Round 1 + 2 Flashcards
What are neurons responsible for?
Transmitting and integrating information in the brain, coordinating and regulating activity.
List the five components of a neuron.
- Dendrites
- Cell body
- Axon
- Axon hillock
- Terminals
What is the function of dendrites?
Receive inputs from other neurons; major input region.
What does the cell body of a neuron contain?
The nucleus and other organelles; involved in synthesis or processing of proteins, lipids, and other materials.
What is the role of the axon?
Conducting region that branches out to form terminals contacting other neurons or cells.
What is the axon hillock?
Integration region that collects all information received by a neuron before relaying it.
What are terminals in a neuron?
The endings of axons through which neurons signal information to the next cell.
What do neurons have for structural support?
A skeleton consisting of microfilaments, neurofilaments, and microtubules.
What is the ratio of glial cells to neurons?
1:1
List the functions of glial cells.
- Provide structural support
- Nourish neurons
- Create blood-brain barrier
- Scavenge debris
- Provide myelin sheath
- Repair nervous system after injury
- Control local environment around neurons
What is the primary role of astrocytes?
Deliver nutrients from blood to neurons and control the chemical environment around neurons.
What do oligodendrocytes and Schwann cells provide?
Myelin sheath around the axon of some neurons, insulating axons to increase transmission speed.
What is the function of microglia?
Act as the main immune defense mechanism in the CNS, scavenging debris and responding to damage.
What do ependymal cells line?
The brain’s fluid spaces (ventricles) and produce cerebrospinal fluid.
Differentiate between tropic and trophic molecules.
- Tropic: Stimulate glands to produce hormones
- Trophic: Aid in growth and development of other molecules
What does the CNS consist of?
The brain and spinal cord; control center of the nervous system.
What is the role of afferent neurons?
Carry information from the periphery to the CNS.
What is the role of efferent neurons?
Carry information from the CNS to body parts.
List the subdivisions of the PNS.
- Autonomic nervous system
- Somatic nervous system
What are the two divisions of the autonomic nervous system?
- Sympathetic: Fight or flight
- Parasympathetic: Rest and digest
Where are nerve cell bodies located in the CNS?
In groups called nuclei.
Where are nerve cell bodies located in the PNS?
In groups called ganglia.
What are nerve tracts?
Collections of nerve axons running together (white matter).
True or False: Cell bodies and axons stay together in the nervous system.
True
What is the primary function of neurons?
Transmitting and integrating information in the brain, coordinating and regulating activity
What are the five components of a neuron?
- Dendrites
- Cell body
- Axon
- Axon hillock
- Terminals
What is the role of dendrites in a neuron?
Receive inputs from other neurons, major input region
What does the cell body of a neuron contain?
The nucleus and other organelles, where synthesis or processing of proteins, lipids, and other materials occurs
What is the function of the axon in a neuron?
Conducting region, often long, that branches to form terminals contacting other neurons or cells
What occurs at the axon hillock?
Integration region that collects information before determining if there is sufficient excitation to relay information
What are the terminals of a neuron?
Endings of axons through which neurons signal information to the next cell, output regions
What is the function of glial cells in the nervous system?
- Provide structural support
- Nourish neurons
- Create blood-brain barrier
- Scavenge debris
- Provide myelin sheath
- Repair nervous system after injury
- Control local environment around neurons
What is the ratio of glial cells to neurons?
1:1
What is the primary function of astrocytes?
- Deliver nutrients from blood to neurons
- Control chemical environment around neurons
- Modulate capillary blood flow
- Repair nerve cells after injury
- Provide buffer reserve of fuel
What do oligodendrocytes and Schwann cells do?
Provide a myelin sheath around the axon of some neurons, insulating the axon and increasing speed of information transmission
What is the role of microglia?
- Scavenge cell debris
- Respond to CNS damage
- Reorganize shape to scan environment
- Play a role in brain development and plasticity
What do ependymal cells do?
- Line brain’s fluid spaces
- Produce cerebrospinal fluid
- Protect axon stumps from degeneration
- Allow alternate neuronal connections to grow
What is the difference between tropic and trophic molecules?
- Tropic: turns towards a chemical stimulus to produce a stimulus
- Trophic: aids in growth and development of other molecules
What does the central nervous system (CNS) consist of?
