Chapter 1: Structure and Function Flashcards
What is the difference between the function of a neuron and the function of a glial cell?
Neurons underlie all our behaviour, they work in circuits to receive, integrate, and distribute information across billions of cells.
Glial cells are all non-neuronal cells in the brain. They function to provide structural, nutritional, and other support to the brian
What is the Neuron Doctrine?
Neurons and other brain cells are structurally, metabolically, and functionally independent.
Information is transmitted from neuron to neuron across tiny gaps called synapses.
What are the four functional zones of a neuron?
- Input zone: recieves information from other neuorns and specialized sensory structures. This area is made up of the dentrites.
- Integration Zone: initiates neural electrical activity. It integrates information and determines whether or not to send a signal of its own. It is made up of the Soma.
- Conduction Zone: where the action potential is propagated. Made up of axons
- Output Zone: sends information to other neurons, made up of axon terminals.
What are three types of neurons and their characteristics?
Motor Neurons: they transmit messages to the muscles and glands. They have long axons.
Sensory Neurons: they are neurons that are affected by changes in the environment. they vary in shape and size depending on its sense specialization.
Inter-neurons: Neurons that receive input and send output to other neurons. this is the most common type of neuron. They have small axons.
What are three neuron shape classifications?
Multi-Polar: Have many dendrites and a single axon; the most common type
Bi-Polar: have a single dendrite and single axon; is most common in the sensory system.
Uni-polar: has a single branch that leaves the cell body and extends in two directions. One ends in the input zone, the other ends in the output zone. They transmit touch information from the body to the spinal cord.
What are the 3 components of the synapse?
The specialized membrane on the presynaptic axon terminal. This are transmits information by releasing neurotransmitters.
The synaptic clef: the space between the pre and post synaptic neurons. It is ~20-40nm
the specialized postsynaptic membrane which receives information y responding to the neurotransmitters from the presynaptic neuron.
What is the phenomenon of neuroplasticity?
The phenomenon where new patterns of synaptic activity and new neural circuits form in response to changes in experience and the environment. It involves synapses coming and going, dendrites changing shape, and dendritic spines waxing and waning.
What is the job of the axon hillock?
To integrate information from coming synapses and determine if when the neuron is to produce its own signal.
What is axon transport?
This is when substances like enzymes and proteins move up and down the hollow tube like axon. Anterograde transport is the movement from the cell body to the axon terminals. Retrograde transport is movement from the axon terminals to the cell body.
Axon transport is far slower than the movement of electrical impulses and action potentials down the axon membrane
What are the 4 main types of Glial cells?
Oligodendrocytes: these en-sheath the axons with myelin in the Central nervous system. They can provide myelin to multiple axons at once
Schwann Cells: These en-sheath the axons with myelin in the peripheral nervous system. they can provide myelin to only one axon at a time.
Astrocytes: star shaped cells that weave between neurons with tentacle like extensions. They perform functions like increasing blood flow, forming tough protective membranes, and secreting chemical signals that affect synaptic transformation and formation.
Microglial: small, mobile cells that remove cellular debris from injured or dead cells.
What are the two divisions of the peripheral nervous system?
The somatic nervous system: made up of nerves that interconnect the brain, major muscles, and sensory systems of the body
Autonomic Nervous system: nerves that connect to the viscera (internal organs)
What are cranial nerves (provide examples)?
Are one of two types of nerves in the somatic nervous system. These nerves connect directly with the brain. There are 12 pairs:
- Olfactory Nerves
- optic nerves
- oculomotor
- trochlear
- trigeminal
- abdcens
- facial
- Vestibulocochlear
- glossophraygeal
- vagus
- spinal accessory
- hypoglossal
What are spinal nerves? What are the different types?
They are one of two types of nerves in the somatic nervous system. There are 32 pairs. Each nere has motor fibres in the ventral (front) part o the spine and sensory fibres in the dorsal (back) part of the spine.
There are: 8 cervical nerves (neck) 12 thoratic nerves (torso) 5 lumbar nerves (lower back) 5 socral nerves (pelvic) 1 coccygeal nerve (bottom)
What are the characteristics of the divisions of the autonomic nervous system?
The Sympathetic Nervous system: acts as fight or flight, prepares the body for action. The neurons of the sympathetic nervous system travel from the spinal cord to the sympathetic ganglia which then innervates the major organ systems
The parasympathetic Nervous System: prepares the body to relax, the rest and digest system. The neurons of the parasympathetic nervous system travel from the central nervous system to the parasympathetic ganglia which then innervates the major organ systems.
What are the 3 different planes for dividing the brain?
Sagital –> divides the brain into left and right
Coronal –> divides the brain into front and back
Horizontal –> divides the brain into upper and lower
