Chapter 11 - Terminology Flashcards
The Central Nervous System (CNS) consists of ________.
The brain and spinal cord
The Peripheral Nervous System (PNS) consists of _________.
The nerves
The ________ carry signals to and from the CNS.
Nerves
A nerve consists of a bundle of long neuron “arms” called _______, which are bundled with blood vessels and surrounded by connective tissue sheaths.
Axons
Nerves are classified according to their _________.
Origin or destination
Nerves that originate from or travel to the brain are called ________.
Cranial Nerves
Nerves that originate from or travel to the spinal cord are called ________.
Spinal Nerves
There are ____ pairs of cranial nerves and _____ pairs of spinal nerves.
12; 31
Sensory information is gathered (and “carried toward”) by the ______ of the PNS.
Sensory / Afferent Division
Motor output is performed (and “carried away”) by the ______ of the PNS.
Motor / Efferent Division
Sensory stimuli are first detected by sturctures of the PNS called ______.
Sensory Receptors
The _______ sensory division of the PNS consists of neurons that carry signals from skeletal muscles, bones, joints, and skin, along with organs of vision, hearing, taste, smell, and balance.
Somatic
The ______ sensory division of the PNS consists of neurons that transmit signals from the heart, lungs, stomach, intestines, kidneys, and urinary bladder.
Visceral
The CNS disregards about ______% of all integrated sensory data subconsciously.
99
The sensory stimuli that the CNS does respond to leads to a ________.
Motor Response
Organs that carry out the motor output/effects of the nervous system are called _______.
Effectors
The _______ motor division of the PNS consists of neurons that transmit signals to skeletal muscles.
Somatic or voluntary
The visceral motor division of the PNS, aka the __________, consists of neurons that transmit signals primarily to thoracic and abdominal viscera. It regulates involuntary control of secretion from certain glands and contraction of smooth and cardiac muscle.
Autonomic Nervous System (ANS)
The excitable cell type responsible for sending and receiving signals in the form of action potentials are _____.
Neurons
The three parts of a neuron are _______.
Cell body, one axon, and one or more dendrites
The long “arm” that typically carry electrical signals away from the cell body of a neuron, and generate and conduct action potentials, is called ______.
The axon
The part of a neuron that carries electrical signals from other neurons to the cell body is called _____.
The dendrites
The ribosomes and rough endoplasmic reticulum in a neuron cell body together form clusters called _______.
Nissl Bodies
The structural filaments that bundle together and extend from the cell body into the dendrites and axon of a neuron are called _______.
Neurofibrils
The part of the axon that attaches to and extends from the cell body is called _______.
The axon hillock
The axon is wrapped by an insulating and protective covering, which helps to keep an electric current contained, called ______.
Myelin Sheath
The branches the extend from an axon are called ________.
Axon collaterals
The axon and its collaterals split at their axon terminals into multiple fine branches called _______.
Telodendria
The axon of a neuron has cytoplasm called _______ and a plasma membrane called _________.
Axoplasm; axolemma
Smaller substances within the axoplasm, such as proteins, move only away from the cell body at a rate of 1-3mm/day. This process is called ________.
Slow Axonal Transport
Vesicles and organelles within the axoplasm travel either toward or away from the cell body at a rate of 200mm/day, called ________, or 400mm/day, called _______.
Retrograde axonal transport; Anterograde axonal transport
The classification of neuron that have a single axon and multiple highly-branched dendrites, and which also make up 99% of neurons in the human body, is called ________.
Multipolar neurons
The classification of neuron that has only one axon and only one dendrite, and which are typically sensory neurons in humans, is called ________.
Bipolar neuron
The classification of neuron that begin as bipolar neurons but eventually the axon and dendrite fuse to make a double-headed axon (peripheral axon and central axon), and which make up sensory neurons for touch, pressure, and pain, is called _________.
Pseudounipolar neurons
In the CNS clusters of cell bodies are called _______, but in the PNS clusters of cell bodies are called _______.
