How can 1 system using the same neurotransmitter have opposite effects at different parts of the body
- Receptors
What are the two main receptors in the SNS
- Alpha
Beta
Explain alpha (a) receptors
- On Smooth muscle cells of organs and blood vessels around organs
- NE binds to a receptors: this causes constriction
- Less blood flow occurs
Explain Beta(B) receptors
- On Heart and blood vessels around lungs and muscle
- NE binds to B receptors: relax
- More blood flow occurs
In addition to the a and B receptors what does the pre ganglionic neurons release and onto what
Release ACh onto the adrenal glands(located just above the kidneys)
What does the adrenal medulla release and where (also what do these neurotransmitters do)
a) Releases epinephrine and NE into the blood stream
b) These neurotransmitters go to heart lungs and muscles to boost the effects of the sympathetic nervous system
- Same effects just slower
Can the PNS use ach to mediate different effects
- Yes it can
Two main receptors in the PNS
-Muscarinic (mAChR)
-Nicotinic (nAChR)
Muscarinic receptors (mAChR)
M1-M5
- Metabotropic G protein coupled receptors (GPCRs)
- Alter Ca, K and intracellular signalling (eg cAMP)
Nicotinic receptors (nAChR
- Ionotropic ligand-gated ion channels
- Increase na, K and Ca permeability into the cell depending on type of nAChR
- A lot of old insecticide are nAChR inhibitors
- This causes muscles to go into paralysis
What are cranial nerves
- Go from the brain almost to the effector organ (most PNS nerves don’t pass through the spinal cord but exceptions are sacral nerves that innervate bladder, sex organs and rectum)
What do some cranial nerves also carry Even though its part of the parasympathetic nervous system
- Voluntary motor fibers (moving your eyes)
- Sensory fibers (taste to and from the brain)
- Some cranial nerves carry both
How many cranial nerves are there and what about them do we need to know
- 12
- We need to know name, function, and is it sensory motor or both
Cranial nerve 1
- Olfactory
- Scents from nose to brain
- sensory
Cranial nerve 2
- Optic
- Vision from eye to brain
- Sensory
Cranial nerve 3
- Oculomotor
- 4/6 muscles that move the eyes
- Motor
Cranial nerve 4
- Trochlear
- Moves eyes down (a single muscle it controls)
- Motor
Cranial nerve 5
- Trigeminal
- Face and jaw (Sense anything on your face and jaw/ Also sends info from brain to jaw to make movements)
- Both motor and sensory
Cranial nerve 6
- Abducens
- Moves eyes side to side
- Motor
Cranial nerve 7
- Facial
- Muscles for facial expression (Senses and sends information to your brain/ Relays info from brain to face to coordinate facial expressions
- both motor and sensory
Cranial nerve 8
- Auditory
- Info from cochlea to brain
Sensory
- Info from cochlea to brain
Cranial nerve 9
- Glossopharyngeal
- Tongue and pharynx
Both sensory and motor
- Tongue and pharynx
Cranial nerve 10
- Vagus
- Sends info to heart entire digestive tract, lungs, pancreas, spleen, bladder/ Also sends info from all of these organs for a homeopathic response
- Both motor and sensory
Cranial nerve 11
- Spinoaccessory
- Head and shoulder movement
- Motor
