Name 4 types of neurotransmitters.

Acetylcholine, Catecholamines, Amino Acids, & Gaseous.

How is Acetylcholine (ACh) synthesized? What enzyme is involved?

Acetylcholine is synthesized from acetyl-CoA and Choline by enzyme acetyltransferase

Where is Acetylcholine (ACh) produced?

Acetylcholine is synthesized in the presynaptic terminal.

After disassociation with its receptor, what happens to Acetylcholine (ACh)?

Enzyme acetylcholinesterase degrades Ach into acetate and choline

What happens to Choline?

Choline is recycled in the presynaptic terminal.

What are the 2 major classes of ACh receptors?

Nicotinic and Muscarinic

What are Nicotinic receptors?

Nicotinic receptors are ligand-gated ion channels that are permeable to Na+, K+, and Ca2+.

What are the 2 subtypes of Nicotinic receptors? Where are they found?

1. N1 or NM found on skeletal muscle2. N2 or NN found on neurons

What are Muscarinic receptors?

Muscarinic receptors are G-protein coupled receptors.

What are the subtypes of Muscarinic receptors? Where are they found?

1. M2 receptor inhibit ADENYLYL CYCLASE (found in cardiac tissue)2. M3 receptor activates PHOSPHOLIPASE C (found in smooth muscle)

What are Catecholamines?

Organic compound that has catechol and a side amine

catechol

What are the 3 most abundant types of Catecholamine?

Dopamine, Epinephrine, & Norepinephrine.

From what compound are Catecholamine derived? Cite derivation for each.

Catecholamines are derived from amino acid TYROSINE.

Dopamine is derived from TYROSINE; Norepinephrine is derived from Dopamine. Epinephrine is derived from norepinephrine.

To which receptors do Epinephrine (Adrenalin) and Norepiphrine (Noradrenalin) bind to?

Both catecholamine bind to 3 adrenergic receptors: 1, 2, &

State the activity of each adrenergic receptor (having to do with adrenaline).1 activates PHOSPHOLIPASE C activates ADENYLYL CYCLASE2 inhibits ADENYLYL CYCLASE

*****What is the function of enzyme MAO (MONOAMINE OXIDASE)?

It recycles epinephrine/norepinephrine

Name 2 amino acid neurotransmitters?

Glutamate and GABA (gamma aminobutyric acid).

How are Glutamate and GABA synthesized?

Glutamine (amino acid) Glutamate GABA (Starting material is Glutamine)

What enzyme synthesizes GLUTAMINE from Glutamate?

Glutaminase

Name the type of receptors Glutamate and GABA binds to and the downstream effect that they have?

Glutamate receptors are ligand-gated Na+ channels: causes EPSP

GABA receptors are ligand-gated Cl- channels: causes IPSP

Do all neuron cells have enzyme to produce GABA? No

In what type of signaling is gaseous neurotransmitter involved in? Why?

Gaseous neurotransmitters are involved in paracrine signaling since gases permeate through cell membrane and affect neighboring cells.

What is the main signaling chemical for gaseous neurotransmitters?

Nitric Oxide (NO)

How is nitric oxide synthesized? What enzyme is involved?

Nitric oxide is synthesized from amino acid ARGININE by enzyme NITRIC OXIDE SYNTHASE.

Where is the nitric oxide receptor located?

Nitric oxide receptors are intracellular receptors (float in cytoplasm)

What is the function of nitric oxide receptor?

It inhibits GUANYLYL CYCLASE.

What is a cholinergic receptor?

A receptor that releases Acetylcholine (ACh)

What is an adrenergic receptor?

A receptor that releases epinephrine or norepinephrine.

What are the 2 components of the nervous system?

Central Nervous System brain and spinal cord

Peripheral Nervous System Nerves and ganglia outside of CNS

What are the 2 components of the peripheral nervous system?

SOMATIC NERVOUS SYSTEM & AUTONOMIC NERVOUS SYSTEM.

What is the SOMATIC NERVOUS SYSTEM?

Voluntary control of body movement via skeletal muscle.

What is the AUTONOMIC NERVOUS SYSTEM?

Involuntary control of glands, blood vessels, and internal organs.

What is the layout of neurons in SOMATIC NERVOUS SYSTEM?

1 somatic neuron (or motor neurons) that makes monosynaptic connection to skeletal muscle.

What type of neurotransmitter do somatic neurons release? What receptor does it bind to?

Acetylcholine binds to nicotinic receptor NM on skeletal muscle.

What is NEUROMUSCULAR JUNCTION?

Meeting of neuron with muscle.

What causes ALS (Amyotrophic Lateral Sclerosis)? (Lou Gehrigs disease)

Death of somatic motor neuron

What causes Poliomyelitis?

Polio virus by attacking ventral horn of spinal cord; somatic motor neuron die

What is the layout of neurons in autonomic nervous system?

