Exam 2 Flashcards
What kind of neuron is efferent? (Unipolar, Bipolar, or Multipolar)
Multipolar
True or False
Action potentials travel faster in thinned neurons
False
How do signals spread through electrical synapses?
By diffusion of ions through gap junctions
Match the channel type to its typical function in neurons: Ligand-Gated ion channels
Generation of graded potential
Match the channel type to its typical function in neurons: Voltage-gated Potassium channels
Termination of action potential
Match the channel type to its typical function in neurons: Voltage-gated Sodium channels
Generation of action potential
Match the channel type to its typical function in neurons: Voltage-gated Calcium channels
Release of neurotransmitters
Myelin speeds up signal transmission by…
Prevention of ion loss through the membrane
Nicotine ______ acetylcholine receptors that are _____
Activates, ionotropic
True/False
Neurotransmitters don’t get released into the cleft
TRUE, vesicles only open up and release the neurotransmitter but do not come out into the synaptic cleft, as they are larger than the width of the gap
What is the mechanism of neurotransmitter uptake?
By sodium-coupled transport
How can inhibition of acetylcholinesterase alleviate curare poisoning?
By increasing the concentration of acetylcholine, so it would displace curare
Rest and digest are controlled by what specific nervous system?
Parasympathetic
Parasympathetic responses are mediated by acetylcholine, which bind to _______ receptors on target organs.
Muscarinic
Skeletal muscle acetylcholine receptors are _____ type
Nicotinic
How are hydrophobic hormones carried through the blood?
Complexed with proteins
What happens after water-soluble hormones bind to receptors?
Hormone-receptor complexes are taken into the cell
Signaling by the second messengers is initiated
What is the specialized organ for detection of pheromones?
Vomeronasal organ
Exocytosis of insulin is stimulated by ______
Calcium
True/False
Upregulation of glucose transporters is stimulated by cystolic calcium increase
FALSE
True/False
There is movement in isometric contraction
FALSE
True/False
Passive force contributes to resistance in both stretching and compression
FALSE- it only contributes in stretching
A twitch lasts longer than calcium elevation. The possible reason is that interaction between Troponin and calcium is characterized by what?
Low dissociation rate
The processes that occur both in neurons and skeletal muscle cells include all except:
a) The ability to generate action potential
b) Fusion of vesicles with the plasma membrane
c) The presence of molecular motors
d) Participation of calcium in a critical function
B
What property of a muscle is most critical for generation of small, precise movements?
Small motor units
What property of asynchronous muscles of flying insects is responsible for the high frequency of wing beat?
Activation by stretch
What is the direct function of calmodulin in the smooth muscle?
Activate an enzyme that activates myosin ATPase
What is the significance of the initial segment? What biochemical feature enables this task?
It’s the site where action potential is initiated due to the high density of the voltage-gated channels.
What types of cells produce Myelin?
Oligodendrocytes in the brain and Schwann cells in the PNS
Why does myelin speed up signal propagation?
The time consuming process of action potential generation occurs only at specific points along the axon.
How is the neurotransmitter removed from the synaptic cleft?
- It can diffuse away from the synaptic cleft
- It can be taken up by the presynaptic neuron for reuse
- Enzymatically degraded
What channels are responsible for excitatory post-synaptic integration?
Na+ or nonspecific cations
What receptors affect stimulation of acetylcholine?
Muscarinic receptors
What type of neuron takes information from the sensory organs toward the CNS and what is their morphology?
Afferent (sensory) neurons, unipolar or bipolar
What type of neuron takes information from the CNS and sends it to muscles/glands? What is their morphology?
Efferent (motor), multipolar
What type of neuron takes information from the CNS and moves it around in the CNS?
Interneurons (multipolar or other morphology)
Where do action potentials in neurons originate?
Trigger zone
How can action potential be sped up?
Increasing axon diameter and/or insulating the axonal membrane
What are the Nodes of Ranvier?
Myelin free areas within myelinated neurons that allow ion exchange for action potential
True/False
The fastest neurons are myelinated
True