Chapter 2 - Neuro Functionality Flashcards
What are neurons in the nervous system?
The communicators of the nervous system, the basic unit of the nervous system, are each composed of a cell body, a receptive component called a dendrite, and a transmitting component called an axon.
What are Glial Cells?
They provide support for and contribute to information processing neurons, it is also called glia or neuroglia. It is a nonneural brain cell that provides structural, nutritional, and other types of support to the brain.
What is the Neuron Doctrine?
The hypothesis is that the brain is composed of cells that are distinct structurally, metabolically, and functionally.
What are Synapses?
The tiny gap between neurons where information is passed from one to the other.
What is a cell body in a neuron?
It is also called soma. The region of a neuron that is defined by the presence of the cell nucleus
What are some types of organelles in the Cell Body?
- Mitochondria - Produces energy.
- Cell Nucleus - Contains genetic material.
- Ribosomes - translates genetic instructions into proteins.
What are the four distinct zones structures that are directly related to info processing?
- Input Zones
- Integration Zones
- Conduction Zones
- Output Zones
What is an Input Zone?
The dendrites are a part of this zone and allow for the information to be received via the synapses of other neurons. The dendrite can be elaborate to connect with other neurons.
What are Integration Zones?
The information is then integrated by the cell body, combining the information the neuron has received to determine whether or not to send a signal of its own.
What are Conduction Zones?
The axon carries the neuron’s electrical signals away from the cell body. Before the axon ends it splits into multiple branches called axon collaterals.
What are Output Zones?
At specialized ends of the axon called axon terminals - where synapses form -, the activity of the neurons is transmitted across the synapses to other cells.
What are the different classifications of info processing neurons?
- Multipolar Neurons
- Bipolar Neurons
- Unipolar Neurons
What is Multipolar Neuron?
These neurons have many dendrites and a single axon, they are the most common type of neuron.
What is a Bipolar Neuron?
These have a single dendrite at one end of the cell and a single axon at the other end.
This type of neuron specializes in sensory systems, such as vision. So it is especially common in these systems.
What is a Unipolar Neuron?
(also called monopolar) have a single extension, usually thought of as an axon, that branches in two directions after leaving the cell body.
One end is the input zone with branches like dendrites; the other, the output zones. Such cells transmit touch information from the body to the spinal cord.
What is an Interneuron?
A neuron that is neither a sensory neuron nor a motor neuron; receives input from and sends output to other neurons
What is a Motor Neuron?
A nerve cell that transmits motor messages, stimulating muscles or glands
What is a Sensory Neuron?
A neuron that is directly affected by changes in the environment, such as light, odor, or touch
What are Dendrites?
It’s like a branch-like arborization (the elaborate branching of the dendrites of some neurons)
What does Presynaptic mean?
Referring to the region of a synapse that releases the neurotransmitter
What does Postsynaptic mean?
Referring to the region of the synapses that receives and responds to neurotransmitters
What three principle components do synapses break down into?
- Presynaptic Membrane/cell
- Synaptic Cleft
- Postsynaptic Membrane/cell
What is the Presynaptic Membrane?
The specialized membrane of the axon terminal of the neuron transmits information by releasing a neurotransmitter
What is the Synaptic Cleft?
The space between the presynaptic and postsynaptic membranes
What is the Postsynaptic Membrane?
The specialized membrane on the surface of the cell receives information by responding to neurotransmitters from a presynaptic neuron
What are Synaptic Vesicles?
A small, spherical structure that contains molecules of neurotransmitters
What are Neurotransmitters?
chemicals that are released from an axon terminal to communicate with other neurons -
What are Receptors?
A protein that binds and reacts to neurotransmitters or hormones
What is Neural Plasticity?
Which is the ability of the nervous system to change in response to experience or the environment
In what ways can information move through an axon?
- Anterograde Transport (toward axon terminal)
- Retrograde Transport (toward the cell body for recycling)
The axon has two speeds for electrical signals, what are they?
- rapid outside the axon
- slow inside the axon
What do Glial cells do?
Support and enhance neural activity, they communicate with each other and with neurons
What are the four types of Glial cells?
- Astrocytes
- Microglial
- Oligiodenrocytes
- Schwann Cells
What do Astrocytes do?
Largest glia, is star-shaped, with many functions such as regulation of blood flow and synapses formation and pruning, function, and maintenance. They can attach to blood vessels and help communication between neurons.
What is a Microglial involved with?
It is involved in response to injury or disease and synaptic pruning during development.
What does Phagocytosis do?
Engulfing and ingestion of other materials (dead cells)
What do Oligiodenrocytes do and where is it located?
In the CNS oligodendrocytes provided myelin
What does a Schwann Cell do and where is it located?
In the PNS Schwann, cells provide myelin
What is Myelin?
Myelinating glial cells wrap around the axon forming a myelin sheath. The Nodes of Ranvier are gaps between segments of myelin.
What do Glial cells continue to do through a life that neurons do not?
they divide continually
When Astrocytes respond to brain injury what do they do?
They increase in size and cause swelling. Can cause
-Edema, a condition characterized by an excess of watery fluid collecting in the cavities or tissues of the body
It is also involved in regulating brain chemistry
-implicated in epilepsy
What is Microglial possibly involved in?
Alzheimer disease
What is Gross Neuroanatomy?
Features of the nervous system visible to the naked eye
What is the Peripheral Nervous System?
All parts of the nervous system found outside the skull and spinal column
What is the Central Nervous System?
Consists of the Brain and the Spinal cord
What does the PNS consist of?
The PNS consists of nerves or bundles of axons
- Some nerves, motor nerves, transmit information from the CNS to the muscles, organs, and glands. (efferent nerves)
- Others, sensory nerves, convey information from the body to the CNS (afferent nerves)
What is the Somatic Nervous System?
Nerves that interconnect the brain and the major muscles and sensory systems
Cranial nerves and spinal nerves
What is the Autonomic Nervous System?
- Nerves that primarily control the viscera (organs)
- Controls the organs of the body
- Autonomic ganglia - bundles of nerve cell bodies
- Connect peripheral and CNS
- Preganglia - in the CNS
- Postganglia - in the PNS
What are the Three Major Divisions of the Autonomic Nervous System?
- Sympathetic Nervous system (Fight or Flight)
- Parasympathetic Nervous System (Rest and Digest)
- Entric Nervous System (The Guts Brain)
What is the Sympathetic Nervous system and how does it affect our body in fight or flight?
It is our fight or flight response and it affects our body by:
- Dilates Pupils
- Inhibits salivation
- Relaxes airways
- Accelerates heartbeat
- Inhibits digestion
- Constricts blood vessels in the skin
What is the Parasympathetic Nervous System and how does it affect our body in rest and digestion?
It is our rest and digest response and it affects our body by:
- Constricts pupils
- Stimulates salvation
- Constricts airways
- Slows heartbeat
- Stimulates digestion
- Dilates blood vessels in the skin
What is the Enteric Nervous System and how does it affect our body?
It is our guts brain and it affects our body by:
- Regulates the function of the gut
- Located in the sheaths of tissue in the esophagus, stomach, small intestine, and colon
- Maintains fluid and nutrients in the body
- Under control of CNS
What do Spinal Nerves do?
Carry sensory information from the body (mostly skin) to the CNS, and carry motor information from the CNS to muscles and glands.
What root does Sensory info and Motor info go through?
Sensory Info comes via the Dorsal root
Motor Info comes via the Ventral root