Brain and spinal cord, control center of the body
What are the two main subdivisions of the peripheral nervous system (PNS)?
- Autonomic nervous system
- Somatic nervous system
What are the functions of sensory neurons?
Transmit information from sensory organs to the CNS
What are the different structural classifications of neurons?
- Unipolar cells
- Pseudo unipolar cells
- Bipolar neurons
- Multipolar neurons
What are dendritic spines?
Extensions of dendrites that receive excitatory input and facilitate chemical flow into the cell
What is the function of the cytoskeleton in neurons?
Provides structural rigidity and facilitates transport of nutrients and waste products
What is myelination and its purpose?
Formation of a myelin sheath around axons to insulate them and speed up information flow
What is a synapse?
The junction where a neuron communicates with another cell to relay information
What is the synaptic cleft?
A 20 nanometer gap between cells in vertebrates
What molecules do neurons use to carry information across the synapse?
Chemical neurotransmitters
What is the primary function of neurons?
Transmitting and integrating information in the brain, coordinating and regulating activity.
List the 5 components of a neuron.
- Dendrites
- Cell body
- Axon
- Axon hillock
- Terminals
What are dendrites?
Finely branched structures that receive inputs from other neurons, major input region.
What does the cell body of a neuron contain?
The nucleus and other organelles where synthesis or processing of proteins, lipids, and other materials occurs.
What is the role of the axon?
A single, often long process that conducts information to other neurons or cells.
What is the function of the axon hillock?
Integration region that collects all information received by the neuron before determining if there is sufficient excitation to relay that information.
What are terminals in the context of neurons?
The endings of axons through which neurons signal information to the next cell, output regions.
What is the ratio of glial cells to neurons?
1:1
List the functions of glial cells.
- Provide structural support
- Nourish neurons
- Create blood-brain barrier
- Scavenge debris
- Provide myelin sheath
- Repair the nervous system
- Control local environment around neurons
What are astrocytes?
A class of cells that deliver nutrients from blood to neurons and control the chemical environment around neurons.
What is the function of oligodendrocytes?
Provide a myelin sheath around the axon of some neurons.
What do Schwann cells do?
Provide a myelin sheath around the axon of some neurons in the PNS, insulating the axon and increasing the speed of information transmission.
What are microglia?
Specialized immune cells that act as the main active immune defense mechanism in the central nervous system.
What is the role of ependymal cells?
Line the brain’s fluid spaces and produce cerebrospinal fluid.
Define ‘tropic’ in the context of hormones.
A molecule/hormone that turns towards a chemical stimulus to produce a response.
Define ‘trophic’ in the context of hormones.
A molecule/hormone aiding in the growth and development of other molecules.
What does CNS stand for and what does it consist of?
Central Nervous System; consists of the brain and spinal cord.
What is the role of afferent neurons?
Carry information from the periphery to the CNS.
What is the role of efferent neurons?
Carry information from the CNS to body parts.
List the subdivisions of the PNS.
- Autonomic nervous system
- Somatic nervous system
What is the function of the autonomic nervous system?
Controls internal structures and is divided into sympathetic and parasympathetic systems.
What are the two types of ganglia in the PNS?
- Nuclei in the CNS
- Ganglia in the PNS
What are sensory neurons?
Afferent neurons that transmit information from sensory organs to the CNS.
What are motor neurons?
Efferent neurons that transmit information from the CNS to control muscles.
What are local interneurons?
Neurons within the CNS that transmit information over short distances.
What are projection interneurons?
Neurons that transmit information over long distances within the CNS.
What are neuroendocrine cells?
Cells in the CNS that release hormones into the blood supply.
What are unipolar cells?
Neurons with a single process and no dendrites.
What are pseudo unipolar cells?
Cells with a cell body in the middle of the axon, making up principal sensory neurons.
What are bipolar neurons?
Neurons with two extensions, typically found in the olfactory and taste systems.
What are multipolar neurons?
Neurons with one axon and many dendrites, commonly seen in interneurons.
What are dendritic spines?
Extensions of dendrites that receive excitatory input.
What role does actin play in dendritic spines?
Allows spines to change shape and adapt based on activity.
What are the three types of dendritic spines?
- Thin spines
- Mushroom spines
- Stubby spines
What is the cytoskeleton in neurons made up of?
Microfilaments, neurofilaments, and microtubules.
What is the main function of myelination?
