Nervous System Intro Flashcards
Define the study of neuroscience
Fields dealing with the structure and function of the nervous system and the brain (ex: neurochem, experimental pysch)
Define the study of biopysch
Analyzing how the brain, neurotransmitters, other aspects of biology can influence behaviours, thoughts, feelings
List the characteristics of the brain (6)
- Highly complex
- 3lbs (ize of a grapefruit)
- 75% water
- Pink/grey colour
- Grows 4x in size from infancy to adulthood
- Nearly 100B nerve cells
Define the body’s two communication systems and how they differ
Nervous system (communicates quickly)
Endocrine system (comms. more slowly)
Biological foundations for thoughts, emotions, behaviours
How do the nervous and endocrine systems work together? What happens if one fails?
Help in life situations (ex: stress) to help the body reach homeostasis
Failure can impact brain and mental functions, which can be either temporary or life-altering
Explain hypothyroidism
Not enough thyroid to produce hormones in the body. Caused by a failure in the comms. systems, leading to a change in personality. Associated with: lethargy, poor motor coordination, depression, bipolar disorder, confusion, loss of cognitive skills
Define neuron + 3 categories
Specialized cells that can receive, carry, and transmit info to other cells
Sensory, motor, inter-
Define nerve
Cluster of neuron cells
How do neurons operate
- Electrochemical impulse is received by cell from “feed neuron”
- Info carried down length of neuron
- Info passed on to next neuron
Define sensory neuron
Info from sensory receptors carried from spinal cord to brain (5 senses) ex: touching something cold
Define motor neuron
Sends messages from brain to muscles, organs, glands, allowing them to act. Helps with tasks such as catching or picking up something
Define interneurons
Fills gaps between sensory and motor neurons, which cannot directly communicate. Transmit impulses between neurons (ex: reflex arc) in complex pathways
List all the parts of a neuron (5) DON’T FORGET TO REVIEW THE IMAGE IN THE NOTES!!
- Dendrite
- Soma
- Axon
- Myelin sheath
- Nodes of Ranvier
Define dendrite
Receiver branching off at end of a neuron, accepting (most) incoming messages and sending down to soma
Define soma
Cell body, allowing cell to work properly and stay healthy. Analyzes received messages and decides when is the right time to send it to the axon.
Define axon
Nerve fibre, long slender projection of nerve cell moving electrical impulses away from soma. Can be very short or long (ex: 1m in sciatic nerve found behind leg)
Define myelin sheath
Protective coating surrounding axon to protect electrical signals. Made up of schwann cells (glial cell providing physical/chemical support)
Define nodes of Ranvier
Microscopic gaps between myelin cells protecting axon. Help keep action potential going throughout cell by maintaining intensity of charge so that it can reach the end of the cell
Define action potential
Neuron firing and impulse travelling down axon, causing neurotransmitters to be released by terminal buttons.
Explain how action potential works
Axon energized from ions containing small neg- charges in normal state known as resting potential. When cell is excited, action potential reverses charge to pos+, allowing electrical signal to race down axon. Must then recharge (refractory period) before next action potential
How does the “All or nothing” principle apply to action potential?
Depolarization, first movement where impulse passes, must reach a certain threshold or the action potential will not be triggered
How do cells communicate?
Synapse (gap between neurons) slowly transfers info between cells
Define synaptic transmission
Message transforms from electrical to chemical to flow across synaptic cleft
How do cells connect to one another?
Synaptic vesicles (sacs in axon terminals) containing neurotransmitters, ruptured when action potential reaches. Connect to dendrite like lock and key.
Define reuptake
Neurotransmitters are reabsorbed once message is sent out
Define acetylcholine
Neurotransmitter enabling muscle action, learning, memory. Low levels cause Alzheimer’s
Define dopamine
Neurotransmitter influencing movement, learning, attention, emotions. In excess can cause schizophrenia. Decrease can cause Parkinson’s (tremors, loss of mobility).
Define serotonin
Neurotransmitter affecting mood, hunger, sleep, arousal. Decrease = depression. Prozac can increase supply.
Define norepinephrine
Neurotransmitter (adrenaline) controlling alertness, arousal. Lack of can depress mood.
Define GABA (gama-aminobutryicacid)
Inhibitory neurotransmitter. Lack of linked to seizures, tremors, insomnia.
Define glutamate
Excitatory neurotransmiter involved in memory. Oversupply linked to migraines, seizures
Difference between CNS and PNS?
Central: brain, spinal cord
Peripheral: nerves (sensory, motor neurons) going into brain and spinal cord, connecting with CNS and rest of body
