This summary includes all the information that you need for the course Physiology. The summary is 150 pages long, because it contains a lot of information, but also a lot of describing pictures which means that you can go fast through it. In the summary is also described what is important to know f...
➢ The nervous system
• Central Nervous System (CNS)
- Brain (in the skull)
- Spinal Cord (in the spine)
• Peripheral Nervous System (PNS)
- Located outside of the skull and spine
- Serves to bring information into the CNS and carry signals out of the CNS
◼ Peripheral Nervous System
• Somatic nervous system
- Afferent nerves (sensory)
- Efferent nerves (motor)
• Autonomic nervous system
- Sympathetic and parasympathetic nerves
- Both afferent and efferent nerves
➢ Autonomic nervous system
- The heart frequency is dependent on both parasympathetic and sympathetic
nervous system.
- Common: They are existing of 2 different parts → 2 neurons → Preganglionic
neuron and postganglionic neuron
- Acetylcholine is the neurotransmitter of the preganglionic neuron and activates
cholinergic receptors.
- Difference: Para uses the same neurotransmitter called acetylcholine but the
sympathetic nervous system uses a neurotransmitter called noradrenalin.
➢ Parasympathetic nervous system
• Long preganglionic nerves originating in the brain stem, ganglion is located in the
target organ
• Extremely short postganglionic nerves
• Most important nerve: the vagus nerve
• Postganglionic neurotransmitter: acetylcholine
• Activates muscarinic cholinergic receptors
➢ Sympathetic nervous system
- Noradrenalin and adrenalin uses the same receptors
→ The sensitivity of the receptors is different
- Every varicosities is an end station / nerve endings → It allows to activate a
muscle at once.
➢ Exercise // Sympathetic nervous system
Sympathetic activity is increased during exercise because the function of the sympathetic
nervous system is to activate transport mechanisms.
The autonomic nervous system:
- Innervates those systems that can’t be controlled by the conscious brain such as
heart, smooth muscle, blood vessels, most visceral organs (liver, pancreas) and
all endocrine glands
- Nervous parasympathetic and sympathetic system
→ Plays an important role in the integration of peripheral body functions
➢ Claude Bernard
He saw that the left one didn’t eat for a long time → There’s almost no blood running
through the gut and the pancreas when the animals are fasting.
Claude Bernard decided that there’s a neural factor → The whole cardiovascular system is
already anticipating on the fact that the food is coming in (smell and sight) → He was the
first one who said that the brain is influencing all kind of systems.
➢ Autonomic nervous system
Claude Bernard defined the nerfs assimilators and the nerf dissimilators and that’s basically
the sympathetic and the parasympathetic nervous system → Some that store energy and
some that release energy→ That’s basically the autonomic nervous system
Activation of the body leads to increased activity of the sympathetic nervous system →
fight and flight
- Increase in heart rate and blood pressure, mobilization of the energy substrates
glucose and free fatty acids from liver and white adipose tissue → catabolic
processes)
The parasympathetic nervous system is activated when the body returns to the resting
condition → Rest and digest
- Reduction in heart rate, vasodilation (=the dilatation of blood vessels, which
decreases blood pressure), storage of energy substrates in glycogen, fat and
muscle → anabolic processes
We have 2 systems:
1. Fight and flight = sympathetic
2. Rest and digest= parasympathetic
→ Both systems are working but the balance between these 2 systems are changing
→ You should know this for you exam!
,The parasympathetic nerve is one nerve that originates in the brain stem and goes to all the
different organs = the nervus vagus = the vagal nerve
The sympathetic nerve originates in the spinal cord. All these ganglion chains go to all the
different organs.
You see that the sympathetic and parasympathetic nerve are going to the pacemaker, but
there is another nerve ending of the sympathetic nerve going to the ventricle of the heart
→ So the contraction of the heart is purely sympathetically regulated.
Common in sympathetic and parasympathetic neuron:
- They’re excising of 2 different parts → There are actually 2 neurons with a kind of
relay station, called an autonomic ganglion, in the middle = a cell that is a kind of
connection.
One of the neurons is originating in the CNS and then going to this autonomic ganglion and
then there’s the next neuron → Preganglionic neuron and the postganglionic neuron that
ends on the target tissue
The preganglionic neuron has as a neurotransmitter Acetylcholine and it activates
cholinergic receptors and it’s a subtype of the receptors that we call the nicotinic receptors.
Difference: Parasympathetic system uses the same neurotransmitter called acetylcholine
but the sympathetic nervous system uses a neurotransmitter called noradrenalin
(=norepinephrine).
The ganglion = a nerve cell cluster of nerve cell bodies located in the autonomic nervous
system and sensory system, mostly outside the central nervous system except certain
nuclei.
➢ Parasympathetic nervous system
Efferent pathway → 2 neurons and a relay station : the ganglion
1. Preganglionic neuron neurotransmitter → Acetylcholine
2. Postganglionic neuron neurotransmitter → Acetylcholine
, - Long preganglionic nerves originating in the brain stem and travel all the way through the
organs → Ganglion is located in the target organ
- Extremely short postganglionic nerves
→ Completely the opposite in the sympathetic nervous system
-Most important nerve → The vagus nerve→ The parasympathetic nervous system is also
known as the vagal nervous system
-Postganglionic neurotransmitter: Acetylcholine
-Activates muscarinic cholinergic receptors
The vagus nerve = the tenth cranial nerve and interfaces with the parasympathetic control
of the heart, lungs and digestive tract. The vagus nerves are paired but are normally
referred to in the singular.
➢ Sympathetic nervous system
Efferent pathway → 2 neurons and a relay station: the ganglion
1. Preganglionic neuron neurotransmitter → Acetylcholine
2. Postganglionic neuron neurotransmitter → Noradrenalin
-Short preganglionic nerves originating from the spinal cord, because the ganglions are very
close to the spinal cord → ganglion in the ‘sympathetic ganglion chain’
-Long postganglionic nerves innervate the target organs
-Postganglionic neurotransmitter → Noradrenalin (norepinephrine)
-Noradrenalin (norepinephrine) activates (nor)adrenergic receptors = Adrenoceptors.
→ Noradrenalin and adrenalin uses the same receptors
→ The sensitivity of the receptors is different
The spinal cord = a long, thin, tubular structure made up of nervous tissue, which extends
from the medulla oblongata in the brainstem to the lumbar region of the vertebral column.
It encloses the central canal of the spinal cord, which contain cerebrospinal fluid.
→ Every varicosities (dot) is an end station / nerve endings → It allows to activate a muscle
at once→ So it’s one neuron spreading all out over the whole muscle and then you get this
almost chain of varicosities and these are all nerve endings.
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