Adrenergic Pharmacology Flashcards
The ionic composition of the blood and the interstitial fluid resembles ___ water.
sea
The Na+ concentration outside of cells is ___ (low/high). K+ concentrations therefore are ___ (low/high).
high (remember that seawater is salty); low (opposite of Na+)
Why is Cl- low inside the cell (cytoplasm)?
because it has been replaced by proteins. Proteins have a negative charge and this balances the other charges inside the cell (therefore no need for Cl-).
The Na+ concentration inside the cell is ___ (low/high) and K+ is ___ (low/high).
low; high
Cells have ___ channels that are working at rest and they provide membrane permeability at rest.
K+
The membrane is 100X more permeable to K+ than Na+ and therefore, the Na+K+ ATPase pump kicks out 3 Na+ and allows 2K+ in (with a net of 1Na+ going out) to maintain the electrochemical gradient.
Because there is more K+ ___ the cell, there is a net flow to the ___ because of the concentration gradient. Therefore there is a little less K+ than ___ inside which creates an inside that is ___ compared to the outside.
inside; outside; Cl-; electronegative
T/F. The net efflux of K+ continues until the chemical force leading K+ inside is balanced by the electrical force pushing it out.
False, The net efflux of K+ continues until the chemical force leading K+ OUTSIDE is balanced by the electrical force BRINGING IT BACK.
What happens if a cell suddenly becomes permeable to Na+ at one location?
At the site, the Na+ current would counteract the K+ current, leading to depolarization.
Depolarization is the same as saying the cell becomes less electronegative or less polarized (or depolarized)
T/F. Voltage-gated channels can be opened or closed based on the potential across the membrane.
True.
T/F. The channels for K+ respond quicker to changes in voltage than the channels for Na+.
False, The channels for Na+ respond quicker to changes in voltage than the channels for K+.
Place the following statements in order
- As hyperpolarization continues, the Na+ and K+ channels are closed and the cell is at its resting state.
- As the Na+ enters the cell, it spreads to neighboring regions thereby spreading the depolarization.
- Once the local depolarization reaches threshold, the voltage gated Na+ channels open.
- Continued depolarization will cause the K+ channels to open (slower) and hyperpolarization resumes. Now the Na+ channels begin to close.
- stimulus causes Na+ to enter the membrane and the cell begins to depolarize due to the Na+ current coming in.
5, 3, 2, 4, 1
what cells are excitable?
nerve and skeletal muscle
Action potentials in ___ tissue is much slower than in nerve or skeletal muscle.
cardiac
Action potentials reach the nerve ___ and this causes ___ channels to open. ___ enters the cell and tells the vesicles to fuse with the presynaptic membrane to dumps its contents into the ___. The transmitter postsynaptic receptor proteins and open their ___ gates to let Na+ in, which starts local ___.
terminal; Ca2+; Ca2+; synapse; ion; depolarization
Which division of the CNS projects from the CNS to targets in PNS and elicits an appropriate response?
efferent (motor) division
The ___ division projects from PNS target to the CNS and provides information.
afferent (sensory)
What nervous system provides motor innervation of all skeletal muscles?
somatic nervous system
Define homeostasis.
the tendency of a higher animal, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus that would tend to disturb its normal condition or function
What two areas affect homeostasis?
- Autonomic nervous system
2. Endocrine system
What does the autonomic nervous system regulate and coordinate?
- smooth muscle
- heart
- secretory glands (can self-regulate, but affected by the ANS)
T/F. Many organs are affected by both the sympathetic and parasympathetic systems.
True.
The parasympathetic innervation comes from the ___ region and the sympathetic innervation comes from the ___ region.
craniosacral; thoracolumbar
T/F.The ganglia of the parasympathetic system are close to the spinal cord in a chain and the sympathetic ganglia are close to target organs.
False, The ganglia of the SYMPATHETIC systems are close to the spinal cord in a chain and the PARASYMPATHETIC ganglia are close to target organs.
Match:
- Long postganglionic fibers
- Short postganglionic fibers
- Lots or postganglionic branching so that multiple organs can be mobilized at once
- Very little postganglionic branching
A. Sympathetic
B. Parasympathetic
1 - A
2 - B
3 - A
4 - B
T/F. There are ganglia located at the skeletal muscle.
False, there are no ganglia at these muscles.
What are the receptors used in the following systems at the EFFECTOR site- sympathetic innervation of adrenal medulla, sympathetic, parasympathetic, and somatic?
sympathetic innervation of adrenal medulla = adrenergic receptors
sympathetic = adrenergic receptor
parasympathetic = muscarinic receptor
somatic = nicotinic receptor
The preganglionic neurons of the sympathetic system release ___ which binds to the ___ receptor on the adrenal ___. The adrenal gland then releases ___ into the blood to bind to ___ receptors on effector organs (heart and vessels).
acetylcholine; nicotinic; medulla; epinephrine; adrenergic
Preganglionic sympathetic fibers release ___ which bind to ___ receptors on postganglionic fibers. These fibers release ___ to bind to ___ receptors on effector organs (heart and vessels).
acetylcholine; nicotinic; norephinephrine; adrenergic
Preganglionic parasympathetic fibers release ___ which bind to ___ receptors on postganglionic fibers. These fibers release ___ to bind to ___ receptors on effector organs (heart and vessels).
acetylcholine; nicotinic; acetylcholine; muscarinic
The ___ fibers release acetylcholine which binds to ___ on striated muscles.
somatic; nicotinic
Which receptors open postsynaptic membranes and let sodium in?
nicotinic receptors
Which receptors are GPCRs that transmit a signal inside the cell?
muscarinic
What is released from the postganglionic sympathetic fibers in renal vessels?
dopamine
T/F. When epi and norepi are released from the adrenal glands under sympathetic control into the blood they have widespread effects.
True.
What precursor amino acid is transported in adrenergic neurons into the nerve endings to synthesize catecholamine transmitters and store them in vesicles?
Tyrosine
Tyrosine → ___ → ___→ ___ → ___.
tyrosine → DOPA → dopamine → norepi → epi
How are adrenergic and cholinergic transmitters dealt with differently one inside the synaptic cleft?
adrenergic - transmitters are transported back into the presynaptic terminus (reuptake)
cholinergic - transmitter is hydrolyzed in the synapse (cholinesterases)
How many dopamine receptors are there? Where are they found?
5 (D1-D5)
in CNS and periphery (kidneys, some smooth muscle)