Anatomy: Nervous System Flashcards
What is the CENTRAL Nervous System?
Located in brain and nerves
Integrates information and generates responses; involved in conscious thought and reflexes.
What is the PERIPHERAL Nervous System?
Located outside CNS (Spinal Nerves & Cranial Nerves)
Transmits Sensory info back to the CNS
Controls involuntary functions (via the autonomic nervous system) and voluntary movements (via the somatic nervous system).
MOTOR OUTPUT
What is the Sensory (Afferent) Division of the PNS, what does it consist of and what are their functions?
Consists of Somatic Sensory Division and Visceral Sensory Division.
Somatic: Carries general sensory signals from muscles, bones, joints, and skin to the CNS.
Visceral: Carries signals from ORGANS to the CNS.
What is the Motor (Efferent) Division of the PNS, and what does it consist of and what are their functions?
Consists of Somatic Motor Division, and Autonomic Nervous System.
Somatic: Carries Signals from the CNS to the skeletal muscles to perform an action. (voluntary)
Autonomic: Carries signals to smooth muscles, cardiac muscles, and glands. (involuntary)
What are Neurons?
Fundamental building unit of the Nervous System; Conducts electrical pulses.
What are the Dendrites of the Neuron?
The receptive region that receives the signals from other cells.
What is the Axon of the Neuron?
Conducting region, sends electrical signal.
What is the Axon Terminal of the Neuron?
Secretory region, sends or SECRETES chemical signal to the cell.
Can Neurons undergo Mitosis after being damaged?
NO, instead, astrocytes go to fill in for that tissue.
What are Astrocytes? (Neuroglial Cells) (CNS)
Glial Cells that provide structural support to neurons in the brain and spinal cord.
Creates Blood-Brain Barrier.
What are Oligodendrocytes? (Neuroglial Cells) (CNS)
Glial Cells are produce Myelin, a fatty substance that insulates neuronal axons, facilitating faster electrical signal transmission.
They create Myelin Sheets around the neuron, increasing the speed of nerve impulse conduction.
What are Microglial Cells? (Neuroglial Cells) (CNS)
Immune Cells, digest pathogens through Phagocytosis.
What are Ependymal Cells? (Neuroglial Cells) (CNS)
Cells that line the spaces in the brain (ventricles) and the central canal of the spinal cord.
Produce cerebrospinal fluid (CSF), which cushions and protects the brain and spinal cord.
What are Schwann Cells? (Neuroglial Cells) (PNS)
Cells that wrap around the axons of peripheral neurons to form myelin sheaths
What are Satellite Cells? (Neuroglial Cells) (PNS)
Similar to Astrocytes, but simply surround and support Neuron Cell Bodies.
What are Leak Channels?
Channels that are always opened and don’t need a stimulus to open.
What are Voltage-Gated Channels?
Receives an action potential which leads to the release of something that is due to the opening of this channel.
What are Ligand-Gated Channels?
Chemical messenger binds to channel, and When Ligands bind, channel opens
What are Mechanically-Gated Channels?
Ion channels that respond/open to physical forces acting on the cell membrane.
What is an EPSP?
Excitatory Postsynaptic Potential
A temporary depolarization of the postsynaptic membrane potential due to the influx of positively charged ions (usually sodium, Na⁺).
Increases in the likelihood of an action potential.
What will happen if Myelin was lost on an Axon? Give an example.
Higher energy demands, and various neurological symptoms, significantly affecting the function of the nervous system.
Example: Multiple sclerosis (MS) – patients may experience a range of symptoms, including weakness, sensory disturbances, coordination problems, and cognitive issues.
What is an IPSP?
Inhibitory Postsynaptic Potential
A temporary hyperpolarization of the postsynaptic membrane potential, making it less likely to fire an action potential.
What is Spatial Summation?
Involves simultaneous stimulation from multiple neurons, leading to combined effects on the postsynaptic neuron.
What is Temporal Summation?
Involves repeated stimulation of the same neuron over a short period, leading to cumulative effects.
