The brain, neurons, drugs and disease CM Flashcards
The nervous system consists of two major subdivisions, , the ____ and the____nervous system
- central (CNS)
2. peripheral (PNS)
the____ consists of the brain and _____
- CNS
2. Spinal cord
the ____ consists of the spinal cord and cranial ____ outside of the CNS.
- PNS
2. nerves
the principle cellular unit of the nervous system is the _____
neuron
how many neurons are there approximately in an ‘average’ brain?
100 billion
how many synaptic connections are there between the neurons in the brain? approx.
0.15 quadrillion
Labels of a neuron
Dendrite Soma Nucleus Axon Node of Ranvier Myelin Sheath Schwann Cell Axon terminal
Ions are _____ that are important for determining the difference in _______ between the inside and outside that all cells need to ______
- Charged particles
- Electrical charge
- function
neurotransmitter _____ cross the synapse and ____ to _____ on the postsynaptic ______
- molecules
- bind
- receptors
- membrane
in the synapse, when neurotransmitter molecules bind to receptors, this causes….
ion channels to open in the postsynaptic neuron
______ of ions causes changes in ____ of inside relative to outside of the neuron
- Influx/ Efflux
2. Voltage
In the Axon hillock, the voltage changes _____ from point of origin
Spread away
Whether action potential is generated depends on….
size of the voltage change reaching the axon hillock
an action potential travels from the ______, along the length of the ____, to the _________
- Axon hillock
- Axon
- terminal buttons
______ provides electrical insulation of the neuron- prevents ‘cross talk’ across ____ and loss of ____
- Myelin
- neurons
- signal
Myelin speeds up the _____ of the AP, it effectively jumps from one ________ to the next.
- relay
2. Node of Ranvier
As long as the ____ travels from one end of the axon to the other, no information is lost in ________
- Action potential
2. Conduction
What is the neurolemma?
A thin plasma membrane surrounding the neuron
when the neuron is at rest, what charge does the inside of the neurolemma have?
negative charge
What is the Resting Membrane Potential (RMP)?
the charge inside the neurolemma
What is the RMP amount?
-70mV
What is the neuron when it has a RMP of -70mV?
polarised
the AP is a wave of__________ that travels along the axon
depolarisation
Particles carrying an electrical charge =
Ions
___________ of the neurolemma
Selective permeability
___________ of ions along concentration gradient
Passive diffusion
attraction/repulsion of charges=
Electrostatic pressure
_______ of ions across neurolemma
Active Transport
What does Active transport do?
it uses energy to transport ions against concentration gradient
ATP
Adenosine Triphosphate
ADP
Adenosine Diphosphate
What are sodium ions when the neuron is at rest?
More highly concentrated on the outside of the neuron
the membrane is fairly ______ to sodium ions
impermeable
_______ and ______ forces push sodium ions into the neuron when it is at rest, a few ‘leak’ into the neuron
- Electrostatic
2. Diffusion
What are potassium ions when the neuron is at rest?
more highly concentrated on the inside of the neuron
the membrane is fairly_______ to potassium ions
permeable
A little ‘net’ _____ force push potassium ions out of the neuron, causing a small ‘leak’.
diffusion
What are chlorine ions when the neuron is at rest?
more highly concentrated on the outside of the neuron
the membrane is fairly______ to chlorine ions
permeable
______ and _______ forces roughly _____ out chlorine ions
- Electrostatic
- Diffusion
- Balance
there is little _____ at rest for chlorine ions
movement
Big negatively charged ______ ions are stuck ____ the ion
- Protein
2. Inside
Protein ions contribute a lot to the resting ___________ of the inside of the neuron
negative charge
the membrane potential is a balancing act of _______ and ____________
- membrane permeability
2. ion concentrations
Disrupting the balance of membrane permeability and ion concentration in a neuron can initiate an ______
action potential
neurotransmitters change…
membrane permeability