc - mitogen, sox2, EGFR)
May be a mutated gene (ex: EGFR deletion, c-Kit, Ras)
Activation by mutation, upregulation (ex: copy number alterations - amplification, epigenetics - histone modification), and chromosomal translocation
135
Tumor suppressor gene
Any gene that functions to restrict cell cycle progression, usually in response to perceived genomic alterations
2 classic TSGs: retinoblastoma protein (Rb) and p53
Lost by mutation, copy number alterations, inhibited by overexpressed oncogene, or micro-RNA
136
Genomic regulation of gene expression
Physical changes to genomic code in cell
Mutations/copy number alterations or variations
Heritable
137
Epigenetic regulation of gene expression
Refer to changes in how cell expresses its genes without changing coding sequence
Promotor regulation/DNA methylation/chromatin structure
"Programming" is heritable (good except in cancer)
138
Cell senescence
Cell cycle arrest, cell permanently blocked form re-entering cycle
DNA damage response (DDR) detects severe DNA damage or oncogene induced (cell detects something is wrong)
139
Cell immortalization
Cells manipulated to proliferate indefinitely
Telomeres act as "timestamp" on every cell and shorten with every cell division
Telomerase enzyme expression lengthens telomeres (cancer cells)
140
Explain how a benign brain tumor can kill a patient
Expansile mass in confined space (brain/spinal cord) can create pressure that causes damage (seizures, death)
Damage to adjacent tissue (ulceration, necrosis)
Atrophy of normal tissue/alter function
141
Paraneoplastic syndrome
Systemic effects of neoplastic disease, neoplastic mediators
Complex pathogenesis, significant morbidity, may precede tumor identification
Cachexia - metabolic reprogramming
142
Cancer initiators
Mutagens, DNA damage or mutation
Direct reacting carcinogen (binds to DNA to cause lesion)
Procarcinogen - require metabolism to activate (cytochrome p450)
143
Cancer promoters
Positive selective pressure for initiated cells
Generally drive cell proliferation but not mutation
Exert effects amidst profound tumor heterogeneity
144
DNA viral transformation
Production of viral protein (ex: herpes, papilloma, pox, polyoma)
Early genes - subvert cellular machinery for replication
Often function as a dominant oncogene
145
RNA viral transformation
Inserting into host genome (ex: lymphoma in cats, cows - FeLV, BLV)
Retroviruses: more complex transformation
Mammalian gene regulation through LTR sequences
Insertional mutagenesis - insertion into genomic DNA (could insert into "quiet" part of genome and never be transcribed)
146
E6 viral proteins
Ubiquitin ligase - p53 degradation
No breaks in cell cycle, no DNA repair, no apoptosis
High chance to develop mutation
147
E7 viral proteins
Bind and sequester Rb in cytosol
"Frees" E2F transcription factor - cell cycle entry
148
Examples of bacterial induced cancer
Helicobacter spp.
Other spirochetes (Treponema) - bovine proliferative pododermatitis (hairy foot warts)
149
Examples of parasite induced cancer
Spirocerca lupi
Cysticercus fasciolaris
Schistosoma haematobium
Heterakis isolonche
150
Glutamate ionotropic receptors
NMDA
AMPA
Kainate
Glutamate binds to ligand-gated ion channels to allow sodium into neuron
151
Glutamate metabotropic receptors
Class I, II, and III
G protein coupled receptors, 2nd messenger system
Fine tune action potential, modulate neurotransmission
152
Inhibitory GABA receptors
GABAa = ionotropic
GABAb = metabotropic
153
The EAAT-4, excitatory amino acid transporters 1-4, function is to
Transport extracellular glutamate into the presynaptic neuron, postsynaptic neuron, or astrocyte
154
The composition of the dendritic spine is
Contains receptors for neurotransmitters
N-Cadherin is one of the proteins that stabilize synaptic architecture (also EphR & neurexin)
Contains the postsynaptic density, which is composed of >1000 proteins
155
The function of the GABAb receptors are to
Reduce intracellular cAMP
Stimulate the opening of K+ channels
Promote hyperpolarizing of the neuron
Prevent firing of action potentials
156
Benzodiazepines and GABA bind at the same site on the GABAa receptor
True or false
False
157
GABA transaminase (GABA-T) removes GABA by directly forming
Succinic semialdehyde (SSA) via transamination with alpha-ketoglutarate, which also reforms glutamate
158
2 reasons for vasodilation during inflammation
Slow down blood flow to allow leukocyte accumulation
Increase total blood flow and vascular permeability to allow WBCs to migrate into interstitium
159
Why do we tent skin in a patient to evaluate hydration status?
