chp 9

Question 1

cooperative effects

Answer 1

-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

Question 2

complementary effects

Answer 2

-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.

Question 3

organs with dual interventions

Answer 3

-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

Question 4

nonadrenergic, noncholinergic fibers

Answer 4

-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.

Question 5

NOT ALL POSTGANGLIONIC NEURONS RELEASE ACh/norepinephrine
^^ WE CALL THESE NONADRENERGIC / NONCHOLINERGIC

Answer 5

*Examples: ATP, VIP, NO

Question 6

muscarinic: (cholinergic)

Answer 6

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

Question 7

nicotinic (cholinergic)

Answer 7

Nicotinic: found in autonomic ganglia
-Blocked by curare
-Ligand-ion gated channels for Na+ and K+ -Stimulated by ACh from preganglionic neurons

Question 8

remember this

Answer 8

ACh released from preganglionic neurons in parasympathetic and sympathetic IS
STIMULATORY
**ACh released from postganglionic neurons of parasympathetic system can be
INHIBITORY OR STIMULATORY

Question 9

**FROM THE RECEPTOR SUBTYPES, FOCUS ON ALPHA-2 AND BE

Answer 9

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&raquo_space; cAMP
● Beta receptors are sensitive to blood epinephrine
● Alpha receptors&raquo_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

Question 10

*Adrenergic Receptors (KEY P

Answer 10

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&raquo_space; cAMP
● Beta receptors are sensitive to blood epinephrine
● Alpha receptors&raquo_space; Ca2+ second messenger system
-Alpha receptors are sensitive to norepinephrine

Question 11

-THERE ARE DIFFERENT WAYS TO RESPOND TO ADRENERGIC STIMULATION:

Answer 11

**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

Question 12

know the concept behind varcosities

Answer 12

-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

Question 13

ADRENERGIC SYNAPTIC TRANSMISSION

Answer 13

-For sympathetic postganglionic neurons, NOREPINEPHRINE IS THE RELEASED NEUROTRANSMITTER
-^^ THESE ARE ADRENERGIC SYNAPSES
-Adrenergic neurotransmitters are CATECHOLAMINES (HINT BACK TO CHAPTER 7

Question 14

CHOLINERGIC SYNAPTIC TRANSMISSION

Answer 14

-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&raquo_space; CHOLINERGIC SYNAPSES

Question 15

PARASYMPATHETIC FUNCTIONS:

Answer 15

-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

Question 16

FUNCTIONS OF THE AUTONOMIC NERVOUS SYSTEM

Answer 16

**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&raquo_space; RELEASE norepinephrine from postganglionic neurons + secrete epinephrine from adrenal medulla

Question 17

SACRAL NERVES IN PARASYMPATHETIC SYSTEM

Answer 17

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

Question 18

vagus nerve

Answer 18

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

Question 19

glossopharyngeal

Answer 19

Preganglionic fibers exit the medulla and synapse on the otic ganglion
● Postganglionic fibers innervate the parotid salivary gland

Question 20

facial nerve

Answer 20

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

Question 21

KNOW ABOUT 4 OF THE CRANIAL NERVES W/ PARASYMPATHETIC DIVISION

Answer 21

Oculomotor(III)Nerve(KEYPOINTSTOKNOW): -Preganglionic fibers exit midbrain and synapse on ciliary region -Postganglionic fibers innervate the ciliary muscle of eye

Question 22

PARASYMPATHETIC (Craniosacral) DIVISION

Answer 22

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

Question 23

ADRENAL GLANDS IN SYMPATHETIC SYSTEM

Answer 23

Adrenal cortex&raquo_space; Secretes steroid hormones; DIFF embryonic origin than adrenal medulla
● Adrenal medulla&raquo_space; Secretes epinephrine and norepinephrine in response to MASS ACTIVATION
● ^^ ADRENAL MEDULLA directly targeted by preganglionic neurons; originally was a modified ganglion

Question 24

Collateral Ganglia (

Answer 24

-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

Question 25

REMEMBER ^^, because the preganglionic neurons can travel up/down the ramus at
any level, you get two things, which are kind of flipped in concept

Answer 25

Convergence: SEVERAL preganglionic neurons at DIFFERENT levels synapse ONLY ON ONE postganglionic neuron
● Divergence: ONE preganglionic neuron synapses on SEVERAL postganglionic neurons at different levels
● BOTH are important to increase our “fight or flight” responses, make the sympathetic division constantly active»»» between the TWO ITS THE DIVERGENCE THAT REALLY LETS THIS HAPPEN

Question 26

w/n each ramus, the preganglionic neurons can go up or down the trunk, to then
synapse with a postganglionic neuron

