Short reflex goes only through the PNS and does not travel through the CNS.
Long reflex passes through the CNS (brain and/or spinal cord).
What does the limbic system do with regards to homeostatic response?
Integrates homeostatic response with memory.
Example: Locking up the brakes on the car in near crash produces future response as well.
What are Chromaffin Cells?
Sympathetic nerves release ACh on these cells and they release Catecholamines into the blood stream.
What does the adrenal medulla make?
Catecholamines (only site for Epinephrine), PNMT, Cortisol
which are the paravertebral ganglia?
which are the prevertebral ganglia?
which are the terminal ganglia?
Para = Sympathetic chain ganglia
Pre = Collateral chain ganglia (Celiac, Superior/Inferior Mesenteric)
Terminal = Eye and Facial Glands
ANS innervation controls the activity of what organs?
Cardiac Muscle
Smooth Muscle
Glands
Adipose Tissue
True / False the Smooth muscle of blood vessels found everywhere (except brain, heart, and genitals) has both parasympathetic and sympathetic innervation?
False. It has only sympathetic innervation
The brain, heart, genitals have both.
Which division innervates Glands?
Sympathetic Only
Which division innervates Adipose?
Sympathetic Only (Beta-3 Adrenergic)
In a neuroeffector Junction a varicosity is analogous to what in a neuromuscular junction?
Terminal Knob
Where does MAO degrade Catecholamines?
Level of Mitochondria
Where are the preganglionic neurons located in the Sympathetic Nervous System?
Thoracolumbar region
Where do Preganglionic Sympathetic Neurons synapse? (specific regions)
Sympathetic Chain ganglia
Collateral Ganglia
Adrenal Medullae (chromaffin cells)
Alpha 1 Receptor
Higher affinity for NE over E
Causes smooth muscle contraction
Antagonists (A blockers) lower B.P. (Prazosin)
Causes sweat gland secretion
What does Prazosin do?
Antagonizes Alpha 1 receptors
Alpha Blocker
Leads to less smooth muscle contraction (passive dilation)
Decrease in Blood pressure
Alpha 2 Receptor
Higher affinity for NE over E
Inhibits GI tract
Beta 1 Receptor Properties
Equal Affinity NE and E
Increases contractility of Heart and Heart Rate
Antagonists (Beta Blockers) lower B.P.
Located on the atrial and ventricular myocardiocytes.
What does sympathetic nervous system do to your lungs?
dilates them
What does sympathetic nervous system do to your GI tract?
Inhibits
What does sympathetic nervous system do to your adrenal medullae?
Stimulates (produce epi)
What does sympathetic nervous system do to your erector pilli muscles?
contracts
What does sympathetic nervous system do to your blood vessels in skin?
constrict
Where does most sympathetic innervation occur on heart?
from the bottom of atria down.
Where does most parasympathetic innervation occur on the heart?
above Atria
Chronotropy?
Dromotropy?
Inotropy?
Lusitropy?
Chronotropy = Heart Rate
Dromotropy = Conduction Rate
Inotropy = Contractility
Lusitropy = Speed at which heart relaxes
How much smooth muscle do arterioles have?
Capillaries?
Arterioles are loaded with smooth muscle
Capillaries have NO smooth muscle
2 agonists of Alpha 1 Receptors
Phenylephrine
Pseudoephedrine
Name 3 drugs that Lower B.P by inhibiting influx of Calcium into smooth muscle cell and preventing smooth muscle contraction (Calcium Channel Blockers)
Nifedipine
Verapamil
Diltiazem
What is the effect of epinephrine on a B-2 receptor of a smooth muscle cell?
B-2 activates Gs
Gs Increases cAMP conc.
cAMP inhibits MLCK
leads to a relaxation of SM
"Beta 2 Mediated Dilation"
Parasympathetic effector cells have what type of receptors?
muscarinic
What does parasympathetic nervous system do to your pupils?
constricts
What does parasympathetic nervous system do to your heart?
slows it down
What does parasympathetic nervous system do to your lungs?
constricts them
What does parasympathetic nervous system do to your GI tract?
activates it
Excitatory or Inhibitory
Muscarinic 1?
Muscarinic 2?
M1 = Excitatory
M2 = Inhibitory
What does Atropine do?
Inhibits M2 receptors. Leading to increase in H.R.
What does ACh do to M3 receptor in Endothelial cell?
ACh binds to M3 receptor
activates Ca/Calmodulin complex
activates NO synthase
convert arginine into NO using Oxygen
What does Nitric Oxide (NO) do?
NO acts as a 2nd messenger and activates Guanylate Cyclase increasing cGMP conc.
cGMP causes Smooth muscle relaxation
What does Viagra do?
Inhibits cGMP phosphodiesterase. This reduces the breakdown of cGMP to GMP and leads to smooth muscle relaxation.
Where are the 2 main baroreceptors?
Carotid Sinus Baroreceptor (most important)
Aortic Baroreceptor
What do Baroreceptors do?
Send afferent info to brain stem
lead to lower
Where are the 3 main chemoreceptors located and what are they most sensitive to?
Carotid Bodies (P CO2)
Aortic Bodies (P CO2)
Medullary Chemoreceptors (H+ CO2 derived though)
4 layers of small intestine from Deepest to most superficial.
Mucosa (epith, lamina, muscle)
Submucosa (glands, blood vessels, nerves)
Musclaris (sm, nerves)
Serosa (CT, peritoneum)
3 Phases of digestion?
Cephalic - sight / taste of food triggers secretion of gastric enzymes.
Gastric - Food has entered and distended stomach gastric secretions continue.
Intestinal - chyme has entered the duodenum so gastric secretion is inhibited.