Neurobiology III ( Lecture 21 - 23) Flashcards
What is the PNS in charge of
transmitting signals from the CNS to effector parts of the body
Branch out the PNS and name their functions
PNS
- — Somatic
- ——- Skeletal system
- — autonomic
- ——- Sympathetic (excitement or activity)
- ——- Parasympathetic ( resting )
Cell bodies of somatic neurons are located at the ______
spinal cord
(T/F) somatic motor neurons (myelinated) leave the CNS and pass other synapses to skeletal muscles
False
Somatic Motor Neurons leave the CNS and pass without any synapses to skeletal muscles
Somatic Motor Neurons release the neurotransmitter _____
Ach ( Acetylcholine)
Excitation of motor neurons leads to _______ of skeletal muscles ONLY
contraction.
In order to cause relaxation, inhibition of motor neurons are needed in the spinal cord
The Autonomic NS is made up of _____ (#) neurons in series that connect the _____ and ______ cells.
two
CNS and effector cells
The first and second neuron bodies of the autonomic neurons are located at ? (1) (2)
(1) CNS
(2) autonomic ganglion
What is the neurotransmitter released between pre and postganglionic neurons
ACh
(T/F) the signal from postganglionic fiber sent to effectors can only be excitatory
False. Signals from the postganglionic fiber to the effectors can be both excitatory and inhibitory
What neurotransmitter is released between postganglionic neurons and target?
This differs between the parasympathetic and sympathetic system
What is Dual innervation ?
both the parasympathetic and sympathetic system innervate most organs
What is the sympathetic NS responsible for
it is responsible for fight or flight / excitation & physical activities
What is the parasympathetic NS responsible for
responsible for rest & digest. // stimulates digestion and slows down cardiac heart rate
(T/F) Neurons of the sympathetic and parasympathetic divisions leave the CNS the same level.
False. They leave at different levels
What region does the sympathetic fibers exit the CNS
The sympathetic fibers leave the CNS at the lumbar and thoracic regions
What region does the parasympathetic fibers exit the CNS
the parasympathetic fibers leave the CNS at the brainstem and sacral regions
How does the sympathetic fibers leave the CNS (Explain)
Sympathetic fibers leave the CNS through the lumbar ad thoracic region.
Sympathetic ganglias lie close to the spinal cord and forms 2 chains of ganglia called the sympathetic trunks
How does the parasympathetic fibers leave the CNS (Explain)
Parasympathetic fibers leave the CNS at the brainstem and sacral region.
Parasympathetic ganglions are usually located near organs that the postganglionic neurons can innervate
One important cranial neuron from the parasympathetic NS is the _______. It originates from the _______ and carries about ____% of all parasympathetic fibers.
vagus nerve
medulla oblongata
75%
The ______ is a modified sympathetic ganglion
adrenal medulla
Explain the adrenal medulla pathway
1) preganglionic sympathetic cord projects from the spinal cord to the adrenal medulla where they synapse
2) The pregonglionic sympathetic cord produces ACh at the on to chromaffin cells in the adrenal medulla
3) Chormaffic cells are postganglionic specialized cells that lack axons. Once they are stimulated, the release catecholamines directly into the blood.
In the Somatic branch of the PNS, the neurotransmitters released between the somatic motor neuron and effectors is _______
Acetylcholine (ACh)
The neurotransmitter ______ is also used between the pre and postganglionic neurons in both the ________ and _______ branches of the autonomic NS
ACh
parasympathetic and sympathetic
Neurotransmitter between parasympathetic postganglionic neurons and effects is the _____
AcH
Neurotransmitter between sympathetic postganglionic neurons and effects are _____ or ________
Epinephrine or Norepinephrine
What are Agonists
molecules that bind to receptors and trigger signaling pathways
What are antagonists
molecules that bind to receptors but do not trigger signaling pathways
The __________ is found in the ______ NS and responds to nicotine found in tobacco products. It is also found between the ______ and _______ in the ______ system.
Nicotine ACh-R
Somatic
pre and post ganglionic receptors
Autonomic NS
The ______ is found in the autonomic NS and responds to the mushroom poison, muscarine.
Muscarinic AChR
_______ is a competitive ______ of M-AchR
Atropine
antagonist
Adrenergic receptors of which many subtypes exist are activated by ________
catecholamines
Receptor ______ expressed by a target cell determines the cell’s response to a signal
An example would be _____ receptors that are activated by ______.
subtypes
Androgenic
catecholamines
(T/F) There are cells in the body with no charge
False
All cells in the body have a slight charge
Within the Intracellular Fluid, _____ is a major cation
Potassium (K+)
Within the Extracellular Fluid, ______ is a major cation
Sodium ( Na+)
In the intracellular fluid, ______ and _______ are the major anion
phosphate ions and negatively charged proteins
In the extracellular fluid, ______ is the major anion
Chlorine (Cl-)
The intracellular fluid is slightly _______.
negative
The extracellular fluid is slightly ______
positive
The 2 compartments exist in a state of _____________
electrical disequilibrium
What is the Law of Conservation of electrical charges
The net amount of electrical charges produced within the cell is 0. The human body is overall electrically neutral
(T/F) The phospholipid bilayer of the artificial cell is permeable to ions
False
The phospholipid bilayer of artificial cell is not permeable to ions
What is an electrical gradient
When the electrical net charge between the intracellular and extracellular ion is different
What is an concentration gradient
When there is one more positive ion outside the cell compared to the inside
(T/F) Electrical gradients are measured on an absolute scale
False. Electrical gradients are normally measured on a relative scale.
Explain the difference between an absolute scale vs relative scale
Absolute scale involves the counting the number of ions on either side of the membrane.
Relative scale involves counting the difference in charge between two points.
Neurons and muscle cells typically have a resting potential of ____ to _____ mV
-40 to -90 mV