Answer 26

Since postganglionic neurons are unmyelinated, they rejoin spinal nerves through gray rami communicantes
● BASICALLY, the postganglionic neurons go back to spinal nerves and they travel as part of the spinal nerves, just to get to their effector organs
● Sympathetic axons are distributed to skeletal muscle + skin&raquo_space; target blood vessels + involuntary organs

Question 27

Sympathetic Division (Thoracolumbar region)

Answer 27

ORIGIN: Lumbar and thoracic regions w/n the spinal cord
● The preganglionic neurons separate from somatic motor fibers + SYNAPSE with
postganglionic neurons
● Ganglia in the rows are connected, forming CHAIN of ganglia
● Nerves on chain are connected, each on PARALLEL side of spinal cord = forms the
sympathetic trunk
● PREGANGLIONIC NEURONS ARE MYELINATED
● POSTGANGLIONIC NEURONS ARE UNMEYLINATED
● STEPS:
-The myelinated preganglionic neurons leave the spinal cord in ventral roots of spinal nerves
-Myelinated preganglionic cells diverge from spinal nerves to white rami communicantes

Question 28

touching back

Answer 28

Somatic neurons ONLY release ACh, which ALWAYS has an excitatory effect
● Autonomic neurons can release BOTH ACh and norepinephrine; THE EFFECTS CAN
EITHER BE EXCITATORY OR INHIBITORY

Question 29

Visceral Effector Organs

Answer 29

Involuntary effectors are independent of innervation
● Opposite to skeletal muscles, which go into paralysis + atrophy when motor nerves are
cut
● NO NERVE STIMULATION = SMOOTH MUSCLE HAS RESTING TONE (TENSION)
● **Denervation hypersensitivity = Increased sensitivity of autonomic motor neurons to
stimulating agents, due to damage
WILL ONLY INCLUDE MATERIAL THAT YOU WILL
SEE ON THE EXAM. I’ve divided each section by header name (Eg; Extracellular matrix,
followed by material you will need to know from this section)
ALOT OF CHAPTER 9 TAKES FROM CHAPTER 7
9.1: Neural Control Of Involuntary Effectors (What you will need to know):
-Autonomic Neurons (KEY POINTS):

EXTENDS TO THE EFFECTOR ORGAN
postganglionic neuron
IN THE TEXTBOOK, FOCUS ON TABLE 9.1 (COMPARISON OF AUTONOMIC MOTOR AND
SOMATIC MOTOR SYSTEM) , I HIGHLY EMPHASIZE THIS

● Having autonomic innervation can INCREASE OR DECREASE rate of intrinsic contractions
● Autonomic motor neurons can have an inhibitory or stimulatory effect
● Important to be aware that cardiac + skeletal muscle cells can contract without nerve
stimulation. Having autonomic innervation would just increase or decrease this
contraction frequency, IT DOES NOT CAUSE IT HOWEVER
● AUTONOMIC NERVES MAINTAIN RESTING TONE; they have a “baseline” rate of firing
that could go up or down

Question 31

++++++

Answer 31

**Know where the preganglionic and postganglionic neurons originate;
-Preganglionic: Originate in midbrain + hindbrain and in upper thoracic to 4th sacral levels of spinal cord
-Autonomic ganglia: head, neck, abdomen
-Postganglionic: Ganglia
**The fact that both types of neurons are in different locations helps to differentiate between sympathetic and parasympathetic divisions of autonomic system

Question 32

Neural Control Of Involuntary Effectors (What you will need to know):
-Autonomic Neurons (KEY POINTS):

Answer 32

● REMEMBER THAT NEURONS IN PNS CONDUCT IMPULSES AWAY FROM CNS
● THESE ^^ ARE MOTOR NEURONS; YOU HAVE SOMATIC AND AUTONOMIC
● Autonomic motor control involves two neurons in efferent pathway,
● Centers in brain + spinal cord constitute autonomic neurons
● PATHWAY SUMMARY:
-The 1st neuron DOES NOT directly target effector organ
-The 1st neuron synapses with 2nd neuron w/n autonomic ganglion
**Remember from chapter #7 that ganglion = collection of cell bodies outside CNS -The 1st neuron is known as preganglionic neuron
-The 2ns neuron is known as&raquo_space; THIS HAS THE AXON THAT
** FROM THE TOP HERE ^^, KNOW HOW TO COMPARE AND CONTRAST THE PREGANGLIONIC TO POSTGANGLIONIC NEURONS, your key takeaways should be this:
-Preganglionic: Synapses in autonomic ganglion + has cell bodies in brain and spinal cord
-Postganglionic: Has cell bodies in the ganglion + synapses on effector cell