Week 1 - Lecture PPT - Nervous System Lecture Notes Flashcards

Flashcards covering key concepts from Week 1 notes on nervous system structure, function, cells, and myelination.

What are the anatomical divisions of the nervous system and what are their components?

CNS (brain and spinal cord) and PNS (cranial nerves, spinal nerves, nerve plexuses, and peripheral nerves)

What are the distinctions between Afferent vs. Efferent nerves?

Afferent nerves carry sensory information to the CNS; efferent nerves carry motor information from the CNS.

What is the difference between the Somatic and Autonomic nervous systems?

The somatic nervous system controls voluntary movements, while the autonomic nervous system controls involuntary functions.

What are the subdivisions of the autonomic nervous system and what are their functions?

The sympathetic (fight or flight) and parasympathetic (rest and digest) nervous systems.

What is the most important point of action of a neuron that dictates its general function?

The components of a neuron.

What is a neuroglia?

A supportive and protective cell for neurons.

In terms of cell placement and characteristics, what are the differences between gray matter and white matter?

Gray matter has cell bodies and dendrites; white matter has axons.

What are the four main types of tissue?

Nervous, epithelial, muscle, and connective.

What are the two main types of nervous tissue cells?

Neurons and neuroglia.

What is the main difference between a neuron and a neuroglia?

Neurons are electrically excitable; neuroglia are not.

What is the CNS composed of?

The brain and spinal cord.

What is the PNS composed of?

Cranial nerves, spinal nerves, nerve plexuses, and peripheral nerves.

What is the sensory function of the nervous system?

Detect changes (stimuli) through sensory receptors.

What is the integrative function of the nervous system?

Analyze incoming sensory information, store some aspects, and make decisions regarding appropriate behaviors.

What is the motor function of the nervous system?

Respond to stimuli via effectors (e.g., muscles, glands).

What is the general function of the PNS?

Communication lines between sensory receptors and the CNS, and between the CNS and effectors (glands, muscles).

Which nerves carry sensory information to the CNS and which carry motor information from the CNS?

Afferent nerves carry sensory information; efferent nerves carry motor information.

What is the function of the somatic nervous system (SNS)?

Voluntary control of skeletal muscles.

What is the function of the autonomic nervous system (ANs)?

Involuntary control of smooth muscle, cardiac muscle, and glands.

What is the function of the enteric nervous system (ENS)?

Involuntary control of the gastrointestinal tract.

What type of information do somatic sensory neurons carry?

Conscious sensory information (temperature, pain, touch, proprioception, muscle stretch, special senses).

What type of information do visceral sensory neurons carry?

Unconscious sensory information (blood pressure, blood gases, distension of organs, pH changes).

What do somatic motor neurons control?

Voluntary control of skeletal muscle contraction.

What are the two divisions of the autonomic motor neurons?

Sympathetic and Parasympathetic.

What do autonomic motor neurons control (generally)?

Involuntary controls.

What is the main point of action of the sympathetic motor division?

The 'fight or flight' response.

What is the main point of action of the parasympathetic motor division?

The 'rest and digest' response.

What is the general function of sensory (afferent) neurons?

Carry information to the CNS.

What is the general function of motor (efferent) neurons?

Carry action potentials from the CNS.

Where are interneurons located and what is their function?

Located within the CNS; they process sensory information and elicit motor responses.

What organelles are located within the Cell Body (Soma)?

Contains typical cell organelles, a nucleus with a large nucleolus, and Nissl bodies.

What is the main component in Nissl bodies?

Rough endoplasmic reticulum.

What term is used to describe bundles of cell bodies in the PNS?

Ganglia.

What term is used to describe bundles of cell bodies in the CNS?

Nuclei.

What do dendrites do?

Receive input from neighboring neurons.

What is the main function of an axon?

Conduct action potentials away from the cell body.

What is found at the axon terminals?

Synaptic end bulbs containing synaptic vesicles.

Where are action potentials initiated in a neuron?

At the axon hillock; they propagate along the axon to the terminals.

What is a synapse?

Junction between two neurons or neuron and an effector cell where communication occurs.

What is a presynaptic neuron?

Neuron sending the signal.

What is a postsynaptic neuron?

Neuron receiving the signal.

What happens during synaptic transmission?

The presynaptic neuron releases neurotransmitters that bind to receptors on the postsynaptic neuron, transmitting the signal.

What are bundles of axons called in the CNS?

Tracts.

What are bundles of axons called in the PNS?

Nerves.

Are neuroglia electrically excitable?

No.

How many types of neuroglia are there?

6 (4 in the CNS, 2 in the PNS).

What is the function of astrocytes in the CNS?

Provide strength, support, and form the blood-brain barrier.

What is the function of microglia in the CNS?

Phagocytes that remove debris and pathogens.

What is the function of ependymal cells in the CNS?

Produce cerebrospinal fluid (CSF).

What is the function of oligodendrocytes in the CNS?

Form myelin sheaths around axons. Oligodendrocytes

What is the function of satellite cells in the PNS?

Regulate the extracellular environment of PNS neurons.

What is the function of Schwann cells in the PNS?

Form myelin sheaths around axons.

What is myelin sheath made of and what is its function?

Multilayered lipid and protein covering around axons; it provides electrical insulation and increases the speed of neural impulse conduction.

What are the gaps in the myelin sheath called?

Nodes of Ranvier.

What cells form myelin sheaths in the CNS?

Oligodendrocytes.

What cells form myelin sheaths in the PNS?

Schwann cells.

What does gray matter mainly consist of?

Cell bodies and dendrites.

What does white matter mainly consist of?

Axons (myelinated).

How is the nervous system organized?

Anatomically (CNS vs PNS) and functionally (sensory vs motor; somatic vs autonomic).

What types of cells compose nervous tissue?

Neurons and neuroglia.

What are the functional clusters of nervous tissue cell bodies and axons called in the CNS and PNS?

Cell bodies: nuclei (CNS) and ganglia (PNS); Axons: tracts (CNS) and nerves (PNS).

What is the main benefit to neuron action of myelination? How does it take place?

Increases speed of action potential propagation; myelin is formed by Schwann cells in the PNS and oligodendrocytes in the CNS.