Fluid in interstitium = fluid reservoir, can draw fluid when dehydrated (decreasing elasticity)
Hallmark for dehydration = hypoalbuminemia (increased colloid osmotic pressure)
160
Transudate
Low protein, few cells
Mostly water (fluid leakage)
Increased hydrostatic pressure, decreased colloid osmotic pressure
Decreased protein synthesis or protein loss
161
Exudate
High protein, high cells
Higher permeability (fluid and protein leakage)
Inflammation
Vasodilation and stasis, increased interendothelial spaces
162
2 molecular events that characterize "activated" endothelium
Upregulation of adhesion molecules
Endothelial retraction
163
Weibel-Palade bodies
Found in endothelial cells
Store selectins, immediately shuttle them to surface of cell
164
Selectins
Bind glycolipids, expressed on leukocytes
Mediate transient, low affinity binding ("rolling")
Upregulated during acute inflammation
165
Integrins
Bind to ligands and extracellular matrix
Nomenclature is complex/confusing
Inflammation - swaps low affinity integrins for high affinity
Also mediates migration and trapping of leukocytes in interstitium/ECM
166
PECAM-1
Platelet endothelial cell adhesion molecule 1 (aka CD31)
Expressed on platelets, endothelial cells, leukocytes
Function in homophilic manner (binds itself)
167
Describe how a mutation in CD18 (leukocyte adhesion deficiency) results in neutrophilia during inflammation
Affects integrin function, neutrophils constantly roll along blood vessel, can never exit circulation
Macrophages demand more neutrophils, bone marrow sends more through blood
Very increased neutrophil count on CBC
CLAD - Irish setters, BLAD - Holsteins
168
Neutrophil extracellular traps (NETs)
Neutrophils degranulate and spew dissolved DNA to trap bacteria
Concentrates ROS and enables enhanced killing
169
Classical pathway
Ag-Ab complexes
C3b deposited on microbe (opsonization)
Recognition of bound C3b by phagocyte C3b receptor
Phagocytosis of microbe
170
Alternative pathway
Complement mediated spontaneous deposition on foreign surfaces
C3b deposited on microbe (opsonization)
Recruitment and activation of leukocytes
Detection of microbes by leukocytes - inflammation
171
Lectin pathway
Recognition of mannose, rich on bacterial cell walls
C3b deposited on microbe (opsonization)
Formation of membrane attack complex (MAC) - lysis of microbe
172
Opsonization
Coating of a pathogen with something (usually Ab's or C3b) to aid phagocytosis in recognizing and engulfing pathogens (C3b is nonspecific)
173
Fibrosis
Organized deposition of collagen by fibroblasts
Often accompanied by scattered, residual lymphocytes/WBCs
174
Granulation tissue
Growth of fibroblasts and small blood vessels
Allows for controlled maintenance of chronic, ongoing inflammation, while promoting healing
175
Second intention healing and proud flesh
1st intention: surgical closure
2nd intention: granulation tissue
Proud flesh: unable to turn off granulation tissue, keeps growing (more damage - faster growth)
176
5 agents that cause granuloma
Higher order bacteria (resistant to degradation by neutrophils)
Fungi/yeast organisms
Parasites
Foreign material
Intracellular bacteria
177
Cytokines
Small proteins that may be pro/anti-inflammatory
Source cell, target cell, effector mechanism
Predominantly made by leukocytes
May be secreted or cell-associated
178
Chemokines
Specialized cytokine subset
Homeostatic or inflammatory
Classification is molecular based
May guide chemoattraction or chemorepulsion
179
Major pro-inflammatory cytokines
IL-1
TNF
IFN-gamma
(also IL-2, IL-6, IL-17, IFNalpha/beta)
180
Major anti-inflammatory cytokines
IL-10
TGFbeta
(also IL-12, IL-20)
181
Major cytokines driving acute inflammation
TNF
IL-1
IL-6
182
Major cytokines driving chronic inflammation
IL-12
IFNgamma
183
Type I interferons
IFNalpha and IFNbeta
Classical antiviral activity - activates genes to interfere with viral replication, activates NK cells
184
Type II interferons
IFNgamma
Broader role in pro-inflammatory response, cell growth regulation, and endothelial cell activation
185
Eicosanoids
Produced by leukocytes, mast cells, endothelial cells
Mediate all aspects of inflammation, primarily derived from arachidonic acid
Vasoconstriction/dilation, increased vascular permeability
(Prostaglandins, leukotrienes, thromboxanes, prostacyclins)
186
Arachidonic acid pathway
COX or LOX
COX: vasodilation/constriction, platelet aggregation, vascular permeability
LOX: chemotaxis, bronchospasm, vascular permeability, inhibition of inflammation
187
Why are corticosteroids such potent immunosuppressants?
Inhibits beginning of both COX and LOX pathways
(all aspects of inflammation)
188
4 effects of bradykinin
PAIN
Vasodilation
Vascular permeability
Increases PLA2 activity (arachidonic acid pathway)
189
Acute vs. chronic inflammation
Acute: inflammation, leukocytes traveling to tissue, damaging to kill pathogen
Chronic: proliferative, very irregular shape/margins, fibrosis - contraction/scar tissue, healing/repair
190
Erosion vs. ulceration
Erosion: epithelium gone, basement membrane still intact
Ulcer: epithelium and basement membrane gone, scarring
191
Unipolar neurons are
a. interneurons
b. motor neurons
c. sensory neurons
Sensory neurons
192
The axon hillock is the site where action potentials are generated
True or false
True
193
The ventricles and central canal are lined with choroid epithelial cells
True or false
False
194
___ provide myelin, axonal support, axonal pathfinding during nerve development, and regeneration
Schwann cells
195
___ regulate excitability, synaptic transmission and secrete ECM, involved in axonal pathfinding and cell migration in the PNS
Satellite cells
196
A nerve fiber is made of
An axon, myelin sheath, and Schwann cell
197
Axons are myelinated in the CNS by ___ and the PNS by ___
Oligodendrocytes
Schwann cells
198
A ___ is a cluster of neuron soma in the CNS whereas in the PNS is called ___
Nucleus
Ganglion
199
The sciatic nerve is a mixed nerve containing
Sensory and motor fibers
200
The cerebrospinal fluid is an ultrafiltrate of the blood plasma made in the central canal
True or false
False
201
A ___ is a group of axons, myelinated and unmyelinated, bundled together and covered by perineurium
Fascicle
202
The ___ conducts signals from the CNS along motor neurons to the target muscles and glands
Efferent nerve
203
Spinal motor neurons are located at the
Ventral horn
204
The white matter of the spinal cord does not contain
a. axons
b. neuroglia
c. perikarya
Perikarya
205
Tracts located at the medulla oblongata have myelinated and unmyelinated axons
False
