chp 9 Flashcards
(32 cards)
cooperative effects
-Occurs when both divisions produce different effects that work together to promote a single action.
-Example: Erection and ejaculation: Parasympathetic division causes vasodilation and erection; sympathetic causes ejaculation
Example - Urination: Parasympathetic division aids in urinary bladder contraction; sympathetic helps with bladder muscle tone to control urination. 1) Medications for overactive bladder block specific receptors
complementary effects
-Occurs when both divisions produce similar effects on the same target
Salivary gland secretion: Parasympathetic division stimulates secretion of watery saliva; sympathetic constricts blood vessels so the secretion is thicker.
organs with dual interventions
-VISCERAL ORGANS TARGETED BY BOTH SYMPATHETIC AND PARASYMPATHETIC SYSTMES
-SYSTEMS ACT AS ANTAGONISTS
1.Heart rate – sympathetic increases , parasympathetic decreases
2. Digestive functions – sympathetic decreases, parasympathetic increases 3.Pupil diameter – sympathetic dilates, parasympathetic constricts
nonadrenergic, noncholinergic fibers
-Important for erection of the penis.
-Parasympathetic neurons innervate blood vessels, causing relaxation and vasodilation using nitric oxide.
-Nitric oxide can also produce smooth muscle relaxation in the stomach, intestines, urinary bladder, and the brain.
NOT ALL POSTGANGLIONIC NEURONS RELEASE ACh/norepinephrine
^^ WE CALL THESE NONADRENERGIC / NONCHOLINERGIC
*Examples: ATP, VIP, NO
muscarinic: (cholinergic)
Located in visceral organs
-Blocked by atropine
-Utilizes G-proteins and second messenger systems -Stimulated by releasing ACh from postganglionic neurons -5 types; can be stimulatory or inhibitory
nicotinic (cholinergic)
Nicotinic: found in autonomic ganglia
-Blocked by curare
-Ligand-ion gated channels for Na+ and K+ -Stimulated by ACh from preganglionic neurons
remember this
ACh released from preganglionic neurons in parasympathetic and sympathetic IS
STIMULATORY
**ACh released from postganglionic neurons of parasympathetic system can be
INHIBITORY OR STIMULATORY
**FROM THE RECEPTOR SUBTYPES, FOCUS ON ALPHA-2 AND BE
ALPHA-2 RECEPTORS:
-Location: presynaptic axons
-Stimulating alpha-2 = inhibiting of norepinephrine release in synapse (-ve feedback system)
-Different subtypes = different responses
-Alpha-2 receptors altered by drugs to stop presynaptic neurons in brain
● BETA-3 RECEPTORS:
-Location: Adipose tissue
-Promotion of heat production and lipolysis
● Beta receptors»_space; cAMP
● Beta receptors are sensitive to blood epinephrine
● Alpha receptors»_space; Ca2+ second messenger system
● Alpha receptors are sensitive to norepinephrine
**Agonists and antagonists can mimic adrenergic responses RECALL THAT:
-Agonists = promotion of process(s) stimulated by neurotransmitters -Antagonists = block action of neurotransmitters
*Adrenergic Receptors (KEY P
You have alpha and beta receptors
● Alpha has alpha-1 and alpha-2 subtypes
● Beta has beta-1, beta-2 and beta-3 subtypes
● ALL USE G-PROTEINS AND SECOND MESSENGER SYSTEMS (Think back to
chapter 6 and 7)
Beta receptors»_space; cAMP
● Beta receptors are sensitive to blood epinephrine
● Alpha receptors»_space; Ca2+ second messenger system
-Alpha receptors are sensitive to norepinephrine
-THERE ARE DIFFERENT WAYS TO RESPOND TO ADRENERGIC STIMULATION:
**IN BLOOD = EPINEPHRINE
** IN SYMPATHETIC NERVES = NOREPINEPHRINE
-Either can have stimulatory or inhibitory effects; IF ITS STIMULATION:
● Smooth muscle of blood vessels, dilatory muscles of iris, heart -IF ITS INHIBITION:
● Bronchioles in lungs and blood vessels, inhibits contraction and causes dilation
know the concept behind varcosities
-Varicosities are swellings w/n postganglionic neurons’ axons
