nervous system, neurons, NT quiz

Neurotransmitters

• Nervous system

• transmit through neural network 

• fast acting

• effects quick but short duration

Hormones

• Endocrine system

• transmit through blood stream 

• slow acting 

• effects take time to begin but are long lasting 

neurotransmitters are

chemical messengers in brain .

After connecting to the receiving receptor and sending the message. returns to presynaptic neuron through reuptake

2 main types of neurotransmitters

• Excitatory = causes receiving cell to increase neural firing

• Inhibitory = causes receiving cell to decrease neural firing

What does the neurotransmitter serotonin do

• regulates mood , sleep, wakefulness, eating, and aggressive behaviors

• Inhibitory

• If there is not enough → Mood disorders, anxiety , insomnia, OCD

What does the neurotransmitter norepinephrine do 

• Fight or flight

• stress arousal eating 

• increases attention and memory for emotionally charged events

• not enough → depression 

• Too much → anxiety, stress, nervous tension 

• Excitatory 

What does the neurotransmitter Acetylcholine do 

• Skeletal muscles contract, regulates heart muscles

• transmits messages between brain and spinal cord

• memory formation, learning, general intellectual functioning

• not enough → low arousal and attention 

• alzheimer’s disease 

• Too much → violent muscle contractions/spasms

• excitatory 

What does the neurotransmitter Glutamate do 

enhances transmission of info from senses to brain

deals with learning and memory

excitatory

too much → overstimulated → seizures and migraines

What does the neurotransmitter Glutamate do 

• Inhibitory neurotransmitter

• offsets other excitatory messages

• regulates sleep-wake cycle

• not enough → anxiety, seizures, insomnia

• too much → sleep and eating disorders

What does the neurotransmitter endorphins do 

• natural opiate

• regulates pain perception

• inhibitory 

• released during exercise and linked to positive emotions

• too much → artificial heights 

• too little → feel pain 

What does the neurotransmitter Dopamine do 

• Voluntary coordinated motor movements

• attention learning memory

• reward sensations

• not enough → parkinson’s disease

• too much → schizophrenia, bipolar, adhd

• Both inhibitory and excitatory

What does the neurotransmitter Substance P do 

• modulation of pain

• excitatory

• contraction of smooth muscle and dilation of blood vessels

• potent neurotransmitter especially in transmission of signals from pain receptors

What are hormones

Chemical messenger that travels through bloodstream

released by glands in the endocrine system

affects brain and other parts of the body [ growth , reproduction, metabolism, mood ] 

slower transfer but effects last longer

adrenaline

• increases heartbeat

• fight or flight 

• = epinephrine 

Melatonin

• regulation of circadian rhythms 

• sleepiness

Ghrelin

• released by hypothalamus 

• signals hunger and need to eat 

Leptin

• released by hypothalamus 

• allows you to feel full 

oxytocin

• stimulates contractions in childbirth; love hormone

Electroencephalography

• electrical signals from brain ( neurotransmission )

• strength : shows level of activity and speed

• Weakness : does not show what part of the brain ats this way 

• Ex: sleep studies 

Positron emission Tomography

• shows glucose absorption or blood flow in the brain 

• where it is being absorbed in an active brain ( radioactive glucose is being tracked ) 

• PET color codes are based on consumption rates

• Weakness : less precise than fMRI, uses radiation 

• ex: brain activity difference s

functional magnetic resonance imaging

• magnet measures change in blood flow and creates 3d image 

• slices of brain in specific detail and location of activity 

• ex: searching for abnormalities and lesions 

• lesion = disruption or damage to tissue

Heritability

proportion of variabtion among individuals that we can attribute to ourgenes 

interaction

impact of one factor depends on another factor ( genes affect how people react to and influence us ) 

epigenetics

study of how n environment can later or influence genetics and genetics expression

monozygotic 

identical 

dizygotic

fraternal

Twin similarity breakdown

most similar = identical and raised together

2nd = idental and raised apart

3rd = fraternal and raised together

Nervous Systems breakdown

Central nervous system [ brain and spinal cord . spinal cord connects brain with peripheral nervous system , decision making portion ] 

Peripheral NS [ motor and sensory neurons that receive information and transmit central nervous system decisions ] 

• somatic ns = voluntary control of skeletal muscles

• autonomic NS = functions of gland and internal organ muscles 

  • sympathetic NS = fight or flight, dilates pupils, speeds breathing, relaxes bladder 

  • Parasympathetic NS = slows down, increases digest

Neuron

nerve cell and basic building block of the nervous system . Bundle of axons and link the central NS with the body’s receptors, muscles, and glands

Types of Neurons

• Sensory

  • Receive information from outside world and sends to the brain via the spinal cord ( afferent neurons ) 

• Motor 

  • Carry signal from the spinal cord to the muscles and glands ( effeerent ) 

• Interneurons 

  • connect sensory and motor neurons toge3ther

  • found in the brain and spinal cord 

Parts of the neuron

Dendrite, cell body/some, axon, myelin sheaths, axon terminal, terminal buttons, synapse, receptor

Dendrite = recieves messages from neighboring cells

Cell body/soma =neurons life support center, indicates whether to continue message or not

axon = passes messages away from cell body to neighboring neurons, muscles, and glands 

myelin sheath = covers up some axons to protect and speed up neutral signal 

axon terminal = end of axon that leads to neighboring cells to send message 

terminal buttons = end of axon terminal where neurotransmitters are stored and released to send message 

synapse = junction between sending and receiving neurons; synaptic gap where neurotransmitters are released 

Receptor = cell on dendrites that Neurotransmitters connect to in order to send message to next neuron and start process over 

• after NT connects, the excess will be reabsorbed by the sending neuron ,called reuptake

Action potential

• neural impulse or a brief electrical charge that travels down an axon 

  • triggered by an electrical shock that is above the cells treshold 

  • all or nothing principle = no varying levels of action potential- it either fires ta the same level or does it 

Refractory period

time it takes to recover from one action potential 

Steps of action potential 

1. Resting potential 

2. Threshold passed 

3. voltage rises = depolarization 

4. Voltage falls - repolarization 

5. refractory period 

Glial cells are

non neuron cell in the nervous system that provides support, protection, and nourishment of neurons

• insulation for axons and myelin , communication, and waste transport ( removes used neurotransmitters )

• glue that hold neural network together

• outnumbers neurons

• also plays a role in learning thinking and memory 

The degeneration of myelin sheath →

slows communication to muscles and brain regions → multiple sclerosis 

Agonists effect on neurons

• increae actions of NT ,

• either by increasing production or releae of NT 

• blocks reuptake ( stays in synapes longer ) 

• mimicsthe NT effects 

Antagonists effect on neurons

• decrease NT action by blocking production or release of  neutrosansmittors or block receptor sites 

Reuptake inhibitor effect on neurons

• block the reabsorption of NT back into sending neuron 

• ex: antidepressents partially block the reuptake of mood -enhancing NT , making it stay in the synaptic gap longer and increasing its effects ( selective serotonin reuptake inhibitors ) 

Depressants

• Drugs that reduce neural activity and slow body functions

• Ex: Alsochoo, opiods, tranquilizers

Stimulants

Drugs that excite neural activity and speed up body functions

ex: cocaine, Caffeine, Nicotine, Ectasy

Hallucinogens

Psychedelic drugs that distort perception and evoke sensory images in absense of sensory input

ex: LSD , ecstasy, marijuana

Opioids

Opium and its Derivatives, depress neural activity, temporarily lessening pain and anxiety

ex: heroin, fentanyl