Final - Exam 1 and New Bio Content Flashcards
Excitatory Synapses are a type of _ potential
graded
The equilibrium potential in excitatory synapses is roughly _mV
0mV, more positive charge
Excitatory Synapses are more permeable to _.
cations (Na+, K+, Ca++)
-Na and Ca channels are open and K channels are closed so they don’t leave cell.
Examples of excitatory NTs:
ACh (skeletal)
Glutamate
Substance P
NE
Epi
Dopamine
Inhibitory Synapses have a _ channel and are found on dendrites on the NT synapse.
Cl-
Inhibitory Synapses cause equilibrium potential to become _ polarized, moving Vm _ to the threshold.
hyperpolarize, farther
Inhibitory Synapses Vm is:
-90mV
Examples of Inhibitory synapses involve:
GABA and Glycine
Examples of Excitatory synapses involve:
nAChR and Glutamate
Inhibitory PostSynaptic Potential (IPSP) _ excitability and makes AP _ likely
depresses, less
Examples of inhibitory NTs:
GABA
Glycine
ACh (cardiac)
Serotonin
Enkephalins
Endorphins
Cl- ion channels for inhibitory synapses are found on _ in the NT synapse
dendrites
Demyelination of the neurons in the CNS/ Oligodendrocyte defect causes this pathology:
Multiple Sclerosis
-autoimmune; Lhermitte sign (tingling shooting down torso/arms)
-loss of axons
Tx- corticosteroids and immunotherapy, avoid stress
Which autoimmune disease causes muscle weakness by antibodies damaging nAChr on the post-synapse (nicotinic ACh receptors)?
Myasthenia Gravis
-tx: Neostigmine + Prednisone + possibly plasmapheresis
What is happening in Myasthenia gravis?
paralysis, no AP can be generated because IgG antibodies damage nicotinic ACh receptors on post synaptic membrane
Myasthenic Crisis:
-s/s
-tx
S/S: severe muscle weakening(diaphragm) -> respiratory distress/ DIB
Tx: anticholinesterase drugs (Neostigmine-AChE inhibitor), corticosteroids, immunosuppressants, plasmapheresis
Cholinergic Crisis:
-s/s
-tx
S/S: resembles myasthenic crisis (extreme diaphragm musc. weakness/DIB) BUT occurs 30-60 min after taking anticholinesterase drugs-neostigmine); too much ACh -> overactivation of muscles -> weakness
Tx: withhold anticholinesterase drugs until serum level falls, vent. support, prevent respiratory complication
Tensilon Test:
Edrophonium (anticholinesterase inhibitor) helps determine which of the 2 types of Myasthenia Gravis crises are happening
Demyelination of neurons in PNS/ Schwann cell defect causes this pathology:
Guillian-Barre
Tx: vent support, IVIg, corticosteroids, plasmapheresis
Acute, ascending motor paralysis would be a symptom of _ - _ syndrome.
Gullian-Barre
-neuronal matter can be restored since occurring in PNS
What is happening in LEMS?
muscle weakness and paralysis, no AP generated because antibodies damage voltage-gated ion channels in presynaptic nerve terminals
Which autoimmune disease causes muscle weakness by antibodies attacking voltage gated Ca++ channels on the presynaptic motor nerve terminal -> weak end plate potentials -> no AP?
LEMS
-tx: Neostigmine to boost the ACh there is at NM junction + chemo/radiation if necessary
-unlike MG, do not benefit from plasmapheresis
Which of the following statements is true about smooth muscle?
A. Actin and myosin generate force through the crossbridge cycle.
B. Smooth muscle has more troponin than skeletal muscle.
C. Smooth muscle has the fastest myosin ATPase activity compared to skeletal and cardiac muscle.
D. Smooth muscle receives neural input from the somatic nervous system.
A
Smooth muscle is similar to skeletal muscle in which of the following ways?
A. The mode of entry of calcium into the cytoplasm of the muscle cell
B. Both possess actin and myosin and the mode of entry of calcium into the cytoplasm of the muscle cells
C. The type of calcium-binding molecules they possess
D. Both possess actin and myosin
E. All answers are correct
F. Neuronal regulation
D
During skeletal muscle contraction, thick and thin filaments bind together forming __________.
A. tropomyosin
B. crossbridges
C. myosin heads
D. troponin complex
B
Thick and thin filaments overlap within the __________.
A. Z line
B. H zone
C. A band
D. I band
C
What terminates smooth muscle contraction?
A. Removal of calcium from troponin
B. Removal of calcium from tropomyosin
C. Dephosphorylation of myosin by a phosphatase
D. Dephosphorylation by a kinase
C
Molecules common to both skeletal and smooth muscle crossbridge cycling include __________.
A. myosin light chain kinase, calmodulin, and actin
B. calmodulin
C. phosphatases
D. myosin light chain kinase
E. actin
F. myosin light chain kinase and actin
E
When an action potential travels along the sarcolemma of a muscle cell __________.
A. DHP receptors in the T-tubule undergo a conformational change and Ca2+ flows down its concentration gradient through the ryanodine receptors
B. voltage sensitive Ca2+ channels in the sarcoplasmic reticulum open, DHP receptors in the T-tubule undergo a conformational change and Ca2+ flows down its concentration gradient through the ryanodine receptors
C. voltage sensitive Ca2+ channels in the sarcoplasmic reticulum open
D. Ca2+ flows down its concentration gradient through the ryanodine receptors
E. Ca2+ pumps in the sarcoplasmic reticulum are activated
F. DHP receptors in the T-tubule undergo a conformational change
B
After the myosin ATPase hydrolyzes ATP into ADP + Pi, __________.
A. the two products stay attached to the myosin head
B. the two products stay attached to the myosin head, the myosin head is cocked and binds to a different G-actin molecule, ready for the power stroke
C. the myosin head is cocked and binds to a different G-actin molecule, ready for the power stroke
D. the myosin head has nothing bound, ready for the power stroke
B
Drugs that stimulate the neuromuscular signaling include Anti-AChE drugs, a couple examples would be:
neostigmine, physostigmine
Drugs that inhibit the neuromuscular signaling:
Curariform drugs and botox
Drugs that stimulate the neuromuscular signaling include ACh-like drugs, a few examples would be:
nicotine, carbachol, methacholine
Drugs that stimulate neuromuscular signaling:
ACh-like drugs and Anti-AChE drugs