Parts of a Neuron
Dendrites
Receives information from the axon terminal and conducts it to the cell body (soma) (branches on the large part of the neuron)
Serotonin
Dopamine
-Function mood, sleep, appetite (too little can cause anxiety, depression, OCD)
-Motor movement, attention pleasure, rewarding feelings (too much can cause schizophrenia, hallucinations, too little can cause Parkinson's disease)
Central nervous system
Made of the brain and spinal cord; transmits messages to and from sensory neurons, motor neurons, and glands of the peripheral nervous system (interneurons reside here)
Pituitary gland
Negative feedback system
-Master gland; tells what the other glands to do; controls growth of the skeletal system
-Operates like a thermostat, if the body gets too much or little of a hormone then the pituitary gland sends a message to produce more/less of the hormone- seeks homeostasis
Action potential
A neural impulse; a brief electrical charge that travels down an axon (a neuron will always fire fully as well)
Soma
Contains the nucleus which sends messages from the dendrites to the axon
Acetylcholine
Memory, learning, motor movement (causes muscles to contract) (too much can cause depression, too little can cause paralysis, Alzheimer's, memory loss)
Peripheral nervous system
Made up of the sensory and motor neurons that connect the central nervous system to the rest of the body
Pineal body
Hypothalamus
-Regulates melatonin for sleep patterns and the circadian rhythm
-Links the nervous and endocrine system; the hypothalamus coordinates messages from brain
Threshold
Level of stimulation required to trigger a neural impulse
Axons
Where messages get sent from the soma to the axon terminal (long part of the neuron)
Endorphins
Body's natural painkiller (too much: can't feel necessary pain, too little can cause chronic pain, low pain tolerance, anxiety, depression)
Somatic nervous system
Part of the peripheral nervous system; controls the voluntary movement of the musculoskeletal system
Parathyroids
Thyroids
-Regulates calcium levels in our blood; calcium helps to strengthen bones, blood clotting, neurotransmission
-Controls the metabolism in the body and the production of protein, can affect weight loss
Reuptake
Sending neuron reabsorbs the excess neurotransmitters
Myelin sheath
Nodes of Ranvier
-An insulating layer around the axon that speeds up the electrical impulses
-Sections of the axon that do not have myelin sheath
Norepinephrine/epinephrine
Energy, attention, metabolism, fight or flight response (too much can cause ADD, anxiety, high blood pressure, hypertension, too little can cause fatigue, depression)
Autonomic nervous system
Part of the peripheral nervous system; controls the visceral and unconscious functions of the body such as heart rate, sweat glands
Thymus
Adrenals
Pancreas
-Develops immune system by producing white blood cells during infancy to fight off germs
-Fight or flight hormone, produces adrenaline when needed, emergency response of the body
-Produces insulin and glucose which keep blood sugar levels balanced and turns food into energy
Refractory period
Resting potential
-A period after a neuron fires in which it is less susceptible to other neurons
-Negatively charged ions wait for stimulation within the axon. The neuron is said to be inactive and is waiting for another action potential
Axon terminal
Synapse
-End of a neuron that connects and sends impulses to dendrites (at the end of the long part- the axon of the neuron)
-Meeting part between neurons; between axon tip and dendrite
GABA
Agonist
Antagonist
Inhibitory neurotransmitters (slows/blocks neurotransmission when needed; has a calming effect) (too much can cause an imbalance by preventing certain neurons from firing, too little can cause insomnia, inability to focus, hyperactivity, anxiety)
-Medication that would act like a neurotransmitter to trick the neuron into sending an electrical charge
-Serves as a cap on a neuron receptor to block the flow of a neurotransmitter (blocks it)
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Sympathetic nervous system
Parasympathetic nervous system
-Division of the autonomic nervous system that causes the fight or flight response
-Division of the autonomic nervous system that calms the body down after the fight and flight response is no longer necessary
Ovaries
Testis (including testosterone)
-Produces estrogen which results in wider hips, breast development, body hair
-Produces androgens such as testosterone which deepens the voice, enlarges the muscles/bones, correlated with risk-taking, produces more when around women
Depolarization
In a neuron, it fires when positive ions outside of the soma enter the cell and mix with the negative ions inside of the cell. The depolarization of negative and positive ions creates the electrical impulse (Action potential) that reveals down the axon the pushes the transmitters out of the synapse (cell becomes less negative)