Pharm 736 Exam 1 Flashcards
Peripheral Nervous System Divisions
Somatic Nervous System
Autonomic Nervous System
Somatic Nervous system Functions
Innervation of Striated (skeletal) muscle
Control of voluntary movement
No ganglia between spinal cord and target muscle
Autonomic Nervous System functions
Innervation of smooth muscle, glands, organs, blood vessels, fat skin, etc.
Involuntary control of bodily functions (respiration, BP, secretions, body Temp, digestion, HR)
Sympathetic Division of ANS
SNS
Innervation which produces an excited state
Fight, Flight, Fright response
coordinated activation to prepare body for exertion/trauma
Adrenal Medulla functions like a sympathetic ganglion but releases epinephrine into bloodstream
Parasympathetic division of ANS
PNS
Innervation producing a relaxed state
Rest and Digest responses
Target organs activated as they are needed
Location of cell’s Soma in Somatic, Sympathetic and Parasympathetic systems.
Somatic: Cell bodies located in the spinal cord.
Sym/Para: Cell bodies in Spinal cord and Ganglion
Parasympathetic pre-ganglionic neurons are _______ compared to ganglionic cell bodies.
Longer
Sympathetic ganglionic cell bodies are _______ compared to post-ganglionic neurons
shorter
What NT is used for both parasympathetic and Somatic Innervation?
Acetylcholine
what types of receptors are used in the Parasympathetic system?
Neuronal Nicotinic Receptor (ion channel) Muscarinic Receptor (GpCR)
What type of receptors are used in the somatic system?
Muscular Nicotinic Receptor (ion channel)
what type of receptors are used in the Sympathetic system?
Neuronal Nicotinic Receptors (ion channel)
alpha and beta Adrenergic Receptors (GpCR)
Where is Acetylcholine released and what by within the PNS?
Nerve terminals of Neurons originating from Spinal Cord
Neurons from ganglion in parasympathetic system.
Where is Norepinephrine released and what by?
Released by postganglionic neurons in Sympathetic
Where is Epinephrine released and what by?
Epinephrine is released by the adrenal medulla into general circulation
Why is Dopamine important for SNS?
It is a precursor to Norepinephrine and Epinephrine in SNS
What are Catecholamines?
They are catechol ring structures with an attached amine, that include EPI, NE and Dopamine.
They are a subset of neurotransmitters known as biogenic amines including histamine, serotonin and melatonin.
Organs and responses during Parasympathetic Innervation
All - Basal tone Heart - Slow down HR Lung - constrict bronchioles Stomach - increase secretion Intestine - Increase motility Colon/Bladder - Empty Eye - normal
What are the Organs and responses during Sympathetic innervation
Heart - Speed HR Lungs - Dilate Bronchioles Stomach - Decrease secretion Adrenal Gland - Release Adrenaline GI - Decrease Motility Colon/Bladder - Delay Emptying Eye - Pupil Dilation (Mydriasis)
Adrenergic Receptors (type) and Subtypes
(G-protein coupled receptors)
alpha-1 (A,B,C)
alpha-2 (A,B,C)
Beta (1,2,3)
What are the G protein type, Effector Enzymes, and 2nd messengers for alpha-1 adrenergic receptors?
Gaq
Increased Phospholipase C-Beta enzymes
Increase IP3, DAG and Ca2+
What is the G protein type, Effector Enzymes, and 2nd messengers for alpha-2 adrenergic receptors?
Gai
Decreased Adenyl Cyclase, Increased K+ channels
Decrease cAMP
What is the G Protein Type, Effector Enzymes, and 2nd messengers for Beta adrenergic receptors
Gas
Increased Adenylyl Cyclase
Increase cAMP and Increased Ca2++ (heart)
Baroreflex Pathway Cardiac Effects Key Points
If BP increases then HR decreases
If BP decreases then HR increases
Baroreflex Pathway Vascular Effects Key points
Signals from pathway change the tone of the major blood vessels in compensation for changes in BP
Chronic Application of Agonists will result in? Full vs Partial?
- Desensitization, cells attempt to avoid overstimulation by blocking ability of receptor.
- Partial agonists tend to cause very little receptor desensitization compared to full.
Long term usage of antagonists use may result in?
