Nervous System

System that is responsible for short-term regulation and immediate control of all the other body systems.

System responsible for the long-term regulation of the body.

Brain and Spinal cord (dorsal cavity)

Cranial nerves and spinal nerves (not in the dorsal cavity)

Sensory information from the receptors to the brain

Motor commands to muscles and glands from the brain

Touch, pain, position, taste, smell, vision, sound and temperature are what type of receptor

Somatic and autonomic are what type of receptor

Efferent system's voluntary control of skeletal muscles

Efferent systems's involuntary control of smooth muscle, and cardiac muscle and glandular activity

Part of the autonomic nervous system that is "fight of flight"

Part of the autonomic nervous system that is "rest and digest"

Most common neuron in the CNS

The typical spinal neuron (efferent)

Neuron that controls skeletal muscle and are interneurons

Uncommon neuron of the afferent system

Neuron involved in the senses of sight, smell and hearing

Neuron in the afferent system involved in the senses of touch, pressure, pain, position and other mechanical stimulus.

Neuron found in the brain that connects neurons to each other without and axon.

An encapsulated receptor found in deep layers of the skin that senses vibratory pressure and touch.

How many types of neuroglial cells are in the CNS

Secrete CSF = cerebral spinal fluid, ciliated cells, line the central canal.CSF cushions and distributes nutrients to the brain and spinal cord.

Maintains the blood-brain barrier by wrapping around capillaries.

large, most numerous helper cells, also involved in signaling

Create framework of microfilaments or the cytoskeleton of neurons

Repairs tissue, although may not regain normal function

Involved in embryonic development of neural tissue, groups and directs neurons,

Control the environment around neurons of ions, nutrients, recycling neurotransmitters, etc.

myelinate the axons of neurons in the CNS

gaps in the myelin

“white matter” because of the high amount of lipids in the Oligodendrocyte membrane

Unmyelinated cells are

white blood cell origin, microphages, clean up debris, bacteria, waste materials

How many types of neuroglial cells are found in PNS?

regulate the environment like astrocytes in the CNS

myelinates the axon of one axon only, and many are needed towrap an entire axon.

How do Schwann cells respond to injury to the axon?

progressive destruction of myelin sheaths in the CNS and PNS.

diseases include MS and heavy metal toxicities.

‘Grey Matter’ of the brain and cord. Large nucleus and a cytoplasm full of :Mitochondria

produce ATPs, to move vesicles, run the Na+/K+ pump

make cell look grey and make neurotransmitter proteins.

Where are chemically gated channels that react to a neurotransmitter found?

highly branched area that receives the information from the other neurons and haschemically gated channels and nearby receptors that bind to the neurotransmitter.

‘White matter’. Long process with microtubules, vesicles, mitochondria and many enzymes.

may be myelinated by the Oligodendrocyte, little repair is possible.

may be myelinated by the Schwann cell. Some repair of the axon is possible.

trigger zone.

The axon end at ____________ or ____________ which contain vesicles of neurotransmitter

has electrically gated channels that react to the action potential

specialized site where the synaptic terminal releases the neurotransmitter to communicatewith another cell.

The cell releasing the neurotransmitter is called

the cell receiving the neurotransmitter is called

Cranial nerves and spinal nerves, (not in the dorsal cavity)

Sensory receptors monitor temperature, pressure, touch, sight, smell, hearing,

Sensory receptors monitor position and posture, movement of joints and muscles

Sensory receptors monitor deep pressure and pain in viscera and taste

Motor neurons
Skeletal muscle – voluntary movement

Motor neurons
Sympathetic and Parasympathetic systems – involuntary control

motor neurons that innervate skeletal muscles have a cell body in the CNS and are some ofthe longest multipolar neurons in our body.

neurons innervate everything that is not skeletal muscle, ie. smooth muscle, glands, fatcells and the heart.

function in between other neurons and are in the responsible for the communication and coordination of the nervous systems also responsible for learning, memory andhigher functions that are not well understood.

resting potential or transmembrane potential of –70 mvolts is maintained by the

There arechemically gated Na+ channels & chemically gated K+ channels on the

voltage gated Na+ channels & voltage gated K+ channels on the

The action potential depends on the movement of

Polarized =

Repolarized =

Depolarized =

Hyperpolarized =

An excitatory neurotransmitter binds to the receptors on the dendrites and cell body and opens the

If enough Na+ ions enter the cell to achieve threshold at the axon hillock, the axon’s

After the cell is depolarized, the Na+ channels begin to close and the

At the synaptic knobs, the action potential causes the release of

Once a neuron achieves threshold and fires off an action potential, it goes to the synaptic knobs. Thisis called The

A neuron may reach threshold one of 2 ways:
One single neuron may fire several times in quick succession, called:

A neuron may reach threshold one of 2 ways:

Several neurons may fire together at the same time, which is called:

A neuron that synapses on another neuron and causes some depolarization (more +) toward thethreshold is said to have produced an