Insulates axons to prevent current leakage and speed up information flow.
What is a synapse?
The junction where a neuron communicates with another cell.
What is the synaptic cleft?
A 20 nanometre gap between cells in vertebrates.
What protects the CNS?
Bones, meninges, cerebrospinal fluid.
What is the main function of the spinal cord?
Connects the brain to the PNS, serving as the main pathway for information.
How many pairs of spinal nerves are there?
31 pairs
What are cranial nerves?
12 pairs of nerves that carry information to and from the brain.
What regions make up the brain?
- Brain stem
- Cerebellum
- Cerebrum
What is the function of the brainstem?
Connects the spinal cord and controls involuntary body functions.
What is the role of the midbrain?
Involved in relaying auditory information and reflex responses.
What is the cerebellum responsible for?
Coordination, balance, posture, movement, and fine motor skills.
What structures are included in the diencephalon?
- Thalamus
- Hypothalamus
- Epithalamus
- Sub-thalamus
What is the thalamus often referred to as?
The switchboard of information relaying sensory and motor signals.
What is the function of the hypothalamus?
Regulates activities involving internal organs through hormone release.
What is the function of the hypothalamus?
Regulates activities involving internal organs via hormone release and nerve connections
The hypothalamus performs functions such as controlling body temperature, hunger, thirst, fatigue, sleep, complex homeostatic functions, and circadian cycles.
What connects the hypothalamus to the pituitary gland?
Pituitary stalk
The pituitary stalk allows for communication between the hypothalamus and both the anterior and posterior pituitary glands.
What are the two parts of the pituitary gland?
Anterior pituitary and posterior pituitary
The anterior pituitary produces its own hormones under the control of hypothalamic releasing factors, while the posterior pituitary secretes hormones produced in the hypothalamus.
What is the function of the amygdala?
Involved in complex behavior and emotional responses, particularly related to fear and social organization
The amygdala recognizes potential threats and works through the autonomic nervous system.
What does the limbic system regulate?
Emotions and behaviors related to fear and motivation
The limbic system also plays a role in memory foundation and consolidation.
What is the role of the basal ganglia?
Coordinates and smooths a sequence of behaviors to achieve desired movement outcomes
The basal ganglia regulate voluntary movement and work with the substantia nigra.
What is the primary function of the hippocampus?
Involved in memory consolidation and spatial memory
The hippocampus is crucial for transferring information from short-term to long-term memory.
What characterizes electrical neuron communication?
Neurons transmit information through electrical or chemical signaling
Electrical signaling occurs through the flow of current along the neuron, while chemical signaling occurs between cells when a gap is present.
What is resting membrane potential (RMP)?
The difference in electrical charge across the cell membrane, typically -60 to -90 mV
RMP indicates that the inside of a neuron is more negative than the outside.
What happens during depolarization of a neuron?
The resting membrane potential becomes less negative
This change in membrane potential is crucial for neuron signaling.
What is an action potential (AP)?
A large change in membrane potential that propagates along the neuron
An AP occurs after the membrane potential changes significantly, allowing the neuron to transmit information.
How can action potentials be sped up?
- Increase axon diameter
- Add myelin insulation
These methods reduce current leakage and enhance signal transmission efficiency.
What are the two types of chemical signaling?
Synaptic and non-synaptic signaling
Synaptic signaling occurs in neurons using neurotransmitters, while non-synaptic signaling uses hormones and local chemical mediators.
What distinguishes water-soluble chemicals from lipid-soluble chemicals?
Water-soluble chemicals transmit information for short periods; lipid-soluble chemicals have long-lasting effects
Lipid-soluble chemicals can alter DNA and affect cell function long-term.
Where are receptors for water-soluble chemicals typically located?
On the cell membrane facing outside
This is because water-soluble chemicals cannot penetrate the cell membrane.
What is the role of ligands in receptor interactions?
Ligands bind to receptors causing a shape change that leads to a cellular response
Agonists mimic natural ligands, while antagonists block receptor sites.
What are the three types of membrane-bound receptors?
- Ion channel receptors
- G-protein linked receptors
- Tyrosine kinase linked receptors
Each type of receptor has distinct mechanisms for altering cell function.
What is the function of intracellular receptors?
Bind to DNA to alter biochemical functions affecting cell function
Intracellular receptors respond to lipid-soluble chemicals.