Consist of 2 neurons: 1st neuron comes from CNS (preganglionic neuron) synapses with the 2nd neuron (postganglionic neuron) outside of CNS; 2nd neuron then synapses with the effector organ.

What are the 2 subsystems found in autonomic nervous system?

Sympathetic NS & Parasympathetic NS

What is characteristic of neurons in PARASYMPATHETIC NERVOUS SYSTEM?

Long preganglionic neurons and Short postganglionic neurons

Where are preganglionic neurons innervated in PARASYMPATHETIC?

In the brainstem and sacral level of spinal cord(Cranial nerve 3, 7, 9, 10 & Sacral nerve 1, 2)

What is the only neurotransmitter mediating parasympathetic?

Acetylcholine

Describe how a neurotransmitter is released to effector cells in parasympathetic nervous system.

Preganglionic neuron release ACh that binds to NICOTINIC RECEPTORS NN of postganglionic neuron.

Postganglionic neuron release ACh to MUSCARINIC RECEPTORS (M2 OR M3) of effector organ.

For each of the following effector organ, state which receptor is involved in binding ACh and the response in Parasympathetic Nervous System.

EyeM3; pupillary constriction

HeartM2; decrease heart rate

Vasculature (blood vessels)Minimal

BronchioleM3; contraction of lungs

GI TrackM3; increase motility (contraction); sphincter relaxation, salivary secretion thin, high volume

SweatNo effect

BladderM3; detrusor muscle contraction, internal urethral sphincter relaxation

What is characteristic of neurons SYMPATHETIC NERVOUS SYSTEM?

Short preganglionic neurons and long postganglionic neurons

Where are preganglionic neurons innervated in SYMPATHETIC?

In the thoracic and lumbar level of spinal cord

Describe how a neurotransmitter is released to effector cells in sympathetic nervous system?

Preganglionic neuron release ACh that binds to NICOTINIC RECEPTORS NN of postganglionic neuron.

Postganglionic neuron release NE to adrenergic receptors (1 2 ) of effector organ.

What are 2 unique pathways sympathetic nervous system possesses?

Preganglionic neurons sometime release ACh to ANDRENAL MEDULLA located on top of kidneys; ANDRENAL MEDULLA releases NE or EPI into bloodstream and bind to adrenergic receptors on effector organs

Postganglionic neurons sometime release ACh to MUSCARINIC RECEPTORS and control SWEAT

For each of the following effector organ, state which receptor is involved in binding ACh or NE and the response in Sympathetic NS.

Eye1; pupillary dilation (radial muscle contraction)

Heart1; increase heart rate; NE

Vasculature (blood vessels)1; vasoconstriction (contraction)

Bronchiole2; relaxation of lungs==================================================================================================================GI Track2; decrease motility (relaxation)1; sphincter contraction1; salivary secretion thick, low volume

SweatM3; increase sweat; ACh is released by sympathetic

Bladder2; detrusor muscle relaxation1; internal urethral sphincter contracts

What are the 3 muscles found in the bladder? State the type of muscle for each.

Detrusor Muscle smooth muscleInternal Urethral Sphincter smooth muscleExternal Urethral Sphincter skeletal muscle

What is micturition?

Urination

When urinating, what occurs with all 3 muscles?

Detrusor muscle is contractedInternal Urethra Sphincter is relaxedExternal Urethra Sphincter is relaxed

When not urinating, what occurs with all 3 muscles?

Detrusor muscle is relaxedInternal Urethra Sphincter is constrictedExternal Urethra Sphincter is constricted

What are pudentals?

Somatic nerves in the pelvic

How is detrusor muscle contracted?

Parasympathetic, M3 receptors

How is internal urethra sphincter relaxed?

Parasympathetic, M3 receptors

How is external urethra sphincter relaxed?

Inhibition of pudental nerves by CNS

How is detrusor muscle relaxed?

Sympathetic, 2 receptors

How is internal urethra sphincter contracted?

Sympathetic, 1 receptorsHow is external urethra sphincter contracted?

Pudentals activate NICOTINIC NM or N1 receptors .

Describe the micturition reflex.

When detrusor muscle is stretched, stretch receptors within the walls of bladder fire action potentials to CNS.

If unable to urinate, Sympathetic NS release Norepinephrine to 2 receptors, telling the detrusor muscle to relax, and 1 receptors tell the internal urethral sphincter to contract. CNS stimulate pudendal nerves to close external urethral sphincter.

If able to urinate, parasympathetic NS release Acetylcholine to M3 receptors, telling the detrusor muscle to contract, and internal urethral sphincter to relax. CNS inhibits pudendal nerve.

Where in the spinal cord are sympathetic nerves controlling the bladder innervated? Parasympathetic nerves?

Lumbar level of spinal cordSacral level of spinal cord

If spinal cord is severed above L1, what happens to micturition reflex?What are the consequences?

Micturition is no longer inhibited by CNS

Lower bladder capacity, frequent emptying of bladder, loss of voluntary control.