A neuron may also synapse on another neuron which inhibits it by causing hyperpolarization(more -) away from threshold. It opens the chemically gated K+ gates which creates a larger gap tothreshold. Such an event is called an

An action potential comes down the axon and reaches the

This opens Ca+ ion channels and Ca+ ions flow into the synaptic knob, which allows the excytosis of the vesicles filled with a

The neurotransmitter, Ach, binds to the receptors on the post-synaptic membrane and openschemically gated Na+ channels, causing a depolarization of the membrane and a gradedpotential, an

The neurotransmitter is released from the receptors and broken down by an enzyme andreabsorbes by the pre-synaptic knob. In the case of acetylcholine that enzyme is

Indirectopening of the channels is done by activating a

an excitatory neurotransmitter for skeletal muscles

actslike acetylcholine at these ‘nicotinic receptors’

block acetylcholinesterase and increase the amount of neurotransmitter at the synapse, causingtremors and death

blocks acetylcholine’s binding on receptors in the body and can beused as an antidote to the acteylcholinesterase drugs also causes increased heart rate and decreased bronchial secretions for example

blocks acetylcholine atskeletal muscle receptors and causes paralysis

involved in consciousness. It is an important neurotransmitter for the Sympathetic system, or fight and flight system. Norepinephrine is brokendown by Monoamine Oxidase, MAO.

increases the amount of norepinephrine available at the synapse.such as Elavil

decreases heart rate, blood pressure and has a calming effect. It is also used toreduce ‘stage fright’. It has recently been experimentally used to ‘prevent post-traumatic stresssyndrome’ if given within a short time of the event.
such as Propranolol

block the re-uptake of norepinephrine and also acts as a transmitter itself so it ishighly stimulatory

typically excitatory and is linked to an extremely pleasurable feeling in our brain. It isalso responsible for fine movement and coordination

Too much dopamine has been linked to

Too little dopamine is responsible for the muscle rigidity associated with

Dopamine is broken down by

an addictive stimulant that blocksthe re-uptake of dopamine and norepinephrine into the pre-synaptic cell

the number of receptors on the cell membranes decreases so that an increased dose is required to have the same effect

responsible for our moods, feelings of well-being, appetite and our sleep cycles.

thought to be due to a lack of serotonin

a precursor to serotonin

Prozac

Serotonin is broken down by

Glycine and GABA are both

Drugs like valium and barbiturates enhance theeffect of

GABA reduces

involved with the transmission of the sensation of pain

the body’s natural pain reliever, or opiod because they inhibit the action ofSubstance P

drugs from theopium poppy are powerful analgesics that have been used since 4000BC
bind to many receptors in the body acting likeendorphins. Analgesia, lethargy and constipation are common effects of

stimulates many areas of the CNS at ‘nicotinic’ acetylcholine receptors. It causesincreased heart rate, blood pressure and is a mood-altering drug. Tolerance and addiction arecommon side effects

a commonly used stimulant with a variety of effects. It stimulates the brain, the heart,increases respiration, blood pressure and the amount of Norepinephrine and epinephrine in the body.People develop a tolerance and addiction, however, withdrawal is usually limited to headaches andrestlessness

Summary –drugs and toxins may act in the following ways:
Morphine binds to endorphin receptors and mimics the effect of natural endorphins.
Nicotine binds to particular acetylcholine receptors and mimic the effects of natural endorphins

Summary –drugs and toxins may act in the following ways:
Atropine blocks acetylcholine receptors in the parasympathetic system. (muscarinic)
Curare and succinyl choline block acetycholine receptors in skeletal muscle .
Beta blockers block Norepinephrine at beta receptors. (beta 1, beta 2 receptors)

Summary –drugs and toxins may act in the following ways:
Amphetamines and Cocaine block Norepinephrine and Dopamine inactivation
Organophosphate insecticides block acetylchoinesterase
MAO inhibitor drugs block the breakdown of Norepinephrine, Dopamine and Serotonin
Serotonin re-uptake inhibitor blocks the removal of serotonin at the synapse

Summary –drugs and toxins may act in the following ways:
Tetanus Toxin blocks the release of glycine, which inhibits neurons so muscles contract.
Botulism Toxin blocks the release of acetylcholine so muscles are unable to contract.

binds to endorphin receptors and mimics the effect of natural endorphins.

binds to particular acetylcholine receptors and mimic the effects of natural endorphins

blocks acetylcholine receptors in the parasympathetic system. (muscarinic)

block acetycholine receptors in skeletal muscle.

block Norepinephrine at beta receptors. (beta 1, beta 2 receptors)

block Norepinephrine and Dopamine inactivation.

block acetylchoinesterase

block the breakdown of Norepinephrine, Dopamine and Serotonin

blocks the removal of serotonin at the synapse.

blocks the release of glycine, which inhibits neurons so muscles contract.

blocks the release of acetylcholine so muscles are unable to contract.