Supersensitization, up-regulation of receptors makes the subject more sensitive to agonists.
Why are Beta Blocker users at risk for heart attack immediately following therapy cessation?
Supersensitization of cells, increased likelihood for two weeks following cessation.
Describe PNS and SNS cooperation Sweating and Pulmonary Secretions
Sweating
- PNS controls generalized hydration of skin
- SNS responsible for localized cholinergic sweating in palms, underarms
Pulmonary Secretions
- PNS controls mucus secretions in lungs
- SNS controls water secretions in lungs
Male Sexual Response in Autonomic Nervous System
Point (Erection) - PNS
Shoot (Ejaculation) - SNS
Organs/Tissues exclusively controlled by SNS include:
Blood Vessels (sympathetic innervation)
Kidney (vasoconstriction and renin secretion)
Liver (Glycogenolysis, fat cell lipolysis)
Skeletal Muscle METABOLISM
Describe Cardiac Signal Transduction Pathway (Beta)
Increased cAMP signals Phospho Kinase A, which signals troponin to cause contraction with Ca2+
Describe Smooth Muscle Signal Transduction (alpha-1)
Increased IP3 causes ER to release Ca2+ which binds to Calmodulin and activates the Myosin Light chain Kinase to trigger myosin to contract
Describe Receptor Regulation in desensitization
Stimulatory hormone activates Gprotein (Gas) receptor which signals GRKinase by Gbetagamma which causes other receptors to produce Arrestin, which stops the receptor response.
alpha-1 (Gaq) receptor locations/Function
Blood Vessels/Vasculature in dermal, GI, Renal, bladder and nasal membranes (not skeletal/heptic)
- Constriction, Increased peripheral resistance, increased diastolic BP
Eye
- Contraction of radial Muscles –> Mydriasis
Bladder/GI Sphincters
- Constrict sphincters, decrease outflow
alpha-2 (Gai) Receptor Locations/Functions
Eye
- Decrease production of aqueous humor
Pancreatic Islet
- Decrease Insulin release, increased blood glucose
Presynaptic nerve terminals
- Neurotransmiiter release
CNS/Brainstem
- Decreased BP, Inhibit Baroreflex
Spinal Cord
- Inhibit Pain Transmission
Nasal Vasculature
- Constriction
Beta-1 (Gas) receptor locations/functions
Heart
- Inc HR , Contractility & force –> inc cardiac output
Kidney
- Inc Renin Secretion –> vasoconstriction
Eye
- Inc Production of Aqueous humor
Beta-2 (Gas) receptor locations/functions
Hepatic and Skeletal Muscle/Vascular Smooth muscle
- Relaxation, Inc blood flow to liver/skeletal muscle
Pulmonary smooth muscle
- Relaxation –> inc airflow
GI long smooth muscle
- Relaxation –> decreased motility
Bladder detrusor muscle
- Relaxation –> Decrease outflow
Pregnant Uterus (myometrium) - Relaxation
Skeletal Muscle
- Inc Glycogenolysis, Inc K+ uptake
Mast Cells
- Decrease Granulation
Pancreas
- Inc Glucagon Secretion
Liver
- Glycogenolysis
Eye
- Inc production of aqueous humor
Beta-3 (Gas) Receptor Location and Function
Fat
- Lipolysis (complex process)
Adrenergic Presynaptic Nerve Terminal transporters include:
Norepinephrine transporter
alpha-2 adrenergic receptor (autoreceptor)
Ca2++ channel
K+ Channel
Support Cell plays what role at the synaptic cleft?
contains reuptake II which is a non selective receptor with a very high capacity.
What enzyme converts Tyrosine to DOPA?
Tyrosine Hydroxylase
H2O and Dihydrobiopferin as byproduct
What enzyme converts DOPA to Dopamine?
Aromatic Amino Acid Decarboxylase (AADC)
CO2 as byproduct
What enzyme converts Dopamine to Norepinephrine?
Dopamine B-hydroxylase (DBH)
H20 dehydroascorbic acid as byproduct
Where and what is norepinephrine further converted into and by what enzyme?
Epinephrine in the Adrenal Gland
Phenylethanolamine N-methyltransferase enzyme
Homocysteine as byproduct
