Physiology Week 2 Flashcards
Somatic motor neurons are _____ and _____. They always release _____.
- Long and Myelinated
2. ACh
In the Autonomic NS, Preganglionic neurons are _____, and always release ____, while Postganglionic neurons are _____ and can release ______.
- Myelinated
- ACh
- Un-myelinated
- ACh OR NE
Somatic motor neurons synapse ______, and therefore do not have _____.
- On their target effectors
2. Ganglia
The Enteric NS is the 3rd division of the ________.
ANS
The major neurotransmitter in the SYMPATHETIC NS is _______.
NorEpinephrine
If your skin is very warm, is there more sympathetic or parasympathetic activity occurring in your body?
Parasympathetic: Because blood vessels are relaxed and filled with more blood as BP is reduced.
List the 6 organs/glands/muscles/tissues that are ONLY innervated by the Sympathetic NS and NOT the Parasympathetic NS:
- Vascular Smooth Muscle
- Sweat glands
- Pilo-erector Muscles
- Liver
- Adipose Tissue
- Kidney
List the 2 organs/glands/muscles/tissues that are ONLY innervated by the Parasympathetic NS and NOT the Sympathetic NS:
- Gastric/Pancreatic Secretions
- Lacrimal Glands
Sympathetic trunk Ganglia are also called ________.
ParaVertebral Ganglia
Pre-Ganglionic released ACh binds to ______ receptors, and post-ganglionic released ACh binds to ________, while Epinephrine/NE bind to ________ receptors.
- Nicotinic
- Muscarinic
- Adrenergic (alpha and beta)
The Adrenal Medulla is considered to be a __________.
Modified Post-Ganglionic Neuron
Which cells on the Adrenal Medulla do the pre-ganglionic neurons synapse with?
Chromaffin Cells which release Catecholamines
The majority of vascular smooth muscle uses ________ as its neurotransmitter.
NE
Metabolic rate will _________ with generalized sympathetic activity.
INCREASE
Somatic motor neurons release ________ that binds to ______ receptors.
- ACh
2. Nicotinic
Sympathetic post-ganglionic neurons release NE which binds to ________ receptors, but also release ACh which binds to _______.
- Alpha/Beta/1/2 Receptors
2. Muscarinic
Parasympathetic post-ganglionic neurons release ACh that ALWAYS binds to _______ receptors.
Muscarinic
All NICOTINIC cholinergic receptors are _________, meaning when they are bound, they allow ________. When ACh binds these, the response is ALWAYS ________.
- Ligand-Gated Cation-selective channels
- The movement of Sodium and Potassium
- Stimulatory
All MUSCARINIC cholinergic receptors are _________, meaning when they are bound, they allow __________.
- GPCR’s
2. Activation of second messenger systems
List the 3 places that Nicotinic receptors are found:
- Motor End Plates of Skeletal Muscle (Somatic System)
- ALL autonomic Post-Ganglionic Neurons (Ganglia)
- Chromaffin Cells of Adrenal Medulla
When ACh binds Muscarinic receptors, the effect is described as ___________.
EITHER stimulatory or inhibitory
List the 2 places that Muscarinic receptors are found:
- ALL effector organs of the Parasymp. NS
- Certain effector organs of the Symp. NS
i. e. Sweat Glands, vascular smooth muscle OF skeletal muscle.
Where are Adrenergic receptors found?
In the target tissues of the SNS
Alpha-1 Adrenergic Receptors:
- Where are they found? (6)
- What physiological effect do they elicit?
- What mechanism do they use to elicit it?
- Found in:
- Vascular S.M.
- Skin
- GI Tract
- Bladder
- Sphincters
- Radial Muscle/Iris - S.M. Contraction/Constriction
- Increase of IP3 to Increase Ca2+
Alpha-2 Adrenergic Receptors:
- Where are they found? (2)
- What physiological effect do they elicit?
- What mechanism do they use to elicit it?
- Found in:
-GI Tract WALL
-ON Post-ganglionic motor neurons - Relaxation and DECREASE NE release
- Inhibition of Adenylyl Cyclase to DECREASE cAMP
(serve as negative feedback)
Beta-1 Adrenergic Receptors:
- Where are they found? (4)
- What physiological effect do they elicit?
- What mechanism do they use to elicit it?
- Found in:
-Heart (mainly)
-Salivary Glands
-Adipose Tissue
-Kidney - Increase Heart Contractility/Rate/Contraction and lipolysis, and Renin secretion from kindey
- Stimulation of AC to INCREASE cAMP
(opposite of Alpha-2 receptors)
Beta-2 Adrenergic Receptors:
- Where are they found? (5)
- What physiological effect do they elicit?
- What mechanism do they use to elicit it?
- Found in:
-Vascular S.M. OF Skeletal Muscle
-GI Tract WALL
-Bladder
-Bronchioles
-Uterus - Relaxation of Smooth Muscle/Dilation
- Stimulation of AC to INCREASE cAMP
(Same as Beta-1 receptors)
Nicotinic Cholinergic Receptors:
- Where are they found? (3)
- What physiological effect do they elicit?
- What mechanism do they use to elicit it?
- Found in:
- Motor End Plate of Skeletal Muscle (Somatic)
- Ganglia (Post-ganglionic neurons of ANS)
- Adrenal Medulla - Various Effects
- Ionic: Depolarization via opening of Na+ and K+ channels
Muscarinic Cholinergic Receptors:
- Where are they found? (3)
- What physiological effect do they elicit?
- What mechanism do they use to elicit it?
- Found in:
- ALL effector organs of PNS
- Sweat Glands
- Vascular S.M. of Skeletal Muscle - Various Effects
- Increase IP3 to Increase Ca2+
What is the difference between N1/Nm receptors and N2/Nn receptors?
N1 receptors are Nicotonic Cholinergic receptors of the SOMATIC NS, while N2 receptors are Nicotinic Cholinergic receptors of the Autonomic NS.
Describe how ACh can negatively feedback on itself:
If it binds to Muscarinic receptors, only the M1, M3, and M5 receptors are stimulatory and activate PLC with a G-subQ. The M2 and M4 receptors are inhibitory and will use a G-sub-i to inhibit AC and decrease cAMP.
How is ACh recycled after eliciting its effect?
Cholinesterases hydrolyze it into acetate and choline. That Choline can then be taken back up by the Na+-coupled Choline symporter in pre-ganglionic neurons to be acetylated and packaged into secretory vesicles as de novo ACh.
What is required for ACh to elicit its effect on its nicotinic receptor?
2 molecules of ACh must bind to 2 alpha-subunits of the 5-subunit cholinergic receptor to allow the movement of Na+ and K+.
What type of GPCR G-subunit do each of the 5 muscarinic receptor types bind?
Gq: M1 and M5 —> Increases IP3–> PLC
Gi: M2 and M4 –> Decreases AC –> cAMP (in heart)
Gs: M3 –> Increases AC –> cAMP
The most discussed muscarinic receptors are the M2, which is found in ________, and the M3 which is found in ________.
- The HEART (SA and AV nodes)
2. Smooth muscle, Glands, etc.