Lecture 5 Flashcards
What are the two main divisions of the nervous system?
Central nervous system (CNS) and peripheral nervous system (PNS)
The CNS consists of the brain and spinal cord, while the PNS includes all nerves outside these regions.
What is the primary function of the peripheral nervous system (PNS)?
Interactions with the external environment and execution of motor commands
What does the central nervous system (CNS) consist of?
The brain and spinal cord
What does embryology study?
The development of embryos and fetuses from fertilization to birth or hatching
What are the three main parts of the brain referred to in neuroscience?
Forebrain, midbrain, and hindbrain
What are sutures in the context of neurodevelopment?
Ossified tissue between separate bone plates that make up the skull
What are the protective layers of tissue below the skull called?
Meninges
The meninges consist of dura mater, arachnoid mater, and pia mater.
What is cerebrospinal fluid (CSF) and what are its functions?
A clear, colorless fluid that surrounds the brain and spinal cord, serving as a protective cushion, providing essential nutrients, and removing waste products
What are the fluid-filled cavities within the brain that produce cerebrospinal fluid called?
Ventricles
What is the visible surface of most of the brain called?
The cerebrum (telencephalon)
What are gyri and sulci?
Gyri: ridges on the surface of the brain; Sulci: depressions or fissures in the surface of the brain
What are the four lobes of the cerebrum?
Frontal lobe, temporal lobe, parietal lobe, occipital lobe
What is the primary function of the frontal lobe?
Executive function, decision making, planning, problem solving
What separates the left and right hemispheres of the brain?
Longitudinal fissure
What structure connects the left and right hemispheres of the brain?
Corpus callosum
What is lateralization of brain function?
The phenomenon where certain brain functions are typically controlled by one hemisphere only
Which hemisphere of the brain is primarily responsible for language?
Left hemisphere
What is the role of the thalamus?
Relaying most sensory signals to their respective cortices
What are the two key regions of the limbic system?
Hippocampus and amygdala
What is the primary function of the hippocampus?
Formation and consolidation of new memories, particularly declarative or episodic memories
What is the function of the cerebellum?
Coordination of fine movement and balance
What terms describe the relative locations of brain regions?
Medial/Lateral, Dorsal/Ventral, Anterior/Posterior
What is a neuron?
Specialized cells in the nervous system that transmit electrical and chemical signals
What are glial cells?
Non-neuronal cells that support and protect neurons in the nervous system
What is gray matter composed of?
Cell bodies of neurons
What is the function of white matter?
Transmitting signals between regions on the cerebral cortex
What are tracts in the context of the nervous system?
Bundles of nerve fibers or axons forming a specific pathway for transmitting information
What are nerves?
Bundles of specialized cells in the peripheral nervous system (PNS) that transmit signals between the CNS and the body
What are the main parts of a neuron?
Soma, nucleus, membrane
What is the function of dendrites?
Gather incoming information from other cells
What is the purpose of the myelin sheath?
Insulating material that speeds up action potentials
What is resting potential?
The baseline electrical charge across a neuron’s membrane when at rest
What maintains the resting potential in neurons?
Ion channels and sodium-potassium pump
What is resting potential?
The baseline electrical charge across a neuron’s membrane when at rest
It is about -70 millivolts.
What maintains the resting potential of a neuron?
Two key features:
* Ion Channels
* Sodium Potassium Pump
Ion channels allow specific ions to pass through the membrane, while the sodium-potassium pump actively transports ions to maintain charge balance.
What is the role of ion channels in resting potential?
Specialized proteins in the cell membrane that selectively allow specific ions to pass through
Ions include sodium, potassium, calcium, and chloride.
What is the function of the sodium-potassium pump?
It actively transports sodium ions out of cells and potassium ions into cells
This maintains ion balance essential for cell function.
What is an action potential?
A very brief shift in a neuron’s electrical charge that travels along an axon
The electrical charge changes from about -70mv to about +30mv.
Where does an action potential typically begin?
Near the soma (cell body) of the neuron
It then propagates down the length of the axon rapidly.
What role does myelin play in action potential propagation?
It increases the speed at which the charge propagates down the axon
This allows neurons to send information over long distances.
What is the all-or-none law in neuronal firing?
When an action potential begins, it is fully executed; there are no ‘half’ action potentials
Neurons either fire an action potential or they don’t.
How is stimulus intensity transmitted in neurons?
By the rate of action potentials
Faster firing indicates a more intense stimulus.
What is the absolute refractory period?
The minimum length of time after an action potential during which another action potential cannot begin
This period is crucial for the reset of the neuron’s charge.
What is the synapse?
A specialized junction or connection between two neurons that allows for the transfer of electrochemical signals
It is where communication and signal transmission occur in the nervous system.
What is the synaptic gap?
The small space between the axon terminal of a pre-synaptic neuron and a post-synaptic neuron
Chemicals are released here to allow for chemical communication between neurons.
What are the roles of pre-synaptic and post-synaptic neurons?
The pre-synaptic neuron sends a signal, while the post-synaptic neuron receives it
This interaction is essential for neuronal communication.