-Varicosities are responsible for releasing neurotransmitters ALONG AXON LENGTH
-They produce synapses in passing
-BOTH SYMPATHETIC AND PARASYMPATHETIC target a major chunk of the same tissues BUT RELEASE DIFF NEUROTRANSMITTERS, with ANTAGONISTIC effects
ADRENERGIC SYNAPTIC TRANSMISSION
-For sympathetic postganglionic neurons, NOREPINEPHRINE IS THE RELEASED NEUROTRANSMITTER
-^^ THESE ARE ADRENERGIC SYNAPSES
-Adrenergic neurotransmitters are CATECHOLAMINES (HINT BACK TO CHAPTER 7
CHOLINERGIC SYNAPTIC TRANSMISSION
-In BOTH parasympathetic and sympathetic systems, ACh is used by ALL preganglionic neurons
-Parasympathetic postganglionic neurons also release ACh
-YOU do have sympathetic postganglionic neurons that release ACh, those neurons target
skeletal muscle blood vessels + sweat glands»_space; CHOLINERGIC SYNAPSES
PARASYMPATHETIC FUNCTIONS:
-Basically the OPPOSITE of sympathetic functions;
-BODY IS IN “rest and digest” and no fight or flight response
-^^ Release of ACh from postganglionic neurons to DO THIS ^^^ -DECREASES heart rate, increase digestive activities
FUNCTIONS OF THE AUTONOMIC NERVOUS SYSTEM
**BREAK IT DOWN WITH SYMPATHETIC FUNCTIONS FIRST:
-Actively regulates the heart and blood vessels
-Preps body for physical activity, increase heart rate + blood glucose levels, by moving blood to skeletal muscles
-FIGHT OR FLIGHT response»_space; RELEASE norepinephrine from postganglionic neurons + secrete epinephrine from adrenal medulla
SACRAL NERVES IN PARASYMPATHETIC SYSTEM
Preganglionic nerves from the S2 to S4 sacral region of the spinal cord target the lower part of the large intestine, rectum, urinary and reproductive organs
● YOU FIND TERMINAL GANGLIA IN THESE ORGANS
vagus nerve
Preganglionic fibers exit medulla, branch into several plexi and nerves and travel to ganglia within effector organs
● Effector organs are heart, lungs, esophagus, stomach, pancreas, liver, intestines
glossopharyngeal
Preganglionic fibers exit the medulla and synapse on the otic ganglion
● Postganglionic fibers innervate the parotid salivary gland
facial nerve
Preganglionic neurons that originate in facial nerve travels to pterygopalatine ganglion -Pterygopalatine ganglion sends postganglionic neurons to the following:
● Nasal mucosa ● Pharynx
● Palate
● Lacrimal glands
- In submandibular ganglion, postganglionic neurons synapse on salivary glands
KNOW ABOUT 4 OF THE CRANIAL NERVES W/ PARASYMPATHETIC DIVISION
Oculomotor(III)Nerve(KEYPOINTSTOKNOW): -Preganglionic fibers exit midbrain and synapse on ciliary region -Postganglionic fibers innervate the ciliary muscle of eye
PARASYMPATHETIC (Craniosacral) DIVISION
Preganglionic neurons come from brain or sacral region of spinal cord
● Preganglionic neurons synapse in ganglia that are NEXT TO/NEAR the target organ
● Terminal ganglia = provide the postganglionic neurons that synapse with effector cells
ADRENAL GLANDS IN SYMPATHETIC SYSTEM
Adrenal cortex»_space; Secretes steroid hormones; DIFF embryonic origin than adrenal medulla
● Adrenal medulla»_space; Secretes epinephrine and norepinephrine in response to MASS ACTIVATION
● ^^ ADRENAL MEDULLA directly targeted by preganglionic neurons; originally was a modified ganglion
Collateral Ganglia (
-NOT ALL PREGANGLIONIC NEURONS THAT LEAVE THE SPINAL CORD GO INTO THE SPINAL TRUNK TO SYNAPSE
● These preganglionic neurons that DO NOT synapse form splanchnic nerves
● Preganglionic neurons in splanchnic nerves synapse in collateral/paravertebral ganglia
● REGIONS IN COLLATERAL GANGLIA WHERE THE SYNAPSE OCCURS:
- Celiac, superior mesentric, inferior mesentric ganglia
● Postganglionic neurons that come from collateral ganglia target digestive, urinary and reproductive system organs