Lecture one Flashcards
What happens when sodium channels open?
Depolarization occurs
Depolarization is the process where the membrane potential becomes less negative.
What follows depolarization in neuron action?
Repolarization
During repolarization, potassium channels close and some potassium leaks out, returning the membrane potential to resting levels.
What do Schwann cells do?
Form myelin sheaths around neurons
Myelin sheaths enhance the speed of neural signal transmission.
What are Nodes of Ranvier?
Gaps in myelin sheaths that facilitate saltatory conduction
Saltatory conduction allows action potentials to jump between nodes, speeding up transmission.
Which neurons are typically myelinated?
Fastest neurons
Examples include visceral sensory neurons and those involved in reflex actions.
What are the two types of synapses?
Electrical synapses and chemical synapses
Electrical synapses allow direct electrical communication, while chemical synapses involve neurotransmitter release.
What is the role of neurotransmitters?
Facilitate communication between neurons and target cells
Target cells can include muscles and glands.
What is the function of Acetylcholine (ACh)?
Stimulates muscle contraction
ACh binds to nicotinic and muscarinic receptors.
What type of neurotransmitter is GABA?
Inhibitory neurotransmitter
GABA reduces the likelihood of an action potential.
What is the significance of glutamate?
Excitatory neurotransmitter critical for learning and memory
Glutamate plays a vital role in synaptic plasticity.
What does dopamine regulate?
Reward, pleasure, and movement
Abnormal dopamine levels are linked to Parkinson’s disease.
What effect does serotonin have?
Regulates mood and appetite
Serotonin is often associated with feelings of well-being.
What is norepinephrine involved in?
Fight or flight responses and alertness
It is typically an excitatory neurotransmitter.
What is Substance P associated with?
Communicating pain signals
Substance P is a short peptide neurotransmitter.
What do endorphins do?
Relieve pain
Endorphins block substance P to reduce pain perception.
What does Neuropeptide Y stimulate?
Hunger and fat storage
Neuropeptide Y plays a role in energy balance.
What are ionotropic receptors?
Ligand-gated channels that allow ions to flow directly
They cause immediate changes in membrane potential.
What are metabotropic receptors?
Receptors that trigger a cascade of intracellular events
Often involve G-proteins leading to changes in cellular activities.
What is the capacity for neuron regrowth?
Limited capacity
Schwann cells can aid regeneration if damage is not extensive.
What is the distinction between white matter and gray matter?
White matter contains myelinated axons, gray matter contains unmyelinated axons and neuron cell bodies
This distinction is important in understanding brain structure.
What are the major sections of the brain?
Cerebrum, cerebellum, brainstem
Each section has distinct functions related to processing and regulation.
What is the primary function of the Primary Motor Cortex?
Sends commands to muscles for movement
It is responsible for voluntary motor control.
What does the Primary Sensory Cortex do?
Processes sensory input like touch, temperature, pain
It plays a crucial role in sensory perception.
What is the role of Broca’s Area?
Involved in language production
Damage to Broca’s Area can impair speech but not comprehension.
What does the homunculus representation illustrate?
Areas of the brain dedicated to different body parts
It emphasizes the precision of control in motor functions.
What is the relationship between neurotransmitters and learning?
Learning and memory involve creating and modifying neuronal connections
Neurotransmitters enhance the effectiveness of signals needed for learning.
What can neurotransmitter levels influence?
Mood and cognitive functions
For example, serotonin levels are linked to depression.
Fill in the blank: The neurotransmitter involved in muscle contraction is _______.
Acetylcholine
Fill in the blank: The inhibitory neurotransmitter that reduces the likelihood of action potential is _______.
GABA
Fill in the blank: The neurotransmitter critical for learning and memory is _______.
Glutamate
Fill in the blank: The neurotransmitter associated with motivation and movement regulation is _______.
Dopamine
Fill in the blank: The neurotransmitter that regulates mood is _______.
Serotonin
Fill in the blank: The neurotransmitter involved in alertness is _______.
Norepinephrine
Fill in the blank: The peptide that communicates pain signals is _______.
Substance P
Fill in the blank: The peptide that relieves pain is _______.
Endorphins
Fill in the blank: The neuropeptide that stimulates hunger is _______.
Neuropeptide Y