Nuclei; ganglia
The cells that “glue” neurons together and function in maintaining the surrounding environment and protection are called ________.
Neuroglial cells
The six types of neuroglial cells, four found in the CNS and two found in the PNS, are _______.
CNS: Astrocyte, oligodendrocyte, microglial, and ependymal
PNS: Schwann and Satellite
The most numerous and largest neuroglia in the CNS are called _______.
Astrocytes
The functions of astrocytes include ________.
- Anchoring neurons and blood vessels in place
- Regulating the extra cellular environment in the brain
- Assisting in the formation of the blood brain barrier
- Repairing damaged brain tissue
The neuroglia that form layers of the plasma membrane myelin sheath of axons in the CNS are called ________.
Oligodendrocytes
The neuroglia that form the plasma membrane myelin sheath of axons in the PNS are called ________.
Schwann cells
Flat cells that surround cell bodies of neurons in the PNS are called ______.
Satellite cells
The segments of an axon that are covered by neuroglia are called ______.
Internodes
Between each internode on an axon is a gap where no myelin is found, called _______.
Nodes of Ranvier
The color difference between white matter and gray matter regions within the spinal cord and brain is due to the distribution of _______.
Myelinated vs. unmyelinated neurons
The two different types of neuronal synapses that occur between two neurons are called:
Electrical and chemical
A neural synapse between an axon and a dendrite is called ________.
Axodendritic
A neural synapse between an axon and a cell body is called ______.
Axosomatic
A neural synapse between an axon and another axon is called _________.
Axoaxonic
At neuronal synapses, the neuron that is sending the message from its axon terminal is called _______.
Presynaptic
At neuronal synapses, the neuron that is receiving the message from its dendrite, cell body, or axon is called _______.
Postsynaptic
The transfer of chemical or electrical signals between neurons at a synapse is called ______.
Synaptic transmission
The type of neuronal synapse that occurs between cells that are electrically coupled via precisely aligned gap junctions that form pores through which ions and small substances travel is called _______.
Electrical synapse
Two unique features of electrical synapses are ________.
- Synaptic transmission is bidirectional (current may flow in either direction between cells)
- Synaptic transmission is nearly instantaneous (time between depolarization of the presynaptic and change in potential of the postsynaptic is less than 0.1 millisecond)
The more efficient and most common of synapses in the nervous system is called ______.
Chemical synapse
The three important structural characteristics of chemical synapses are _______.
- The presynaptic neuron houses synaptic vesicles containing neurotransmitters, which converts the action potential from an electrical to a chemical signal.
- The presynaptic and postsynaptic cells have more space between them, which is called a synaptic cleft, filled with extra cellular fluid and proteins.
- The postsynaptic neuron has neurotransmitter receptors that binds the neurotransmitters released from the presynaptic neuron and allows for a response.
What are the 4 events that occur at a chemical synapse?
- An action potential in the presynaptic neuron triggers Ca+ channels in the axon terminal axolemma to open.
- An influx of Ca+ causes synaptic vesicles in the axon terminal to fuse with the presynaptic membrane and release neurotransmitters into the synaptic cleft via exocytosis.
- Neurotransmitters diffuse across the synaptic cleft and bind to receptors in the membrane of the postsynaptic neuron.
- The binding of neurotransmitters causes ion channels to open and allow ions to enter, resulting in a local potential and possibly action potential within the postsynaptic neuron.
The two types of neurotransmitter receptors are called _______.
Ionotropic and Metabotropic
The type of neurotransmitter receptor that directly binds to a neurotransmitter and controls the movement of ions into or out of the neuron when bound is called ______.
Ionotropic
The type of neurotransmitter receptor that is connected to a separate metabolic process, which binds a neurotransmitter and releases a second messenger that activates the receptor, is called _______.
Metabotropic
The analysis and interpretation of sensory stimuli to determine an appropriate response is a process within the CNS called ________.
Integration
