Chapter 6: Nervous System & Synaptic Transmission Flashcards
Test 2
What are the different nervous systems?
Peripheral
Central
Somatic
Autonomic
Sympathetic
Parasympathetic
Enteric
What does Afferent mean?
Towards the CNS
Up
Sensory/Pain
What does Efferent mean?
Away from the CNS
Down
Motor
What does CNS consist of?
Brain
Spinal cord
Cranial nerve 2
What does the PNS consist of?
neurons that extend outward from the brain and spinal cord
What are somatic sensory receptors?
Touch, pressure, pain, temperature sensors
What are visceral sensory receptors?
monitors internal organs: cvs, respiratory, digestive, etc
What are special sensory receptors?
provide sensations of smell, taste, vision, balance, hearing
What is the CNS responsible for?
Higher order of processing/functioning
Describe the somatic nervous system
Consciously controls skeletal muscle
Describe the autonomic nervous system
Includes Parasympathetic, sympathetic, and enteric nervous systems
Unconsciously controls cardiac muscle, smooth muscle, and glands
Describe the Enteric Nervous System
“Gut feeling”
Mulitple layers of neurons controlling GI functions
Mainly under parasympathetic control
Has some sympathetic functioning
Describe the Parasympathetic nervous system
Mediates “rest and digest” responses
shunts blood to: endocrine, GI, urogenital
decrease HR and increasing digestion
Brings you back down to normal (conserves energy)
Describe the Sympathetic nervous system
Mediates “fight-or-flight” responses
Increasing HR/BP/RR(dilates bronchioles)
Shunts blood from GI tract to Skeletal/Smooth muscle
Which nervous system has sensory input?
Somatic nervous system
What is another name for the cell body of a motor neuron?
Nuclei
Where is the nuclei of the somatic neuron located?
Ventral horn of grey matter in the spinal cord
Reflex arc only goes to the ______ and activates________
spinal cord
Efferent divisons
What are the collection of cell bodies of neurons called in the autonomic nervous system?
ganglia
Where are ganglia located?
outside of the spinal cord
What is an individual neuron cell body in the Autonomic NS called?
Ganglionic neuron
Define a nervous system
Several layers of neurons interacting
NS =
Nervous system
What NS is primative in nature?
Enteric NS
Up to _____ of blood can be shunted during a sympathetic response
75%
T/F: Sympathetic NS is continuously stimulated when scared
T
What is an ergotropic response?
Movement related to the “fight or flight” response
What happens during the fight or flight response
A combo of:
Epinephrine being released from adrenal glands
Norepinephrine being released from CNS
How many times is the Parasympathetic Response activated?
1x
then it brings us back to normal
What is trophotropic response?
Rest that is leading to growth
What 2 nervous systems balance each other?
Sympathetic and Parasympathetic
Discuss the differences in “fight-or-flight” and “rest-and-digest” mode.
“fight-or-flight”:
Sympathetic NS
Shunts blood to heart and skeletal muscles
Increases HR/BP/RR
Ergotropic response
RUN AWAY
“rest-and-digest”
Parasympathetic NS
Shunts blood to endocrine, GI, urogenita
Increase GI, decrease HR
Trophotropic response
Leads to growth
What is cranial nerve X
10
Vagus nerve (heart)
Where is the Sympathetic NS located?
Thoracolumbar
T1 - L2
Describe the Pre/Post ganglionic fibers in the sympathetic NS
Pre: Short; terminate in the ganglia paravertebral chains; close to spinal cord
Post: Long; terminates on affected tissue/organ
Describe the Pre/Post ganglionic fibers in the parasympathetic NS
Pre: Long; leaves CNS through cranial nerves and sacral spinal roots
Post: Short; terminate on organ
Where is the parasympathetic NS located?
Craniosacral
Cranial Nerves III, VII, IX, X
S3 - S4
What is a chain ganglia?
“paravertebral ganglia”
series of interconnected ganglia on either side of the spinal cord
What does a chain ganglia do?
allows signals to travel to reach targets at different levels (organs/tissues), which is essential during stress or emergency situations—such as rapidly increasing heart rate and dilating the pupils.
What NS is a chain ganglia in?
Sympathetic
Where does the ganglia in the parasympathetic NS?
In the visceral effector organs
What type of neuron does the Autonomic NS use?
A 2-neuron chain
1st neuron (preganglionic) is lightly myelinated
2nd neuron (post) extends to effector organ
What does the preganglionic fibers release in the autonomic NS?
Ach
What does the postganglionic fibers release in the autonomic NS?
Ach or Norepinephrine
depending on whether we are inhibiting or stimulating effect
Define Sympathomimetic
Drug that memics the affects of Norepinephrine in the Sympathetic NS
How do direct acting Sympathomimetic work?
Ex)
Directly bind to the receptor
Ex) epi, isoproterenol, albuterol
How do indirect Sympathomimetic work?
Ex)
Dont bind to receptor
Influx of norepinephine for a longer period of time in the synapse
Ex) Ephedrine, amphetamines
What does inotropic affect?
Contractility
What does chronotropic affect?
Heart rate
What does Sympathomimetic do?
Vasoconstriction
Increace Inotropic/chronotropic effects
decrease bronciole tone
decrease uterine muscle tone
What is a Sympatholytics?
Inhibits the sympathetic NS effects
PNS =
parasympathetic nervous system
SNS =
sympathetic nervous system
CNS =
Central nervous system
What are the Cholinergic receptor?
Muscarinic
Nicotinic
What are the Adrenergic receptors?
Alpha
Beta
Dopamine
How many cholinoreceptors subtypes do we have?
5 muscarinic
2 nicotinic
Which muscarinic subtypes are inhibitory?
2, 4
Which muscarinic subtypes are excitatory?
1,3,5
Where are the nicotinic subtypes located?
peripheries
N(n): neuronal at the ganglion
N(m): muscle at skeletal muscle end plates
How many Adrenoreceptor subtypes are there?
2 Alpha
3 Beta
How many Dopamine subtypes are there? Where are they mostly located?
5
Brain, smooth muscle of the renal vascular bed, cvs