1.3A) The Neuron and Neuron Firing

Neuron (Nerve Cell)

the basic building block of the nervous system

the basic building block of the nervous system

Neuron (Nerve Cell)

Dendrite

listens and receives short messages from other cells

listens and receives short messages from other cells

dendrite

axon

speaks and passes messages to other cells, can be long

speaks and passes messages to other cells, can be long

axon

Myelin Sheath

Fatty tissue that insulates and builds until age 25, needed for efficiency, judgement, and self control

Fatty tissue that insulates and builds until age 25, needed for efficiency, judgement, and self control

Myelin Sheath

Glial Cells (Glue Cells)

Aren’t apart of the neuron, but instead supports it by providing nutrients and myelin

Aren’t apart of the neuron, but instead supports it by providing nutrients and myelin

Glial Cells (Glue Cells)

More glial cells =

more complex brain

more complex brain =

more glial cells

Multiple sclerosis

caused by degeneration of myelin sheath

caused by degeneration of myelin sheath

multiple sclerosis

Myasthenia gravis (MS)

antibodies destroy the communication between nerves and muscle, resulting in the weakness of skeletal muscles

antibodies destroy the communication between nerves and muscle, resulting in the weakness of skeletal muscles

Myasthenia gravis (MS)

the neural impulse

electrical charge

electrical charge

the neural impulse

Excitatory Signals

Increases the likelihood of action potential, increases neural transmitters, and accelerates to encourage the neuron to fire

Increases the likelihood of action potential, increases neural transmitters, and accelerates to encourage the neuron to fire

Excitatory Signals

Inhibatory Signals

Decreases the likelihood of action potential, slows neural transmitters, and like a brake that discourages the neuron to fire

Decreases the likelihood of action potential, shows neural transmitters, and like a brake that discourages the neuron to fire

Inhibatory Signals

Threshold

When excitatory signals override inhibitory signals, this triggers action potential except during the refractory period

When excitatory signals override inhibitory signals, this triggers action potential except during the refractory period

threshold

Action Potential (neural impulse)

all or nothing, where the signal fires at full strength or none at all

all or nothing, where the signal fires at full strength or none at all

Action Potential (neural impulse)

refractory (rest) period

after firing a signal, it reaches a resting stage where it cannot fire again, no matter what

after firing a signal, it reaches a resting stage where it cannot fire again, no matter what

refractory (rest) period

resting potential

positively charged outside and negatively charged inside the axon

positively charged outside and negatively charged inside the axon

resting potential

More sensation =

more neurons firing more often

more neurons firing more often

more sensation

synapse

space between the axon and dendrite of two neurons

space between the axon and dendrite of two neurons

synapse

Synaptic cleft/gap

neurotransmitter molecules released into the synpatic cleft

neurotransmitter molecules into the synaptic cleft

synaptic cleft/gap

neurotransmitters

chemical messengers that cross the synaptic gap between neurons

chemical messengers that cross the synaptic gap between neurons

neurotransmitters

reuptake

unused neurotransmitters reabsorbed into sending neuron

unused neurotransmitters reabsorbed into sending neuron

reputake

what utilizes reuptake

drugs (rx and street)

drugs (rx and street) utilizes what

reuptake

agonist

molecule that increases a neurotransmitter’s action

molecule that increases a neurotransmitter’s action

agonist

antagonist

molecule that inhibits or blocks a neurotransmitter’s action

molecule that inhibits or blocks a neurotransmitter’s acion

antagonist

Example of an agonist

morphine amplifies euphoria

morphine amplifies euphoria

example of an agonist

Example of an antagonist

botox inhibits facial muscles

botox inhibits facial muscles

example of an antagonist

Reuptake inhibitors

prevent neurotransmitters from absorbing into the sending neuron, forcing them into the postsynaptic neuron

prevents neurotransmitters from absorbing into the sending neuron, forcing them into the postsynaptic neuron

reuptake inhibitors

Hormones

chemical messengers in the endocrine system

chemical messengers in the endocrine system

hormones

endocrine system

has glands that secrete hormones

has glands that secrete hormones

endocrine system

Nervous System

the body system that has fast but shorter effects using neurons

the body system that has fast but shorter effects using neurons

Nervous System

the body system that has slow but longer effects using hormones in the blood stream

endocrine system

endocrine system

the body system that has slow but longer effects using hormones in the blood stream

hypothalamus

the brain part that controls the pituitary gland

the brain part that controls the pituitary gland

hypothalamus

Pituitary Gland (master gland)

regulates the growth hormone, oxytocin bonding, other glands

regulates the growth hormone, oxytocin bonding, other glands

Pituitary Gland (master gland)