Neurotransmitters Flashcards
Describe the three parts of a neuron
- Dendrites
- Cell Body (soma)
- Axon
What are the three types of neurons?
- Sensory
- Interneurons/Associational
- Motor Neuron
Describe the sensory neuron
Carry impulses from peripheral sensory receptors to the CNS
Describe the interneuron/associational
Transmit impulses from neuron to neuron (sensory to motor)
Describe the motor neuron
Carry away from the CNS to an effector
Describes dendrites
they care nerve impulses towards cell body
Describe the nucleus
process nerve impulses
Describe the axon
conductive conjunctions that carry nerve impulses away from the cell body
What is myelin sheath?
-layer of lipid material
- helps propagate speed
- Makes signal travel fast down the axon.
Why is myelin sheath important for growth?
babies are born only with axons without the myelin sheath which is why see or talk.
It is critical periods for learning because myelin sheath enables brain signals to travel fast
As you get older, brain will slowly travel fast!
Describe the process on how neurotransmitters are released
- AP travels down axon to the axon terminal
- This causes the voltage gated calcium channels to open
- Calcium diffuses into the presynaptic neuron
- Calcium signals neurotransmitter vesicles
- Vesicles move to the membrane and protein dock
- Triggers release of neurotransmitters via exocytosis
- Neurotransmitters are released into presynaptic cleft
- Neurotransmitters bind to receptors
- Causes a signal initiation in postsynaptic cell
What happens to neurotransmitter leftovers?
Re-uptake molecules re-uptakes any available neurotransmitters back into presynaptic neuron for later use.
Name different ways to alter transmission
- Competitive inhibitors (antagonist can block receptor)
- Block reuptake (drug called SSRI)
- Block calcium channels
- Change the AP
- Interfere neurotransmitter
- Agonist enhances uptake amount
- Change the receptors
- Change the docking protein
Describe a neurotransmitter
- chemical messengers
- Work broadly
- Excitatory OR inhibitory OR both
What are the classification systems of a neurotransmitter
- Amino acids
- Peptides
- Monamines
- Others
Glutamate
- Most abundant neurotransmitter
- Excitatory
- Important for learning, memory, and cognition
-Increase membrane permeability to Na+,
K+ and Ca2+
Describe the clinical importance of Glutamate
role in bipolar disorder and schizophrenia
Serotonin
- AKA 5HT
- Inhibitory or Excitatory
- Amino acid L-tryptophan
- Can’t be created by body so must be supplied from deity (turkey, eggs, fish, cheese, milk)
- Can increase with light, exercise, diet
- LOVE AND HAPPINESS (high)
- DEPRESSION (little)
Describe the clinical importance of Serotonin
- Deficiency- depression
- Anxiety
- Panic
- ADH
- Dementia & Alzheimer’s
- Too much- links to schizophrenia
Norepinephrine
- EXCITATORY and inhibitory
- arousal/attention, learning, memory and eating
- Fight or flight
-Main neurotransmitter of sympathetic nerves
in cardiovascular system
Describe the clinical importance of norepinephrine
- Can be used to treat heart failure
- depression & ADHD (low levels)
- Anxiety (high levels)
STRESS
GABA
Inhibitory
- prevents overstimulation via regulating other excitatory neurotransmitters especially counterbalances glutamate
- Improves mental focus & relaxation
- Motor control, vision
Describe the clinical importance of GABA
Too little (epilepsy, anxiety)
Alcohol and benzodiazepines increase GABA which leads to sedation
Dopamine
EXCITATORY and Inhibitory
-Motivation Reward
-Involved with movement, decision making
creativity
- LOVE and SCHIZOPHRENIA (high)
- ANXIETY and DEPRESSION (little)
-Vasodilation
Describe the clinical importance of Dopamine
SCHIZONPHRENIA (too much)
Parkinson disease
Role in substance abuse
Epinephrine
EXCITATORY or Inhibitory
- Fight or flight
- Attentiveness, arousal, mental focus, cognition
- sexual arousal
STRESS
Describe the clinical importance of Epinephrine
- High levels- ADHD, anxiety
- Used to treat shock, cardiac arrest & anaphylaxis
Acetylcholine
EXCITATORY and Inhibitory
-Primary neurotransmitter in PSNS
Involved in: thought, attention, learning & memory
- activating muscle action
Describe the clinical importance of Acetylcholine
-Alzheimer’s- shortage of Ach
-Myasthenia gravis- reduction in acetylcholine
receptors
-Nicotine- increases the release
Oxytocin
Excitatory & Inhibitory
-“Love Hormone”- released during hugs!
-Released during and facilitates childbirth
and lactation
Histamine
Excitatory and inhibitory
-Involved in: arousal (wakefulness and attention), eating,
cognition
-Best known for its role in immune and inflammatory response (BENADRYL)
Describe the clinical importance of Histamine
- Immune, inflammatory and hypersensitivity reactions
- Increases gastric acid secretion- H2 Antagonists
- Side effect of histamine blockers- drowsiness
Substance P
-Excitatory &inhibitory
- Vasodilation
- Pain responsive neuron
- Causes pain particularly in arthrities
Describe the clinical importance of Substance P
- Too much- fibromyalgia & rheumatoid arthritis
- Some pain medications (morphine) blocks release of substance P
Nitric Oxide
- Unconventional neurotransmitter
- Interacts with many other neurotransmitters
-Causes vasodilation (treat angina and
hypertensive emergencies)
-Induces bronchodilation (treat hypoxemia,
pulmonary hypertension)
- Stimulates gastric emptying
- Anti-inflammatory
- Anxiolytic and analgesic
